ABSTRACT
In epidemiological studies of the potential adverse health effects associated with chemical compounds in the environment and the workplace, an increased level of sophistication is possible in order to control confounding factors such as gender, ethnic background, education, and age. The lack of information on gender differences sometimes results from the fact that the need to contrast the performance or neurophysiological measures of males to females is just not present in certain male-dominated occupations. When data from epidemiological studies are analyzed separately for males and females, data are said to be “stratified for gender.” A researcher based in a large city of the United States, however, is normally challenged with the task of looking for toxic causation among people who, in cases such as New York, literally represent a sample of all people of the world. Environmental and occupational health investigators continue to strive for good control of possible demographic factors in our search for possible toxic causation.
