Health physics, biological effects

The objective of an EIA Is to document the potential physical, biological, social and health effects of a planned activity. This will enable decision makers to determine whether an activity is acceptable and if not, identify possible alternatives. Typically, ElA s will be carried out for... 

Molecular structural analysis is a developing method. The objective of a molecuhu structural analysis is to demonstrate a physical, structural, or chemical similarity between tlie chemical in question and a known toxic chemical tliat produces toxic and healtli effects in experimental animals and/or humans. Unfortunately, scientists do not fully understand tlie effects of slight changes in tlie chemical structure and tlieir biological effect on humans. As a result, tills type of analysis is useful in preliminary studies to identify potential health hazards for further e. amination with more established metliods in short-tenii tests or tests in experimental animals, hi its present stage of development, molecular structural analysis caiuiot be used to make absolute decisions about tlie appropriate levels of exposure of humans to chemicals... 

Environmental Impact Assessment (EIA) has evolved as a comprehensive approach to project evaluation, in which environmental factors, as well as economic and technical considerations (e.g. Cost Benefit Analysis), are given appropriate consideration in the decisionmaking process. The purpose of an EIA study is to determine the potential environmental, social and health effects of a proposed development. It attempts to define and assess the physical, biological and socio-economic effects, so that logical and rational decisions are made. The identification of possible alternative sites and/or processes may assist in the reduction of potential adverse impacts. 

Structure-activity relationships (SARs) and quantitative structure-activity relationships (QSARs), referred to collectively as QSARs, can be used for the prediction of physicochemical properties, environmental fate parameters (e.g., accumulation and biodegradation), human health effects, and ecotoxicological effects. A SAR is a (qualitative) association between a chemical substructure and the potential of a chemical containing the substructure to exhibit a certain physical or biological effect. A QS AR is a mathematical model that relates a quantitative measure of chemical structure (e.g., a physicochemical property) to a physical property or to a biological effect (e.g., a toxicological endpoint). 

In order to adequately develop a medical surveillance plan, one must perform a thorough assessment of the physical, biologic, and/or chemical hazards to which personnel may be exposed and which have the potential to cause adverse health effects. For certain chemical substances, medical surveillance is prescribed by law. The standards are set by the Occupational Safety and Health Administration (OSHA). Attention to sensitivity, specificity, and predictive value is particularly important in occupational screening programs. The primary purpose of medical surveillance is the elimination of exposures that cause disease. Medical surveillance s ultimate goal is prevention. 

Since improperly handled radiation may produce deleterious effects to humans, it is important that individuals who use radiation sources learn the fundamentals of dosimetry, definition of dose units, biological effects of radiation, standards for radiation protection, and operation of health physics instruments. This chapter briefly discusses all these items. If more detailed treatment of these topics is needed, consult the bibliography and references given at the end of the chapter. 

Additionally, other health-related variables include age, sex, physical condition, and size (mass). This relationship is referred to as dose/response, or in other words, the amount of the exposure and the resulting biological effect. Each plant or animal species has its own individual response to a given chemical. A substance administered at a dose large enough to be lethal to rabbits may have a lesser effect on rats or dogs. 

Health physics—A scientific field that focuses on protection of humans and the environment from radiation. Health physics uses physics, biology, chemistry, statistics, and electronic instrumentation to help protect individuals from any damaging effects of radiation. 

Nowadays, nano materials have become the most interested topic of materials research and development due to their unique structural properties (unique chemical, biological, and physical properties as compared to larger particles of the same material) that cover their efficient uses in various fields, such as ion exchange and separation, catalysis, bio molecular isolation and purification as well as in chemical sensing [10]. However, the understanding of the potential risks (health and environmental effects) posed by nano materials hasn t increased as rapidly as research has regarding possible applications. 

The unusual physical complaints and findings in workers overexposed to teUurium include somnolence, anorexia, nausea, perspiration, a metallic taste in the mouth and garlic-like odor on the breath (48). The unpleasant odor, attributed to the formation of dimethyl teUuride, has not been associated with any adverse health symptoms. Tellurium compounds and metaboUc products have been identified in exhaled breath, sweat, urine, and feces. Elimination is relatively slow and continuous exposure may result in some accumulation. No definite pathological effects have been observed beyond the physical complaints outlined. Unlike selenium, teUurium has not been proved to be an essential biological trace element. 

The National Institute of Environmental Health Sciences (NIEHS) is the principal federal agency for biomedical research on the effects of chemical, physical, and biologic environmental agents on human health and well-being. ContactNAEiTS, PO Box 12233, 104 T.W. Alexander Drive, Research Triangle Park, NC 27709 Phone 919-541-3212. 

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