Through this project, Chiayi City atmospheric aerosols PM2.5 sampling and analysis to understand the suspended particulate hazards to public health and affect sexual relationships . The work includes the completion of the first quarter (northerly wind season) each of the specific areas of PM2.5 direct reading taken 40 points times the second quarter (southerly wind season) each of the specific areas of mining PM2.5 direct reading 20:00 times , manual sampling part , on EPA Xing Jia Guomin primary station for three quarters (May, July and September) 12:00 samples were analyzed samples PM2.5 mass concentration and composition ratio with the various sources of pollution as a control , and using receptor modeling analysis Chiayi station , the sources of pollution sources and explore the contributions of the main pollutants . The following is the work accomplished during this project received a preliminary summary of the results :
1. Chiayi City due to heavy traffic intersection in the evening rush hour on weekdays higher concentrations of PM2.5 , PM2.5 concentration in the afternoon non- peak hours was significantly lower off-peak sharp differences are significant , suggesting that the impact of traffic by traffic , the traffic Holidays and contribution of different types on weekdays , at off-peak hours of traffic than usual , leading to frequent crossing of the holiday traffic peak concentration of PM2.5 from sharp narrowing the gap . Frequent human activities on weekdays at the PM2.5 concentration mixed residential and commercial area than pure residential high, sharp deviation from the peak concentration in pure residential area larger, and on holidays appear sharp reversal characteristics of off-peak hours , suggesting that residents of Holiday pure residential area more frequent in the afternoon activities . Suburban background concentrations were lower than when the peak off-peak day average standards and regulations .
2. Chiayi City car commuting situation recirculated air mode even weekday rush hour car concentration is also just 0.6 μg/m3, display of riding in a car commuting people get good barrier, eliminating exposure to PM2.5 concentrations. PM2.5 concentrations inside and outside the cycle air conditioning mode increased slightly but still very low value (1~2 μg/m3), shows the air filter elements for air moving well, can be controlled at a relatively low concentration of PM2.5 .
3. Chiayi City commuter locomotive situational PM2.5 concentrations showed intermittent readings , presumably due to high wind speed locomotive traveling between the tangent to make direct reading sampler attract insufficient due to the high value appears weekdays in Chiayi city 's roads , high value holidays appeared in the holiday Zhongxiao northbound . In addition locomotive traveling major contribution from the semaphore concentration during idling stop, etc. , so by "heavy traffic intersection" of the sampling results obtained motorcyclists PM2.5 exposure concentration information.
4. Chiayi City Bus commuter situational high concentrations of PM2.5 values concentrated in the first 2 to 6 minutes , especially at bus stops and other areas not on the front of the car is much higher than the concentration of exposure concentrations up to 25 μg/m3, also the highest of all kinds of commuter scenario , whereas in the road between the bus and the car interior concentrations comparable concentrations , it is recommended that the public as a commuter bus terms of tools , then wait at bus stops and other areas should make their own protective measures , you can significantly reduce the exposure to PM2.5 .
5. The first season (May) Chiayi station daily average PM2.5 manual sampling ranged 9.7~54.9 μg m-3, the first two of PM2.5 mined high concentrations , and in the post- secondary sampling both before and after intermittent rain, rainfall intensity and visible without large or long delay can effectively reduce the concentration of PM2.5 in the air . Spatial distribution of educating people in the city west and north of Grace Elementary School Girls have a higher concentration of PM2.5 , wind northwest side due to the sampling period , the aforementioned downtown upwind of sampling points downwind concentrations than the Chiayi station is high, show that apart from urban traffic and human activities, there may be sources of pollution in the city's northwest on the concentration of PM2.5 generated contributions. Component part of the Ka-hing elementary to soluble ions in PM2.5 (SO42-, NO3-, NH4 +, F- and Cl-) accounted for up to 37.7% , followed by total carbon content , occupy 35.1% of total metal there are 10.3% and failed to analyze the composition of 16.9%. Up to SO42- ion components , accounting for 20.5% of PM2.5 mass , followed by 6.1% of Cl- , NO3- addition to the 5.6%, NH4 + and Na + 4.4% 3.2% . Up to OC carbonaceous component , accounting for PM2.5 mass 17.6%, EC was 13.7%.
6. The second season (June to August) Chiayi station daily average PM2.5 manual sampling ranged 8.8~19.9 μg m-3 between the typhoon season brought abundant rainfall impact and lead to strong thermal convection in summer afternoon thunderstorms occur frequently mined season low concentration of PM2.5 , which can effectively reduce rainfall provable concentration of PM2.5 in the air . Spatial distribution Grace Girls in the city have a higher concentration of PM2.5 , showing that the measuring point is close to the city due to traffic and human activities arising PM2.5 higher than other regions. Season at Hing Ka Elementary mass ratio of each component accounted for , the highest water-soluble ions (SO42-, NO3-, NH4+, F- and Cl-) with 43.0%, followed by the total carbon content of about 30.8% , metal there are 21.9% and total failure analysis of the ingredients are 4.3%. Ionic components still to SO42- up , accounting for 29.1% of PM2.5 mass , followed by 8.3% Na+ , NO3- addition to the 8.0%, K+ and Cl- 5.3% 5.2% . Carbonaceous components still OC most, accounting for PM2.5 mass 17.2%, EC was 13.5%, EC and OC percentage compared to the average in the first quarter is not much difference .
7. The third quarter (September to October) Chiayi station daily average PM2.5 manual sampling ranged 19.2~38.8 μg m-3 , between the northwest wind and Southeast wind between conversion of the occasion, so overall Chiayi station and the perimeter of the station PM2.5 concentrations than similar. Mined season have increased the concentration of PM2.5 trend , no rain situation to eliminate air PM2.5, so its concentration has a more representative , which means that Chiayi City usually present in the air of the high concentration of PM2.5. Season two samples 102 years on September 7 and the 13th country in the Ka-hing quality accounted for a small proportion of each component , water-soluble ions (SO42-, NO3-, NH4 +, F- and Cl-) accounted for up to 37.8% followed by the total carbon content, occupy 30.1%, 19.9 %, and the total amount of metal failed to analyze the composition of 12.2%. Accounted for most of the ion composition ratio of SO42-, PM2.5 mass accounted for 23.5%, followed by 6.3% NO3-, Cl- addition to the 6.3%, K+ and Na + 4.2% of 6.3%. Carbonaceous components EC and OC proportion similar , EC accounted for 15.1% of PM2.5 mass , while the OC was 15.0% .
8. Manual sampling at three seasons of this project are synchronized with the EPA manual sampling , parallel comparison of R2 0.9998,0.9877 and 0.974 , respectively , both highly linear correlation ; manual sampling plan and the automatic and continuous monitoring with EPD the comparison of the three quarters of R2 were 0.962,0.960 and 0.917 , is also highly linear correlation , and the slope of the linear regression 0.948,1.506 and 1.481 , showing the second and third quarters first / automatic sampling, the results were significantly different , subject to a conversion factor can be observed in the EPD automatic sampling of PM2.5 concentrations higher trend, especially at low concentration of PM2.5 in the air prone to overestimate the results. Consolidated annual sampling results of the comparison operation , the project manual and EPA Manual of R2 is 0.978 , a slope of 1.033 , compared to the average show two methods are very similar ; manual sampling of the annual plan with the EPD automatic and continuous monitoring the comparison , R2 is 0.924 , a slope of 1.036 , also shows that the average ratio for the two methods are very similar.
9. Hing Ka stations receptor model analysis of the first quarter , the largest sources of emissions from transport (between 29.7-103.1 %, with an average of 44.6%), followed by ammonium sulfate (range 14.7-27.1 %, with an average of 18.9%) , the third largest source of pollution compared to biomass burning (range 0-39.2 %, with an average of 17.4%) , followed in descending order crust (average 10.0%), sea salt spray (average 9.5%) , iron and steel industry (3.8%) , nitrate (1.7%) and cement industry (0.8%) , but not quantitatively overestimated by 6.7% . With the exception of ammonium sulfate, sea salt spray, stable steel industry analysis , other sources resolved at parse time scale of a large jump .
10. Ka-hing stations receptor model analysis of the second quarter , the largest sources of emissions from transport (between 50.8-67.3 % , with an average of 55.2%) , followed by ammonium sulfate (range 31.5-45.1 % , with an average of 35.0%) , the third largest source of pollution compared to salt spray (range 14.3-25.4 % , with an average of 17.5%) , followed in turn, are the steel industry (average 10.4%) , electricity industry (average 1.9%) and nitrate (1.7%) , raw mass burning (0.0%) and crustal material (0.0%) did not find this analysis , without quantitative overestimated by 20.5% . With the exception of ammonium sulfate, sea salt spray, stable steel industry analysis , other sources resolved at parse time scale of beating bigger.
11. Ka-hing stations receptor model analysis of the third quarter , the largest source of pollution is still as transport emissions (range 35.8-59.4 % , with an average of 50.5%) , followed by ammonium sulfate (between 15.7-36.2% , with an average 23.5 %) , the third largest source of pollution compared to biomass burning (range 16.2-22.8 % , with an average of 18.7%) in the first quarter situation is the same , after the order is sea salt spray (average 9.8%) , crustal material (an average of 4.2%) and cement industry (3.1%) , while the steel industry (0.0%) , nitrate (0.0%) did not find this analysis , without quantitative overestimate of 9.7%. With the exception of ammonium sulfate, sea salt spray, stable steel industry analysis , other sources resolved at parse time scale of beating bigger.
12. The plan of the city's original nature of the pollution control strategy recommendations , including
(A) stationary sources control : oil and gas recovery control , catering fume control;
(B) Mobile Source Management: idling motor vehicle parking management, periodic inspection locomotives , diesel vehicles self-management;
(C) Fugitive Source Control : Adopt road sweeping , banning open burning, promote temples in m / reactive voucher;
(D) Low-carbon city / air quality related projects oriented: stroke motorcycles replace old and subsidy policies to promote oil and gas dual-fuel vehicles, electric cars and motorcycles subsidies.
As for the city and the county's second -derived PM2.5 transmission part, a national integrated prevention in EPA recommended before the city and neighboring counties such as Chiayi County, Yunlin County , Tainan County and Tainan City and other components PM2.5 information common strategic alliance for the purpose of reach high concentrations downwind counties appear to be traced when the main contribution to the value of the source , not just in the area for the control of native species, the alliance through regular meetings, proposed regional pollution event, and with each season meteorological conditions in order to reach the Southwest District PM2.5 air quality integrated management results.
