Behavioral toxicological disorders
During the 20th century we saw the growth, if not the beginnings in all cases, of a number of neurobehavioral disorders associated with mainly manufactured chemicals introduced to the environment. These chemicals, and in some instances microscopic organisms, were introduced in at least two ways: through the food chain and in the air. At their worst, these materials are described as environmental hazards, some of them remaining controversial, while more defi nitive evidence is available for the harmful effects of others. A simple example of more defi nitive evidence led to the banning of aerosol deodorant sprays, which contained harmful hydrocarbons. More controversial phenomena are “passive smoking” and “global warming”, both of which are associated with dramatic polarization of advocates on both sides of the issues surrounding these matters.