|By France-biotech, CC-BY-SA-3.0. SOURCE.|
The field involves chemistry, biology, pathology, pharmacology, physiology, medicine, and many other fields, and is divided into observational studies (effects of substances), mechanistic studies (explaining how the effects occur), risk assessment (the probability that exposure will cause adverse effects), regulatory toxicology (whether there's too much risk in allowing people to be exposed to a substance), clinical toxicology (tries to determine whether effects are caused by a certain chemical), and forensic toxicology (evaluation and testimony in legal situations).
There are three types of toxic substances: toxicants (anything that causes adverse biological effects), toxins (proteins created by living organisms that have immediate effects), and poisons (toxicants that cause death or illness in a short amount of time). Toxic substances can be systemic (they affect multiple organs) or limited to certain sites. Xenobiotics are substances that enter the body (from the Greek word xeno, or "foreigner").
There are four kinds of reactions: additivity reactions (two or more chemicals have the same affect as they would individually, just simultaneously), antagonism (one chemical reduces the effect of another), potentiation (a chemical causes another to become more toxic), and synergism (two chemicals multiply each other and create a greater response). Toxicokinetics is the movement of a chemical through the body, and toxicodynamics is how it interacts with the body it's in.
|An example of a DNA adduct, by TimVickers. |
Public domain image. SOURCE.
William Baird is a professor at the EMT and Biochemistry and Biophysics Department at Oregon State University, who received a Ph.D. from the McArdle Laboratory of Cancer Research. His research group focuses on how different chemicals can cause cancer, including the environmental pollutants polycyclic aromatic hydrocarbons (PAH). The research also includes how enzymes activate and detoxify PAH, how PAH binds to DNA (forming "adducts", or DNA bound to a carcinogen) and how the structure of chromatin (proteins and DNA in the nucleus of the cell) and DNA sequence affect how adducts form.
Emily Monosson (Contributing Author); NLM (Content Source); Sidney Draggan (Topic Editor) "Toxicology". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth November 4, 2006; Last revised Date September 16, 2011; Retrieved March 29, 2012
Do you think people will ever figure out how to manufacture things with fewer toxins?
-----The Golden Eagle