The goals of this study are (1) to maintain acid deposition network for conducting a long-term monitoring and data analysis, (2) to maintain the integrated atmospheric mercury and heavy metals monitoring network and analyze the data, (3) to establish and maintain an integrated atmospheric modeling system for studying the long-range transport of air pollutants and local air pollutants in order to assess their impact to Taiwan air quality, and further to provide fundamental information to EPA for air pollution management, (4) to recalculate the AQI index when extreme air pollution events occur in order to highlight the contribution from local air pollutants and provide a reference for the EPA, (5) to investigate the impact of acid rain and fog acidity to the ecosystem’s nutrient cycling, (6) to update and maintain the web site of Taiwan’s acid rain, (7) to promote international, cross-strait and southeast Asia countries cooperation and technical exchanges on regional air pollutant transport issues. To date, our achievements are highlighted below: 1. 1196 samples were collected from 14 acid deposition stations all over Taiwan in 2018. The average pH for all the samples was 5.72. 2. The acid rain situation in Taiwan has slightly improved. The annual average pH values for most of the sites is greater than 5.0. Annual average pH values at Northern Taiwan sites are still lower than in southern Taiwan. 3. 459 samples were collected from 12 mercury wet deposition stations all over Taiwan in 2018. The average mercury concentration from each station was between 8.3 – 26.2 ng L-1, with the lowest average measured at Chenggong station and the highest at Pengjia islet station. The weighted mean mercury concentration was between 6.4 – 15.3 ng L-1, with the lowest at Yilan station and the highest at Taichung station. This range of mercury concentration in Taiwan is now lower than the vast majority of countries worldwide. 4. The web site (http://acidrain.epa.gov.tw) for Taiwan’s acid rain studies has been updated with more information. 5. We have continued to promote and participated in international collaborations and technical exchanges, for example with Quality Assurance Science Activity Center of UN, and the World Meteorological Organization Global Precipitation Chemistry and Deposition Science Assessment. 6. Since January 2016, the cross-strait stations, Fuzhou and Matsu have been established to cooperate in acid deposition monitoring and data exchange. Moreover, after Prof. Lin visited Chiang-Mai University in Thailand this year, we have great chances to cooperate in acid deposition monitoring with Chiang-Mai station of EANET in the future.

long-range transport, acid rain, atmospheric mercury