Mercury going to ground

Matt Charette and colleagues at Woods Hole Oceanographic Institution (WHOI) have discovered a significant pollution route for total mercury flowing from groundwater into coastal waters. Mercury is most toxic as methyl mercury rather than its elemental form and the next step will be to quantify the impact of total mercury in the marine environment. Mercury pollution originates from industrial emissions, which ultimately precipitate as rain or snow on to land or directly into the oceans. Inland deposits of mercury are also weathered and carried to the coast in runoff from streams and rivers, where they accumulate in the sediments that build up along the shoreline. "This pathway for delivering nutrients and contaminants into the ocean has long been overlooked and ignored because it was difficult to quantify," explains Charette, "This study is a first of its kind for quantifying the amount of mercury flowing out of the system."