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Example of a power plant and other source health effects study in Tong Liang, China

Chemically speciated PM2.5 and particle-bound polycyclic aromatic hydrocarbon (PAH) measurements were made at three sites near urban Tong Liang, Chongqing, a Chinese inland city where coal combustion is used for electricity generation and residential purposes outside of the central city. Elevated PM2.5 and PAH concentrations were observed at all three sites, with the highest concentrations found in winter and the lowest in summer. This reflects a coupling effect of source variability and meteorological conditions. The PM2.5 mass estimated from sulfate, nitrate, ammonium, organics, elemental carbon, crustal material, and salt corresponded with the annual average gravimetric mass within ± 10%. Carbonaceous aerosol was the dominant species, while positive correlations between organic carbon and trace elements (e.g., As, Se, Br, Pb, and Zn) were consistent with coal-burning and motor-vehicle emissions. Ambient particle-bound PAHs of molecular weight 168-266 were enriched by 1.5 to 3.5 times during the coal-fired power plant operational period. However, further investigation is needed to determine the relative contribution from residential and utility coal combustion and vehicular activities. In order to support an ongoing epidemiological health-effect study, we have performed a dispersion modeling study of the transport and dispersion of SO2 pollutants emitted from the Tong Liang power plant. The dispersion modeling study for the periods of the power plant operation in 2002 and 2003 was conducted using an EPA preferred regulatory dispersion model Industrial Source Complex 3 Short Term (ISC3ST). The simulated extremes in SO2 monthly averages, daily averages, and 3-hr averages are over 100, 300, and 600 μ g m-3, respectively. These are very high values and their possible impact should be carefully analyzed. The other issue of concern is that the extremes and high concentrations are simulated with similar values for both years. This can imply that the impact of the power plant can be expected for many years on a similar level. The results from the dispersion modeling study have been used to correlate with the ongoing epidemiological health-effect study.

PM2.5; PAH; trace elements

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