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Does dichlorvos constitute a genotoxic hazard?
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References Korte, A., and G. Obe, The influence of chronic ethanol u p t a k e and acute acetaldehyde t r e a t m e n t on the c h r o m o s o m e s of bone marrow cells and peripheral l y m p h o c y t e s of Chinese hamsters, Mutation Res., 1980, in press. Obe, G., and H. Ristow, Mutagenic, cancerogenic and teratogenic effects of alcohol, Mutation Res., 65 (1979) 229--259. Ohe, G., A.T. Natarajan, M. Meyers and A. DenHertog, I n d u c t i o n of c h r o m o s o m a l aberrations in peripheral l y m p h o e y t e s of h u m a n blood in vitro, and of SCEs in bone-marrow cells of mice in vivo by ethanol and its m e t a b o l i t e acetaldehyde, Mutation Res., 68 (1979) 291--294. Obe, G., D. G~bel, H. Engeln, J. Herha and A.T. Natarajan, C h r o m o s o m a l aberrations in peripheral lymp h o c y t e s of alcoholics, Mutation Res., 1980, in press.
Ramel, C., Wallenberg Laboratory, University of Stockholm, S-106 91 Stockholm {Sweden) Does dichlorvos constitute a genotoxic hazard? Dichlorvos has a worldwide use as an insecticide. It is primarily applied as resin strips, which continuously emit vapour of dichlorvos. This use implies that people are exposed to the same concentrations as the target insects. The extensive exposure of people to dichlorvos has necessitated a rigorous control of long term effects, in particular mutagenic and carcinogenic hazards. The biotransformation proceeds along two pathways, demethylation and esterase catalyzed hydrolysis. The demethylation is predominant in microorganisms and is responsible for mutations induced in bacteria. In mammals hydrolysis is predominant and results in the transient formation of dichloroacetaldehyde, which has been reported as a mutagen in mammals. The evaluation of the possible genotoxic risks of dichlorvos must be based on a thorough knowledge of exposure, biotransformation, mutagenicity and carcinogenicity of dichlorvos. Whether the extensive experimental data on dichlorvos can be considered sufficient to eliminate an unacceptable genotoxic risk must be founded on a quantitative risk estimate. The o u t c o m e of this evaluation will no d o u b t create a precedent for the regulatory handling of genotoxic chemicals in general and may therefore be of great importance.
Thompson, M.H., and M.J. Hill, Central Public Health Laboratory, Colindale Avenue, London, NW9 (U.K.) The role of bacterial metabolism in the gut to human cancer Identification of the active agents associated with the incidence of large bowel cancer (LBC) has y e t to be made, although preformed carcinogens may be excluded. In the case of LBC we have demonstrated that the bacterial and biochemical composition of faeces varies between low and high risk populations, both in an international study and in suitable case controlled studies. In particular those groups more at risk exhibited higher faecal concentrations of
References Korte, A., and G. Obe, The influence of chronic ethanol u p t a k e and acute acetaldehyde t r e a t m e n t on the c h r o m o s o m e s of bone marrow cells and peripheral l y m p h o c y t e s of Chinese hamsters, Mutation Res., 1980, in press. Obe, G., and H. Ristow, Mutagenic, cancerogenic and teratogenic effects of alcohol, Mutation Res., 65 (1979) 229--259. Ohe, G., A.T. Natarajan, M. Meyers and A. DenHertog, I n d u c t i o n of c h r o m o s o m a l aberrations in peripheral l y m p h o e y t e s of h u m a n blood in vitro, and of SCEs in bone-marrow cells of mice in vivo by ethanol and its m e t a b o l i t e acetaldehyde, Mutation Res., 68 (1979) 291--294. Obe, G., D. G~bel, H. Engeln, J. Herha and A.T. Natarajan, C h r o m o s o m a l aberrations in peripheral lymp h o c y t e s of alcoholics, Mutation Res., 1980, in press.
Ramel, C., Wallenberg Laboratory, University of Stockholm, S-106 91 Stockholm {Sweden) Does dichlorvos constitute a genotoxic hazard? Dichlorvos has a worldwide use as an insecticide. It is primarily applied as resin strips, which continuously emit vapour of dichlorvos. This use implies that people are exposed to the same concentrations as the target insects. The extensive exposure of people to dichlorvos has necessitated a rigorous control of long term effects, in particular mutagenic and carcinogenic hazards. The biotransformation proceeds along two pathways, demethylation and esterase catalyzed hydrolysis. The demethylation is predominant in microorganisms and is responsible for mutations induced in bacteria. In mammals hydrolysis is predominant and results in the transient formation of dichloroacetaldehyde, which has been reported as a mutagen in mammals. The evaluation of the possible genotoxic risks of dichlorvos must be based on a thorough knowledge of exposure, biotransformation, mutagenicity and carcinogenicity of dichlorvos. Whether the extensive experimental data on dichlorvos can be considered sufficient to eliminate an unacceptable genotoxic risk must be founded on a quantitative risk estimate. The o u t c o m e of this evaluation will no d o u b t create a precedent for the regulatory handling of genotoxic chemicals in general and may therefore be of great importance.
Thompson, M.H., and M.J. Hill, Central Public Health Laboratory, Colindale Avenue, London, NW9 (U.K.) The role of bacterial metabolism in the gut to human cancer Identification of the active agents associated with the incidence of large bowel cancer (LBC) has y e t to be made, although preformed carcinogens may be excluded. In the case of LBC we have demonstrated that the bacterial and biochemical composition of faeces varies between low and high risk populations, both in an international study and in suitable case controlled studies. In particular those groups more at risk exhibited higher faecal concentrations of