For environmental agents

Kimmel CA, Kimmel GL, Euling SY (2006) Developmental and reproductive toxicity risk assessment for environmental agents. In Hood RD (ed) Developmental and reproductive toxicology, a practical approach. CRC Press, Boca Raton, FL... 

The availability of radioimmunoassay (RIA) procedures for environmental agents holds some promise in minimizing the need for the more sophisticated and expensive instrumental methods of analysis by eliminating negative samples and for routine monitoring of exposure in environments known to be contaminated by certain classes of compounds. There are a number of fundamental problems involved in development of such RIA procedures and in their use (Table 3). Double-antibody RIA s have been developed (29) for quantitating a number of chlorinated aromatic hydrocarbons of current concern from environmental samples including animal tissues. These chlorinated hydrocarbons include members of the dibenzo-p -dioxin, dibenzofuran, and biphenyl classes of compounds. The use of RIA procedures for trace residue analysis is discussed further in another paper in this conference. 

Total frequencies of environmental illness are difficult to measure. When causes can be identified, however, scientists observe that frequencies of occurrence of a particular illness vary directly with the severity and extent of exposure. Particularly frequent in the workplace are skin lesions from many different causes and pulmonary diseases related to the inhalation of various dusts, such as coal dust (black lung), cotton dust (brown lung), asbestos fibers (asbestosis), and silica dust (silicosis). Environmental agents can also cause biological effects without overt clinical illness (for example, chromosome damage from irradiation). 

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. 

The process for assessing environmental health risks Is complex Information regarding 1) the environmental agent, 2) the pathways by which exposure occurs, and 3) the biologic effects observed after exposure must be assembled and simultaneously evaluated Incomplete knowledge or Inadequate methodology In any of these three areas can severely Inhibit accurate or useful estimates of health risk ... 

Even though exposure to environmental agents such as agricultural chemicals, pesticides, and radiation has been associated with leukemia, none of these agents is linked conclusively with the development of leukemia. An increased frequency of ALL is associated with higher socioeconomic status. It is postulated that less social contact in early infancy and thus a late exposure to some common infectious agents may have some impact.7 In most individual instances, there is no reasonable or obvious explanation for the development of leukemia. 

Synthetic polymers are best known for their insulating dielectric properties which have been exploited for numerous applications in both the electrical and electronic industries. It was found recently that some polymers can also be rendered conductive by an appropriate treatment, thus opening the way to a new field of applications of these materials (2, 3). Usually, electrical conductivity is obtained by doping a neutral polymer, rich in unsaturation, with donor or acceptor molecules. These polymers are rather difficult to synthesize, which makes them very expensive besides they are often sensitive to environmental agents, like oxygen or humidity, thus restricting their practical use to oxygen-free systems. 

No specific biologic marker/test is available for pulmonary agents as a class however, exposure to bromine might be indicated by detection of elevated bromide levels in serum (reference level is 50-100 mg/L), or if chlorine or bromine is released and they are detected in environmental samples. The case can be confirmed if laboratory testing is not performed because either a predominant amount of clinical and nonspecific laboratory evidence is present or an absolute certainty of the etiology of the agent is known. 

Indoor and outdoor exposure to many chemical substances (formaldehyde, asbestos, PVC, many metals, like Cr, As, Be, Ti, V, pesticides and nitrosoamines) can also spur the development of cancer. Here we can only state that the International Agency for Research of cancer has identified 60 environmental agents that can aggravate cancer for humans during exposure to polluted urban air (Misch, 1994). 

Inclusion in drinking water is rarely used for oral administration of human drugs to test animals, though it sees more frequent use for the study of environmental agents. 

Strictly, natural exposure can be carried out for any of the environmental agents. For example, if the product is to spend its life in water at 70 °C then exposure to water at 70 °C can be considered natural ageing. Exposure to water at 80 °C could be called natural ageing at worst possible conditions or with a safety factor. Natural exposure defined in this way is carried out by adapting the standard laboratory methods for air ageing and exposure to liquids as there are no specific natural exposure standards. 

Oswald EO, Albro PW, McKinney JD. 1974. Utilization of gas-liquid chromatography coupled with chemical ionization and electron impact mass spectrometry for the investigation of potentially hazardous environmental agents and their metabolites. J Chromatogr 98(2) 363-448. 

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