ASSESSMENT OF CYTOGENETIC CHANGES IN HUMAN-POPULATIONS AT RISK IN EGYPT

Humans are exposed to numerous environmental agents that can increase the probability of mutagenicity and carcinogenicity. Most of environme ntal exposures involve concurrent or sequential exposure to several ag ents in air, water, and food. Interactive effects in carcinogenesis ha ve been described for a certain number of combinations of agents. They are described in terms of enhancement or inhibition of carcinogenesis . Risk assessment of exposure to environmental agents can start either from laboratory studies after exposure to different agents or from ep idemiological studies in relation to actual exposure. The use of genot oxicity testing is essential for assessment of potential human toxicit y so that hazards can be prevented. Cytogenetic monitoring of human po pulations exposed to environmental agents has proved to be a useful to ol for detecting their mutagenic effects. Cytogenetic analysis of huma n chromosomes in peripheral lymphocytes allows direct detection of mut ation in somatic cells. Various methods can be used for chromosomal an alysis (conventional chromosomal analysis, sister chromatid exchange, micronucleus frequency detection). Micronucleus frequency can be detec ted either in peripheral blood lymphocytes or in exfoliated cells. Dif ferent examples of human population studies are presented in this revi ew. Several problems which are found in biomonitoring studies are disc ussed.