期刊名称：Journal of Natural and Environmental Sciences
印刷版ISSN：1309-7474
出版年度：2011
卷号：2
期号：1
页码：19-24
语种：English
出版社：Journal of Natural and Environmental Sciences
摘要：The air pollution regulatory process is structured to protect the public from being exposed to concentrations of air pollutants that may cause health effects with an adequate margin of safety. The National Ambient Air Quality Standards (NAAQS) are concentration limits for so-called “criteria pollutants” that apply in locations where the public reside (community-oriented monitoring sites). Areas found to have concentrations exceeding the NAAQS can be designated as non-attainment, and corrective actions may be required by State Implementation plans. State permit engineers use the NAAQS to regulate by limiting the frequency with which the concentration of each criteria pollutant at or beyond the property lines may exceed the applicable standard. Failure to meet standards may require the installation of more elaborate and expensive abatement systems to be in compliance. The measurement of particulate matter concentrations that are subject to either NAAQS, used as a concentration to determine non-attainment, or permit conditions must be accurate to prevent inappropriate regulation.The Federal Reference Method (FRM) of determining PM10, PM10-2.5 (PM coarse), and PM2.5 concentrations is the gravimetric method. In FRM-based monitoring, ambient air is drawn through special filters at a specified flow rate. The filters are weighed before and after sampling at an appropriate location, and the net mass of particles accumulated on the filter is divided by the total volume of air sampled to compute the time-averaged concentration for the sampling period. By contrast, the Tapered Element Oscillating Microbalance (TEOM) is an EPA-designated Federal Equivalent Method monitor for measuring PM concentrations, which uses a fundamentally different technique to measure aerosol mass. Many state air pollution regulatory agencies (SAPRA) have installed TEOMs at community-oriented monitoring sites, and some SAPRAs have located TEOMs at the property line of PM sources to determine if the source is meeting its permit conditions; still, it is not clear that monitoring data from TEOMs and FRMs are strictly comparable..Lambeth (2008), with the Texas Commission on Environmental Quality (TCEQ), collected PM concentration data from co-located TEOM and gravimetric samplers. Skloss (2008) performed a similar study at cattle feedyards by co-locating TEOM and gravimetric samplers.. The goal of these 2 studies was to obtain an equation or series of equations that could be used to estimate the FRM gravimetric concentrations from TEOM sampler measurements. In addition, Auvermann (2008) measured PM10 and TSP concentrations with TEOM samplers near cattle feedyards for two years. Preliminary results suggest that when PM concentrations are low, concentration data from TEOMs and FRM samplers do not differ significantly. When concentrations are high, however TEOM concentrations appear to be consistently 25 to 35 % higher than the FRM concentrations.
关键词：Air pollutants; Federal reference method (FRM); Tapered element oscillating microbalance (TEOM);Biological and Agricultural Engineering
