Compliance with the new PM2.5 standard -- attainment or non-attainment?
- Fluor Daniel Fernald, Cincinnati, OH (United States)
The revisions to the United States (US) national ambient air quality standards for particulate matter (PM) will have an impact on a number of counties and metropolitan areas in the US. The US Environmental Protection Agency (EPA) added two new PM2.5 (particulate matter with an aerodynamic diameter less than or equal to a nominal 2.5 micrometers) standards in July 1997 which included: (1) a new annual PM2.5 standard of 15 ug (micrograms)/m{sup 3} and (2) a new 24-hour PM2.5 standard of 65 ug/m{sup 3}. Some reports indicated that the EPA initially projected that as many as 150 counties in the US will not be able to attain the new PM2.5 standards. This paper examines three sources of PM2.5/PM10 (particulate matter with an aerodynamic diameter less than or equal to a nominal 10.0 micrometers) ratios for 67 monitoring locations in the US and Canada. Based on the minimum, mean, and maximum PM2.5/PM10 ratios, estimates of the number of Metropolitan Statistical Areas (MSAs) in the US that could potentially exceed the new annual PM2.5 standard were made. Additionally, a theoretical estimate of the number of counties that would exceed the new 24-hour standard was made based on 1995 PM10 EPA Trends reports data. The mean ratio of PM2.5/PM10 calculated in this paper was 0.53. Based on this mean ratio, about 54 MSAs in the US could be expected to exceed the 15 ug/m{sup 3} annual PM2.5 standard. Using the minimum (0.36) and maximum (0.76) PM2.5/PM10 ratios, the number of MSAs exceeding the 15 up/m{sup 3} standard would be 6 and 180, respectively. Using the same PM2.5/PM10 ratios, the theoretical number of counties exceeding the new 24-hour standard PM2.5 concentration would be 35, 6, and 109 based on the mean, minimum, and maximum ratios, respectively.
- OSTI ID:
- 361975
- Report Number(s):
- CONF-980632--
- Country of Publication:
- United States
- Language:
- English
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