The Purdue Agricultural Air Quality Laboratory, PAAQL, is part of the Department of Agricultural and Biological Engineering at Purdue University. PAAQL specializes in odor assessment using olfactometry , chemical analyses using gas chromatography , and continuous emissions monitoring of ammonia, hydrogen sulfide, carbon dioxide and particulate matter. PAAQL personnel have been working on the science and research of odors and other agricultural emissions since January of 1994. Our research has served industry, government and agriculture, in addition to communities at large.

Here is a link to the Manure Survey!


Some of our specialized capabilities and areas of expertise include:

  • Mobile laboratories that allows continuous emissions monitoring at an actual farm site. A single laboratory can collect quality data from up to three barns simultaneously, and can be monitored from off-site via an internet connection.
  • A buoyant and convective flux chamber (BCFC) for estimating lagoon emissions.
  • Extensive experience monitoring ventilation of barns and agricultural buildings, and in designing ventilation systems.

PAAQL's laboratories on the Purdue University campus include state-of-the-art analytical equipment for samples collected on-site. Our core laboratory capabilities include the following:

  • Olfactometry - PAAQL is in full compliance with both the ASTM and CEN standards regarding olfactometry technique. In a typical year, we analyze over 1200 samples of various origin using olfactometry.
  • Gas chromatography - More than 500 samples have been analyzed using gas chromatography. PAAQL recently purchased an Agilent 6890 Gas Chromatograph and 5875 Mass Spectrometer, greatly adding to its analytical capabilities as part of a custom-designed analytical system. Incorporation of a GERSTEL odor port also allows for the identification of individual compounds which are responsible for offensive odors.
  • Access to the Swine Environmental Research Building (SERB), a wean-to-finish swine facility which combines clean laboratory space with independent systems for ventilation, feeding, watering, and waste collection for up to 720 pigs.
  • Environmentally controlled laboratory space is available, in which quality research can be performed under specific controlled settings.   


The National Air Emission Monitoring Study (NAEMS) was developed in response to a 2003 National Academy of Sciences (NAS) report which highlighted possible air pollution problems arising from animal feeding operations (AFOs). It was designed by the Air Quality Group of the USDA's Natural Resources Conservation Service (NRCS) to address the issues in the NAS report, and to determine whether AFOs were likely to have compliance issues regarding the Clean Air Act and/or the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly known as "Superfund"). Farms were chosen to be representative of four main industries: pork, dairy, eggs and broilers. NAEMS will originally study emissions of ammonia, hydrogen sulfide, carbon dioxide, volatile organic compounds (VOCs), and particulate matter. Other pollutants (such as methane and pathogenic bacteria) are being added as the study progresses, and as PIs at PAAQL and the sub-contracting NAEMS universities use the NAEMS setup to leverage new projects.

NAEMS is nationwide in scope, including farms and university researchers from around the country. The NAEMS team will conduct data collection year-round for two consecutive years. Because of its duration and scope, NAEMS is the most comprehensive agricultural air emission study ever conducted. PAAQL, with collaboration from the Purdue Applied Meteorology Laboratory (PAML), is the lead institution for NAEMS.

Update - EPA's Environmental Appeals Board approves first NAEMS Consent Agreements (more info).

Click here for the USEPA's Press Release concerning the ratification of the Consent Agreements.

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