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The elimination of beta-hexachlorocyclohexane (beta-HCH) in humans was investigated in a group of 40 former workers of a lindane-producing plant by analyzing at least 2 blood specimens (3 specimens in 3 workers) from different time points. Assuming a first-order kinetic model for excretion, the median half-life of beta-HCH is 7.2 yr calculated by concentrations in whole blood and 7.6 yr calculated by concentrations in extractable lipids. In univariate analyses an influence of age, percent body fat, and liver disease (additionally in whole blood an influence of contents of extractable lipids) on clearance was observed. All factors show a positive correlation with half-life. According to a multiple regression model, influence of percent body fat calculated according to Deurenberg et al. (1991) is an important covariate in the description of the variations of the clearance rate (calculated on the basis of extractable lipids) of beta-HCH. The data support the assumption of first-order kinetics.

Epidemiologic evidence on the relationship between chemical pesticides and cancer is reviewed. In animal studies, many pesticides are carcinogenic, (e.g., organochlorines, creosote, and sulfallate) while others (notably, the organochlorines DDT, chlordane, and lindane) are tumor promoters. Some contaminants in commercial pesticide formulations also may pose a carcinogenic risk. In humans, arsenic compounds and insecticides used occupationally have been classified as carcinogens by the International Agency for Research on Cancer. Human data, however, are limited by the small number of studies that evaluate individual pesticides. Epidemiologic studies, although sometimes contradictory, have linked phenoxy acid herbicides or contaminants in them with soft tissue sarcoma (STS) and malignant lymphoma; organochlorine insecticides are linked with STS, non-Hodgkin's lymphoma (NHL), leukemia, and, less consistently, with cancers of the lung and breast; organophosphorous compounds are linked with NHL and leukemia; and triazine herbicides with ovarian cancer. Few, if any, of these associations can be considered established and causal. Hence, further epidemiologic studies are needed with detailed exposure assessment for individual pesticides, taking into consideration work practices, use of protective equipment, and other measures to reduce risk.

365 individuals exposed to hexachlorocyclohexane (HCH) during its manufacture were studied and compared with 146 controls. These 502 cases were divided into five groups on the basis of serum total HCH levels. Exposure was mainly through skin. Results indicate that neurological symptoms reported were due to recent exposure to HCH and were related to the intensity of exposure. ECG abnormalities were seen in exposed cases. A significant positive correlation to liver related enzymes gamma GT, LAP and Alp. P was observed. beta-globulins significantly increased along with an increase in total HCH. Changes in IgM levels were similar as observed in IgA. Remarkably high concentration of HCH residues were found in the serum samples of all exposed workers. beta-HCH contributed more than 80% of the total HCH built up. Presence of circulating immune complexes was also detected in representative samples. Further, repeated biological monitoring was advised to be carried out among such workers exposed to HCH, to evaluate signs of severe health impairment in them.

The accumulation of hexachlorocyclohexane, one of the most commonly used chlorinated insecticides, was studied in a high-risk group of people who are exposed during its manufacturing process. The serum HCH concentration was estimated by quantitating its alpha, beta, gamma and delta-isomers with the help of GLC analysis. Exposed workers involved in maintenance work were found to have 3 times higher HCH residues than the controls, while in the plant operators and supervisors the levels were 5 times higher. The most severely exposed were the handlers who are in direct contact with the insecticide. The level of serum HCH residues in them was found to be about 12 times higher than those in the controls. The percentage composition of the insecticide, with respect to the different isomers, varied up to 20% for the gamma-isomer, up to 30% for alpha-isomer and had between 60%-100% of the beta-isomer in the samples. The serum levels of the insecticides were clearly related to the workers' job-related close contact, intensity, frequency, and the duration of their exposure. The total of HCH residues in the sera studied were in the range of 0.143-1.152 ppm. The importance of these findings and the relevant protective measures are discussed.

While the health of the general population is not adversely affected by the exposure the pesticides in food and environment, workers, who have during their occupation been intensely exposed to pesticides, exhibit a higher prevalence of slight neurotoxic symptoms. In the present study the electroencephalograms of 3 of a group 10 workmen, who had been continually exposed to hexachlorcyclohexane, show pathological findings. The electromyograms of 8 of these 10 workman demonstrate a disturbance of the peripherical motoneuron. All probands, who exhibit o pathological EEG, also show a polyneuropathy.