Soil contamination

{{short description|Pollution of land by human-made chemicals or other alteration}} thumb|Excavation showing soil contamination at a disused gasworks in England {{Pollution sidebar|Soil}}

'''Soil contamination''', '''soil pollution''', or '''land pollution''' as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity,<ref>{{cite journal |doi=10.1016/j.jclepro.2019.05.098 |title=Impact of industrial activities on heavy metal contamination in soils in three major urban agglomerations of China |journal=Journal of Cleaner Production |volume=230 |pages=1–10 |date=1 September 2019 |last1=Zhou |first1=Xi-Yin |last2=Wang |first2=Xiu-Ru |bibcode=2019JCPro.230....1Z |url=https://z-lib.fm/book/106904967/898fd4 |access-date=26 January 2026 }}</ref> agricultural chemicals<ref>{{cite book |doi=10.1007/978-94-009-1626-5_11 |chapter=Sources, potential adverse effects and remediation of agricultural soil contaminants |title=Contaminants and the soil environment in the Australasia-Pacific region |isbn=978-94-009-1626-5 |pages=323–59 |year=1996 |last1=Chaney |first1=Rufus L. |last2=Oliver |first2=Danielle P. |editor-last1=Naidu |editor-first1=Ravi |editor-last2=Kookana |editor-first2=Rai S. |editor-last3=Oliver |editor-first3=Danielle P. |editor-last4=Rogers |editor-first4=Shane |editor-last5=McLaughlin |editor-first5=Michael J. |chapter-url=https://www.academia.edu/104199928 |publisher=Kluwer Academic Publishers |location=Dordrecht, The Netherlands |access-date=26 January 2026 }}</ref> or improper disposal of waste.<ref>{{cite journal |doi=10.1007/s42452-020-03678-y |title=Evaluation of soil contamination status around a municipal waste dumpsite using contamination indices, soil-quality guidelines, and multivariate statistical analysis |journal=SN Applied Sciences |volume=2 |article-number=1864 |date=22 October 2020 |last1=Afolagboye |first1=Lekan Olatayo |last2=Ojo |first2=Amos Abayomi |last3=Talabi |first3=Abel Ojo |issue=11 |url=https://www.academia.edu/71988665 |access-date=27 January 2026 }}</ref> The most common chemicals involved are petroleum hydrocarbons,<ref>{{cite book |doi=10.1016/S0065-2113(08)60959-1 |chapter=Contamination of soils by petroleum hydrocarbons |title=Advances in agronomy |volume=13 |isbn=978-0-12-000713-4 |pages=197–216 |year=1961 |last1=Ellis |first1=Roscoe Jr |last2=Adams |first2=Russell S. Jr |editor-last=Norman |editor-first=Arthur Geoffrey |chapter-url=https://z-lib.sk/book/69722266/9a9d2e |publisher=Elsevier |location=Amsterdam, The Netherlands |access-date=27 January 2026 }}</ref> polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene),<ref>{{cite journal |doi=10.1016/j.scitotenv.2017.06.247 |title=Polycyclic aromatic hydrocarbons contamination in surface soil of China: a review |journal=Science of the Total Environment |volume=605–606 |pages=1011–20 |date=15 December 2007 |last1=Zhang |first1=Pei |last2=Chen |first2=Yinguang |pmid=28693106 |url=https://z-lib.sk/book/97396838/9d5bd4 |access-date=27 January 2026 }}</ref> solvents,<ref>{{cite book |doi=10.1007/978-1-4419-1401-9_1 |chapter=Groundwater contamination by chlorinated solvents: history, remediation technologies and strategies |title=In situ remediation of chlorinated solvent plumes |isbn=978-1-4419-1401-9 |pages=1–28 |year=2010 |last=McCarty |first=Perry L. |series=SERDP/ESTCP Environmental Remediation Technology |editor-last1=Stroo |editor-first1=Hans F. |editor-last2=Ward |editor-first2=C. Herb |chapter-url=https://archive.org/details/mc-carty-2010 |publisher=Springer |location=New York, New York |access-date=16 February 2026 }}</ref> pesticides,<ref>{{cite journal |doi=10.1016/j.apsoil.2019.09.006 |title=Soil biological activity as an indicator of soil pollution with pesticides: a review |journal=Applied Soil Ecology |volume=147 |article-number=103356 |date=March 2020 |last1=Wołejko |first1=Elżbieta |last2=Jabłońska-Trypuć |first2=Agata |last3=Wydro |first3=Urszula |last4=Butarewicz |first4= Andrzej |last5=Łozowicka |first5=Bożena |bibcode=2020AppSE.14703356W |url=https://www.academia.edu/88908883 |access-date=27 January 2026 }}</ref> and heavy metals.<ref>{{cite journal |last1=Anweting |first1=Idongesit B. |last2=Ebong |first2=Godwin Asukwo |last3=Okon |first3=Iniobong Edet |last4=Udofia |first4=Ifreke Mfon |last5=Oladunni |first5=Nathaniel |date=24 May 2024 |title=Evaluating the concentration of Pb, Hg, Co, V, As, Fe, Cu, Cd, Cr, Mn, Ni, and Zn and their potential sources in soil from two abattoirs in Itu and Ikot Ekpene Local Government Areas of Akwa Ibom State, Nigeria |journal=Journal of Applied Sciences and Environmental Management |volume=28 |issue=5 |pages=1335–43 |doi=10.4314/jasem.v28i5.2 |doi-access=free }}</ref> The concern over soil contamination stems primarily from health risks, from direct contact with contaminated soil or consumption of plants growing in contaminated soil,<ref>{{cite journal |doi=10.1007/s11104-023-06436-2 |title=Health risk associated with soil and plant contamination in industrial areas |journal=Plant and Soil |volume=498 |issue=1–2 |pages=295–323 |date=14 December 2023 |last1=Kicińska |first1=Alicja |last2=Wikar |first2=Justyna |doi-access=free }}</ref> vapour inhalation from the contaminants,<ref>{{cite journal |doi=10.1080/10807039.2012.707929 |title=Health risk assessment and vapor intrusion: a review and Australian perspective |journal=Human and Ecological Risk Assessment |volume=18 |issue=5 |pages=984–1013 |date=27 September 2012 |last1=Turczynowicz |first1=Leonid |last2=Pisaniello |first2=Dino |last3=Williamson |first3=Terry |bibcode=2012HERA...18..984T |url=https://www.researchgate.net/publication/263249137 |access-date=27 January 2026 }}</ref> or from secondary contamination of water supplies within (groundwater) and underlying the soil (aquifer).<ref>{{cite journal |last1=Petkovic |first1=Sava |last2=Gregoric |first2=Enika |last3=Slepcevic |first3=Vesna |last4=Blagojevic |first4=Srdjan |last5=Gajic |first5=Bosko |last6=Kljujev |first6=Igor |last7=Žarković |first7=Branka |last8=Djurovic |first8=Nevenka |last9=Draskovic |first9=Radovan |date=8 April 2011 |title=Contamination of local water supply systems in suburban Belgrade |url=https://z-lib.sk/book/68072758/835cb9 |journal=Urban Water Journal |volume=8 |issue=2 |pages=79–92 |doi=10.1080/1573062X.2010.546862 |bibcode=2011UrbWJ...8...79P |access-date=27 January 2026 }}</ref> Mapping of contaminated soil sites and the resulting cleanups are time-consuming and expensive tasks, and require expertise in geology, hydrology, chemistry, computer modelling, and GIS in Environmental Contamination, as well as an appreciation of the history of site pollution.<ref>{{cite journal |last1=George |first1=Rebecca |last2=Joy | first2=Varsha |last3=Aiswarya |first3=S. |last4=Jacob |first4=Priya Achamma |title=Treatment methods for contaminated soils: translating science into practice |url=https://www.academia.edu/66178557 |journal=International Journal of Education and Applied Research |volume=4 |issue=1 |pages=17–19 |date=June 2014 |access-date=28 January 2026 }}</ref> It has been suggested that the examination of humus forms, which necessitates only a cursory glance upon ground floor thickness and structure of the underlying mineral horizon, could used at low cost for the early detection and mapping of potential soil contamination.<ref>{{cite journal |last1=Korkina |first1=Irina N. |last2=Vorobeichik | first2=Evgenii L. |title=Humus Index as an indicator of the topsoil response to the impacts of industrial pollution |url=https://www.academia.edu/104413182 |journal=Applied Soil Ecology |volume=123 |pages=455–63 |date=February 2018 |doi=10.1016/j.apsoil.2017.09.025 |bibcode=2018AppSE.123..455K |access-date=28 January 2026 }}</ref>

In North America and Europe the extent of contaminated land is best known for as many of the countries in these areas have a legal framework to identify and deal with this environmental problem.<ref>{{cite web |title=Soil Monitoring Law |url=https://environment.ec.europa.eu/topics/soil-health/soil-monitoring-law_en |website=environment.ec.europa.eu/ |date=December 2025 |access-date=29 January 2026 }}</ref><ref>{{cite journal |last1=Ramón |first1=Francisca |last2=Lull |first2=Cristina |title=Legal measures to prevent and manage soil contamination and to increase food safety for consumer health: the case of Spain |url=https://riunet.upv.es/server/api/core/bitstreams/5fddca1f-1c75-4176-94d7-caf9e017b847/content |journal=Environmental Pollution |volume=250 |pages=883–91 |date=July 2019 |doi=10.1016/j.envpol.2019.04.074 |pmid=31085474 |bibcode=2019EPoll.250..883R |access-date=29 January 2026 |hdl=10251/121387 |hdl-access=free }}</ref><ref>{{cite journal |last1=Li |first1=Wenbiao |last2=Li |first2=Zijian |last3=Jennings |first3=Aaron |title=Regulatory performance dataset constructed from U.S. soil jurisdictions based on the top 100 concerned pollutants |url=https://www.researchgate.net/publication/327908530 |journal=Data in Brief |volume=21 |issue=6 |pages=36–49 |date=December 2018 |doi=10.1016/j.dib.2018.09.049 |pmid=30338272 |access-date=29 January 2026 |pmc=6186953 |bibcode=2018DIB....21...36L }}</ref> Other countries tend to be less tightly regulated despite some of them have undergone significant industrialization and are searching for more regulation.<ref>{{cite web |last1=Sun |first1=Yiming |last2=Li |date=December 2019 |title=Soil contamination in China: studies on the status, priorities, policies, management and risk assessment |url=https://files01.core.ac.uk/download/pdf/322487825.pdf |website=Lancaster University |access-date=29 January 2026 }}</ref><ref>{{cite journal |last1=Yakovlev |first1=Aleksandr Sergeevich |last2=Evdokimova |first2=Mariya V. |title=Approaches to the regulation of soil pollution in Russia and foreign countries |url=https://www.researchgate.net/publication/367800896 |journal=Eurasian Soil Science |volume=55 |issue=5 |pages=641–50 |date=24 May 2022 |doi=10.1134/S1064229322050131 |bibcode=2022EurSS..55..641Y |access-date=29 January 2026 }}</ref>

== Causes == Soil pollution can be caused by the following (non-exhaustive list): * Microplastics * Oil spills * Mining and activities by other heavy industries * Accidental spills may happen during activities, etc. * Corrosion of underground storage tanks (including piping used to transmit the contents) * Acid rain * Intensive farming * Agrochemicals, such as pesticides, herbicides and fertilizers * Petrochemicals * Industrial accidents * Road debris * Construction activities * Exterior lead-based paints * Drainage of contaminated surface water into the soil * Ammunitions, chemical agents, and other agents of war * Waste disposal ** Oil dumping and fuel dumping ** Nuclear wastes ** Direct discharge of industrial wastes to the soil ** Discharge of sewage ** Landfill and illegal dumping ** Coal ash ** Electronic waste ** Contamination by rocks containing large amounts of toxic elements. ** Contamination by Pb due to vehicle exhaust, Cd, and Zn caused by tire wear. ** Contamination by strengthening air pollutants by incineration of fossil raw materials.

The most common chemicals involved are petroleum hydrocarbons, solvents, pesticides, lead, and other heavy metals.<ref>{{cite web |last1=Rodríguez-Eugenio |first1=Natalia |last2=McLaughlin |first2=Michael |last3=Pennock |first3=Daniel |title=Soil pollution: a hidden reality |url=https://openknowledge.fao.org/server/api/core/bitstreams/3f7e6959-db0b-44d3-971e-109bcfe78195/content |website=Food and Agriculture Organization of the United Nations |location=Rome, Italy |year=2018 |access-date=29 January 2026 }}</ref>

Any activity that leads to other forms of soil degradation (erosion, compaction, etc.) may indirectly worsen the contamination effects in that soil remediation becomes more tedious.<ref>{{cite web |last1=Thompson |first1=Richard |title=Technologies for remediating polluted soils |url=https://openknowledge.fao.org/server/api/core/bitstreams/fe5df8d6-6b19-4def-bdc6-62886d824574/content/src/html/chapter-13-4.html |website=Food and Agriculture Organization of the United Nations |location=Rome, Italy |year=2021 |access-date=29 January 2026 }}</ref> [[File:Agbogbloshie, Ghana 2019.jpg|left|thumb|263x263px|E-waste processing in Agbogbloshie, Ghana. Improper disposal of manufactured goods and industrial wastes, often means that communities in the global south have to process goods. Especially without proper protections, heavy metals and other contaminates can seep into the soil, and create water pollution and air pollution.]]

Historical deposition of coal ash used for residential, commercial, and industrial heating, as well as for industrial processes such as ore smelting, were a common source of contamination in areas that were industrialized before about 1960.<ref>{{cite journal |last1=Kamara |first1=Saidu |last2=Foday |first2=Edward Hingha Jr |last3=Wang |first3=Wei |title=A review on the utilization and environmental concerns of coal fly ash |journal=American Journal of Chemistry and Pharmacy |volume=2 |issue=2 |pages=53–65 |date=2 July 2023 |doi=10.54536/ajcp.v2i2.1609 |doi-access=free }}</ref> Coal naturally concentrates arsenic, cadmium lead and zinc during its formation, as well as other heavy metals to a lesser degree.<ref>{{cite journal |last1=Mastalerz |first1=Maria |last2=Drobniak |first2=Agnieszka |title=Arsenic, cadmium, lead, and zinc in the Danville and Springfield coal members (Pennsylvanian) from Indiana |url=https://z-library.sk/book/34976655/d23afd |journal=International Journal of Coal Geology |volume=71 |issue=1 |pages=37–53 |date=1 June 2007 |doi=10.1016/j.coal.2006.05.005 |bibcode=2007IJCG...71...37M |access-date=30 January 2026 }}</ref> When the coal is burned, most of these metals become concentrated in the ash (the principal exception being mercury, which evaporates).<ref>{{cite journal |last1=Vassilev |first1=Stanislav V. |last2=Vassileva |first2=Christina G. |title=Geochemistry of coals, coal ashes and combustion wastes from coal-fired power stations |url=https://www.researchgate.net/publication/223430970 |journal=Fuel Processing Technology |volume=51 |issue=1–2 |pages=19–45 |date=March 1997 |doi=10.1016/S0378-3820(96)01082-X |bibcode=1997FuPrT..51...19V |access-date=30 January 2026 }}</ref> Coal ash and slag may contain sufficient lead to qualify as a "characteristic hazardous waste",<ref>{{cite journal |last1=Block |first1=Chantal |last2=Dams |first2=R. |title=Lead contents of coal, coal ash and fly ash |url=https://www.academia.edu/54387722 |journal=Water, Air, & Soil Pollution |volume=5 |issue=2 |pages=207–11 |date=December 1975 |doi=10.1007/BF00282962 |bibcode=1975WASP....5..207B |access-date=30 January 2026 }}</ref> defined in the US as containing more than 5&nbsp;mg/L, further revised to 1.5&nbsp;mg/L of extractable lead using the TCLP procedure.<ref>{{cite journal |last1=Intrakamhaeng |first1=Vicharana |last2=Clavier |first2=Kyle A. |last3=Townsend |first3=Timothy G. |title=Hazardous waste characterization implications of updating the toxicity characteristic list |url=https://z-library.sk/book/108173053/dc5fb9 |journal=Journal of Hazardous Materials |volume=383 |article-number=121171 |date=5 February 2020 |doi=10.1016/j.jhazmat.2019.121171 |pmid=31539659 |bibcode=2020JHzM..38321171I |access-date=30 January 2026 }}</ref> In addition to lead, coal ash typically contains variable but significant concentrations of polynuclear aromatic hydrocarbons (PAHs; e.g., benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, phenanthrene, anthracene, and others).<ref>{{cite journal |last1=Buha-Marković |first1=Jovana Z. |last2=Marinković |first2=Ana D. |last3=Nemoda |first3=Stevan D. |last4=Savić |first4=Jasmina Z. |title=Distribution of PAHs in coal ashes from the thermal power plant and fluidized bed combustion system; estimation of environmental risk of ash disposal |url=https://z-library.sk/book/113437289/256602 |journal=Environmental Pollution |volume=266 |issue=Part 3 |article-number=115282 |date=November 2020 |doi=10.1016/j.envpol.2020.115282 |pmid=32799176 |bibcode=2020EPoll.26615282B |access-date=30 January 2026 }}</ref> These PAHs are known human carcinogens<ref>{{cite journal |last1=Straif |first1=Kurt |last2=Baan |first2=Robert |last3=Grosse |first3=Yann |last4=Secretan |first4=Béatrice |last5=El Ghissassi |first5=Fatiha |last6=Cogliano |first6=Vincent |date=December 2005 |title=Carcinogenicity of polycyclic aromatic hydrocarbons |url=https://z-library.sk/book/50455780/590754 |journal=The Lancet Oncology |volume=6 |issue=12 |pages=931–2 |doi=10.1016/S1470-2045(05)70458-7 |pmid=16353404 |access-date=27 January 2026 }}</ref> and the acceptable concentrations of them in soil are typically from 0.1&nbsp;mg/kg to 10&nbsp;mg/kg, with a strong variation from a PAH to another.<ref>{{cite journal |last1=Kalf |first1=Dennis F. |last2=Crommentuijn |first2=Trudie |last3=Van de Plassche |first3=Erik J. |date=February 1997 |title=Environmental quality objectives for 10 polycyclic aromatic hydrocarbons (PAHs) |url=https://z-library.sk/book/47966267/710e3f |journal=Ecotoxicology and Environmental Safety |volume=36 |issue=1 |pages=89–97 |doi=10.1006/eesa.1996.1495 |pmid=9056405 |bibcode=1997EcoES..36...89K |access-date=30 January 2026 }}</ref> Coal ash and slag can be recognised by the presence of off-white grains in soil, gray heterogeneous soil, or (coal slag) bubbly, vesicular pebble-sized grains.<ref>{{cite journal |last1=Fisher |first1=Gerald L. |last2=Prentice |first2=Bruce A. |last3=Silberman |first3=David |last4=Ondov |first4=John M. |last5=Biermann |first5=Arthur H. |last6=Ragaini |first6=Richard C. |last7=McFarland |first7=Andrew R. |date=April 1978 |title=Physical and morphological studies of size-classified coal fly ash |url=https://z-library.sk/book/61444112/911ef7 |journal=Environmental Science & Technology |volume=12 |issue=4 |pages=447–51 |doi=10.1021/es60140a008 |bibcode=1978EnST...12..447F |access-date=30 January 2026 }}</ref>

Treated sewage sludge, known in the industry as biosolids, has become controversial as a "fertilizer". As it is the byproduct of sewage treatment, it generally contains more contaminants such as organisms, pesticides, and heavy metals than other soil.<ref>{{cite journal |last=Snyder |first=Caroline |title=The dirty work of promoting "recycling" of America's sewage sludge |journal=International Journal of Occupational and Environmental Health |date=19 July 2013 |volume=11 |issue=4 |pages=415–27 |doi=10.1179/oeh.2005.11.4.415 |pmid=16350476 |url=https://www.researchgate.net/publication/7420466 |access-date=30 January 2026 }}</ref><ref>{{Cite journal |last1=Sidhu |first1=Harmanpreet S |last2=Slater |first2=Gregory F |date=2026-04-04 |title=Beyond the Chemical Load: Wastewater Residuals as Drivers of Antibiotic Resistance Proliferation and Dissemination into Soil, Water, and Food Webs |url=https://academic.oup.com/etc/advance-article/doi/10.1093/etojnl/vgag089/8586885 |journal=Environmental Toxicology and Chemistry |article-number=vgag089 |language=en |doi=10.1093/etojnl/vgag089 |pmid=41936068 |issn=0730-7268}}</ref><ref>{{Cite journal |last1=Sidhu |first1=Harmanpreet S. |last2=Okeme |first2=Joseph |last3=Slater |first3=Gregory F. |date=2025-12-18 |title=Unexpected Mobility and Bioaccumulation of Effluent- and Biosolids-Borne PBDEs and Chlorinated Paraffins in an Organic-Rich Soil System |url=https://doi.org/10.1021/acs.est.5c15509 |journal=Environmental Science & Technology |volume=60 |issue=1 |pages=1321–1333 |doi=10.1021/acs.est.5c15509 |pmid=41411671 |issn=0013-936X}}</ref> In the European Union, the Urban Waste Water Treatment Directive allows sewage sludge to be sprayed onto land, although several European countries have introduced more stringent requirements in comparison with the directive.<ref>{{cite journal |last1=Hudcová |first1=Hana |last2=Vymazal |first2=Jan |last3=Rozkošný |first3=Miloš |date=30 June 2019 |title=Present restrictions of sewage sludge application in agriculture within the European Union |url=https://swr.agriculturejournals.cz/pdfs/swr/2019/02/06.pdf |journal=Soil and Water Research |volume=14 |issue=2 |pages=104–20 |doi=10.17221/36/2018-SWR |bibcode=2019SWatR..14..104H |access-date=30 January 2026 }}</ref> 10 million tons dry matter of sewage sludge have been produced in Europe every year over the period 2003–2006. This has good agricultural properties due to the high nitrogen, phosphate and potassium content.<ref>{{cite journal |last1=Antoniadis |first1=Vasileios |last2=Koutroubas |first2=Spyridon D. |last3=Fotiadis |first3=Sideris |date=8 January 2015 |title=Nitrogen, phosphorus, and potassium availability in manure- and sewage sludge-applied soil |url=https://z-library.sk/book/74880594/357b7f |journal=Communications in Soil Science and Plant Analysis |volume=46 |issue=3 |pages=393–404 |doi=10.1080/00103624.2014.983241 |bibcode=2015CSSPA..46..393A |access-date=30 January 2026 }}</ref> However, there is a need to control sewage sludge application to agricultural land so that pathogenic microorganisms do not get into water courses<ref>{{cite journal |last1=Lewis |first1=David L. |last2=Gattie |first2=David K. |date=1 July 2002 |title=Pathogen risks from applying sewage sludge to land |url=https://z-library.sk/book/gjG2ykQ7RW |journal=Environmental Science & Technology |volume=36 |issue=13 |pages=287A–293A |doi=10.1021/es0223426 |access-date=30 January 2026 }}</ref> and to ensure that there is no accumulation of heavy metals in the topsoil.<ref>{{cite journal |last1=Alloway |first1=Bryan J. |last2=Jackson |first2=Andrew P. |date=March 1991 |title=The behaviour of heavy metals in sewage sludge-amended soils |url=https://z-library.sk/book/52026337/13effa |journal=Science of the Total Environment |volume=100 |pages=151–76 |doi=10.1016/0048-9697(91)90377-Q |pmid=2063180 |bibcode=1991ScTEn.100..151A |access-date=30 January 2026 }}</ref> Composting of sewage sludge allows to decrease its content in pathogens<ref>{{cite journal |last1=Dumontet |first1=Stefano |last2=Dinel |first2=Henri |last3=Baloda |first3=Suraj B. |date=24 April 2012 |title=Pathogen reduction in sewage sludge by composting and other biological treatments: a review |url=https://z-library.sk/book/53758814/833687 |journal=Biological Agriculture and Horticulture |volume=16 |issue=4 |pages=409–30 |doi=10.1080/01448765.1999.9755243 |access-date=30 January 2026 }}</ref> and organic pollutants (bioremediation, to the exception of persistent organic pollutants)<ref>{{cite journal |last1=Lü |first1=Huixiong |last2=Chen |first2=Xiao-Hong |last3=Mo |first3=Ce-Hui |last4=Huang |first4=Yu-Hong |last5=He |first5=Min-Ying |last6=Li |first6=Yan-Wen |last7=Feng |first7=Nai-Xian |last8=Katsoyiannis |first8=Athanasios |last9=Cai |first9=Quan-Ying |date=May 2021 |title=Occurrence and dissipation mechanism of organic pollutants during the composting of sewage sludge: a critical review |url=https://archive.org/details/lu-et-al.-2021 |journal=Bioresource Technology |volume=328 |article-number=124847 |doi=10.1016/j.biortech.2021.124847 |pmid=33609883 |bibcode=2021BiTec.32824847L |access-date=30 January 2026 }}</ref> but not that of heavy metals, although these are in a less bioavailable form.<ref>{{cite journal |last=Smith |first=Stephen R. |date=January 2009 |title=A critical review of the bioavailability and impacts of heavy metals in municipal solid waste composts compared to sewage sludge |url=https://www.researchgate.net/publication/222219291 |journal=Environment International |volume=35 |issue=1 |pages=142–56 |doi=10.1016/j.envint.2008.06.009 |pmid=18691760 |bibcode=2009EnInt..35..142S |access-date=2 February 2026 }}</ref>

=== Pesticides and herbicides ===

A pesticide is a substance used to kill a pest. A pesticide may be a chemical substance, biological agent (such as a virus or bacteria), antimicrobial, disinfectant or device used against any pest. Pests include harmful insects, plant pathogens, weeds, mollusks, birds, mammals, fish, nematodes (roundworms) and microbes that compete with humans for food, destroy property, spread or are a vector for disease or cause a nuisance. Although there are benefits to the use of pesticides,<ref>{{cite journal |last1=Cooper |first1=Jerry |last2=Dobson |first2=Hans |date=September 2007 |title=The benefits of pesticides to mankind and the environment |url=https://www.researchgate.net/publication/222969719 |journal=Crop Protection |volume=26 |issue=9 |pages=1337–48 |doi=10.1016/j.cropro.2007.03.022 |bibcode=2007CrPro..26.1337C |access-date=2 February 2026 }}</ref> there are also drawbacks, such as potential toxicity to humans<ref>{{cite journal |last1=Mostafalou |first1=Sara |last2=Abdollahi |first2=Mohammad |date=8 October 2016 |title=Pesticides: an update of human exposure and toxicity |url=https://www.researchgate.net/publication/308945180 |journal=Archives of Toxicology |volume=91 |issue=2 |pages=549–99 |doi=10.1007/s00204-016-1849-x |pmid=27722929 |access-date=2 February 2026 }}</ref> and other organisms.<ref>{{cite journal |last1=DeLorenzo |first1=Marie E. |last2=Scott |first2=Geoffrey I. |last3=Ross |first3=Philippe E. |date=1 January 2001 |title=Toxicity of pesticides to aquatic microorganisms: a review |url=https://z-library.sk/book/32651239/5708fe |journal=Environmental Toxicology and Chemistry |volume=20 |issue=1 |pages=84–98 |doi=10.1002/etc.5620200108 |bibcode=2001EnvTC..20...84D |access-date=2 February 2026 }}</ref><ref>{{cite web |last1=Borke |first1=Jesse |title=Pesticides |url=https://medlineplus.gov/ency/article/002430.htm |publisher=National Library of Medicine |location=Bethesda, Maryland |date=4 August 2025 |access-date=2 February 2026 }}</ref><ref>{{cite web |url=https://www.acmt.net/wp-content/uploads/2022/06/FAQ_Pesticide.pdf |title=Pesticides |publisher=American College of Medical Toxicology |location=Phoenix, Arizona |access-date=2 February 2026 }}</ref>

Herbicides are used to kill weeds, especially on pavements<ref>{{cite journal |last1=Melander |first1=Bo |last2=Holst |first2=Niels |last3=Grundy |first3=Andrea C. |last4=Kempenaar |first4=Corné |last5=Riemens |first5=Marleen M. |last6=Verschwele |first6=Arnd |last7=Hansson |first7=David |date=2 September 2009 |title=Weed occurrence on pavements in five North European towns |url=https://www.academia.edu/74278444 |journal=Weed Research |volume=49 |issue=5 |pages=516–25 |doi=10.1111/j.1365-3180.2009.00713.x |bibcode=2009WeedR..49..516M |access-date=2 February 2026 }}</ref> and railways,<ref>{{cite journal |last=Torstensson |first=Lennart |date=February 2001 |title=Use of herbicides on railway tracks in Sweden |url=https://z-library.sk/book/63112104/9544c2 |journal=Pesticide Outlook |volume=12 |issue=1 |pages=16–21 |doi=10.1039/b100802l |access-date=2 February 2026 }}</ref> but also in agricultural crops either for destructing the total vegetation (e.g. glyphosate) or only a class of undesired plants (e.g. 2,4-D). The so-called auxin herbicides are similar to auxins and are selective to dicots.<ref>{{cite journal |last=Grossmann |first=Klaus |date=February 2010 |title=Auxin herbicides: current status of mechanism and mode of action |url=https://www.researchgate.net/publication/26889628 |journal=Pest Management Science |volume=66 |issue=2 |pages=113–20 |doi=10.1002/ps.1860 |pmid=19823992 |bibcode=2010PMSci..66..113G |access-date=2 February 2026 }}</ref> Glyphosate is a non-selective (broad-spectrum) systemic herbicide which competes with enzymes used in the synthesis of key plant amino acids.<ref>{{cite journal |last1=Amrhein |first1=Nikolaus |last2=Schab |first2=Joachim |last3=Steinrücken |first3=Hans Christian |date=July 1980 |title=The mode of action of the herbicide glyphosate |url=https://z-library.sk/book/38109741/dfb328 |journal=Naturwissenschaften |volume=67 |issue=7 |pages=356–7 |doi=10.1007/BF01106593 |bibcode=1980NW.....67..356A |access-date=3 February 2026 }}</ref> Most herbicides are biodegradable by soil bacteria.<ref>{{cite journal |last1=Singh |first1=Baljinder |last2=Singh |first2=Kashmir |date=27 August 2014 |title=Microbial degradation of herbicides |url=https://www.academia.edu/16343222 |journal=Critical Reviews in Microbiology |volume=42 |issue=2 |pages=245–61 |doi=10.3109/1040841X.2014.929564 |access-date=2 February 2026 }}</ref> However, one group derived from trinitrotoluene (2,4-D and 2,4,5-T) have the impurity dioxin, which is very toxic and causes fatality even in low concentrations.<ref>{{cite journal |last=Birnbaum |first=Linda S. |year=1994 |title=The mechanism of dioxin toxicity: relationship to risk assessment |url=https://www.academia.edu/146686591 |journal=Environmental Health Perspectives |volume=102 |issue=Suppl. 9 |pages=157–67 |doi=10.1289/ehp.94102s9157 |access-date=3 February 2026 |doi-access=free |pmid=7698077 |pmc=1566802 |bibcode=1994EnvHP.102S.157B }}</ref> Another common herbicide is Paraquat, banned in the European Union but still frequently used in agricultural areas of the United States and Asia.<ref>{{cite journal |last1=Utyasheva |first1=Leah |last2=Amarasinghe |first2=Prabath |last3=Eddleston |first3=Michael |date=24 September 2025 |title=Paraquat at 63–the story of a controversial herbicide and its regulations: it is time to put people and public health first when regulating paraquat |journal=BMC Public Health |volume=25 |issue=1 |article-number=3089 |doi=10.1186/s12889-025-23830-w |doi-access=free |pmid=40993561 |pmc=12462389 }}</ref> It is highly toxic to humans<ref>{{cite web |last1=Borke |first1=Jesse |title=Paraquat poisoning |url=https://medlineplus.gov/ency/article/007834.htm |publisher=National Library of Medicine |location=Bethesda, Maryland |date=7 January 2025 |access-date=3 February 2026 }}</ref> and other animals<ref>{{cite journal |last1=Donaher |first1=Sarah E. |last2=Van den Hurk |first2=Peter |date=16 November 2023 |title=Ecotoxicology of the herbicide paraquat: effects on wildlife and knowledge gaps |url=https://www.researchgate.net/publication/375695633 |journal=Ecotoxicology |volume=32 |issue=5 |pages=1187–99 |doi=10.1007/s10646-023-02714-y |pmid=37973658 |bibcode=2023Ecotx..32.1187D |access-date=3 February 2026 }}</ref> and cannot rapidly degrade in the soil where it is adsorbed and thus protected in clay lattices.<ref>{{cite journal |last1=Huang |first1=Yaohua |last2=Zhan |first2=Hui |last3=Bhatt |first3=Pankaj |last4=Chen |first4=Shaohua |date=2 August 2019 |title=Paraquat degradation from contaminated environments: current achievements and perspectives |journal=Frontiers in Microbiology |volume=10 |article-number=1754 |doi=10.3389/fmicb.2019.01754 |doi-access=free |pmid=31428067 |pmc=6689968 |bibcode=2019FrMic..1001754H }}</ref> Glyphosate is rapidly transformed in AMPA by soil bacteria but its residues are detected in drinking water, agriculture, and food products and have major effects on the health of reproductive systems.<ref>{{cite journal |last1=Mohammadi |first1=Keyhan |last2=Sani |first2=Mahmood Alizadeh |last3=Safaei |first3=Payam |last4=Rahmani |first4=Jamal |last5=Molaee-Aghaee |first5=Ebrahim |last6=Jafari |first6=Seid Mahdi |date=27 August 2021 |title=A systematic review and meta-analysis of the impacts of glyphosate on the reproductive hormones |url=https://www.researchgate.net/publication/354177077 |journal=Environmental Science and Pollution Research |volume=29 |issue=41 |pages=62030–41 |doi=10.1007/s11356-021-16145-x |pmid=34453247 |access-date=2 February 2026 }}</ref> Glyphosate is used in genetically modified crops to kill all vegetation except the target crop, more especially in developing countries where it offers yield and profit gains despite growing concerns about environment and human health.<ref>{{cite journal |last=Clapp |first=Jennifer |date=March 2021 |title=Explaining growing glyphosate use: the political economy of herbicide-dependent agriculture |url=https://uwaterloo.ca/scholar/sites/ca.scholar/files/jclapp/files/explaining_growing_glyphosate_use_2021.pdf |journal=Global Environmental Change |volume=67 |issue=6 |article-number=102239 |doi=10.1016/j.gloenvcha.2021.102239 |bibcode=2021GEC....6702239C |access-date=3 February 2026 }}</ref>

Insecticides are used to rid farms of pests which damage crops. The insects damage not only standing crops but also stored ones and in the tropics it is reckoned that one third of the total production is lost during food storage.<ref>{{cite journal |last=De Lima |first=Caitano P. F. |year=1987 |title=Insect pests and postharvest problems in the tropics |url=https://z-library.sk/book/70921598/4f6b8f |journal=Insect Science and Its Application |volume=8 |issue=4–5–6 |pages=673–6 |doi=10.1017/S1742758400022773 |bibcode=1987IJTIS...8..673D |access-date=3 February 2026 }}</ref> As with fungicides, the first insecticides used in the nineteenth century were inorganic e.g. Paris Green and other compounds of arsenic.<ref>{{cite journal |last=Roark |first=Ruric Creegan |date=May 1935 |title=Insecticides and fungicides |url=https://z-library.sk/book/47822675/742e75 |journal=Industrial and Engineering Chemistry |volume=27 |issue=5 |pages=530–2 |doi=10.1021/IE50305A009 |access-date=3 February 2026 }}</ref> Nicotine has also been used since 1690.<ref>{{cite book |doi=10.1007/978-3-662-03656-3_13 |chapter=Botanical insecticides |title=Insecticides in agriculture and environment: retrospects and prospects |isbn=978-3-662-03656-3 |pages=78–91 |year=1998 |last1=Perry |first1=Albert S. |last2=Yamamoto |first2=Izuru |last3=Ishaaya |first3=Isaac |last4=Perry |first4=Rika |editor-last1=Perry |editor-first1=Albert S. |editor-last2=Yamamoto |editor-first2=Izuru |editor-last3=Ishaaya |editor-first3=Isaac |editor-last4=Perry |editor-first4=Rika |chapter-url=https://archive.org/details/perry-et-al.-1998 |publisher=Springer-Verlag |location=Berlin, Germany |access-date=3 February 2026 }}</ref> Neonicotinoids, i.e. synthetic insecticides derived from nicotin are the last generation of insecticides. They have been scheduled to be highly selective to insect pests, although it appeared that acetamiprid, IMI, and thiacloprid were toxic to birds, thiacloprid to fish, and several neonicotinoids were harmful to honeybees, either by direct contact or ingestion.<ref>{{cite journal |last1=Tomizawa |first1=Motohiro |last2=Casida |first2=John E. |title=Neonicotinoid insecticide toxicology: mechanisms of selective action |journal=Annual Review of Pharmacology and Toxicology |date=February 2005 |volume=45 |pages=247–68 |doi=10.1146/annurev.pharmtox.45.120403.095930 |pmid=15822177 |url=https://z-library.sk/book/43831161/040e6b |access-date=3 February 2026 }}</ref>

There are now three main groups of synthetic insecticides:

1. Organochlorines include DDT, Aldrin, Dieldrin and benzene hexachloride (BHC). They are cheap to produce, potent and persistent but have harmful effects on a lot of beneficial organisms, from microbes<ref>{{cite journal |last1=Lal |first1=Rup |last2=Saxena |first2=D. M. |title=Accumulation, metabolism, and effects of organochlorine insecticides on microorganisms |journal=Microbiological Reviews |date=March 1982 |volume=46 |issue=1 |pages=95–127 |doi=10.1128/MMBR.46.1.95-127.1982 |pmid=6178010 |url=https://journals.asm.org/doi/pdf/10.1128/mr.46.1.95-127.1982 |access-date=3 February 2026 }}</ref> to a wide range of plants and animals, humans included,<ref>{{cite journal |last1=Jayaraj |first1=Ravindran |last2=Megha |first2=Pankajshan |last3=Sreedev |first3=Puthur |date=22 July 2016 |title=Organochlorine pesticides, their toxic effects on living organisms and their fate in the environment |journal=Interdisciplinary Toxicology |volume=9 |issue=3–4 |pages=90–100 |doi=10.1515/intox-2016-0012 |doi-access=free |pmid=28652852 |pmc=5464684 }}</ref> hence their banishment in many (but not all) countries,<ref>{{cite journal |last1=Gómez-Ramírez |first1=Pilar |last2=Pérez-García |first2=Juan Manuel |last3=León-Ortega |first3=Mario |last4=Martínez |first4=José Enrique |last5=Calvo |first5=José Francisco |last6=Sánchez-Zapata |first6=José Antonio |last7=Botella |first7=Francisco |last8=María-Mojica |first8=Pedro |last9=Martínez-López |first9=Emma |last10=García-Fernández |first10=Antonio Juan |date=September 2019 |title=Spatiotemporal variations of organochlorine pesticides in an apex predator: influence of government regulations and farming practices |url=https://ulula.es/wp-content/uploads/2024/11/7_2019-GOMEZ-RAMIREZ-Spatiotemporal-variations-of-organochlorine-pesticides-in-an-apex-predator.pdf |journal=Environmental Research |volume=176 |article-number=108543 |doi=10.1016/j.envres.2019.108543 |pmid=31260915 |bibcode=2019ER....17608543G |access-date=4 February 2026 }}</ref> inasmuch as resistance occurred in a lot of target insect pests.<ref>{{cite journal |last1=Davies |first1=T. G. Emyr |last2=O'Reilly |first2=Andrias O. |last3=Field |first3=Linda M. |last4=Wallace |first4=Bonnie A. |last5=Williamson |first5=Martin S. |date=November 2008 |title=Knockdown resistance to DDT and pyrethroids: from target-site mutations to molecular modelling |url=https://z-library.sk/book/ojLd7wpnjL |journal=Pest Management Science |volume=64 |issue=11 |pages=1126–30 |doi=10.1002/ps.1617 |pmid=18561309 |access-date=16 February 2026 }}</ref> DDT was used on a massive scale from the 1930s, with a peak of 72,000 tonnes used in 1970.<ref>{{cite journal |last1=Voldner |first1=Eva C. |last2=Li |first2=Yi-Fan |date=15 January 1995 |title=Global usage of selected persistent organochlorines |journal=Science of the Total Environment |volume=160–161 |pages=201–10 |doi=10.1016/0048-9697(95)04357-7 |bibcode=1995ScTEn.160..201V |url=https://archive.org/details/voldner-li-1995 |access-date=5 February 2026 }}</ref> Then usage fell as the harmful environmental effects were realized.<ref>{{cite journal |last1=Turuzov |first1=Vladimir |last2=Rakitzky |first2=Valery |last3=Tomatis |first3=Lorenzo |date=February 2002 |title=Dichlorodiphenyltrichloroethane (DDT): ubiquity, persistence, and risks |url=https://pmc.ncbi.nlm.nih.gov/articles/instance/1240724/pdf/ehp0110-000125.pdf |journal=Environmental Health Perspectives |volume=1110 |issue=2 |pages=125–8 |doi=10.1289/ehp.02110125 |pmid=11836138 |pmc=1240724 |bibcode=2002EnvHP.110..125T |access-date=4 February 2026 }}</ref> It was found worldwide in fish and birds<ref>{{cite journal |last1=Woodwell |first1=George M. |last2=Wurster |first2=Charles F. Jr |last3=Isaacson |first3=Peter A. |date=12 May 1967 |title=DDT residues in an East Coast estuary: a case of biological concentration of a persistent insecticide |url=https://www.academia.edu/23911092 |journal=Science |volume=156 |issue=3776 |pages=821–4 |doi=10.1126/science.156.3776.821 |pmid=6022229 |bibcode=1967Sci...156..821W |access-date=5 February 2026 }}</ref> and was even discovered in the snow in the Antarctic.<ref>{{cite journal |last=Peel |first=David A. |date=27 March 1975 |title=Organochlorine residues in Antarctic snow |url=https://z-library.sk/book/42557399/abf8ae |journal=Nature |volume=254 |issue=5498 |pages=324–5 |doi=10.1038/254324a0 |bibcode=1975Natur.254..324P |access-date=5 February 2026 }}</ref> It is only slightly soluble in water<ref>{{cite journal |last1=Bowman |first1=Malcolm C. |last2=Acree |first2=Fred Jr |last3=Corbett |first3=M. K. |date=1 May 1960 |title=Solubility of carbon-14 DDT in water |url=https://z-library.sk/book/61952270/660654 |journal=Journal of Agricultural and Food Chemistry |volume=8 |issue=5 |pages=406–8 |doi=10.1021/jf60111a020 |access-date=5 February 2026 }}</ref> but is very soluble in the bloodstream,<ref>{{cite journal |last1=Dale |first1=William E. |last2=Miles |first2=James W. |last3=Gaixes |first3=Thomas B. |date=1 November 1970 |title=Quantitative method for determination of DDT and DDT metabolites in blood serum |url=https://z-library.sk/book/114241945/d3e87b |journal=Journal of AOAC International |volume=53 |issue=6 |pages=1287–92 |doi=10.1093/jaoac/53.6.1287 |access-date=5 February 2026 }}</ref> and in fats. It affects the nervous<ref>{{cite journal |last1=Van Wendel de Joode |first1=Berna |last2=Wesseling |first2=Katharina |last3=Kromhout |first3=Hans |last4=Monge |first4=Patricia |last5=Garcia |first5=Marco |last6=Mergler |first6=Donna |date=31 March 2001 |title=Chronic nervous-system effects of long-term occupational exposure to DDT |url=https://www.researchgate.net/publication/12039670 |journal=The Lancet |volume=357 |issue=9261 |pages=1014–6 |doi=10.1016/S0140-6736(00)04249-5 |pmid=11293598 |access-date=5 February 2026 }}</ref> and endocrine systems<ref>{{cite journal |last=Jaga |first=Kushik |date=January 2000 |title=What are the implications of the interaction between DDT and estrogen receptors in the body? |url=https://z-library.sk/book/50516671/e00dc1 |journal=Medical Hypotheses |volume=54 |issue=1 |pages=18–25 |doi=10.1054/mehy.1998.0811 |access-date=5 February 2026 |doi-access=free |pmid=10791702 }}</ref> and causes the eggshells of birds to lack calcium causing them to be easily breakable.<ref>{{cite journal |last1=Bitman |first1=Joel |last2=Cecil |first2=Helene C. |last3=Fries |first3=George F. |date=May 1970 |title=DDT-induced inhibition of avian shell gland carbonic anhydrase: a mechanism for thin eggshells |url=https://z-library.sk/book/61556093/347e54 |journal=Science |volume=168 |issue=3931 |pages=594–6 |doi=10.1126/science.168.3931.594 |pmid=4985323 |bibcode=1970Sci...168..594B |access-date=5 February 2026 }}</ref> It is thought to be responsible for the decline of numbers of birds of prey like ospreys and peregrine falcons in the 1950s, now recovering.<ref>{{cite web |last1=Ehrlich |first1=Paul R. |last2=Dobkin |first2=David S. |last3=Wheye |first3=Darryl |title=DDT and birds |url=https://web.stanford.edu/group/stanfordbirds/text/essays/DDT_and_Birds.html |access-date=5 February 2026 |website=web.stanford.edu }}</ref> As well as increased concentration via the food chain, it is known to enter via permeable membranes, so fish get it through their gills and then it accumulates in fatty organs.<ref>{{cite journal |last=Holden |first=A. V. |date=September 1962 |title=A study of the absorption of 14C-labelled DDT from water by fish |url=https://z-library.sk/book/47111653/52fb1f |journal=Annals of Applied Biology |volume=50 |issue=3 |pages=467–77 |doi=10.1111/j.1744-7348.1962.tb06042.x |access-date=5 February 2026 }}</ref> As it has low water solubility and a high affinity to the air-water interface,<ref>{{cite journal |last1=Acree |first1=Fred Jr |last2=Berosa |first2=Morton |last3=Bowman |first3=Malcolm C. |date=July–August 1963 |title=Codistillation of DDT with water |url=https://cdn.toxicdocs.org/Qv/Qvw98LL1KoKn84kGqyoe1b55/Qvw98LL1KoKn84kGqyoe1b55.pdf |journal=Agricultural and Food Chemistry |volume=11 |issue=4 |pages=278–80 |doi=10.1021/jf60128a001 |access-date=5 February 2026 }}</ref> DDT tends to stay at the water surface, so organisms that live there are most affected, in particular mosquito larvae,<ref>{{cite journal |last=Tarzwell |first=Clarence M. |date=11 April 1947 |title=Effects of DDT mosquito larviciding on wildlife. I. The effects on surface organisms of the routine hand application of DDT larvicides for mosquito control |url=https://z-library.sk/book/84325287/c8227e |journal=Public Health Reports |volume=62 |issue=15 |pages=525–54 |doi=10.2307/4586091 |jstor=4586091 |pmid=20340263 |access-date=5 February 2026 }}</ref> the target organisms of malaria control.<ref>{{cite journal |last1=Maharaj |first1=Rajendra |last2=Mthembu |first2=D. Jamela |last3=Sharp |first3=B. L. |date=1 November 2005 |title=Impact of DDT re-introduction on malaria transmission in KwaZulu-Natal |journal=South African Medical Journal |volume=95 |issue=11 |pages=871–4 |pmid=16344885 |url=https://journals.co.za/doi/abs/10.10520/EJC68367 |access-date=5 February 2026 }}</ref> DDT and its breakdown product DDE found in fish that formed part of the human food chain caused concern, with levels found in human liver, kidney and brain tissues around 13 ppm in 1970,<ref>{{cite journal |last1=Trojanowska |first1=Monika |last2=Stankiewicz |first2=Z. |last3=Szucki |first3=Bohdan |last4=Pomorska |first4=K. |last5=Majewska |first5=B. |date=July 1972 |title=DDT and DDE content of human tissues |url=https://z-library.sk/book/40469609/e98857 |journal=Forensic Science |volume=1 |issue=2 |pages=239–43 |doi=10.1016/0300-9432(72)90047-7 |pmid=5045691 |access-date=5 February 2026 }}</ref> with a general decrease since DDT was banished from developing countries but with still high levels in Asia and Africa where DDT is used against malaria.<ref>{{cite journal |last1=Kushik |first1=Jaga |last2=Chandrabhan |first2=Dharmani |year=2003 |title=Global surveillance of DDT and DDE levels in human tissues |url=https://web.archive.org/web/20170809153432id_/http://www.imp.lodz.pl/upload/oficyna/artykuly/pdf/full/Jaga1-01-03.pdf |journal=International Journal of Occupational Medicine and Environmental Health |volume=16 |issue=1 |pages=7–20 |pmid=12705713 |access-date=5 February 2026 }}</ref> DDT was banned by the Stockholm convention in 2001 to stop its further buildup in the food chain. However, the World Health Organization allowed its reintroduction only for control of vector-borne diseases in some tropical countries in 2006.<ref>{{cite journal |last1=Mansouri |first1=Ahlem |last2=Cregut |first2=Mickaël |last3=Abbes |first3=Chiraz |last4=Durand |first4=Marie-José |last5=Landoulsi |first5=Ahmed |last6=Thouand |first6=Gérald |date=3 September 2016 |title=The environmental issues of DDT pollution and bioremediation: a multidisciplinary review |url=https://www.researchgate.net/publication/307621968 |journal=Applied Biochemistry and Biotechnology |volume=181 |issue=1 |pages=309–39 |doi=10.1007/s12010-016-2214-5 |pmid=27591882 |access-date=6 February 2026 }}</ref> U.S. manufacturers continued to sell DDT to developing countries, who could not afford the expensive replacement chemicals and who did not have such stringent regulations governing the use of pesticides.<ref>{{cite web |date=11 September 2025 |title=DDT: a brief history and status |url=https://www.epa.gov/ingredients-used-pesticide-products/ddt-brief-history-and-status |access-date=6 February 2026 |website=www.epa.gov |language=en }}</ref>

2. Organophosphates, e.g. parathion, methyl parathion and about 40 other insecticides are available nationally. Parathion is highly toxic, methyl-parathion less so<ref>{{cite journal |last1=Benke |first1=Geza M. |last2=Cheever |first2=K. L. |last3=Mirer |first3=Franklin E. |last4=Murphy |first4=Sheldon D. |date=April 1974 |title=Comparative toxicity, anticholinesterase action and metabolism of methyl parathion and parathion in sunfish and mice |url=https://z-library.sk/book/51989433/af4bae |journal=Toxicology and Applied Pharmacology |volume=28 |issue=1 |pages=97–109 |doi=10.1016/0041-008X(74)90135-5 |pmid=4851102 |bibcode=1974ToxAP..28...97B |access-date=6 February 2026 }}</ref> but health concerns have resulted in cancellation of the use of methyl-parathion in most food crops in the United States.<ref>{{cite journal |last1=Garcia |first1=Stephanie |last2=Abu-Quare |first2=Aqel |last3=Meeker-O'Connell |first3=Winifred |last4=Borton |first4=Anita |last5=Abou-Donia |first5=Mohamed |date=7 January 2011 |title=Methyl parathion: a review of health effects |url=https://z-library.sk/book/65081872/d61cda |journal=Journal of Toxicology and Environmental Health, Part B |volume=6 |issue=2 |pages=185–210 |doi=10.1080/10937400306471 |pmid=12554434 |access-date=6 February 2026 }}</ref> There is no evidence that malathion affects the ability of humans to reproduce. There is also no conclusive proof that malathion causes cancer in humans, although some studies have found increased incidence of some cancers in people who are regularly exposed to pesticides, such as farmers and pesticide applicators.<ref>{{cite web |last1=Wilson |first1=Jewell D. |last2=Llados |first2=Fernando T. |last3=Singh |first3=Mona |last4=Sutton |first4=Cheryl A. |last5=Sutton |first5=William R. |last6=Nakatsugawa |first6=Tsutomu |last7=Benson |first7=Amy |date=September 2003 |title=Toxicological profile for malathion |url=https://www.atsdr.cdc.gov/toxprofiles/tp154.pdf |access-date=6 February 2026 |website=U.S. Department of Health and Human Services, Public Health Service Agency for Toxic Substances and Disease Registry |location=Atlanta, Georgia }}</ref> This group of insecticides works by preventing normal nerve transmission as acetylcholinesterase is prevented from breaking down the transmitter substance acetylcholine, resulting in uncontrolled muscle movements.<ref>{{cite journal |last1=Tsai |first1=Yi-Hua |last2=Lein |first2=Pamela J. |date=June 2021 |title=Mechanisms of organophosphate neurotoxicity |url=https://www.academia.edu/114049913 |journal=Current Opinion in Toxicology |volume=26 |issue=2 |pages=49–60 |doi=10.1016/j.cotox.2021.04.002 |pmid=34308007 |access-date=6 February 2026 |pmc=8302047 |bibcode=2021COTox..26...49T }}</ref>

3. Neonicotinoids, e.g. acetamiprid, imidacloprid, are the last generation of insecticides and are now largely used for crop protection.<ref>{{cite journal |last1=Elbert |first1=Alfred |last2=Haas |first2=Matthias |last3=Springer |first3=Bernd |last4=Thelert |first4=Wolfgang |last5=Nauen |first5=Ralf |date=November 2008 |title=Applied aspects of neonicotinoid uses in crop protection |url=https://z-library.sk/book/37134719/423fed |journal=Pest Management Science |volume=64 |issue=11 |pages=1099–105 |doi=10.1002/ps.1616 |pmid=18561166 |bibcode=2008PMSci..64.1099E |access-date=6 February 2026 }}</ref> They affect the central nervous system of insects, with higher selectivity for insects than organophosphates and organochlorines.<ref>{{cite journal |last1=Matsuda |first1=Kazuhiko |last2=Kanaoka |first2=Satoshi |last3=Akamatsu |first3=Miki |last4=Sattelle |first4=David B. |date=July 2009 |title=Diverse actions and target-site selectivity of neonicotinoids: structural insights |url=https://www.researchgate.net/publication/24234502 |journal=Molecular Pharmacology |volume=76 |issue=1 |pages=1–10 |doi=10.1124/mol.109.055186 |pmid=19321668 |access-date=16 February 2026 |pmc=2701451 }}</ref> However, their biocidal action includes both pests and beneficial organisms, e.g. pollinators,<ref>{{cite journal |last1=Paoli |first1=Marco |last2=Giurfa |first2=Martin |date=October 2024 |title=Pesticides and pollinator brain: how do neonicotinoids affect the central nervous system of bees? |journal=European Journal of Neuroscience |volume=60 |issue=8 |pages=5927–48 |doi=10.1111/ejn.16536 |doi-access=free |pmid=39258341 }}</ref> predatory insects, parasitoids.<ref>{{cite journal |last1=Cloyd |first1=Raymond A. |last2=Bethke |first2=James A. |date=January 2011 |title=Impact of neonicotinoid insecticides on natural enemies in greenhouse and interiorscape environments |journal=Pest Management Science |volume=67 |issue=1 |pages=3–9 |doi=10.1002/ps.2015 |pmid=20721973 |bibcode=2011PMSci..67....3C |url=https://z-library.sk/book/37135187/ba1e4b |access-date=6 February 2026 }}</ref> The ay also act as endocrine disruptors on juvenile bees.<ref>{{cite journal |last1=Baines |first1=Danica |last2=Wilton |first2=Emily |last3=Pawluk |first3=Abbe |last4=De Gorter |first4=Michael |last5=Chomistek |first5=Nora |date=8 September 2017 |title=Neonicotinoids act like endocrine disrupting chemicals in newly-emerged bees and winter bees |journal=Scientific Reports |volume=7 |issue=1 |article-number=10979 |doi=10.1038/s41598-017-10489-6 |doi-access=free|pmid=28887455 |pmc=5591280 |bibcode=2017NatSR...710979B }}</ref> The dramatic decline of honey bee colonies,<ref>{{cite journal |last=Watanabe |first=Myrna E. |date=26 August 1994 |title=Pollination worries rise as honey bees decline |journal=Science |volume=265 |issue=5176 |page=1170 |doi=10.1126/science.265.5176.1170 |pmid=17787573 |bibcode=1994Sci...265.1170W |url=https://z-library.sk/book/54799428/7ab19a |access-date=6 February 2026 }}</ref> for example, could be linked to, or at least exacerbated by the use of neonicotinoids.<ref>{{cite journal |last1=Klingelhöfer |first1=Doris |last2=Braun |first2=Markus |last3=Brüggmann |first3=Dörthe |last4=Groneberg |first4=David A. |date=October 2022 |title=Neonicotinoids: a critical assessment of the global research landscape of the most extensively used insecticide |journal=Environmental Research |url=https://archive.org/details/klingelhofer-et-al.-2022 |volume=213 |article-number=113727 |doi=10.1016/j.envres.2022.113727 |pmid=35732199 |bibcode=2022ER....21313727K |access-date=6 February 2026 }}</ref> Like nicotine, their molecular base, they are degraded in the soil but the environmental residues of neonicotinoids have enormously increased due to large-scale applications.<ref>{{cite journal |last1=Pang |first1=Shimei |last2=Lin |first2=Ziqiu |last3=Zhang |first3=Wenping |last4=Mishra |first4=Sandhya |last5=Bhatt |first5=Pankaj |last6=Chen |first6=Shaohua |date=19 May 2020 |title=Insights into the microbial degradation and biochemical mechanisms of neonicotinoids |journal=Frontiers in Microbiology |volume=11 |article-number=868 |doi=10.3389/fmicb.2020.00868 |doi-access=free |pmid=32508767 |pmc=7248232 }}</ref>

=== Agents of war ===

The disposal of munitions, and a lack of care in manufacture of munitions caused by the urgency of production, can contaminate soil for extended periods.<ref>{{cite journal |last1=Rodríguez-Seijo |first1=Andrés |last2=Fernández-Calviño |first2=David |last3=Arias-Estévez |first3=Manuel |last4=Arenas-Lago |first4=Danierl |date=7 June 2024 |title=Effects of military training, warfare and civilian ammunition debris on the soil organisms: an ecotoxicological review |journal=Biology and Fertility of Soils |volume=60 |issue=6 |pages=813–44 |doi=10.1007/s00374-024-01835-8 |doi-access=free |bibcode=2024BioFS..60..813R |hdl=11093/7168 |hdl-access=free }}</ref> There is little published evidence on this type of contamination largely because of restrictions placed by governments of many countries on the publication of material related to war effort, in particular under ongoing conflict scenarios.<ref>{{cite journal |last1=Broomandi |first1=Parya |last2=Guney |first2=Mert |last3=Kim |first3=Jong Ryeol |last4=Karaca |first4=Ferhat |date=29 October 2020 |title=Soil contamination in areas impacted by military activities: a critical review |journal=Sustainability |volume=12 |issue=21 |article-number=9002 |doi=10.3390/su12219002 |doi-access=free |bibcode=2020Sust...12.9002B }}</ref> However, mustard gas stored during World War II has contaminated some sites for up to 50 years<ref>{{cite news |last1=Bellamy |first1=Christopher |title=Sixty secret mustard gas sites uncovered |url=https://www.independent.co.uk/news/sixty-secret-mustard-gas-sites-uncovered-1335343.html |work=The Independent |date=4 June 1996 |access-date=9 February 2026 }}</ref> and the testing of Anthrax as a potential biological weapon contaminated the whole island of Gruinard, leaving it in quarantine for 48 years.<ref>{{cite news |title=Britain's 'Anthrax Island' |url=https://news.bbc.co.uk/2/hi/uk_news/scotland/1457035.stm |work=BBC News |date=25 July 2001 |access-date=9 February 2026 }}</ref> There are abandoned delaboration sites around the former World War I front in Belgium and also in France which are still contaminated by arsenic and lead.<ref>{{cite journal |last1=Bausinger |first1=T. |last2=Preuβ |first2=J. |date=June 2005 |title=Environmental remnants of the First World War: soil contamination of a burning ground for arsenical ammunition |journal=Bulletin of Environmental Contamination and Toxicology |volume=74 |issue=6 |pages=1045–52 |url=https://z-library.sk/book/39152197/545647 |doi=10.1007/s00128-005-0686-z |pmid=16158839 |bibcode=2005BuECT..74.1045B |access-date=9 February 2026 }}</ref>

== Human health ==

=== Exposure pathways ===

Contaminated or polluted soil directly affects human health through direct contact with soil<ref>{{cite journal |last1=Jennings |first1=Aaron A. |last2=Li |first2=Zijian |date=12 June 2017 |title=Worldwide regulatory guidance values applied to direct contact surface soil pesticide contamination. I. Carcinogenic pesticides |journal=Air, Soil and Water Research |volume=10 |article-number=12 |doi=10.1177/1178622117711930 |doi-access=free }}</ref> or via inhalation of soil contaminants that have vaporized.<ref>{{cite journal |last1=Weeks |first1=Joseph J. |last2=Hettiarachchi |first2=Ganga M. |last3=Santos |first3=Eduardo |last4=Tatarko |first4=John |date=May–June 2021 |title=Potential human inhalation exposure to soil contaminants in urban gardens on brownfields sites: a breath of fresh air? |journal=Journal of Environmental Quality |volume=50 |issue=3 |pages=782–90 |url=https://www.researchgate.net/publication/349499180 |doi=10.1002/jeq2.20208 |pmid=33616205 |bibcode=2021JEnvQ..50..782W |access-date=9 February 2026 }}</ref> Potentially greater threats are posed by the infiltration of soil contaminants into groundwater aquifers used for irrigation<ref>{{cite journal |last1=Gillispie |first1=Elizabeth C. |last2=Sowers |first2=Tyler D. |last3=Duckworth |first3=Owen W. |last4=Polizzotto |first4=Matthew L. |date=3 March 2015 |title=Soil pollution due to irrigation with arsenic-contaminated groundwater: current state of science |journal=Current Pollution Reports |volume=1 |issue=1 |pages=1–12 |url=https://z-library.sk/book/71427567/2161b2 |doi=10.1007/s40726-015-0001-5 |bibcode=2015CPolR...1....1G |access-date=9 February 2026 }}</ref> or direct human consumption,<ref>{{cite journal |last1=Goodrich |first1=James A. |last2=Lykins |first2=Benjamin W. Jr |last3=Clark |first3=Robert M. |date=3 March 2015 |title=Soil pollution due to irrigation with arsenic-contaminated groundwater: current state of science |journal=Current Pollution Reports |volume=1 |issue=1 |pages=1–12 |url=https://z-library.sk/book/71427567/2161b2 |doi=10.1007/s40726-015-0001-5 |bibcode=2015CPolR...1....1G |access-date=9 February 2026 }}</ref> sometimes in areas far from any apparent source of above-ground contamination (long-range diffuse soil contamination).<ref>{{cite journal |last1=Fabietti |first1=Gabriele |last2=Biasioli |first2=Mattia |last3=Barberis |first3=Renzo |last4=Ajmone-Marsan |first4=Franco |date=11 July 2009 |title=Soil contamination by organic and inorganic pollutants at the regional scale: the case of Piedmont, Italy |journal=Journal of Soils and Sediments |volume=10 |issue=2 |pages=290–300 |url=https://www.researchgate.net/publication/225658551 |doi=10.1007/s11368-009-0114-9 |access-date=9 February 2026 }}</ref> Toxic metals can also make their way up the food chain through plants that reside in soils containing high concentrations of heavy metals.<ref>{{cite book |doi=10.1007/978-94-009-1586-2_73 |chapter=Heavy metal transfer in the food chain to humans |title=Fertilizers and environment |year=1996 |last1=Hapke |first1=Hans-Jürgen |pages=431–6 |editor-last=Rodriguez-Barrueco |editor-first=Claudio |isbn=978-94-010-7210-6 |chapter-url=https://z-library.sk/book/53741436/8273c8 |access-date=9 February 2026 }}</ref> This tends to result in the development of pollution-related diseases.

Most exposure to soil contamination is accidental, and can happen through:<ref name="Eugenio2021">{{cite book |doi=10.4060/cb4894en |title=Global assessment of soil pollution: report |year=2021 |isbn=978-92-5-134469-9 |chapter=Environmental, health and socio-economic impacts of soil pollution |first1=Natalia |last1=Rodríguez Eugenio |chapter-url=https://openknowledge.fao.org/server/api/core/bitstreams/fe5df8d6-6b19-4def-bdc6-62886d824574/content/src/html/chapter-04-1.html |publisher=FAO |location=Rome, Italy |access-date=9 February 2026 }}</ref> * Ingesting dust or soil directly * Ingesting food or vegetables grown in contaminated soil or with foods in contact with contaminants * Skin contact with dust or soil * Vapors from the soil * Inhaling clouds of dust while working in soils or windy environments

However, some studies estimate that 90% of human exposure is through eating contaminated food.<ref name="Eugenio2021"/>

=== Consequences ===

Health consequences from exposure to soil contamination vary greatly depending on pollutant type, the pathway of attack, and the vulnerability of the exposed population.<ref>{{cite journal |last1=McKone |first1=Thomas E. |last2=Maddalena |first2=Randy L. |date=July 1997 |title=Soil contamination and human exposure: a comprehensive assessment framework |journal=International Journal of Toxicology |volume=16 |issue=4–5 |pages=319–37 |doi=10.1080/109158197226991 |doi-access=free }}</ref> Researchers suggest that pesticides and heavy metals in soil may harm cardiovascular health, including inflammation and change in the body's circadian rhythm.<ref>{{cite press release |title=Scientists warn of links between soil pollution and heart disease |url=https://www.sciencedaily.com/releases/2022/07/220701102754.htm |work=ScienceDaily |publisher=European Society of Cardiology |date=1 July 2022 |access-date=9 February 2026 }}</ref>

Chronic exposure to chromium, lead, and other metals, petroleum, solvents, and many pesticide and herbicide formulations can be carcinogenic (mutagenic),<ref>{{cite journal |last1=White |first1=Paul A. |last2=Claxton |first2=Larry D. |date=November 2004 |title=Mutagens in contaminated soil: a review |journal=Mutation Research |volume=567 |issue=2–3 |pages=227–345 |url=https://www.academia.edu/2502196 |doi=10.1016/j.mrrev.2004.09.003 |pmid=15572286 |bibcode=2004MRRMR.567..227W |access-date=9 February 2026 }}</ref> can cause congenital disorders,<ref>{{cite journal |last1=Foster |first1=Warreb G. |last2=Evans |first2=Jane A. |last3=Little |first3=Julian |last4=Arbour |first4=Laura |last5=Moore |first5=Aideen |last6=Sauve |first6=Reg |last7=León |first7=Juan Andrés |last8=Luo |first8=Wei |date=11 August 2016 |title=Human exposure to environmental contaminants and congenital anomalies: a critical review |journal=Critical Reviews in Toxicology |volume=47 |issue=1 |pages=59–84 |doi=10.1080/10408444.2016.1211090 |pmid=27685638 |url=https://z-library.sk/book/92035896/2a3016 |access-date=9 February 2026 }}</ref> or other chronic diseases.<ref>{{cite journal |last1=Münzel |first1=Thomas |last2=Hadad |first2=Omar |last3=Lelieveld |first3=Jos |last4=Aschner |first4=Michael |last5=Nieuwenhuijsen |first5=Mark J. |last6=Landrigan |first6=Philip J. |last7=Daiber |first7=Andreas |date=25 September 2024 |title=Soil and water pollution and cardiovascular disease |journal=Nature Reviews Cardiology |volume=22 |issue=2 |pages=71–89 |doi=10.1038/s41569-024-01068-0 |pmid=39317838 |url=https://www.researchgate.net/publication/384299693 |access-date=9 February 2026 }}</ref> Industrial or human-made concentrations of naturally occurring substances, such as nitrate and ammonia associated with livestock manure from agricultural operations, have also been identified as health hazards in soil and groundwater.<ref>{{cite journal |last1=Havlikova |first1=Martina |last2=Kroeze |first2=Carolien |last3=Huijbregts |first3=Mark A. J. |date=25 June 2008 |title=Environmental and health impact by dairy cattle livestock and manure management in the Czech Republic |journal=Science of the Total Environment |volume=396 |issue=2–3 |pages=121–31 |doi=10.1016/j.scitotenv.2008.02.027 |pmid=18394682 |bibcode=2008ScTEn.396..121H |url=https://z-library.sk/book/46035081/41d5f4 |access-date=9 February 2026 }}</ref>

Chronic exposure to benzene at sufficient concentrations is known to be associated with a higher incidence of leukemia.<ref>{{cite journal |last1=Duarte-Davidson |first1=Raquel |last2=Courage |first2=Carol |last3=Rushton |first3=Lesley |last4=Levy |first4=Len |date=January 2001 |title=Benzene in the environment: an assessment of the potential risks to the health of the population |journal=Occupational and Environmental Medicine |volume=58 |issue=1 |pages=2–13 |doi=10.1136/oem.58.1.2 |pmid=11119628 |pmc=1740026 |url=https://www.researchgate.net/publication/12208303 |access-date=10 February 2026 }}</ref> Mercury and cyclodienes are known to induce higher incidences of kidney damage and some irreversible diseases.<ref>{{cite journal |last1=Muccillo–Baisch |first1=Ana Luiza |last2=Mirlean |first2=Nicolai |last3=Carrazzoni |first3=Daniela |last4=Soares |first4=Maria Cristina Flores |last5=Goulart |first5=Gianni Peraza |last6=Baisch |first6=Paulo |date=31 March 2011 |title=Health effects of ingestion of mercury-polluted urban soil: an animal experiment |journal=Environmental Geochemistry and Health |volume=34 |issue=1 |pages=43–53 |doi=10.1007/s10653-011-9389-z |pmid=21451960 |url=https://www.academia.edu/53404083 |access-date=10 February 2026 }}</ref><ref>{{cite journal |last1=Yadla |first1=Manjusha |last2=Yanala |first2=Sandeep Reddy |last3=Parvithina |first3=Sriramnaveen |last4=Chennu |first4=Krishna Kishore |last5=Annapindi |first5=Nagasridhar |last6=Vishnubhotla |first6=Sivakumar |date=May–June 2013 |title=Acute kidney injury in endosulfan poisoning |journal=Saudi Journal of Kidney Diseases and Transplantation |volume=24 |issue=3 |pages=592–3 |doi=10.4103/1319-2442.111077 |doi-access=free |pmid=23640641 }}</ref> PCBs and cyclodienes are linked to liver toxicity.<ref>{{cite journal |last1=Wahlang |first1=Banrida |last2=Hardesty |first2=Josiah E. |last3=Jin |first3=Jian |last4=Falkner |first4=K. Cameron |last5=Cave |first5=Matthew C. |date=April 2019 |title=Polychlorinated biphenyls and nonalcoholic fatty liver disease |journal=Current Opinion in Toxicology |volume=14 |pages=21–8 |doi=10.1016/j.cotox.2019.06.001 |pmid=34485777 |url=https://z-library.sk/book/107335633/faf72f |access-date=10 February 2026 |pmc=8412140 |bibcode=2019COTox..14...21W }}</ref> Organophosphates can cause a chain of responses leading to neuromuscular blockage.<ref>{{cite journal |last1=Karalliedde |first1=Lakshman |last2=Henry |first2=John A. |date=July 1993 |title=Effects of organophosphates on skeletal muscle |journal=Human & Experimental Toxicology |volume=12 |issue=4 |pages=289–96 |doi=10.1177/096032719301200406 |pmid=8104006 |bibcode=1993HETox..12..289K |url=https://z-library.sk/book/66019412/e68e1f |access-date=10 February 2026 }}</ref> Many chlorinated solvents induce liver changes, kidney changes, and depression of the central nervous system.<ref>{{cite journal |last=Ruder |first=Avima M. |date=September 2006 |title=Potential health effects of occupational chlorinated solvent exposure |journal=Annals of the New York Academy of Sciences |volume=1076 |issue=1 |pages=207–27 |doi=10.1196/annals.1371.050 |pmid=17119204 |bibcode=2006NYASA1076..207R |url=https://www.academia.edu/22018165 |access-date=10 February 2026 }}</ref> There is an entire spectrum of further health effects such as headache, nausea, fatigue, eye irritation and skin rash for the above cited and other chemicals, including those commonly used in agriculture.<ref>{{cite book |doi=10.1007/0-387-30105-4_23 |chapter=Neurotoxicity of chemicals commonly used in agriculture |title=Agricultural medicine: a practical guide |isbn=978-0-387-30105-1 |pages=300–23 |date=16 January 2006 |last1=Katz |first1=Nikita B. |last2=Katz |first2=Olga |last3=Mandel |first3=Steven |editor-last=Lessenger |editor-first=James E. |chapter-url=https://z-library.sk/book/53309286/8d0f21 |publisher=Springer |location=New York, New York |access-date=10 February 2026 }}</ref> At sufficient dosages a large number of soil contaminants can cause death by exposure via direct contact, inhalation or ingestion.<ref>{{cite book |doi=10.1039/9781847551719-00352 |chapter=Soil pollution and land contamination |title=Pollution: causes, effects and control |isbn=978-1-84755-171-9 |pages=352–77 |date=20 July 2001 |last=Alloway |first=Brian John |editor-last=Harrison |editor-first=Roy M. |chapter-url=https://z-library.sk/book/43718713/b32f46 |publisher=Royal Society of Chemistry |location=Cambridge, United Kingdom |access-date=10 February 2026 }}</ref>

== Ecosystem effects == thumb|This area is contaminated with stagnant water and refuse, making the environment unhygienic. Not unexpectedly, soil contaminants can have significant deleterious consequences for ecosystems.<ref>{{cite book |doi=10.1016/B978-0-12-849873-6.00003-0 |chapter=Changes in soil ecosystem structure and functions due to soil contamination |title=Soil pollution: from monitoring to remediation |isbn=978-0-12-849873-6 |pages=59–87 |year=2018 |last1=Morgado |first1=Rui G. |last2=Loureiro |first2=Susana |last3=González-Alcaraz |first3=Maria N. |editor-last1=Rocha-Santos |editor-first1=Teresa A. P. |editor-last2=Cachala |editor-first2=Anabela |editor-last3=Duarte |editor-first3=Armando C. |chapter-url=https://z-library.sk/book/99859596/db6d37 |publisher=Academic Press |location=Cambridge, Massachusetts |edition=1st |hdl=10773/25429 |access-date=10 February 2026 }}</ref> There are radical soil chemistry changes which can arise from the presence of many hazardous chemicals even at low concentration of the contaminant species.<ref>{{cite journal |last1=Li |first1=Yongquan |last2=Li |first2=Caili |last3=Xin |first3=Ying |last4=Huang |first4=Tao |last5=Liu |first5=Jin |date=November 2022 |title=Petroleum pollution affects soil chemistry and reshapes the diversity and networks of microbial communities |journal=Ecotoxicology and Environmental Safety |volume=246 |article-number=114129 |doi=10.1016/j.ecoenv.2022.114129 |url=https://archive.org/details/li-et-al.-2022 |access-date=16 February 2026 |doi-access=free |pmid=36193589 |bibcode=2022EcoES.24614129L }}</ref> These changes can manifest in the alteration of the metabolism of soil microorganisms and soil animals resident in a given soil environment.<ref>{{cite book |doi=10.1007/978-1-4419-8011-3_3 |chapter=Mixtures of environmental pollutants: effects on microorganisms and their activities in soils |title=Reviews of environmental contamination and toxicology |volume=211 |isbn=978-1-4419-8011-3 |pages=63–120 |date=1 January 2011 |last1=Ramakrishnan |first1=Balasubramanian |last2=Megharaj |first2=Mallavarapu |last3=Venkateswarlu |first3=Kadiyala |last4=Sethunathan |first4=Nambrattil |last5=Naidu |first5=Ravi |editor-last=Whitacre |editor-first=David M. |chapter-url=https://www.academia.edu/7450948 |publisher=Springer |location=New York, New York |access-date=10 February 2026 }}</ref><ref>{{cite journal |last1=Cortet |first1=Jérôme |last2=Gomot-De Vauflery |first2=Annette |last3=Poinsot-Balaguer |first3=Nicole |last4=Gomot |first4=Lucien |last5=Texier |first5=Christine |last6=Cluzeau |first6=Daniel |date=July–September 1999 |title=The use of invertebrate soil fauna in monitoring pollutant effects |journal=European Journal of Soil Biology |volume=35 |issue=3 |pages=115–34 |doi=10.1016/S1164-5563(00)00116-3 |bibcode=1999EJSB...35..115C |url=https://www.academia.edu/61373140 |access-date=10 February 2026 }}</ref> The result can be virtual eradication of some of the primary food chain, which in turn could have major consequences for predator or consumer species.<ref>{{cite book |doi=10.1007/978-3-642-69314-4_7 |chapter=The contamination of plants and soils with heavy metals and the transport of metals in terrestrial food chains |title=Changing metal cycles and human health |isbn=978-3-642-69314-4 |pages=113–41 |year=1984 |last1=Kloke |first1=Adolf |last2=Sauerbeck |first2=D. R. |last3=Vetter |first3=H. |editor-last=Nriagu |editor-first=Jerome O. |chapter-url=https://z-library.sk/book/72805217/23ef2b |publisher=Springer |location=Berlin, Germany |access-date=10 February 2026 }}</ref> Even if the chemical effect on lower life forms is small, the lower pyramid levels of the food chain may ingest alien chemicals, which then become more and more concentrated for each consuming rung of the food chain.<ref>{{cite journal |last=Clarkson |first=Thomas W. |date=March 1995 |title=Environmental contaminants in the food chain |journal=The American Journal of Clinical Nutrition |volume=61 |issue=Suppl. 3 |pages=682S–686S |doi=10.1093/ajcn/61.3.682S |pmid=7879738 |url=https://z-library.sk/book/100484366/a59102 |access-date=11 February 2026 }}</ref> Many of these effects are now well known, such as the concentration of persistent DDT materials for avian consumers, leading to weakening of egg shells, increased chick mortality and potential extinction of species.<ref>{{cite journal |last1=Jayaraj |first1=Ravindran |last2=Megha |first2=Pankajshan |last3=Sreedev |first3=Puthur |date=December 2016 |title=Organochlorine pesticides, their toxic effects on living organisms and their fate in the environment |journal=Interdisciplinary Toxicology |volume=9 |issue=3–4 |pages=90–100 |doi=10.1515/intox-2016-0012 |pmc=5464684 |pmid=28652852 |doi-access=free }}</ref>

Detrimental impacts of contaminants on soil food chains result in dramatic changes in humus forms, mediated by the disappearance or reduced activity of key organisms, also called soil ecosystem engineers, e.g. earthworms, which arez particularly sensitive to a wide range of soil contaminants.<ref>{{cite journal |last1=Hirano |first1=Takeshi |last2=Tamae |first2=Kazuyoshi |date=28 November 2011 |title=Earthworms and soil pollutants |journal=Sensors |volume=11 |issue=12 |pages=11157–67 |doi=10.3390/s111211157 |doi-access=free |pmid=22247659 |pmc=3251976 |bibcode=2011Senso..1111157H }}</ref> In contaminated land the topsoil passes from a stage in which organic matter is decomposed and incorporated to mineral matter (mull humus, with a good granular soil structure) to a stage in which organic matter accumulates undecayed above a compact mineral soil with poor structure (mor humus).<ref>{{cite journal |last1=Gillet |first1=Servane |last2=Ponge |first2=Jean-François |date=December 2002 |title=Humus forms and metal pollution in soil |journal=European Journal of Soil Science |volume=53 |issue=4 |pages=529–40 |doi=10.1046/j.1365-2389.2002.00479.x |bibcode=2002EuJSS..53..529G |url=https://www.researchgate.net/publication/227520589 |access-date=11 February 2026 }}</ref>

Agricultural lands display certain types of soil contamination, involving in particular heavy metals and metalloids. These contaminants typically alter plant metabolism, often causing a reduction in crop yields.<ref>{{cite journal |last1=Rashid |first1=Abdur |last2=Schutte |first2=Brian J. |last3=Ulery |first3=April |last4=Deyholos |first4=Michael K. |last5=Sanogo |first5=Soum |last6=Lehnhoff |first6=Erik K. |last7=Beck |first7=Leslie |date=31 May 2023 |title=Heavy metal contamination in agricultural soil: environmental pollutants affecting crop health |journal=Agronomy |volume=13 |issue=6 |article-number=1521 |doi=10.3390/agronomy13061521 |doi-access=free |bibcode=2023Agron..13.1521R |hdl=2429/85248 |hdl-access=free }}</ref> This has a secondary effect upon soil conservation, since the languishing crops cannot shield the Earth's soil from erosion.<ref>{{cite book |doi= 10.4324/9780203844236.CH29 |chapter=Soil erosion and contamination |title=Handbook of hazards and disaster risk reduction |isbn=9780203844236 |pages=326–36 |date=29 March 2012 |last=Engel-Di Mauro |first=Salvatore |editor-last1=Wisner |editor-first1=Ben |editor-last2=Gaillard |editor-first2=Jean-Claude |editor-last3=Kelman |editor-first3=Ilan |chapter-url=https://www.academia.edu/33792656 |publisher=Routledge |location=Abingdon-on-Thames, United Kingdom |access-date=12 February 2026 }}</ref> Some of these chemical contaminants have long half-lives and in other cases derivative chemicals are formed from decay of primary soil contaminants.<ref>{{cite web |first1=Bernd M. |last1=Bussian |first2=Natalia |last2=Rodríguez Eugenio |first3=Susan C. |last3=Wilson |title=The chemical nature and properties of soil contaminants |url=https://openknowledge.fao.org/server/api/core/bitstreams/fe5df8d6-6b19-4def-bdc6-62886d824574/content/src/html/chapter-02-2.html |website=Food and Agriculture Organization of the United Nations |location=Rome, Italy |year=2021 |access-date=12 February 2026 }}</ref>

=== Potential effects of contaminants to soil functions ===

Heavy metals and other soil contaminants can adversely affect the activity, species composition and abundance of soil microorganisms, thereby threatening soil functions such as biochemical cycling of carbon and nitrogen.<ref>{{cite journal |last1=Rijk |first1=Ingrid J. C. |last2=Ekblad |first2=Alf |date=April 2020 |title=Carbon and nitrogen cycling in a lead polluted grassland evaluated using stable isotopes (δ13C and δ15N) and microbial, plant and soil parameters |journal=Plant and Soil |volume=449 |issue=1–2 |pages=249–66 |doi=10.1007/s11104-020-04467-7 |s2cid=212689936 |doi-access=free |bibcode=2020PlSoi.449..249R }}</ref> However, soil contaminants can also become less bioavailable by time (natural attenuation),<ref>{{cite journal |last1=Mulligan |first1=Catherine N. |last2=Yong |first2=Raymond N. |date=June 2004 |title=Natural attenuation of contaminated soils |journal=Environment International |volume=30 |issue=4 |pages=587–601 |doi=10.1016/j.envint.2003.11.001 |pmid=15031019 |bibcode=2004EnInt..30..587M |url=https://www.academia.edu/69660980 |access-date=12 February 2026 }}</ref> and microorganisms and ecosystems can adapt to altered conditions.<ref>{{cite journal |last1=Puglisi |first1=Edoardo |last2=Hamon |first2=Rebecca |last3=Vasileiadis |first3=Sotirios |last4=Coppolecchia |first4=Damiano |last5=Trevisan |first5=Marco |date=24 October 2012 |title=Adaptation of soil microorganisms to trace element contamination: a review of mechanisms, methodologies, and consequences for risk assessment and remediation |journal=Critical Reviews in Environmental Science and Technology |volume=42 |issue=22 |pages=2435–70 |doi=10.1080/10643389.2011.592735 |bibcode=2012CREST..42.2435P |url=https://www.researchgate.net/publication/224042316 |access-date=12 February 2026 }}</ref> Soil properties such as pH, organic matter content and texture are very important and modify mobility, bioavailability and toxicity of pollutants in contaminated soils.<ref>{{cite book |doi=10.1007/978-94-007-4470-7_3 |chapter=Chemistry of heavy metals and metalloids in soils |last=Young |first=Scott D. |pages=51–95 |title=Heavy metals in soils: trace metals and metalloids in soils and their bioavailability |edition=3rd |series=Environmental Pollution |year=2013 |volume=22 |isbn=978-94-007-4469-1 |editor-last=Alloway |editor-first=Brian J. |chapter-url=https://z-library.sk/book/53421923/7b12de |access-date=12 February 2026 }}</ref> The same amount of contaminant can be toxic in one soil but totally harmless in another soil.<ref>{{cite journal |last1=Smolders |first1=Erik |last2=Oorts |first2=Koen |last3=Van Sprang |first3=Patrick |last4=Schoeters |first4=Ilse |last5=Janssen |first5=Colin R. |last6=McGrath |first6=Steve P. |last7=McLaughlin |first7=Mike J. |date=1 August 2009 |title=Toxicity of trace metals in soil as affected by soil type and aging after contamination: using calibrated bioavailability models to set ecological soil standards |journal=Environmental Toxicology and Chemistry |volume=28 |issue=8 |pages=1633–42 |doi=10.1897/08-592.1 |pmid=19301943 |bibcode=2009EnvTC..28.1633S |url=https://www.academia.edu/105487384 |access-date=12 February 2026 }}</ref> This stresses the need for soil-specific risk assessment<ref>{{cite journal |last1=Zhang |first1=Jiawen |last2=Liu |first2=Zhengtao |last3=Tian |first3=Biao |last4=Li |first4=Ji |last5=Luo |first5=Jingjing |last6=Wang |first6=Xusheng |last7=Ai |first7=Shunhao |last8=Wang |first8=Xiaonan |date=5 January 2023 |title=Assessment of soil heavy metal pollution in provinces of China based on different soil types: from normalization to soil quality criteria and ecological risk assessment |journal=Journal of Hazardous Materials |volume=441 |article-number=129891 |doi=10.1016/j.jhazmat.2022.129891 |pmid=36103763 |bibcode=2023JHzM..44129891Z |url=https://archive.org/details/zhang-et-al.-2023 |access-date=12 February 2026 }}</ref> and remediation measures.<ref>{{cite journal |last=Scullion |first=John |date=9 February 2006 |title=Remediating polluted soils |journal=Naturwissenschaften |volume=93 |issue=2 |pages=51–65 |doi=10.1007/S00114-005-0079-5 |pmid=16468025 |bibcode=2006NW.....93...51S |url=https://z-library.sk/book/39126770/af1ff3 |access-date=12 February 2026 }}</ref>

== Cleanup options ==

Cleanup or environmental remediation is analyzed by environmental scientists who utilize field measurement of soil chemicals and also apply computer models (GIS in Environmental Contamination) for analyzing transport<ref>{{cite web |last1=Gupta |first1=S. K. |last2=Kincaid |first2=C. T. |last3=Meyer |first3=P. R. |last4=Newbill |first4=C. A. |last5=Cole |first5=C. R. |title=A multi-dimensional finite element code for the analysis of coupled fluid, energy and solute transport (CFEST) |url=https://www.osti.gov/servlets/purl/7099488 |website=Battelle Memorial Institute |location=Columbus, Ohio |date=August 1982 |access-date=12 February 2026 }}</ref> and fate of soil chemicals.<ref>{{cite journal |last=Pistocci |first=Alberto |date=17 April 2008 |title=A GIS-based approach for modeling the fate and transport of pollutants in Europe |journal=Environmental Science & Technology |volume=42 |issue=10 |pages=3640–7 |doi=10.1021/es071548+ |pmid=18546702 |bibcode=2008EnST...42.3640P |url=https://www.researchgate.net/publication/5309962 |access-date=12 February 2026 }}</ref> Various technologies have been developed for remediation of oil-contaminated soil and sediments.<ref>{{cite journal |last1=Agarwal |first1=Ashutosh |last2=Liu |first2=Yu |date=30 December 2015 |title=Remediation technologies for oil-contaminated sediments |journal=Marine Pollution Bulletin |volume=101 |issue=2 |pages=483–90 |doi=10.1016/j.marpolbul.2015.09.010 |pmid=26414316 |bibcode=2015MarPB.101..483A |url=https://www.academia.edu/105955897 |access-date=12 February 2026 }}</ref> There are several principal strategies for remediation of contaminated soils: * Excavate soil and take it to a disposal site away from ready pathways for human or sensitive ecosystem contact. This technique also applies to dredging of bay muds or navigable canals containing toxicants.<ref>{{cite book |doi=10.1007/978-1-4614-6726-7_13 |chapter=Sediment dredging, treatment and disposal |last1=Palermo |first1=Michael |last2=Hays |first2=Donald F. |pages=365–91 |title=Processes, assessment and remediation of contaminated sediments |volume=6 |series=SERDP ESTCP Environmental Remediation Technology |year=2013 |isbn=978-1-4614-6726-7 |editor-last=Reible |editor-first=Danny D. |chapter-url=https://z-library.sk/book/54087108/78268c |access-date=12 February 2026 }}</ref> * Aeration of soils at the contaminated site,<ref>{{cite journal |last1=Rhykerd |first1=Robert L. |last2=Crews |first2=B. |last3=McInnes |first3=Kevin J. |last4=Weaver |first4=Robert W. |date=March 1999 |title=Impact of bulking agents, forced aeration, and tillage on remediation of oil-contaminated soil |journal=Bioresource Technology |volume=67 |issue=3 |pages=279–85 |doi=10.1016/S0960-8524(98)00114-X |bibcode=1999BiTec..67..279R |url=https://z-library.sk/book/5R0Mw0nnjp |access-date=13 February 2026 }}</ref> with attendant risk of creating air pollution.<ref>{{cite journal |last1=Ma |first1=Yan |last2=Du |first2=Xiaoming |last3=Shi |first3=Yi |last4=Hou |first4=Deyi |last5=Dong |first5=Binbin |last6=Xu |first6=Zhu |last7=Li |first7=Huiying |last8=Xie |first8=Yunfeng |last9=Fang |first9=Jidun |last10=Li |first10=Zheng |last11=Cao |first11=Yunzhe |last12=Gu |first12=Qingbao |last13=Li |first13=Fasheng |date=22 September 2016 |title=Engineering practice of mechanical soil aeration for the remediation of volatile organic compound-contaminated sites in China: advantages and challenges |journal=Frontiers of Environmental Science & Engineering |volume=10 |issue=6 |article-number=6 |doi=10.1007/s11783-016-0870-x |bibcode=2016FrESE..10....6M |url=https://z-library.sk/book/Ej8yngnYv9 |access-date=13 February 2026 }}</ref> * Thermal remediation (thermal desorption) by introduction of heat to raise subsurface temperatures sufficiently high to volatilize chemical contaminants out of the soil for vapor extraction.<ref>{{cite journal |last1=Zhao |first1=Cheng |last2=Dong |first2=Yan |last3=Feng |first3=Yupeng |last4=Li |first4=Yuzhong |last5=Dong |first5=Yong |date=April 2019 |title=Thermal desorption for remediation of contaminated soil: a review |journal=Chemosphere |volume=221 |pages=841–55 |doi=10.1016/j.chemosphere.2019.01.079 |pmid=30685623 |bibcode=2019Chmsp.221..841Z |url=https://z-library.sk/book/DjEJDwdzvo |access-date=13 February 2026 }}</ref> Technologies include in situ thermal desorption (ISTD), electrical resistance heating (ERH), and electro thermal dynamic stripping process (ET-DSP). * Bioremediation, involving microbial digestion of certain organic chemicals.<ref>{{cite journal |last1=Agamuthu |first1=Periathamby |last2=Tan |first2=Y. S. |last3=Fauziah |first3=Shahul Hamid |year=2013 |title=Bioremediation of hydrocarbon contaminated soil using selected organic wastes |journal=Procedia Environmental Sciences |volume=18 |pages=694–702 |doi=10.1016/j.proenv.2013.04.094 |url=https://www.researchgate.net/publication/257528000 |access-date=13 February 2026 |doi-access=free |bibcode=2013PrEnS..18..694A }}</ref> Techniques used in bioremediation include landfarming, biostimulation and bioaugmentating soil biota with commercially available microflora.<ref>{{cite journal |last1=Mrozik |first1=Agnieszka |last2=Piotrowska-Seget |first2=Zofia |date=20 July 2010 |title=Bioaugmentation as a strategy for cleaning up of soils contaminated with aromatic compounds |journal=Microbiological Research |volume=165 |issue=5 |pages=363–75 |doi=10.1016/j.micres.2009.08.001 |pmid=19735995 |url=https://www.academia.edu/35680518 |access-date=13 February 2026 }}</ref> * Extraction of groundwater or soil vapor with an active electromechanical system (electrokinetic soil flushing (EKSF)), with subsequent air stripping of the contaminants from the extract.<ref>{{cite journal |last1=de Melo Henrique |first1=João Miller |last2=Isidro |first2=Julia |last3=Saez |first3=Cristina |last4=Dos Santos |first4=Elisama V. |last5=Rodrigo |first5=Manuel A. |date=24 May 2022 |title=Removal of lindane using electrokinetic soil flushing coupled with air stripping |journal=Journal of Applied Electrochemistry |volume=52 |issue=9 |pages=1317–26 |doi=10.1007/s10800-022-01715-9 |doi-access=free }}</ref> * Phytoremediation, or using plants (such as willow) to extract heavy metals.<ref>{{cite journal |last1=Landberg |first1=Tommy |last2=Greger |first2=Maria |date=11 July 2022 |title=Phytoremediation using willow in industrial contaminated soil |journal=Sustainability |volume=14 |issue=14 |article-number=8449 |doi=10.3390/su14148449 |doi-access=free |bibcode=2022Sust...14.8449L }}</ref> * Mycoremediation, or using fungi to metabolize contaminants and accumulate heavy metals.<ref>{{cite journal |last1=Li |first1=Qianwei |last2=Liu |first2=Jicheng |last3=Gadd |first3=Geoffrey Michael |date=17 September 2020 |title=Fungal bioremediation of soil co-contaminated with petroleum hydrocarbons and toxic metals |journal=Applied Microbiology and Biotechnology |volume=104 |issue=21 |pages=8999–9008 |doi=10.1007/s00253-020-10854-y |doi-access=free |pmid=32940735 |pmc=7567682 }}</ref> * Remediation of oil contaminated sediments with self-collapsing air microbubbles.<ref>{{cite journal |last1=Agarwal |first1=Ashutosh |last2=Zhou |first2=Yufeng |last3=Liu |first3=Yu |title=Remediation of oil-contaminated sand with self-collapsing air microbubbles |journal=Environmental Science and Pollution Research |date=15 September 2016 |volume=23 |issue=23 |pages=23876–83 |doi=10.1007/s11356-016-7601-5 |pmid=27628704 |bibcode=2016ESPR...2323876A |url=https://www.researchgate.net/publication/308111450 |access-date=13 February 2026 }}</ref> * Surfactant leaching. * Interfacial solar evaporation to extract heavy metal ions from moist soil.<ref>{{cite journal |last1=Wu |first1=Pan |last2=Wu |first2=Xuan |last3=Xu |first3=Haolan |last4=Owens |first4=Gary |date=October 2021 |title=Interfacial solar evaporation driven lead removal from a contaminated soil |journal=EcoMat |volume=3 |issue=5 |article-number=e12140 |doi=10.1002/eom2.12140 |s2cid=239680091 |doi-access=free |hdl=11541.2/29296 |hdl-access=free }}</ref>

== By country ==

Various national standards for concentrations of particular contaminants include the United States EPA Region 9 Preliminary Remediation Goals (U.S. PRGs),<ref>{{cite web |title=Users' guide and background technical document for USEPA Region 9's preliminary remediation goals (PRG) table |url=https://semspub.epa.gov/work/02/103453.pdf |website=United States Environmental Protection Agency |location=Washington, District of Columbia |year=2004 |access-date=13 February 2026 }}</ref> the United States EPA Region 3 Risk Based Concentrations (U.S. EPA RBCs),<ref>{{cite web |last=Smith |first=Roy L. |title=EPA Region III risk-based concentration table, background information |url=https://semspub.epa.gov/work/05/229825.pdf |website=United States Environmental Protection Agency |location=Washington, District of Columbia |date=9 February 1995 |access-date=13 February 2026 }}</ref> and National Environment Protection Council of Australia Guideline on Investigation Levels for Soil and Groundwater.<ref>{{cite web |title=Guideline on investigation levels for soil and groundwater |url=https://www.nepc.gov.au/sites/default/files/2022-09/schedule-b1-guideline-investigation-levels-soil-and-groundwater-sep10.pdf |website=Australian Government, National Environment Protection Council (NEPC) |location=Canberra, Australia |date=April 2011 |access-date=13 February 2026 }}</ref>

=== People's Republic of China ===

The immense and sustained growth of the People's Republic of China since the 1970s has exacted a price from the land in increased soil pollution.<ref>{{cite journal |last=Delang |first=Claudio O. |title=Causes and distribution of soil pollution in China |journal=Environmental and Socio-Economic Studies |year=2017 |volume=5 |issue=4 |pages=1–17 |doi=10.1515/environ-2017-0016 |doi-access=free |bibcode=2017ESES....5d...1D }}</ref> The Ministry of Ecology and Environment believes it to be a threat to the environment, to food safety and to sustainable agriculture.<ref>{{cite journal |last1=Qu |first1=Changsheng |last2=Shi |first2=Wei |last3=Guo |first3=Jing |last4=Fang |first4=Binbin |last5=Wang |first5=Shui |last6=Giesy |first6=John P. |last7=Holm |first7=Peter E. |date=8 December 2016 |title=China's soil pollution control: choices and challenges |journal=Environmental Science & Technology |volume=50 |issue=24 |pages=13181–3 |doi=10.1021/acs.est.6b05068 |doi-access=free |pmid=27993050 |bibcode=2016EnST...5013181Q }}</ref> According to a scientific sampling, 150 million mu (100,000 square kilometres) of China's cultivated land have been polluted, with contaminated water being used to irrigate a further 32.5 million mu (21,670 square kilometres) and another 2 million mu (1,300 square kilometres) covered or destroyed by solid waste. In total, the area accounts for one-tenth of China's cultivatable land, and is mostly in economically developed areas. An estimated 12 million tonnes of grain are contaminated by heavy metals every year, causing direct losses of 20 billion yuan ($2.57 billion USD).<ref>{{cite news |last1=Xu |first1=Qi |title=Facing up to 'invisible pollution' |url=https://dialogue.earth/en/pollution/724-facing-up-to-invisible-pollution/ |work=Dialogue Earth |date=29 January 2007 |access-date=13 February 2026 }}</ref> Recent survey shows that 19% of the agricultural soils are contaminated with heavy metals and metalloids, and the rate of contamination still increases dramatically.<ref>{{cite journal |last1=Zhao |first1=Fang-Jie |last2=Ma |first2=Yibing |last3=Zhu |first3=Yong-Guan |last4=Tang |first4=Zhong |last5=McGrath |first5=Steve P. |title=Soil contamination in China: current status and mitigation strategies |journal=Environmental Science & Technology |date=16 December 2014 |volume=49 |issue=2 |pages=750–9 |doi=10.1021/es5047099 |pmid=25514502 |bibcode=2015EnST...49..750Z |url=https://z-library.sk/book/QOP3ZqqNvX |access-date=13 February 2026 }}</ref> China established a series of soil pollution remediation systems under the Chinese Soil Pollution Prevention and Control Law which still remain to be improved because of imperfect remediation standards and insufficient public participation.<ref>{{cite journal |last1=Liu |first1=Zhuyi |last2=Yin |first2=Yuhan |last3=Zhang |first3=Yun |last4=Shi |first4=Shangeng |title=Legal system of soil pollution remediation in China and its regulation and guidance to soil pollution remediation |journal=Sustainability |date=25 July 2023 |volume=15 |issue=15 |article-number=11504 |doi=10.3390/su151511504 |doi-access=free |bibcode=2023Sust...1511504L }}</ref>

=== European Union ===

According to the received data from member states in 2012, in the European Union the number of estimated potential contaminated sites was more than 2.5 million and the identified contaminated sites around 342 thousand .<ref name="Panagos2013">{{cite journal |last1=Panagos |first1=Panos |last2=Van Liedekerke |first2=Marc |last3=Yigini |first3=Yusuf |last4=Montanarella |first4=Luca |date=16 June 2013 |title=Contaminated sites in Europe: review of the current situation based on data collected through a European network |journal=Journal of Environmental and Public Health |volume=2013 |article-number=158764 |doi=10.1155/2013/158764 |pmid=23843802 |pmc=3697397 |doi-access=free }}</ref> Municipal and industrial wastes contributed most to soil contamination (38%), followed by the industrial/commercial sector (34%). Mineral oil and heavy metals were the main contaminants contributing around 60% to soil contamination. In terms of budget, the management of contaminated sites was estimated to cost around 6 billion Euros (€) annually.<ref name="Panagos2013"/> The EU's Soil Monitoring Law, entered into force on 16 December 2025, protects and restores soils, ensuring that they are used sustainably.<ref>{{cite web |title=Soil Monitoring Law |url=https://environment.ec.europa.eu/topics/soil-health/soil-monitoring-law_en |website=European Commission |location=Brussels, Belgium |date=December 2025 |access-date=17 February 2026 }}</ref>

===United Kingdom===

Generic guidance commonly used in the United Kingdom are the Soil Guideline Values published by the Department for Environment, Food and Rural Affairs (DEFRA) and the Environment Agency.<ref>{{cite web |title=Soil screening values for assessing ecological risk |date=19 January 2022 |url=https://www.gov.uk/government/publications/soil-screening-values-for-assessing-ecological-risk#full-publication-update-history |website=Environment Agency |location=Bristol, United Kingdom |access-date=17 February 2026 }}</ref> These are screening values that demonstrate the minimal acceptable level of a substance. Above this there can be no assurances in terms of significant risk of harm to human health. These have been derived using the Contaminated Land Exposure Assessment Model (CLEA UK).<ref>{{cite web |title=Contaminated land exposure assessment (CLEA) tool |date=7 September 2015 |url=https://www.gov.uk/government/publications/contaminated-land-exposure-assessment-clea-tool |website=Environment Agency |location=Bristol, United Kingdom |access-date=17 February 2026 }}</ref> Certain input parameters such as Health Criteria Values, age and land use are fed into CLEA UK to obtain a probabilistic output.<ref name="Sun2020">{{cite journal |last1=Sun |first1=Yiming |last2=Wang |first2=Jicai |last3=Guo |first3=Guanlin |last4=Li |first4=Hong |last5=Jones |first5=Kevin |title=A comprehensive comparison and analysis of soil screening values derived and used in China and the UK |journal=Environmental Pollution |date=January 2020 |volume=256 |article-number=113404 |doi=10.1016/j.envpol.2019.113404 |pmid=31735398 |bibcode=2020EPoll.25613404S |url=https://z-library.sk/book/NOVldp9Ajk |access-date=17 February 2026 }}</ref>

Guidance by the Inter Departmental Committee for the Redevelopment of Contaminated Land (ICRCL)<ref>{{cite web |year=1996 |url=http://www.contaminatedland.co.uk/std-guid/icrcl-l.htm |title=ICRCL 59/83 Trigger Concentrations |access-date=4 May 2016 |archive-url=https://web.archive.org/web/20161009165821/http://www.contaminatedland.co.uk/std-guid/icrcl-l.htm |archive-date=9 October 2016 }}</ref> has been formally withdrawn in 2002 by the DEFRA, for use as a prescriptive document to determine the potential need for remediation or further assessment.<ref name="Nathanail2005">{{cite journal |last=Nathanail |first=C. Paul |title=Generic and site-specific criteria in assessment of human health risk from contaminated soil |journal=Soil Use and Management |date=December 2005 |volume=21 |issue=S2 |pages=500–7 |doi=10.1079/SUM2005341 |bibcode=2005SUMan..21S.500N |url=https://www.academia.edu/21010769 |access-date=17 February 2026 }}</ref><ref>{{cite web |title=Note on the withdrawal of IRCL trigger values |date=December 2002 |url=https://webarchive.nationalarchives.gov.uk/ukgwa/20070905205142/http://www.defra.gov.uk/environment/land/contaminated/pdf/clan3-02.pdf |website=DEFRA |location=London, United Kingdom |access-date=17 February 2026 }}</ref>

The CLEA model published by DEFRA and the Environment Agency (EA) in March 2002, updated on September 2009, sets a framework for the appropriate assessment of risks to human health from contaminated land, as required by Part IIA of the Environmental Protection Act 1990.<ref>{{cite web |last=Jeffries |first=Jo |title=CLEA Software (Version 1.05) Handbook |date=September 2009 |url=https://assets.publishing.service.gov.uk/media/5a816e63e5274a2e87dbd977/LIT_10167.pdf |website=Environment Agency |location=Bristol, United Kingdom |access-date=17 February 2026 }}</ref> As part of this framework, generic Soil Guideline Values (SGVs) have currently been derived for ten contaminants to be used as "intervention values".<ref>{{cite web |last=Cavanagh |first=Jo |title=What are "Soil Guideline Values" and which should I use? |url=https://www.landcareresearch.co.nz/publications/soil-horizons/soil-horizons-articles/soil-guideline-values/ |access-date=17 February 2026 |website=Manaaki Whenua |date=10 August 2019 |language=en-US }}</ref> These values should not be considered as remedial targets but values above which further detailed assessment should be considered.<ref>{{cite web |last1=Cole |first1=Simon |last2=Jeffries |first2=Jo |title=Using Soil Guideline Values |date=March 2009 |url=https://assets.publishing.service.gov.uk/media/5a7c94b8ed915d6969f45e46/scho0309bpqm-e-e.pdf |website=Environment Agency |location=Bristol, United Kingdom |access-date=17 February 2026 }}</ref>

Three sets of CLEA SGVs have been produced for three different land uses,<ref name="Claire">{{cite web |title=Soil Guideline Values |url=https://claire.co.uk/information-centre/water-and-land-library-wall.html?view=article&id=178:soil-guideline-values&catid=44 |website=claire.co.uk |location=Reading, United Kingdom |access-date=17 February 2026 }}</ref> namely * residential (with and without plant uptake) * allotments * commercial/industrial

It was intended that the SGVs replace the former ICRCL values.<ref name="Nathanail2005"/> The CLEA SGVs relate to assessing chronic (long term) risks to human health and do not apply to the protection of ground workers during construction, or other potential receptors such as groundwater, buildings, plants or other ecosystems. The CLEA SGVs are not directly applicable to a site completely covered in hardstanding, as there is no direct exposure route to contaminated soils.<ref>{{cite web |date=12 June 2025 |title=LCRM: Stage 1 risk assessment |url=https://www.gov.uk/government/publications/land-contamination-risk-management-lcrm/lcrm-stage-1-risk-assessment |access-date=17 February 2026 |website=gov.uk |language=en }}</ref>

To date, fifteen of fifty-five contaminant SGVs have been published, for the following: arsenic, cadmium, chromium, lead, mercury, nickel, selenium, benzene, ethyl benzene, phenol, xylene, toluene, dioxines, furanes, and dioxin-like PCBs.<ref name="Claire"/> Toxicological data (Tox) has been published for each of these contaminants as well as for benzo(a)pyrene, naphthalene, vinyl chloride, 1,1,2,2 tetrachloroethane and 1,1,1,2 tetrachloroethane, 1,1,1 trichloroethane, tetrachloroethene, carbon tetrachloride, 1,2-dichloroethane, and trichloroethene.<ref>{{cite web |title=TOX Reports for SGV derivation |url=https://claire.co.uk/information-centre/water-and-land-library-wall.html?view=article&id=177 |website=claire.co.uk |location=Reading, United Kingdom |access-date=18 February 2026 }}</ref> The SGVs for ethyl benzene, phenol and toluene are dependent on the soil organic matter (SOM) content (which can be calculated from the total organic carbon (TOC) content).<ref>{{cite web |last1=Moregan |first1=Hannah |last2=Jeffries |first2=Jo |last3=Waterfall |first3=Elizabeth |last4=Earl |first4=Naomi |title=Soil Guideline Values for benzene in soil |year=2009 |url=https://www.southwest-environmental.co.uk/pdf/bezene.pdf |website=Environment Agency |location=Bristol, United Kingdom |access-date=18 February 2026 }}</ref> As an initial screen the SGVs for 1% SOM are considered to be appropriate.<ref name="Sun2020"/>

===Canada===

As of July 2025, there are a total of 24,000 plus contaminated sites in Canada, of which more than 19,000 have been closed after historical reviews, testing, clean-ups or long-term monitoring activities determined that no further action was required.<ref>{{cite web |title=Federal contaminated sites inventory: find sites by Province or Territory |url=https://www.tbs-sct.gc.ca/fcsi-rscf/cen-eng.aspx?dataset=prov&sort=name |date=4 July 2025 |website=Treasury Board of Canada Secretariat |access-date=18 February 2026 }}</ref> One infamous contaminated sited is located near a nickel-copper smelting site in Sudbury, Ontario. A study investigating the heavy metal pollution in the vicinity of the smelter reveals that elevated levels of nickel and copper were found in the soil; values going as high as 5,104ppm Ni, and 2,892 ppm Cu within a 1.1&nbsp;km range of the smelter location. Other metals were also found in the soil; such metals include iron, cobalt, and silver. Furthermore, upon examining the different vegetation surrounding the smelter it was evident that they too had been affected; the results show that the plants contained nickel, copper and aluminium as a result of soil contamination.<ref>{{cite journal |last1=Hutchinson |first1=T. C. |last2=Whitby |first2=L. M. |title=Heavy-metal pollution in the Sudbury mining and smelting region of Canada. I. Soil and vegetation contamination by nickel, copper, and other metals |journal=Environmental Conservation |date=1974 |volume=1 |issue=2 |pages=123–32 |doi=10.1017/S0376892900004240 |bibcode=1974EnvCo...1..123H |s2cid=86686979 |url=https://z-library.sk/book/2R2MlKnBOG |access-date=18 February 2026 }}</ref> Soil quality guidelines have been published for 32 soil contaminants.<ref>{{cite web |title=Canadian soil quality guidelines for the protection of environmental and human health: summary tables |url=https://support.esdat.net/Environmental%20Standards/canada/soil/rev_soil_summary_tbl_7.0_e.pdf |date=September 2007 |website=Environment Canada |location=Gatineau, Quebec |access-date=18 February 2026 }}</ref>{{further|Pollution in Canada#Soil pollution}}

===India===

In March 2009, the issue of uranium poisoning in Punjab attracted press coverage. It was alleged to be caused by fly ash ponds of thermal power stations, which reportedly lead to severe birth defects in children in the Faridkot and Bhatinda districts of Punjab. The news reports claimed the uranium levels were more than 60 times the maximum safe limit.<ref>{{cite news |url=http://timesofindia.indiatimes.com/city/chandigarh/Uranium-deforms-kids-in-Faridkot/articleshow/4347313.cms |title=Uranium deforms kids in Faridkot |date=2 April 2009 |work=The Times of India |first1=Priya |last1=Yadav |access-date=18 February 2026 }}</ref><ref>{{cite news |url=https://news.bbc.co.uk/2/hi/south_asia/7979022.stm |title=Punjab disability 'uranium link' |date=2 April 2009 |publisher=BBC News |first=Asit |last=Jolly |access-date=18 February 2026 }}</ref> Out of total 140 samples collected and analyzed in south-west Punjab, 76% have uranium levels greater than the chemical toxicity limit of World Health Organization (WHO, 30 μg.L−1) and 34% samples have concentration higher than the radiological toxicity limit given by Atomic Energy Regulatory Board (AERB, 60 μg.L−1).<ref>{{cite journal |last1=Bala |first1=Ritu |last2=Karanveer |last3=Das |first3=Debrabata |title=Occurrence and behaviour of uranium in the groundwater and potential health risk associated in semi-arid region of Punjab, India |journal=Groundwater for Sustainable Development |date=May 2022 |volume=17 |article-number=100731 |doi=10.1016/j.gsd.2022.100731 |bibcode=2022GSusD..1700731B |url=https://archive.org/details/bala-et-al.-2022 |access-date=18 February 2026 }}</ref> Research is underway to identify natural or other sources for the uranium. A study suggested that prolonged application of uranium-containing fertilizers could have contributed to its enhanced concentration in the soil,<ref>{{cite journal |last1=Daniel |first1=Ruth |last2=Tripathi |first2=Dhananjay |last3=Singh |first3=Sukhvir |last4=Sharma |first4=Navneet |last5=Yuvraaj |first5=Arihant |last6=Katyal |first6=Deeksha |last7=Kumar |first7=Vinod |date=19 June 2002 |title=Uranium: occurrence, distribution across India and its potential health effects |url=https://www.researchgate.net/publication/361413136 |journal=Journal of Radioanalytical and Nuclear Chemistry |volume=331 |issue=18 |pages=2805–15 |doi=10.1007/s10967-022-08373-3 |access-date=19 February 2026 }}</ref> while a more recent study rather suggested that a complex interplay of hydrogeochemical processes under monsoonal influence could have played a decisive role in uranium mobility and contamination of groundwater above tolerated thresholds.<ref>{{cite journal |last1=Chauhan |first1=Neeraj |last2=Krause |first2=Stefan |last3=Singh |first3=Jaswant |last4=Dehbandi |first4=Reza |last5=Kumar |first5=Pavitra V. |last6=Kumar |first6=Pankaj |last7=Toor |first7=Amrit Pal |last8=Srivastava |first8=Alok |date=4 February 2025 |title=Assessment and mitigation of heavy toxic elements with emphasis on uranium in the Malwa region of Punjab, India |journal=ACS EST Water |volume=5 |issue=2 |pages=838–50 |doi=10.1021/acsestwater.4c00900 |doi-access=free |bibcode=2025ACSEW...5..838C }}</ref>

==See also== {{Div col|small=yes}} * Bioremediation * Bioswale * Constructed wetland * Contamination control * Dutch pollutant standards * Ecological sanitation * Environmental policy in China#Soil pollution * GIS in environmental contamination * Groundwater pollution * Groundwater remediation * Habitat destruction * Index of waste management articles * Land degradation * Landfill * List of solid waste treatment technologies * List of waste management companies * Litter * Nanoremediation * Pesticide drift * Plasticulture * Plastic-eating organisms * Remediation of contaminated sites with cement * Triangle of death (Italy) * Water pollution {{Div col end}}

==References== {{reflist}}

==Further reading== * {{cite journal |last1=Panagos |first1=Panos |last2=Van Liedekerke |first2=Marc |last3=Yigini |first3=Yusuf |last4=Montanarella |first4=Luca |title=Contaminated sites in Europe: review of the current situation based on data collected through a European network |journal=Journal of Environmental and Public Health |date=16 June 2013 |volume=2013 |pages=1–11 |doi=10.1155/2013/158764 |doi-access=free |pmid=23843802 |pmc=3697397 }}

==External links== {{Commons category|Soil pollution}} * [http://www.eugris.info Portal for soil and water management in Europe] Independent information gateway originally funded by the European Commission for topics related to soil and water, including contaminated land, soil and water management. * [http://eusoils.jrc.ec.europa.eu/library/themes/contamination/ European Soil Portal: Soil Contamination] At EU-level, the issue of contaminated sites (local contamination) and contaminated land (diffuse contamination) has been considered by: European Soil Data Centre (ESDAC). * [https://chinadialogue.net/en/pollution/724-facing-up-to-invisible-pollution/ Article on soil contamination in China] * [https://www.hydrology.nl/iahpublications/70-arsenic-in-groundwater.html Arsenic in groundwater] Book on arsenic in groundwater by IAH's Netherlands Chapter and the Netherlands Hydrological Society

{{Soil science topics}} {{Pollution}} {{Environmental science}} {{Public health}} {{Natural resources}}

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{{DEFAULTSORT:Soil Contamination}} Category:Soil contamination Category:Environmental chemistry Category:Environmental issues with soil Category:Pollution Category:Soil chemistry