Toxicology

Toxicology is the study of how external agents (biological, chemical, physical) affect living things, especially people. Harmful chemical agents are usually known as toxins or poisons.

There exist several different types of pollution: air pollution, water pollution, even land and noise pollution. This article will concentrate on air, water and land pollution. Some sources of serious pollution are: chemical plants, oil refineries, nuclear waste dumps, regular garbage dumps (many toxic substances are illegally dumped there), incinerators, PVC factories, corporate animal farms creating huge amounts of animal waste. Some of the more common contaminants are: lead (like in lead paint), chromium, zinc, arsenic, benzene.

The term LD50 refers to the dose of a toxic substance that kills 50 percent of a test population.

The United States Environmental Protetection Agency[?] was supposed to establish "acceptable" levels of exposure to contaminants. One of the ratings chemicals are given are carcinogenicity, or how likely they are to cause cancer. Levels range from, not carcinogenic, likely carcinogen, known carcinogen, and unknown. But scientists are finding out that most of these levels are far too high and people should be exposed less to them. The CalEPA Office of Environmental Health Hazard Assessment has a list of more reasonable levels. (OEHHA (http://www.oehha.ca.gov/prop65/prop65_list/Newlist))

Pollutants are thought to play a part in a variety of maladies, including: cancer, lupus, immune diseases, allergies, asthma.

The US has many departments responsible for tracking various pollutants.

1. Toxic Release Inventory (http://www.scorecard.org/chemical-groups/one-list.tcl?short_list_name=tri00ry) - tracks how much waste companies release into the water and air. Gives permits for releasing specific quantities of these pollutants each year.
2. Superfund (http://www.scorecard.org/chemical-groups/one-list.tcl?short_list_name=hs) - manages Superfund sites and the pollutants in them (CERCLA).
3. OSHA limits for air contaminants (http://www.osha-slc.gov/SLTC/pel/index)
4. Agency for Toxic Substances and Disease Registry (http://atsdr1.atsdr.cdc.gov:8080/atsdrhome) - found out top 20 pollutants, alias for chemicals, how they affect people, what industries use them and what products they are found in.
5. National Toxicology Program (http://ntp-server.niehs.nih.gov/) - from National Institutes of Health. Reports and studies on how pollutants affect people.
6. Toxnet (http://toxnet.nlm.nih.gov/) - more databases and reports on toxicology. From NIH

Related topics

• in vitro toxicology[?]

Additional Resources

1. Scorecard.org (http://www.scorecard.org) - lots of info about pollution in your area, just enter your zip code. Colored maps also show how bad certain types of pollution are in your area.
2. Environmental Protection Agency (http://www.epa.gov)
3. OEHHA (http://www.oehha.ca.gov/prop65/prop65_list/Newlist)
4. National Toxic Mold Coalition and Foundation (http://ntmc0.tripod.com)
5. Environmental Defense Fund (http://www.edf.org)
6. Rachel's Environment and Health News (http://www.rachel.org) - Weekly news about how the polluted environment affects people, and what corporations and governments are doing (or not doing) about it. Also in Spanish.
7. Essential.org (http://www.essential.org) - Some organizations related to consumers and consumer protection, including pollution.
8. CleanUp GE.org (http://www.cleanupge.org) - Info about GE's shady dumping practices on the Hudson river.
9. Extoxnet newsletters (http://ace.orst.edu/info/extoxnet/newsletters/ghindex) - environmental pollution news. Last update 1998.
10. Environmental News Network (http://www.enn.com/) - more news
11. Environmental Working Group (http://www.ewg.org/)
12. Sewage Sludge (http://www.ejnet.org/sludge/) - in the U.S. it is perfectly legal to fertilize food crops with solids from the sewer, which include lots of heavy metals and toxins.
13. Yahoo - Toxicology (http://dir.yahoo.com/Health/medicine/toxicology/) - another great starting point.
14. The ToxTutor from the National Library of Medicine (http://sis.nlm.nih.gov/Tox/ToxTutor) - An excellent resource to review human toxicology.