Weaning China Off Mercury

A team of Japanese researchers discovered high concentrations of mercury at the peak of Mount Fuji in 2013. After further research, they identified the source as China, from which winds had carried the toxic metal hundreds of miles into Japan. The discovery offered a stark illustration of how much mercury floats in the air above China. Much of China’s mercury emissions originate from coal-fired power plants, but another major culprit is its chemical industry. Every year, Chinese industry consumes thousands of metric tons of mercury-based catalysts to harness coal as a raw material for the production of polyvinyl chloride (PVC), a basic plastic. In theory, the mercury should be recovered from spent catalysts, but instead, a lot of it escapes into the environment, harming workers, contaminating crops, and perhaps traveling to Japan. Given China’s abundance of low-cost coal, mercury use by the PVC industry has long seemed to be an