This project was implemented from Jan. 27, 2021 to Dec. 31, 2020. All tasks defined in the Environmental Protection Bureau's contract had been completed including the sampling analysis, maintenance of the manual operation air monitoring stations, regular maintenance of auto air monitoring stations, operation and maintenance of mobile air quality monitoring stations, operation and maintenance of VOCs monitoring vans, regular maintenance of electronic billboard , noise monitoring of mobile noise stations, submit all kinds of reports, training, air quality routine notification, maintain the air quality monitoring website, et cetera.
In the section of Manual Operation Air Monitoring Stations, there were monthly sampling, analysis of dust fall, monthly one-point flow rate calibration, every half months TSP sampling analysis and equipment maintenance, quarterly multiple-points flow rate calibration. All equipment in Manual Operation Air Monitoring Stations are in good conditions. In contrast with year 2020, the geometric mean concentration of TSP in year 2021 was higher than year 2020. The concentration of TSP between 3～152μg/m3 in 2021. The concentration of TSP in summer was lower than in other seasons. The dust fall in Taichung City in 2021 was equally 3.01 g/m2‧30d, the graduation was extremely slightly pollution and higher comparing to last year as 2.45 g/m2‧30d.
In the section of Auto Monitoring Stations, all measurement items were functioning well under weekly, monthly, quarterly, semi-annual and annual maintenance scheme. The data achieved above 93% of data capture rate.
In automatic air quality station, the data was affected between day and night. CO and NO2 were affected by mobile sources of pollution of higher concentration during commuting time, particularly Dali station was obvious; O3 was the result of photochemical reaction at noon time with higher concentration in Dali and Daiping station. In terms of seasonal changing, most pollutants in summer have lower concentration, higher in winter and spring; its causes by typical weather patterns in Taiwan such as Typhoons in summer, strong heat convection, good diffusion conditions so the pollutants is not easy for accumulation. The values of O3 between Mar. to Apr. (spring) and from Sep. to Oct. (autumn) was higher to showing a typical seasonal variation.
In the section of long-term trends of measured value of automatic air quality station, implement a variety of regulatory measures over the years, so SO2 concentration was lower in recent years. NO2 concentration in Zhongming, Dali, and Wuri station were higher due to mobile sources of air pollution; the long-term trend was roughly rendered decline. Most stations of O3 concentration were roughly slight rise from 2017. PM10 concentrations were showing a slight downward in long-term trend ,so it meant that efforts over the years for particle control has the achievement. PM2.5 trend is similar to the PM10 in long-term trend that showed a slight downward.
In 2021, the ratio with poor air quality (AQI>100) in Fengyuan, Shalu, Dali, Zhongming and Xitun revealing monitoring data from Taiwan Environmental Protection Administration report. The monitoring data is 9.2% in Taichung City from Jan. to Dec. .Among Central Air Quality Zone, the higher one was Nantou County standing for 17.5%, followed by Changhua County (11.0%)and Taichung City (9.2%). Among Shan, Hai, Tun, and Shih, four districts of Taichung City; Tun district had the highest ratio with AQI>100（9.9％）, followed by Shih (8.6%) , Shan (6.4%) and Hai (5.8%).
In the section of mobile air quality monitoring van, monitoring regularly the implementation of equipment maintenance; air quality monitoring was based on public petitions and EPB's command. It has been completed 19 monitoring cases until end of Dec.. After monitoring is complete, in addition to submitting the monitoring data and conducting for monitoring data analysis, aggregated monitoring locations near sources may provide reference implementation of audit. Monthly monitoring data of the van was achieved more than 90% of data capture rate in line with the contract requirements. Mobile air quality monitoring van not only implement air quality monitoring, but also assist relevant institutions to analyze 12 samples.
the section of mobile traffic air quality monitoring van, it has been monitored on Taiwan Avenue in Xitun District since January 2011. The average concentration of most traffic pollutants during peak traffic hours during the day is higher than that during night hours, indicating the impact of moving vehicles on air quality. The air quality on holidays is better than on weekdays, which is presumed to be related to the fewer number of carts. The NOx, CO, NMHC, and PM10 concentrations of the traffic air quality monitoring van were higher than those of the neighboring Xitun station, especially NOx and CO. It is presumed that it was affected by the traffic vehicles and road dust on Taiwan Avenue.
In the section of the Noise Monitoring of Mobile Noise Stations, that took twice quarterly monitoring tests at each spot, and according to predetermined progress execution. The measured value of traffic noise monitoring station is relatively stable, and is greatly affected by traffic flow. The environmental volume station is subject to stricter control standards, and the measured value is easily affected by natural or human activities, and occasionally some cases may fail. In the section of the Software Operation/Maintenance and Data Update, updating the database of the Noise Control Information System quarterly.