Human-caused mercury emissions into the atmosphere come principally from burning fossil fuels (75%). Emissions from waste disposal sites, waste incineration and cement manufacture account for most of the rest. The mercury usually returns to the earth, rivers and oceans in snow and rain. Asian countries are responsible for half of these emissions, the US and Europe combined for another quarter.

An extraordinary lack of either forward-thinking or caring by researchers at the University of Georgia (US) has led to the genetic modification of cottonwood trees whose roots extract mercury out of contaminated soil, but then ‘breathe’ it out into the atmosphere. Mercury is being liberated from contained contaminated sites into city streets and into the rivers and seas where we catch our fish. If mercury-spreading GM trees catch on in a big way in the US they could double global mercury emissions in less than ten years.

See also GM trees