Environmental Toxicology is the study of the effects of chemicals on human health and the environment. By applying the principles of biology and chemistry, toxicologists can study the toxic behavior of man-made and natural chemicals. Using this knowledge, toxicologists can predict where chemicals will end up in the environment and in our bodies, determine what toxic impacts chemicals have and establish exposure limits to keep us and our environment healthy. Toxicologists address constantly-changing concerns about the safety of our environment and natural resources.