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Mutagenicity in urine of workers in the naval industry
301 metaphase analysis. The observation revealed that a large fraction of VCH-diepoxide-induced aberrations was preferentially located in the heterochromatic regions of the M chromosome and of 2 S chromosomes. Partially supported by the P.F. 'Controllo della Crescita Neoplastica of CNR'.
132 Rozgaj, R., t). Horvat, J. Ra~i6 and M. Novakovi6, Institute for Medical Research and Occupational Health, 41000 Zagreb (Yugoslavia)
Chromosomal aberrations in persons occupationally exPosed to iridium-192 The industrial application of 7-radiography, one of the test methods without destructions, implies the use of 192Ir, 60Co, 46Sc and other radioisotopes. The people handling radioactive sources are often exposed to ionizing radiation and cases of radiation accidents are not rare (Lloyd, D.C. et al., XI NRPB-R117, Chilton, 1981). Biological consequences of overexposure range from haematological disorders, changes in the capillaries and skin to cytogenetic lesions. In this study structural chromosomal aberrations were analysed in 107 subjects occupationally exposed to 192Ir. The subjects were also under regular film dosimetric control. In 48-h lymphocyte cultures from the peripheral blood 200 metaphases per subject were analysed. In certain subjects, mostly those who had been exposed to radiation for years, a great number of chromosome-type aberrations, such as dicentrics, acentrics and ring chromosomes were found. Due to fractionated radiation doses received at great intervals our results cannot be considered as a reliable biodosimetric estimate and the data obtained by means of physical dosimeters were not always in reasonable agreement with the chromosome data.
133 Rueff, J., A. Laires, M. Gomes, H. Borba and M. Halpern, Faculty of Medical Sciences, Campo de Santana, 130, P-1198 Lisbon Codex (Portugal)
Mutagenicity in urine of workers in the naval industry The demonstration that human cancer can be caused by exogenous factors led to a tendency to concentrate on discrete compounds as being directly implicated in the etiology of certain cancers. The real situation, however, seems rather to be the result of complex interactions between multiple environmental and host factors. This fact
302 raises the question of whether the finding of mutagenicity in body fluids may per se indicate hazardous exposure since data linking levels of body mutagens to cancer risk are still scarce. Our study was aimed to obtain additional information on that question. Mutagenicity in the urine of 17 men occupationally exposed to mineral oils and ferric-oxide particles and 16 age-matched men only exposed to mineral oils was investigated using the Ames assay. Both groups included smokers and non-smokers. Urine samples were collected after an 8-h workday, concentrated and tested following published procedures (Ames, B. et al., Mutation Res., 31 (1975) 347; Yamasaki, E. and Ames, B., Proc. Natl. Acad. Sci. (U.S.A.), 74 (1977) 3555). Mutagenic activity was significantly higher ( P = 0.002) in the first group, the difference being more pronounced than that between smokers and non-smokers ( P = 0.006). Smoking tends to act synergistically with mineral oils plus ferric-oxide particles exposure ( P = 0.05). Our results are in good agreement with experimental data on the enhancing effect of carcinogen-cartier particles in tumor yield (Henry, M. et al., Cancer Res., 35 (1975) 207) and along with other studies on the same question (Falck, K. et al., Mutation Res., 79 (1980) 45) seem to support the view that such type of approach may be taken as an index of hazardous exposure.
134 Salminen, S., and P. Kivel~-Ikonen, National Board of Health, P.O. Box 223, 00531 Helsinki 53 (Finland) The toxicity of benomyl - - regulatory actions in Finland
As a result of joint Scandinavian re-evaluation of the safety of pesticides the Finnish National Board of Health/Toxicology Expert Group prepared a summary report on the toxicity of benomyl, based on the available documentation. The expert group stated that benomyl and carbendazim, a metabolic product of benomyl, should be considered mutagenic. The carcinogenicity of benomyl and carbendazim as inducers of hepatocellular tumors in mice had been ascertained in repeated chronic studies. Benomyl had also been found to be fetotoxic and teratogenic in rats and mice when administered via gastric gavage. Based on the summary report indicating that benomyl poses a potential risk of mutagenicity, carcinogenicity and teratogenicity the National Board of Health decided that the use of benomyl should be restricted to special purposes only to accomplish significant risk reduction. Therefore, it was recommended that the use of benomyl as a food additive should be canceled and no agricultural uses resulting in benomyl residues in foods should be allowed. The residue tolerance in imported fruits and vegetables was recommended to be decreased from 2.0 to 0.2 mg/kg. Also handling requirements and required clothing were to be reconsidered.
132 Rozgaj, R., t). Horvat, J. Ra~i6 and M. Novakovi6, Institute for Medical Research and Occupational Health, 41000 Zagreb (Yugoslavia)
Chromosomal aberrations in persons occupationally exPosed to iridium-192 The industrial application of 7-radiography, one of the test methods without destructions, implies the use of 192Ir, 60Co, 46Sc and other radioisotopes. The people handling radioactive sources are often exposed to ionizing radiation and cases of radiation accidents are not rare (Lloyd, D.C. et al., XI NRPB-R117, Chilton, 1981). Biological consequences of overexposure range from haematological disorders, changes in the capillaries and skin to cytogenetic lesions. In this study structural chromosomal aberrations were analysed in 107 subjects occupationally exposed to 192Ir. The subjects were also under regular film dosimetric control. In 48-h lymphocyte cultures from the peripheral blood 200 metaphases per subject were analysed. In certain subjects, mostly those who had been exposed to radiation for years, a great number of chromosome-type aberrations, such as dicentrics, acentrics and ring chromosomes were found. Due to fractionated radiation doses received at great intervals our results cannot be considered as a reliable biodosimetric estimate and the data obtained by means of physical dosimeters were not always in reasonable agreement with the chromosome data.
133 Rueff, J., A. Laires, M. Gomes, H. Borba and M. Halpern, Faculty of Medical Sciences, Campo de Santana, 130, P-1198 Lisbon Codex (Portugal)
Mutagenicity in urine of workers in the naval industry The demonstration that human cancer can be caused by exogenous factors led to a tendency to concentrate on discrete compounds as being directly implicated in the etiology of certain cancers. The real situation, however, seems rather to be the result of complex interactions between multiple environmental and host factors. This fact
302 raises the question of whether the finding of mutagenicity in body fluids may per se indicate hazardous exposure since data linking levels of body mutagens to cancer risk are still scarce. Our study was aimed to obtain additional information on that question. Mutagenicity in the urine of 17 men occupationally exposed to mineral oils and ferric-oxide particles and 16 age-matched men only exposed to mineral oils was investigated using the Ames assay. Both groups included smokers and non-smokers. Urine samples were collected after an 8-h workday, concentrated and tested following published procedures (Ames, B. et al., Mutation Res., 31 (1975) 347; Yamasaki, E. and Ames, B., Proc. Natl. Acad. Sci. (U.S.A.), 74 (1977) 3555). Mutagenic activity was significantly higher ( P = 0.002) in the first group, the difference being more pronounced than that between smokers and non-smokers ( P = 0.006). Smoking tends to act synergistically with mineral oils plus ferric-oxide particles exposure ( P = 0.05). Our results are in good agreement with experimental data on the enhancing effect of carcinogen-cartier particles in tumor yield (Henry, M. et al., Cancer Res., 35 (1975) 207) and along with other studies on the same question (Falck, K. et al., Mutation Res., 79 (1980) 45) seem to support the view that such type of approach may be taken as an index of hazardous exposure.
134 Salminen, S., and P. Kivel~-Ikonen, National Board of Health, P.O. Box 223, 00531 Helsinki 53 (Finland) The toxicity of benomyl - - regulatory actions in Finland
As a result of joint Scandinavian re-evaluation of the safety of pesticides the Finnish National Board of Health/Toxicology Expert Group prepared a summary report on the toxicity of benomyl, based on the available documentation. The expert group stated that benomyl and carbendazim, a metabolic product of benomyl, should be considered mutagenic. The carcinogenicity of benomyl and carbendazim as inducers of hepatocellular tumors in mice had been ascertained in repeated chronic studies. Benomyl had also been found to be fetotoxic and teratogenic in rats and mice when administered via gastric gavage. Based on the summary report indicating that benomyl poses a potential risk of mutagenicity, carcinogenicity and teratogenicity the National Board of Health decided that the use of benomyl should be restricted to special purposes only to accomplish significant risk reduction. Therefore, it was recommended that the use of benomyl as a food additive should be canceled and no agricultural uses resulting in benomyl residues in foods should be allowed. The residue tolerance in imported fruits and vegetables was recommended to be decreased from 2.0 to 0.2 mg/kg. Also handling requirements and required clothing were to be reconsidered.