Mercury pollution, still spreading
Humans have known about mercury’s toxicity since ancient times, when work in mines that extracted cinnabar — the blood-red, mercury-containing ore — was considered a death sentence. Though powdered cinnabar was commonly used as a paint pigment, its toxic properties were also used to advantage. The powder was sprinkled in tombs of ancient rulers to preserve their remains and was used in ancient India to preserve scarves. Today, scientists know much more about mercury than the ancients did. Its relentless travels in the environment have been traced from industrial sources to sediments and through the food web as it has grown increasingly concentrated, passing from prey to predator to larger predator. The dangers of mercury poisoning have been highlighted in several prominent cases, such as that in Minamata, Japan, where thousands of members of the local fishing community were debilitated by decades of industrial releases into nearby waters. Mercury interferes with the central...