The Asia Mercury Problem

The rapid growth of economic and industrial activities in Asia marked by the massive consumption of coal, petroleum, and fossil fuels has resulted in a dramatic increase of atmospheric mercury emissions. Once emitted, mercury can be transformed to different chemical forms, transported through the atmosphere, and deposited long distances from the point of origin. The long-range atmospheric transport and deposition of mercury is a significant environmental problem of regional and global concern. Asia is the largest source of atmospheric mercury and emissions continue to rapidly increase. It is expected that mercury deposition within Asia will also continue to increase, leading to more mercury health issues in the region. Many industrializing Asian nations have their own sources of mercury emissions, contributing to the local mercury burden, and likely increasing local and regional deposition of mercury.

Global anthropogenic mercury emissions, 2010

Despite the magnitude and extent of Asian mercury emissions, few consistent measurements have been made in the Asia-Pacific region; accessible measurement datasets are very limited.

Source: United Nations Environment Programme (UNEP) The Global Atmospheric Mercury Assessment: Sources, Emissions and Environmental Transport, 2013

Once deposited to waterbodies, natural processes convert inorganic mercury to methylmercury- a highly toxic form that is readily magnified to high concentrations in food webs. Methlymercury concentrations in biota at levels associated with adverse impacts to fish, wildlife, and people have been observed worldwide. In regions where the consumption of fish is a primary part of the diet, such as Southeast Asia, this is a significant concern for the health of humans, in particular children.

Fish consumption advisories now blanket the entire United States, and it is thought that fish with high concentrations will also be found across all of Asia. Methylmercury concentrations in fish and wildlife in the U.S. routinely exceed dietary thresholds that can harm people and wildlife. This same result is expected within Asia. High concentrations of mercury have been found in ocean fish, and in all regions of the oceans.