Mercury

The article "Our Preferred Poison" in the March 2005 issue of Discover magazine brings up the issue dealing with mercury poisoning. The author, Karen Wright, writes, "Mercury is unimaginably toxic and dangerous. A single drop on a human hand can be irreversibly fatal. A single drop in a large lake can make all the fish in it unsafe to eat." This was the opening statement in the article which first grabbed my attention, because I had not thought mercury to be such a deadly substance. After all, it is used in thermometers, so I hadn't thought it to be as fatally toxic as Wright claims it to be.

The people with the most risk of damage by mercury are unborn fetuses and children. Studies seem to show that the metal has the most negative effect on the developing brain, opposed to the mature adult brain. Some scientists speculate mercury could be the cause of autism, mental retardation, cerebral palsy, and Parkinson's disease, amongst others. I don't know how accurate or credible these studies are though. Throughout the article Wright states that no one is sure how little mercury can be ingested before the human body shows signs of poisoning. What scientists do know is the amount of mercury the human body cannot ingest. They found this out due to accidental ingestions of various people throughout the world.

The article mainly focuses on two types of mercury: methylmercury, which is found in most of the fish, and other seafood's we eat, and alloys, called amalgams, which are commonly used with silver to fill in the holes in our teeth.

Methylmercury seems to be the main source of the amount of mercury in our blood. The article describes briefly how the mercury ends up in the fish we eat, how the rain grabs the mercury from the atmosphere and deposits it into the lakes and oceans. Because of the food chain, the largest of the aquatic animals will have the highest amount of mercury, whales and sharks for example. So, communities high in whale