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 (typically rats or other surrogates when the test concerns human toxicity).
The United States Environmental Protection 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.
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.
- Toxic Release Inventory – tracks how much waste companies release into the water and air. Gives permits for releasing specific quantities of these pollutants each year.
- Superfund – manages Superfund sites and the pollutants in them (CERCLA).
- OSHA limits for air contaminants
- Agency for Toxic Substances and Disease Registry – found out top 20 pollutants, alias for chemicals, how they affect people, what industries use them and what products they are found in.
- National Toxicology Program – from National Institutes of Health. Reports and studies on how pollutants affect people.
- Toxnet – more databases and reports on toxicology.