This project is to assess the fine air particulate (PM) concentration’s spatial distribution, compositions and transport paths in PingTung County. In addition, the possible emission sources were identified by modeling with the Chemical Mass Balance (CMB) model with the analyzed sampled compositions, the results are used to plan the control strategies in order to improve the air quality in this area.
The four-season, 24-hour PM sampling with chemical analysis in PingTung County was accomplished. The sampling sites included tourist area (the Dapeng Bay), background site (the National PingTung University of Science and Technology), industrial site (the Pingnan Industrial Park), urban site (the ChungCheng Elementary School) and highly polluted area (the ChaoTung Elementary School). In addition, sites near the heavy traffic areas: the National PingTung Institute of Commerce, the Ligang Bridge, and the Changzhi Junction were sampled together with 24-hour traffic counts recorded. The chemical analyses of PM2.5 content included organic carbon, element carbon, ions, metals, and polycyclic aromatic hydrocarbon, PAHs.
The spatial distribution of PM2.5 showed the highest concentrations were at the heavy traffic and tourist areas, the lowest were in the background site, and other ambient sites were in between. The temporal distribution showed the first season had the highest concentrations (60-13μg/m3), the fourth season next (52-28μg/m3), the third season followed (37-16μg/m3) and the second season was the lowest (18-12μg/m3). The secondary aerosol (SO42-、NO3-、NH4+) had the highest weight percentage of ions (81.8%-96.5%). The metal contents of PM were abundant in earth elements (Mg, Al, Ca, Fe) with over 80% by weight. The PAH concentrations are much higher in the heavy traffic sites (117~141 ng/m3) than those in other ambient sites (31~67 ng/m3). The toxic equivalent (Total-BaPeq) is also higher in the heavy traffic sites (16~24 ng/m3) than other sites’ (4~12 ng/m3).
The results of CMB modeling showed that the source contribution ranking in order: transportation, sulfates, nitrates and sea salts as major sources, and boilers, steel industries, and electric industries as minor sources for possible PM2.5 mass contribution. The highest transportation contribution was in the third season (August to September) ranging from 48%(ChaoTung Elementary School) to 65% ( National PingTung Institute of Commerce). The highest sulfates contribution was in the fourth season (October) ranging from 29% (Dapeng Bay) to 35% (Pingnan Industrial Park). The highest nitrates contribution was in the first season (March-April) ranging from 12%(ChungCheng Elementary School) to 32% (Pingnan Industrial Park). The highest contributions from boilers and electric industries were the highest at the National PingTung Institute of Commerce ranging from 5-12% during the third season and ranging from 3-4% during the first season respectively. At Ligang Bridge, the contribution from the steel industries was the highest about 5~8% in the second season.
This project reviewed the emissions reduced from the air pollution control works implemented by the PingTung County and the current emissions inventory of both PM and PM precursors. In addition, the feasible control strategies with reduction potentials and costs were proposed to improve the air quality in PingTung County.
The PM health risk literature from domestic and international assessment was referenced and the health benefit of improved air quality from 2007-2010 was modeled. In addition, the outreach materials regarding PM and health effects plus the action items which can be anticipated by residents were published. We also involved with other environmental agencies providing related information for exchange and attended meetings.