Environmental medicine can be viewed as an extension of modern biomedicine. Environmental medicine traces its roots to the practice of allergy treatment and the work of Dr. Theron Randolph in the 1940s, who identified a variety of common foods and chemicals that were able to trigger the onset of acute and chronic illness even when exposure was at relatively low levels.

Environmental medicine recognizes that illness in individuals can be caused by a broad range of substances, including foods, chemicals found at home and in the workplace, and chemicals in the air, water, and food. Today there are 3,000 physicians worldwide practicing environmental medicine, and there are several environmental control units in the United States and one in Canada, where patients’ sensitivities are unmasked through fasting and complete avoidance of chemicals that might incite a reaction.

Research in this field has been directed at clinical treatment of patients and at evaluation of the diagnostic and treatment techniques used by practitioners. Other studies have supported the use of the approaches of environmental medicine in treating arthritis, asthma, chemical sensitivity, colitis, depression, eczema, fatigue, and hyperactivity.