Monitoring of human populations at risk by different cytogenetic end points.

Humans are exposed to a large number of environmental genotoxic agents. These can increase the probability that somatic mutation will occur. The use of genotoxicity testing is essential for assessment of potential human toxicity so that hazards can be prevented. Cytogenetic monitoring of human populations exposed to chemicals has proved to be a useful tool for detecting the chemical mutagenic effects. Cytogenetic analysis of human chromosomes in peripheral lymphocytes allows direct detection of mutation in somatic cells. Cytogenetic monitoring of a group of traffic policemen from Cairo, Egypt, was an example of a human population study. The induction of chromosomal damage was studied in a group of 28 traffic policemen with exposure of over 10 years and a control group of 15 policemen trainers. Blood lead level was significantly higher in the traffic policemen (30 +/- 8.7) unit compared to the control group (18.2 +/- 1.2) unit. The percentage of chromosomal aberrations (7.7 +/- 3.1), as well as the mean sister chromatid exchanges (7.5 +/- 3.4), were significantly higher among the traffic policemen than in the control group. The percentage of chromosomal aberrations was 2.8 +/- 2.1 and the mean sister chromatid exchanges was 4.8 +/- 2.9 in the control group. On the other hand, the increase in chromosome damage among the traffic policemen was enhanced further by smoking. Several problems that are found in biomonitoring studies are discussed.