Mercury pollution found to be much worse than expected

Science : An analysis of historical records in the scientific literature and government documents has revealed 540 000 tons more mercury pollution since 1850 than previously thought. The amount is two and a half times that of earlier estimates. Hannah Horowitz and her colleagues at Harvard University looked at not just atmospheric pollution but also soil and water pollution. Mercury was once used to extract gold and silver from mined ores, which caused a peak in emissions in the 1890s. Horowitz’s team discovered a second, larger peak in the 1970s. That peak was likely driven by mercury’s use in a wide range of commercial products, such as thermometers and switches, and industrial processes. One major contributor was latex paints, which were very popular in the US in the early 1970s, before mercury’s use as a preservative was banned in 1991. The team estimates that 57% of the mercury released over the last century and a half is still circulating in the environment.