# Andersen sampler

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Andersen_sampler
> Markdown URL: https://mediated.wiki/source/Andersen_sampler.md
> Source: https://en.wikipedia.org/wiki/Andersen_sampler
> Source revision: 1313833118
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Cascade impactor that measures viable bioaerosols}}
thumb|alt=Schematic of Andersen sampler|upright=1.5|Andersen's schematic for the six-stage Andersen sampler, detailing movement of air and hole sizes for the top two stages<ref name="andersen" />
An '''Andersen sampler''', '''Andersen impactor''', or '''sieve impactor'''<ref>{{cite book |publisher=American Conference of Governmental Industrial Hygienists |date=1989 |title=GUIDELINES FOR THE ASSESSMENT OF BIOAEROSOLS IN THE INDOOR ENVIRONMENT |location=Cincinnati, Ohio |chapter=Air Sampling |isbn=0-936712-83-X}}</ref> is a [cascade impactor](/source/cascade_impactor) used to determine the amount of viable pathogens in a given area, in particular [bacteria](/source/bacteria) and [fungi](/source/fungi). Unlike real-time electronic [particle counter](/source/particle_counter)s, the Andersen sampler imparts pathogens on [petri dish](/source/petri_dish)es, which require incubation. Thus, calculation of the contaminated air requires working backwards from the resulting pathogen growth in each dish.

Andersen samplers have been used to assess the nature of pathogenic aerosols in various scientific papers. It can also be used to study inert aerosols, when each stage of the sampler is used to model respiratory particle deposition.

== Operation ==
Andersen's paper from 1958 describes a six-stage Andersen sampler that counts "viable airborne particles". In each stage, air goes through specifically sized holes, past a petri dish that aerosols impact, before subsequently moving through smaller holes towards the other petri dishes. Each stage gradually increases the velocity of the air; the sampler relies on ''[inertia](/source/inertia)'' for particles to leave the air stream.<ref name="andersen">{{cite journal | doi=10.1128/jb.76.5.471-484.1958 | title=New Sampler for the Collection, Sizing, and Enumeration of Viable Airborne Particles | date=1958 | last1=Andersen | first1=Ariel A. | journal=Journal of Bacteriology | volume=76 | issue=5 | pages=471–484 | pmid=13598704 | pmc=290224 }}</ref>

thumb|upright=0.5|left|The hole pattern can be used to quantify viable particles, without a microscope, under the "positive hole method".
Calculation of the number of viable particles is normally done by counting colonies via a microscope, called the "microscope method" in Andersen's paper. For stages 3 through 6, Andersen provides an alternate means of calculating viable particles via the "positive hole method". The method involves counting the number of colonies from a macroscopic point of view; each visible colony corresponds to a hole in each stage of the Andersen sampler. A conversion table is then used to quickly calculate the number of viable particles.<ref name="andersen" />

Andersen samplers have been used in various places and industries, including (but not limited to), compost facilities, to help mitigate the health impacts of fungal spores,<ref>{{Cite journal |last=Feldman |first=K. |date=1995 |title=Sampling for airborne contaminants |url=https://www.proquest.com/docview/236870502 |journal=Biocycle |volume=36 |issue=8 |page=84 |id={{ProQuest|236870502}} }}</ref> agriculture, to track [bioaerosol](/source/bioaerosol)s more generally from [livestock](/source/livestock),<ref>{{cite journal |last1=Cole |first1=N.A. |last2=PAS |first2=Todd R. |last3=Auvermann |first3=B. |last4=Parker |first4=D. |date=2008 |title=Auditing and assessing air quality in concentrated feeding Operations1,2,3 |journal=Professional Animal Scientist |volume=24 |issue=1 |pages=1–22 |doi=10.15232/S1080-7446(15)30804-4 |url=https://www.proquest.com/docview/230415564 |id={{ProQuest|230415564}} |doi-access=free }}</ref> textiles,<ref>{{cite journal | jstor=3860927 | title=Liberation of Organisms from Contaminated Textiles | last1=Rubbo | first1=Sydney D. | last2=Saunders | first2=Jane | journal=The Journal of Hygiene | date=1963 | volume=61 | issue=4 | pages=507–513 | doi=10.1017/s0022172400021136 | pmid=14099028 | pmc=2134562 }}</ref> apartment buildings,<ref>{{cite journal | jstor=3862904 | title=Microbial Investigation of the Air in an Apartment Building | last1=Simard | first1=Carole | last2=Trudel | first2=Michel | last3=Paquette | first3=Gilles | last4=Payment | first4=Pierre | journal=The Journal of Hygiene | date=1983 | volume=91 | issue=2 | pages=277–286 | doi=10.1017/S0022172400060290 | pmid=6358346 | pmc=2129367 }}</ref> wastewater facilities,<ref>{{cite journal | jstor=25040032 | title=A Study of Bacterial Aerosols at a Wastewater Irrigation Site | last1=Sorber | first1=Charles A. | last2=Bausum | first2=Howard T. | last3=Schaub | first3=Stephen A. | last4=Small | first4=Mitchell J. | journal=Journal (Water Pollution Control Federation) | date=1976 | volume=48 | issue=10 | pages=2367–2379 | pmid=792471 }}</ref> and even the aerosolization of [anthrax](/source/anthrax) following [attacks in 2001](/source/2001_anthrax_attacks).<ref>{{cite journal | doi=10.1001/jama.288.22.2853 | title=Secondary Aerosolization of Viable <EMPH TYPE="ITAL">Bacillus anthracis</EMPH> Spores in a Contaminated US Senate Office | date=2002 | last1=Weis | first1=Christopher P. | journal=JAMA | volume=288 | issue=22 | pages=2853–2858 | pmid=12472327 }}</ref> Samplers have also been used to study inert lead dust, with each stage designed to simulate the deposition characteristics of the respiratory tract.<ref>{{cite journal | doi=10.2307/3434231 | jstor=3434231 | title=Chemical Speciation of Lead Dust Associated with Primary Lead Smelting | last1=Spear | first1=Terry M. | last2=Svee | first2=Wayne | last3=Vincent | first3=James H. | last4=Stanisich | first4=Nick | journal=Environmental Health Perspectives | date=1998 | volume=106 | issue=9 | pages=565–571 | pmid=9721256 | pmc=1533158 }}</ref>
{{clear}}

== History ==
Information on the development of the Andersen sampler was initially classified by the [US army](/source/US_army), but is declassified as of January 24, 1958.<ref>{{cite news|date=1958-01-24|title=Air 'Sampler' at Dugway Aids Studies|work=The Salt Lake Tribune|url=https://www.newspaperarchive.com/us/utah/salt-lake-city/salt-lake-tribune/1958/01-24/page-26|via=newspaperarchive.com}}</ref> A noted early use of the Andersen sampler was the tracking of disease in the states of Oregon and California.<ref>{{cite news|date=1958-01-26|title=Provoan Develops Air Pollution Study Instrument|work=Utah Provo Daily Herald|url=https://www.newspaperarchive.com/us/utah/provo/utah-provo-daily-herald/1958/01-26/page-9|via=newspaperarchive.com}}</ref>

Continued development of the Andersen sampler was then the focus of Andersen 2000, Inc., originally CMC Industries, which had renamed itself following the acquisition of the relevant patents. As of November 1970, the company had released four models of the Andersen sampler, each targeted towards different industries, with one being handheld. However, the stack sampler continued to be the company's most popular model.<ref>{{cite news|date=1970-11-07|title=They Make Pollution Pay|work=The Deseret News|url=https://books.google.com/books?id=B6snAAAAIBAJ&dq=Andersen+sampler&pg=PA11&article_id=7295,1704568|via=Google News Archive}}</ref>

An assessment of the ''Andersen Mark-II'' cascade impactor was published in 1988.<ref>{{cite journal | doi=10.1016/0021-8502(88)90224-8 | title=An assessment of an andersen mark-II cascade impactor | date=1988 | last1=Mitchell | first1=J.P. | last2=Costa | first2=P.A. | last3=Waters | first3=S. | journal=Journal of Aerosol Science | volume=19 | issue=2 | pages=213–221 | bibcode=1988JAerS..19..213M }}</ref>

In 2012, a comparison was made between the "culturable particles" (CP) method and the "culturable organisms" (CO) method with the help of an Aerodynamic Particle Sizer (APS). The distributions between the CP and CO method were different enough for the null hypothesis to be rejected; the authors suggest that this may be due to the higher resolution particle count afforded by the APS, the Andersen sampler's wall losses, or the unintended collection of smaller particles in the earlier stages.<ref>{{cite journal | doi=10.1080/02786826.2012.669507 | title=Use of an Andersen Bioaerosol Sampler to Simultaneously Provide Culturable Particle and Culturable Organism Size Distributions | date=2012 | last1=King | first1=Maria D. | last2=McFarland | first2=Andrew R. | journal=Aerosol Science and Technology | volume=46 | issue=8 | pages=852–861 | bibcode=2012AerST..46..852K }}</ref>

In 2013, a group of researchers improved the collection efficiency of the Andersen sampler by adding [mineral oil](/source/mineral_oil) to the petri dish agar. Results were supported through the use of an optical particle counter.<ref name=":2013">{{cite journal | doi=10.1371/journal.pone.0056896 | doi-access=free | title=Enhancing Bioaerosol Sampling by Andersen Impactors Using Mineral-Oil-Spread Agar Plate | date=2013 | last1=Xu | first1=Zhenqiang | last2=Wei | first2=Kai | last3=Wu | first3=Yan | last4=Shen | first4=Fangxia | last5=Chen | first5=Qi | last6=Li | first6=Mingzhen | last7=Yao | first7=Maosheng | journal=PLOS ONE | volume=8 | issue=2 | article-number=e56896 | pmid=23460818 | pmc=3584084 | bibcode=2013PLoSO...856896X }}</ref>

== See also ==
* {{annotated link|Cascade impactor}}
* [Aerosol impaction](/source/Aerosol_impaction)
* [Particulate matter sampler](/source/Particulate_matter_sampler)
* [Bioaerosol](/source/Bioaerosol)
* [Particle counter](/source/Particle_counter)

== References ==
{{reflist}}

== Further reading ==
{{refbegin}}
* {{cite journal | doi=10.1080/15298668191420819| title=A comparison of two-stage and six-stage Andersen impactors for viable aerosols| date=1981| last1=Gillespie| first1=V.L.| last2=Clark| first2=C.S.| last3=Bjornson| first3=H.S.| last4=Samuels| first4=S.J.| last5=Holland| first5=J.W.| journal=American Industrial Hygiene Association Journal| volume=42| issue=12| pages=858–864}}
* {{cite journal | jstor=40965745 | title=Improved techniques for sampling airborne fungal particles in highly contaminated environments | last1=Blomquist | first1=Göran | last2=Palmgren | first2=Urban | last3=Ström | first3=Gunnar | journal=Scandinavian Journal of Work, Environment & Health | date=1984 | volume=10 | issue=4 | pages=253–258 | doi=10.5271/sjweh.2334 | pmid=6494845 | doi-access=free }}
* {{cite journal | doi=10.1016/0021-8707(70)90012-2 | title=A simplified application of the Andersen sampler to the study of airborne fungus particles | date=1970 | last1=Solomon | first1=William R. | journal=Journal of Allergy | volume=45 | issue=1 | pages=1–13 | pmid=5262360 }}
* {{cite journal | doi=10.2147/VAAT.S74789 | doi-access=free | title=Collection and measurement of aerosols of viable influenza virus in liquid media in an Andersen cascade impactor | date=2014 | last1=Lednicky | first1=John A. | last2=Fennelly | first2=Kevin | last3=Tribby | first3=Matthew | last4=Wu | first4=Chang-Yu | last5=Heil | first5=Gary L. | last6=Radonovich | first6=Lewis | last7=Loeb | first7=Julia | journal=Virus Adaptation and Treatment | page=1 }}
* {{cite journal | doi=10.1128/jb.83.3.663-667.1962 | title=Method for Evaluating Effectiveness of Surgical Masks | date=1962 | last1=Greene | first1=V. W. | last2=Vesley | first2=D. | journal=Journal of Bacteriology | volume=83 | issue=3 | pages=663–667 | pmid=13901536 | pmc=279325 }}
{{refend}}

{{Aerosol measurement devices|state=expanded}}

Category:Occupational safety and health
Category:Aerosol measurement

---
Adapted from the Wikipedia article [Andersen sampler](https://en.wikipedia.org/wiki/Andersen_sampler) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Andersen_sampler?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.