Environmental disease
In epidemiology, environmental diseases are diseases that can be directly attributed to environmental factors (as distinct from genetic factors or infection). Apart from the true monogenic genetic disorders, environmental diseases may determine the development of disease in those genetically predisposed to a particular condition. Stress, physical and mental abuse, diet, exposure to toxins, pathogens, radiation, and chemicals found in almost all personal care products and household cleaners are possible causes of a large segment of non-hereditary disease. If a disease process is concluded to be the result of a combination of genetic and environmental factor influences, its etiological origin can be referred to as having a multifactorial pattern.
There are many different types of environmental disease including:[1]
- Lifestyle disease such as cardiovascular disease, diseases caused by substance abuse such as alcoholism, and smoking-related disease
- Disease caused by physical factors in the environment, such as skin cancer caused by excessive exposure to ultraviolet radiation in sunlight
- Disease caused by exposure to chemicals in the environment such as toxic metals
Categories of environmental disease
- First, there are those caused by the ancient metals : lead and mercury.
- Then there are those caused by the other metals: arsenic, phosphorus, and zinc.
- The newer metals can also cause environmental disease: beryllium, cadmium, chromium, manganese, nickel, cobalt, osmium, platinum, selenium, tellurium, thallium, used by common anions found in natural drinking water. Fluoride is one of the most common found in drier climates where the geology favors release of fluoride ions to soil as the rocks decompose. In Sri Lanka, 90% of the country is underlain by crystalline metamorphic rocks of which most carry mica as a major mineral. Mica carries fluoride in their structure and releases to soil when decomposes. In the dry and arid climates, fluoride concentrates on top soil and slowly dissolves in shallow groundwater. This has been the cause of high fluoride levels in drinking water where the majority of the rural Sri Lankans obtain their drinking water from backyard wells. High fluoride in drinking water has caused very high incidence of fluorosis among dry zone population in Sri Lanka. However, in the wet zone, high rainfall effectively removes fluoride from soils where no fluorosis is evident.
The iodine deficiency has also been noted in some parts of Sri Lanka which has been identified as a result of iodine fixation by hydrated iron oxide found in lateritic soils in wet coastal lowlands.
- Additionally, there are environmental diseases caused by the aromatic carbon compounds including : benzene, hexachlorocyclohexane, toluene diisocyanate, phenol, pentachlorophenol, quinone and hydroquinone.
Also included are the aromatic nitro-, amino-, and pyridilium-deratives: nitrobenzene, dinitrobenzene, trinitrotoluene, paramethylaminophenol sulfate (Metol), dinitro-ortho-cresol, aniline, trinitrophenylmethylnitramine (tetryl), hexanitrodiphenylamine (aurantia), phenylenediamine, and paraquat.
The aliphatic carbon compounds can also cause environmental disease. Included in these are methanol, nitroglycerine, nitrocellulose, dimethylnitrosamine, and the halogenated hydrocarbons: methyl chloride, methyl bromide, trichloroethylene, carbon tetrachloride, and the chlorinated naphthalenes. Also included are glycols: ethylene chlorhydrin and diethylene dioxide as well as carbon disulfide, acrylonitrile, acrylamide, and vinyl chloride. - Other important chemical causes of environmental diseases are the noxious gases which can be categorized as : Simple asphxiants, chemical asphyxiants, and irritant gases. The simple asphixiants are nitrogen, methane, and carbon dioxide.
The chemical asphyxiants are carbon monoxide, sulfuretted hydrogen and hydrogen cyanide.
The irritant gases are sulfur dioxide, ammonia, nitrogen dioxide, chlorine, phosgene, and fluorine and its compounds, which include luroine and hydrofluoric acid, fluorspar, fluorapatite, cryolite, and organic fluorine compounds.
The U.S. Coast Guard has developed a Coast Guard-wide comprehensive system for surveillance of workplace diseases.
The American Medical Association's fifth edition of the Current Medical Information and Terminology (CMIT) was used as a reference to expand the basic list of 50 Sentinel Health Events (Occupational) [SHE(O)] published by the National Institute of Occupational Health and Safety (NIOSH), September, 1983.
The expanded list of 107 sentinel events serves as a framework for the development of a computerized system of occupational health surveillance in the U.S. Coast Guard. This application of SHE(O) surveillance can have application in the early detection and prevention of environmental diseases.
See also
References
The Diseases of Occupations, Sixth Edition, Donald Hunter, C.B.E., D.Sc., M.D., F.R.C.P., Hodder and Stoughton, London. ISBN 0-340-22084-8, 1978. Aviat Space Environ Med. 1991 Aug;62(8):795-7.
- Use of sentinel health events (occupational) in computer assisted occupational health surveillance. Stockwell JR, Adess ML, Titlow TB, Zaharias GR. U.S. Coast Guard Office of Health Services, Washington, D.C.