Mercury Pollution Threat

Mercury pollution can be a serious health threat

Mercury is emitted to the air by power plants, cement plants, certain chemical manufacturers and other industrial facilities. Also it has been used in household items for example a light bulb or glass thermometer, these products release mercury especially when being disposed. 
Mercury pollution released into the environment becomes a serious threat because it gets into the waters and then into the fish we eat.

Mercury in Fish

Once mercury enters the water, naturally bacteria will absorb it and convert it to a form called methyl mercury. Mercury then works its way up the food chain as large fish consume contaminated smaller fish. Instead of dissolving or breaking down, mercury accumulates at ever-increasing levels.

For more reading on this subject:
 http://www.nrdc.org/health/effects/mercury/effects.asp
 http://www.hrw.org/dangers-of-mercury