Epidemiology—A Tool for Studying Environmental Influences on Children’s Health

Epidemiology has made important contributions to understanding the role of environmental factors in children’s health. Epidemiology has provided information on the health effects of all the major environmental influences on children’s health: toxic chemicals, the intrauterine environment, and social, economic, and behavioral influences. Epidemiology has studied the consequences for children’s health of major disasters such as the Dutch famine of 1944, the atomic bombings in Hiroshima and Nagasaki, the Minamata episode in Japan, the Chernobyl radiation disaster in Ukraine, and the attacks on the World Trade Center in New York City. Most of the data about changing patterns of diseases in children and most of the evidence for environmental influences on children’s health are based on epidemiological studies. This chapter reviews the major epidemiological study designs and describes three principal forms of systematic error (confounding bias, selection bias, and information bias) that need to be considered in all epidemiological studies.