Missing mercury pollution is enough for mass poisoning

Small-scale gold mining may be a big source, so the lost mercury could be in soils near mines, Lamborg says.

Alternatively, the lost mercury could be in sediments of estuaries and coastal waters, particularly in Asia. Last month, Helen Amos of Harvard University estimated that up to 90 per cent of the mercury flowing down rivers from mining areas ends up in these sediments (Environmental Science & Technology, doi.org/t2h).

If those sediments get stirred up, local mercury levels could reach those seen at Minamata, which affected thousands of people.

http://www.newscientist.com/article/mg22329811.800-missing-mercury-pollution-is-enough-for-mass-poisoning.html