Chemical Pollution

Rikki Gassman and Katie Clark

PCBs, Pesticides, Mercury, & Other Heavy Metals

Where does mercury come from that's in the environment?

Mercury enters the environment and as a result of a normal breakdown (rocks and soil) through the exposure of wind and water. Mercury is released from natural resources and has remained constant over the years. Mercury concentrations in the environment are increasing is caused by human impact.

What are the effects of mercury (methyl mercury) on living things (especially humans)?

  1. Disruption of the nervous system

  2. Damage to brain functions

  3. DNA damage and chromosomal damage

  4. Allergic reactions, resulting in skin rashes, tiredness and headaches

  5. Negative reproductive effects, such as sperm damage, birth defects and miscarriages

What is biomagnification and how does it apply to mercury? Give a historic example.

This occurs when the concentration of a substance in an organism exceeds the background concentration of the substance in its diet. A study of eagles show that the amount of DDT increases as it moves up the food chain.

What has been/can be done to regulate the amount of mercury in the environment?

To regulate the amount of mercury in the environment, scientists have created reverse osmosis. Water is propelled through a semipermeable membrane during reverse osmosis. A Common membrane material is a polyamide film. This produces high quality water, but is fairly expensive.