Mercury

Like lead, mercury is a heavy metal that can have serious health effects. It is an inorganic contaminant that may get into water supplies via natural deposits or through crop run-off or may seep into water supplies near spills and toxic waste sites that are contaminated with mercury. Once mercury has entered the body, it may be months before all of it leaves. At lower levels, Mercury can cause kidney and nervous system disorders. Long-term exposure can permanently damage the brain, kidneys, and developing fetuses. According to the Hall Water Report, "Pressure is building for EPA to release an overdue report on mercury that suggests the metal is more potent and widespread as a public health threat than previously believed, estimating that 85,000 American women are being exposed to mercury at levels high enough to affect the brain development of unborn children."