occupational disease, illness incurred because of the conditions or environment of employment. Unlike with accidents, some time usually elapses between exposure to the cause and development of symptoms. In some instances, symptoms may not become evident for 20 years or more.

Sources of Occupational Disease

Among the environmental causes of occupational disease are subjection to extremes of temperature (leading to heatstroke or frostbite), unusual dampness (causing diseases of the respiratory tract, skin, or muscles and joints) or changes in atmospheric pressure (causing decompression sickness decompression sickness, physiological disorder caused by a rapid decrease in atmospheric pressure, resulting in the release of nitrogen bubbles into the body tissues. It is also known as caisson disease, altitude sickness, and the bends.
..... Click the link for more information. , or the bends), excessive noise (see noise pollution noise pollution, human-created noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all producing excessive noise. Construction equipment, e.g.
..... Click the link for more information. ), and exposure to infrared or ultraviolet radiation or to radioactive substances. The widespread use of X rays, radium, and materials essential to the production of nuclear power has led to an especial awareness of the dangers of radiation sickness radiation sickness, harmful effect produced on body tissues by exposure to radioactive substances. The biological action of radiation is not fully understood, but it is believed that a disturbance in cellular activity results from the chemical changes caused by
..... Click the link for more information. ; careful checking of equipment and the proper protection of all personnel are now mandatory.

In addition there are hundreds of industries in which metal dusts, chemical substances, and unusual exposure to infective substances constitute occupational hazards. The most common of the dust- and fiber-inspired disorders are the lung diseases caused by silica, beryllium, bauxite, and iron ore to which miners, granite workers, and many others are exposed (see pneumoconiosis pneumoconiosis (n
..... Click the link for more information. ) and those caused by asbestos asbestos, common name for any of a variety of silicate minerals within the amphibole and serpentine groups that are fibrous in structure and more or less resistant to acid and fire. Chrysotile asbestos, a form of serpentine , is the chief commercial asbestos.
..... Click the link for more information. .

Fumes, smoke, and toxic liquids from a great number of chemicals are other occupational dangers. Carbon monoxide, carbon tetrachloride, chlorine, creosote, cyanides, dinitrobenzene, mercury, lead, phosphorus, and nitrous chloride are but a few of the substances that on entering through the skin, respiratory tract, or digestive tract cause serious and often fatal illness.

Occupational hazards also are presented by infective sources. Persons who come into contact with infected animals in a living or deceased state are in danger of acquiring such diseases as anthrax anthrax (ăn`thrăks), acute infectious disease of animals that can be secondarily transmitted to humans.
..... Click the link for more information. and tularemia tularemia (t
..... Click the link for more information. . Doctors, nurses, and other hospital personnel are prime targets for the tuberculosis bacillus and for many other infectious organisms.

Worker Protection

Recognition of the effects of working under deleterious conditions and with harmful substances has resulted in efforts to protect workers from exposure to them. Legislation to prevent or limit the occurrence of occupational disease dates from the Factory Act in England in 1802. Prevention of unhealthy or unsafe working conditions and oversight of healthy and safe workplaces are the responsibility in the United States of the federal Occupational Safety and Health Administration Occupational Safety and Health Administration (OSHA), U.S. agency established (1970) in the Dept. of Labor (see Labor, United States Department of ) to develop and enforce regulations for the safety and health of workers in businesses that are engaged in interstate
..... Click the link for more information. (OSHA) and Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution , noise pollution , and radiation and to ensure the safe handling and
..... Click the link for more information. , as well as many state agencies. Many occupational abuses have been redressed by litigation and legislation in the United States, and workers' compensation workers' compensation, payment by employers for some part of the cost of injuries, or in some cases of occupational diseases, received by employees in the course of their work.
..... Click the link for more information. takes care, by a system of insurance, of those who suffer from occupational diseases.

occupational disease

Illness associated with a particular occupation. The Industrial Revolution's long working hours, dim light, lack of fresh air, and dangerous machinery fostered illness and injury in general, but certain occupations (e.g., mining) carry particular risks (e.g., black lung, a type of pneumoconiosis). Twentieth-century innovations (including use of new chemicals and radioactive materials) caused an increase in certain cancers (e.g., leukemia and bone cancer in workers exposed to radiation) and injuries. So-called “sick buildings” (in which pathogens grow in air circulation systems) contribute to health problems among office workers. Occupational medicine also covers work-related emotional stresses. See also asbestosis; industrial medicine.