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ARS Home » Plains Area » Lubbock, Texas » Cropping Systems Research Laboratory » Cotton Production and Processing Research » Research » Publications at this Location » Publication #176435


item Buser, Michael

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/2006
Publication Date: 2/20/2007
Citation: Buser, M.D., Parnell, Jr., C.B., Shaw, B.W., Lacey, R.E. 2007. Particulate matter sampler errors due to the interaction of particle size and sampler performance characteristics: Background and theory. Transactions of the ASABE. 50(1):221-228.

Interpretive Summary: Agricultural operations are encountering difficulties complying with the current air pollution regulations for particulate matter (PM). The regulations are based on the National Ambient Air Quality Standards (NAAQS) which set maximum limits for the PM that can be emitted by a source based on protecting public health. PM is currently regulated in terms of particle diameters less than or equal to a nominal 10 um (PM10); however, current legislation is under way to also regulate PM with a diameter less than or equal to a nominal 2.5 um (PM2.5). To put these particle diameters in perspective, the average diameter of the human hair is 75 um. Compliance with the PM NAAQS is determined by property line sampling or dispersion modeling. Modeling requires emission rates which are determined from EPA's list of emission factors. Emission factors are industry specific. All property line sampling for compliance purposes requires the use of EPA approved samplers. Ultimately, these samplers would produce an accurate measure of the pollutant indicator. For instance, a PM10 sampler would produce an accurate measure of PM less than or equal to 10 um. However, samplers are not perfect, and errors are introduced due to the interaction of the particle size and sampler performance characteristics. There are several errors associated with the current particulate matter air pollution rules and regulations established by the EPA which should be minimized to assure equal regulation of air pollutants between and within all industries. Potentially, one of the most significant errors is attributed to the interaction of the industry specific PSD and sampler performance characteristics. This manuscript is the first in a series of manuscripts that discusses theoretical errors associated with size specific PM samplers. This manuscript provides the background and theory used in the simulation process for estimating these errors. The bottom line associated with this series of manuscripts is that not all industries are being equally regulated in terms of PM and that all industries should be concerned with the current site-specific regulations implemented by EPA and enforced by SAPRAs.

Technical Abstract: The National Ambient Air Quality Standards (NAAQS) for particulate matter (PM), in terms of PM10 and PM2.5, are ambient air concentration limits set by EPA that should not be exceeded. Further, State Air Pollution Regulatory Agencies (SAPRA) utilize the NAAQS to regulate criteria pollutants emitted by industries by applying the NAAQS as a property line concentration limit. The primary NAAQS are health-based standards, and therefore, an exceedance implies that it is likely that there will be adverse health effects for the public. Prior to, and since the inclusion of PM10 and PM2.5 into EPA's regulation guidelines, numerous journal articles and technical references have been written to discuss the epidemiological effects, trends, regulations, and methods of determining PM10 and PM2.5, etc. A common trend among many of these publications is the use of samplers to collect information on PM10 and PM2.5. Often, the sampler data are assumed to be an accurate measure of PM10 and PM2.5. The fact is that issues such as sampler uncertainties, environmental conditions, and material characteristics for which the sampler is measuring must be incorporated for accurate sampler measurements. The purpose of this manuscript is to provide the background and theory associated with particle size distribution (PSD) characteristics of the material in the air that is being sampled, sampler performance characteristics, the interaction between these two characteristics, and the effect of this interaction on the regulatory process. The information presented in this manuscript will be utilized in a series of manuscripts dealing with the errors associated with particulate matter measurements.