| MERCURY Mercury, also known as quicksilver, is a naturally toxic element found in air, water, and soil (www.erie.gov). Mercury is one of the most toxic heavy metal pollutants in the environment. Just 1/17 of a teaspoon of atmospheric mercury could contaminate a twenty acre lake (www.usgs.gov). Mercury builds up in the tissues of fish and other creatures living in mercury contaminated water, and may be carried up the food chain to humans (www.encyclopedia.com). |  |
| ARSENIC Arsenic is actually not very toxic when compared to some of the other heavy metals. It is very well known as a key ingredient in rat poison, and with constant exposure, people worry about arsenic affecting the chromosomes of humans and their health. However, very small amounts of arsenic could be good for humans to live and even be able to breathe. Arsenic is found naturally in the earth and even in some foods, including apricot pits and apple seeds. This natural form of arsenic is not very dangerous at all. The inorganic form of arsenic, found in contaminated meats, weed killers, and insecticides, however, creates big problems for people. |  |
 | ALUMINUM For a very long time, aluminum was no problem at all as a pollutant. It was only until recently that people began to worry about the effects of aluminum in our environment. In fact, aluminum isn't really even a heavy metal; because its molecular weight is so low it acts differently than the other heavy metals (www.encyclopeda.com). In the wild, aluminum is found in great amounts in the earth and the ocean. Many scientists think that because it is so abundant in nature, it isn't very toxic. Most people get aluminum into their bodies from food. Aluminum is a protective cover over processed cheese, it is used to whiten flour, and it is added to table salt. Most people will get 40-50mg. of aluminum in their diets a day (www.healthy.net). People may also get aluminum into their bodies from aluminum foil and aluminum pots and pans. |
 | BARIUM Barium, a poisonous metal, is used in glass and pottery glazes. It is also another part of rat poison. In moist air, barium will suddenly set on fire. This a an important reason why Barium is often used in fireworks. While it burns in the air, it forms peroxide, which makes hydrogen peroxide when treated with water (www.encyclopedia.com). Barium reacts with many other nonmetals, all of its water-soluble and acid-soluble compounds are poisonous. |
| ZINC Zinc reacts with some acids to get rid of hydrogen. When zinc is heated to high temperatures, between 110 and 150 degrees Fahrenheit, it becomes limp and flexible. Zinc is used in the negative plates in certain electric batteries and is also used for roofing and gutters in construction (www.encyclopedia.com). |  |
| LEAD Lead was one of the first heavy metals used by people, dating back to 6500 B.C. (www.leadinfo.com). Lead is the most plentiful heavy metal pollutant in our environment, and the most common toxic mineral found in our bodies today. In the twentieth century, lead was often used in paint, pencils and pipes. In the 1920's, lead was added to gas, but it was banned by the EPA in 1995 (www.omp.gso). Lead is still a huge heavy metal problem that is used all the time in today's society. |  |
 | CADMIUM Cadmium is found deep in the earth and didn't affect most early civilizations. It is one of the more toxic heavy metal pollutants, and may come from sources such as cigarette smoke, foods, water pipes, coffee, tea, coal burning, and shellfish. The levels of cadmium are much greater in cities and urban areas than in rural regions (www.epa.gov). |
However, heavy metals aren't the only pollutants contaminating our waters. There are also many other types of pollutants such as DDT, PCB's and dioxins. The last group of pollutants are chlorinated solvents and hydrocarbons.
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