EANET

Abstract

The Acid Deposition Monitoring Network in East Asia (EANET) started its preparatory phase in 1998, and subsequently its regular phase in 2001, to respond to the concern of acid deposition and air pollution issues. The EANET covers the monitoring network of wet and dry deposition, soil and vegetation, inland aquatic environment, and catchment scale. Data report and periodic report have been published to evaluate the state of acid deposition and its effects on ecosystems based on the monitoring data. Through implementing the following activities for 20 years: (1) acid deposition and air pollution–related substances monitoring; (2) compilation, evaluation, storage, analysis, and provision of monitoring data; and (3) data quality assurance and quality control (QA/QC), EANET has significantly contributed to promoting cooperation among participating countries in East Asia to address acid deposition and air pollution problems. As of 2019, wet/dry deposition, soil/vegetation, and inland aquatic environment monitoring were performed in 59 sites, 22 sites, 13 lakes/reservoirs, and 6 rivers/streams, respectively. Those samples have been analyzed in the laboratories whose quality has been evaluated through interlaboratory comparison (ILC) projects by using artificial samples.

Trend analysis using the 20 years’ monitoring data in EANET shows decrease in SO₂ concentration, sulfate and hydrogen ion deposition, and recovery from acidification of inland water. However, further reductions of sulfur and nitrogen oxides are required and expected if we look at the achievements made by European Monitoring and Evaluation Program (EMEP) and National Atmospheric Deposition Program (NADP).

Since science and policy are closely interlinked and good policy should be supported by science-based evidence, EANET will continuously promote communication and cooperation with relevant environment-related organizations such as Asia Pacific Clean Air Partnership (APCAP), the World Meteorological Organization (WMO), etc. Additionally, the EANET should accelerate the establishment of new monitoring sites or encourage existing monitoring sites, particularly in data-sparse areas and regions with sensitive ecosystems, in order to accumulate in the network with sufficient data estimating the status of acid deposition in East Asia. Moreover, taking into account changes in the environment surrounding the East Asia region, it is also important to continue the fellowship research program to foster young researchers who will lead the next generation of EANET.