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U.S. Department of Energy
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Speciated fine-particle (<2.5 {micro}m aerodynamic diameter) and vapor-phase acid concentrations in southern California

Conference ·
OSTI ID:361974
; ;  [1]
  1. California Air Resources Board, Sacramento CA (United States). Research Div.
A fine-particle (<2.5 {micro}m aerodynamic diameter) and vapor-phase acid sampling network has been in operation among 12 communities in southern California since late 1993. The data from this network consists of concentrations of particulate matter <10 {micro}m in aerodynamic diameter (PM10), nitrogen dioxide, ozone, vapor-phase hydrochloric, nitric, acetic, and formic acids, particulate matter <2.5 {micro}m in aerodynamic diameter (PM2.5), and the chloride, nitrate, sulfate, and ammonium components of PM2.5. These measurements are the basis of the exposure assessment estimates of the Children`s Health Study, a multi-year study, mainly of lung function development and respiratory illness, taking place in southern California. One of the goals of the Children`s Health Study is to utilize a cost-effective means of obtaining continuous fine-particle and vapor-phase acid data for a multi-year study with enough time resolution to allow seasonal estimates of exposure. A two-week sampler was developed to meet these needs. Four continuous years of vapor-phase acid and PM2.5 mass, chloride, nitrate, sulfate, and ammonium data have been collected. During this time, the sampler has proven to be reliable. A decline in PM2.5 mass, nitrate, and ammonium ions in most of the communities from 1994 to 1997 was observed. In contrast, very little change in vapor-phase acids was observed. There has been increased interest at the national level in fine particles and their characteristics. The network provides a rich database that can be used to characterize southern California communities on the basis of their level of fine particles (and their components) and vapor-phase acids and should prove valuable with respect to both prospective and retrospective health studies. The database also provides a general characterization of the levels of PM2.5 affecting 25 million people in southern California.
OSTI ID:
361974
Report Number(s):
CONF-980632--
Country of Publication:
United States
Language:
English