| Popis: |
Because several PAHs, among which benzo(a)pyrene (BaP), are considered to be carcinogenic substances, the safety of these products has been questioned. An estimate of external dermal exposure to BaP has been generated by application of a mathematical model. This estimate was the starting point in an assessment of the additional risk on local skin tumours. In this assessment risk estimates were derived for two different contact times and for two different periods of use. In the most optimistic scenario a concentration of about 1000 mug BaP/kg product results in an additional risk on dermal tumours of 1 per 10 exp.6 exposed persons. In the most pessimistic scenario, the same risk level (1 per 10 exp.6) is reached at about 100 mug BaP/kg product. Because of several uncertainties, the risk of the entire mixture of PAHs in coal-tar shampoos cannot be assessed. In order to compensate for these uncertainties, an additional factor of 10 can be applied to the concentrations of BaP which are associated with the accepted levels of additional risk. Thus, in the most optimistic scenario a maximal concentration of 100 mug BaP as indicator for total PAH/kg product would be advisable, while for the most pessimistic scenario a maximal concentration of 10 mug BaP as indicator for total PAH/kg product would be advisable. Therefore, the estimates of concentrations for total PAH in coal-tar shampoos which are associated with the accepted risk level of 1 per 10 exp.6 exposed persons may implicate an underestimation of the risk on systemic tumours. |
