Toxicology of Industrial Compounds

correlation between white blood cell DNA adducts and micronuclei and it
was stronger among the GST-individuals (Ichiba et al., 1994).
How important is the role of metabolic phenotype or genotype as a
predictor of cancer risk remains to be established. However it would seem
prudent to assume some role as long as there is significant exposure to a
carcinogen, metabolism of which is regulated by polymorphic genes. It
would be important to note that the question can only be addressed if both
of these conditions are met. In much of the published literature there are
uncertainties regarding the active agents and their metabolic routes in the
tissues studied. Adjustment for a metabolic phenotype or genotype, when
justified, may increase the precision in the measurement.
Risk assessment
K.HEMMINKI 163
Figure 12.3 Total white blood cell DNA adducts, measured by postlabelling,
according to CYP1A1 and GST1 genotype (Ichiba et al., 1994). Controls,
Sweeps.
Monitoring of DNA adducts in occupational setting has mainly been
applied to workers exposed to PAHs. In the case of 32 P-postlabelling
increases in the level of adducts has been noted at exposures around 10 ng
BP m −3 or slightly below. This is close to the detection limit that can
conveniently be attained with personal monitoring or by measuring urinary
1-hydroxypyrene. As the adduct measurements also reflect some aspects of
metabolism and DNA repair, they extend the scope of exposure