Biological Effect Monitoring

Monitoring activities have an important role in occupational and environmental practice. Techniques to detect and to control chemical exposure in order to protect people from environmental and occupational illness are rapidly expanding. Most obvious are the methods related to the evaluation of the presence of xenobiotic chemical agents either in the contaminated environment or in the exposed organism. In the first case the procedures are indicated as environmental monitoring (EM). In inhalatory exposure, estimations can be made of the ‘intake’ or ‘external load’ on the basis of known concentrations in the ambient air. The actual ‘uptake’ or ‘internal load’, however, can only be approximated by means of EM methods. On the other hand, measurement of the chemical agents and/or their metabolites in tissues, secreta or excreta of the exposed organism provides an estimate of the total uptake. The latter approach has been defined biological monitoring (BM) (Berlin 1984). In addition to these methods many other preventive activities have been developed, including periodic medico-physiological examinations of the exposed people. This apparoach is more directly related to the detection of early health effects, and is defined as health surveillance monitoring (HS). Changes in physiological functions of the organism can be indicative of changes in the state of health as a consequence of a certain chemical exposure. Such information on the state of health or early impairment of health is very useful in the prevention of overt intoxications due to continuation of overexposures. Well-known examples in this area are the increased levels of serum transaminases providing information on hepatotoxic effects, e.g. after exposure to certain halogenated alkanes.