The result of exposure to substances (such as radiation) that cause any harm to a person's health. It includes diseases, cancers, birth defects, genetic effects and death.

a biological effect that produces a consequence which is outside the body's normal range of physiological compensation and is thus detrimental to the health or wellbeing of the person

a biological effect which may endanger the normal working of an organism in that it goes beyond the framework of the 'physiological' responses to the action of the external agent

ATSDR deals only with Adverse Health Effects (see definition in this Glossary).

Health effects, health impacts or health risks are changes in health resulting from exposure to a source. Health effects are an important consideration in many areas, such as hygiene, pollution studies, workplace safety, nutrition and health sciences in general. Some of the major environmental sources of health effects are air pollution, water pollution, soil contamination, noise pollution and over-illumination.