This project aims to the following five main parts: Reference reviewes, PM2.5 sampling, analysis and monitoring of special area for PM2.5 Spatio-Temporal hotspot analysis (Large religious activities), special areas for at least three places with control strategy (Yunghe market, Street washing and sweeping, control of cooking fume from catering trade), set up PM2.5 fingerprint (Chiayi City refuse incineration plant), analysis of pollutants emission from the Chiayi City refuse incineration plant and health risk assessment.
Special areas for at least three places with control strategy
Large religious activities
In this study, we aim to study the time-series distribution when using different type of firecrackers, one is environmental-friendly, the other is traditional one. The results from 100,000 environmental-friendly firecrackers indicated the maximum of PM2.5 mass concentration and number concentration was 2.3x104 μg/m3 and 10x104 #/cm3, respectively. The results from 52,000 traditional firecrackers resulted in maximum PM2.5 mass concentration and number concentration was 8x103 μg/m3 and 8x105 #/cm3, respectively. Both showed extreme high concentration during the firecrackers display. Moreover, the number concentration of environmental-friendly firecracker was lower than traditional firecracker, however, the PM2.5 mass concentration showed opposite result, possibly due to the amount of two types firecracker. Therefore, in order to compare the air pollution from two types firecracker, the concentration is suggested to be divided by the amount of firecracker. The results indicated the PM2.5 mass concentration per gram was 1.28 μg/m3 and 8.55 μg/m3; the number concentration per gram was 5.56 #/cm3 and 854 #/cm3 as using environmental-friendly and traditional one respectively, the production of fine particulate matter per gram with the traditional firecracker is higher than the other one.
Yunghe market
In the morning, during the busiest time of market, the mobile measurement results showed that the PM2.5 mass concentration and number concentration was 126 μg/m3, and 4.2×104 #/cm3, respectively. At noon, the PM2.5 mass concentration and number concentration was lower at 88 μg/m3 and 1.6×104 #/cm3, respectively. In the afternoon, after the market closed, the number concentration was lower than the morning and noon due to the decrease in the number of vehicles. However, the PM2.5 mass concentration was higher due to the higher PM2.5 background concentration in Chiayi city during afternoon.
Street washing and sweeping
In this study, aim to understand that the effective way to reduce the fine particulate matter among three different methods to sweep and wash street, the first model is sweep only, the second model is sweeping followed by washing and the last is washing followed by sweeping respectively. The mobile results showed the PM2.5 mass concentration was 155 μg/m3, 150μg/m3, 154 μg/m3 followed by the three different model and the number concentration was 1.2×104 #/cm3, 1.4×104 #/cm3 and 1.8×104 #/cm3 before sweeping and washing street, during the sweeping and washing street, the number concentration and mass concentration were higher due to the emission from the sweeping and washing trunk. Moreover, after the process with washing street about one hour, especially, the sweeping followed by washing, the decrease of number concentration was obvious, the results showed he number concentration was 0.8"×" 104 #/cm3 and the decrease ratio of the number concentration was 42% and 35% with the washing followed by sweeping, indicating the combination of washing is effective way to reduce the number concentration of fine and ultrafine particulate matter, however, among three different methods to sweep and wash street, none of these have obvious decrease of fine particulate matter PM2.5 mass concentration after the process.
Besides, one day and two days after the process of sweeping and washing street, the PM2.5 mass concentration and the number concentration were much lower than the day conducted the process of sweeping and washing street, the possible reason because of the lower background concentration.
Control of cooking fume from catering trade
This study aims to compare the fine particulate matter concentration in different time from the cooking activity with the three designs of range hood in steak restaurant. The first design is using the range hood only; the second design is equipping with one fan circulation device around the stove and using the range hood at same time; the third design is equipping with one fan circulation device but turning off he range hood during cooking. The results showed the dramatic increase concentration of PM2.5 mass concentration, number concentration, black carbon and PAHs was observed in cooking area and dining area during the cooking activity, especially, PM2.5 mass concentration and number concentration. Among the three designs, the increase ratio of PM2.5 mass concentration was the lowest as the second design was operated, moreover, the design which always shows the highest increase ratio of PM2.5 mass concentration and number concentration during the cooking is when the range hood was unutilized, indicating the range hood is necessary to reduce the pollutants from cooking activity, besides, with the fan circulation device operated, the increase ratio of PM2.5 mass concentration and number concentration during cooking activity were both lowest among three different designs. It can lower the increase ratio of PM2.5 mass concentration and number concentration down around 50% and 30% respectively. After finishing cooking about half to 1 hour later, PM2.5 mass concentration and number concentration were observed that decrease gradually from time series results. Due to the continuous cooking activity that the steak is still on the sauté pan in dining area, the increase ratio of concentration showed less obvious consistent tendency among three different designs at cooking and dinner area even the space of cooking and dinner area was connected.
Setup particulate matter (PM2.5) fingerprint from the incineration plant flue.
The concentration of PCDD/Fs in the incineration plant flue is 0.002 ng-TEQ/Nm3.
The concentration of air PCDD/Fs in Chiayi City Museum is 0.016 pg I-TEQ/m3, Chiayi Air Quality Monitoring station is 0.011 pg I-TEQ/m3, HuNei borough chief’s office is 0.024 pg I-TEQ/m3, HuTzi Nei re-planning District is 0.03pg I-TEQ/m3, and farmhouse on the south side of Pa-Chang River is 0.031 pg I-TEQ/m3.
The concentration of PCDD/Fs in plant in Chiayi City Museum is 2.18 pg I-TEQ/g, Chiayi Air Quality Monitoring station is 2.6 pg I-TEQ/g, HuNei borough chief’s office is 1.48 pg I-TEQ/g, HuTzi Nei re-planning District is 2.47 pg I-TEQ/g, and farmhouse on the south side of Pa-Chang River is 1.07 pg I-TEQ/g.
The concentration of PCDD/Fs in soil in Chiayi City Museum is 1.14 ng I-TEQ/kg, Chiayi Air Quality Monitoring station is 0.435 ng I-TEQ/kg, HuNei borough chief’s office is ND, HuTzi Nei re-planning District is 0.42 ng I-TEQ/kg, and farmhouse on the south side of Pa-Chang River is ND.
The concentration of PCBs in the incineration plant flue is 64.16 pg/Nm3.
The concentration of PCBs in plant in Chiayi City Museum is 83.4 pg/g, Chiayi Air Quality Monitoring station is 70.3 pg/g, HuNei borough chief’s office is 67 pg/g, HuTzi Nei re-planning District is 63.4 pg/g, and farmhouse on the south side of Pa-Chang River is 53 pg/g.
The concentration of PCBs in soil in Chiayi City Museum, Chiayi Air Quality Monitoring station, HuNei borough chief’s office, HuTzi Nei re-planning District, and farmhouse on the south side of Pa-Chang River is all ND.
The concentration of PM2.5 in the incineration plant flue is 1819 μg/m3.
The concentration of air PM2.5 in Chiayi Air Quality Monitoring station is 19 μg/m3.
The concentration of hexavalent chromium in the incineration plant flue is ND.
The concentration of air hexavalent chromium in Chiayi City Museum is 0.062 ng/m3, Chiayi Air Quality Monitoring station is 0.035 ng/m3, HuNei borough chief’s office is 0.043 ng/m3, HuTzi Nei re-planning District is 0.054 ng/m3, and farmhouse on the south side of Pa-Chang River is 0.055 ng/m3. All of the above are within the regulated values.
Analyses of the public exposures and the associated adverse health effects in Chiayi city due the pollutant emissions by the Chiayi incineration plant.
Hazard characterization: In this project, the pollutant emissions from the stack of the Chiayi incinerator were sampled and analyzed, followed by collection of the toxicity characteristics and health effects of the observed compounds to identify the associated hazards. In the results by focusing on dioxins and metals, the Group 1 species includes 2,3,7,8-TCDD, cadmium, arsenic, beryllium, and chromium6+. The Group 2 species includes nickel, cobalt, and lead.
Dose-effect relationship: Given the results of hazard characterization, the slope factors and unit risks for cancer risk estimation as well as the reference doses and reference concentrations for non-cancer risk estimation were collected and organized to facilitate the following adverse health risk assessment.
Exposure analysis: To predict the exposures of target pollutants by receptors from the emissions, atmospheric diffusion model and multi-media transport model were employed to understand the fates and distributions of target compounds after the emissions from the incinerator. The lifetime chronic average daily doses of reception groups for different compounds were estimated accordingly. In the results, the maximum exposures for the pollutants emitted from the incinerator occurred in the area 1 in the scenarios including Case I, Case II, or Case III, as the locations of the lowest exposures were all in the area 6.
Descriptive risk characterization: In the estimations of lifetime excess cancer risks posed by the pollutant emissions by the Chiayi incinerator during different simulation scenarios, including the full-year average scenario and two scenarios modified by using the pollutant concentrations analyzed at the receptor locations with the occurrence of effective or ineffective diffusion in the atmosphere, the excess cancer and non-cancer risks estimated for different areas of concern were below the threshold limits of 10-6 and 1, respectively. The estimated excess cancer risks for certain areas were above 10-6 in the scenarios modified by considering the effective and ineffective atmospheric diffusions. It was indicated that the adverse health effects resulted by the incinerator was insignificant from the viewpoints of either carcinogenic or non-carcinogenic risk assessment. It is worth noting that the possible explanation for the estimated excess cancer risks above the threshold limit (10-6) observed in some areas for few scenarios in which effective or ineffective atmospheric diffusion was presumed was associated with the consideration of the concentration differences between the simulations from the atmospheric diffusion model and real observations in the receptor locations, potentially suggesting the presences of other pollutant emission sources in the background in the sampling events.
