Occupational exposure to hexachlorocyclohexane

Abstract

In a lindane (gamma-hexachlorocyclohexane = gamma-benzenehexachloride)-producing factor 57 workers were studied with regard to their blood levels of the three hexachlorocyclohexane isomers: alpha-, beta-, and gamma-HCH. The TLV-TWA (MAK value 1979) for gamma-HCH of 0.5 mg/m3 was not exceeded at any of the workplaces where HCH is synthesized and purified to lindane. Additionally, in some of the workers samples of s.c. adipose tissue were taken for determination of HCH-isomer content. An external group of 20 clerks was examined in the same way for control purposes. In contrast to the control persons, none of whom had HCH-concentrations in serum above the respective detection limits, the values determined in serum of the exposed workers were in the following ranges: alpha-HCH: 10-273 microgram/1, beta-HCH: 17-760 microgram/l, and gamma-HCH: 5-188 microgram/1. Of special interest is the observation of a significant increase of beta-HCH-concentration in serum with the time of employment in lindane production, indicating a pronounced accumulation of this substance in the human organism. Concentrations of this isomer in s.c. adipose tissues were about 300-fold higher than in serum. A significant correlation between both parameters could be established. The results of this study show that adherence to the TLV-TWA of gamma-HCH is not sufficient for control of HCH-exposure. Furthermore, biological monitoring of exposed workers is necessary taking into account the three more important isomers alpha-, beta-, and gamma-HCH.

Divergent Roles for Glutathione in Lindane-Induced Acute and Delayed-Onset Inhibition of Rat Myometrial Gap Junctions

“…The concentration of lindane used in the present study is about 100-fold higher than serum concentrations observed in 700 GLUTATHIONE MODULATION AND GAP JUNCTIONS occupationally exposed human populations (Baumann et al, 1980) and is significantly higher than concentrations reported in human blood samples of populations lacking known exposure to lindane (Kutz et al, 1991). Nonetheless, because lindane induces a sustained inhibition of myometrial gap junction communication at nanomolar concentrations (Loch-Caruso et al, 2003), an improved understanding of lindane effects on gap junctions may have relevance for understanding potential health risks.…”

Differential Toxicity and Environmental Fates of Hexachlorocyclohexane Isomers

“…The β-isomer is generally considered the most persistent and metabolically inactive, with a BCF of 2.9 in various aquatic species and 527 in human fat (see Table 1). For example, in workers involved in the production of lindane, concentrations of β-HCH (46 mg/kg lipid) were 8 and 15 times the concentrations of Rand γ-HCH, respectively (46). Likewise, average lipid β-HCH concentrations in 20 Pakistani citizens (average, 2.4 mg/kg; range, 0.14-21 mg/kg) were 8 and 80 times higher than Rand γ-HCH (47).…”

Strong Associations Between the Pesticide Hexachlorocyclohexane and Type 2 Diabetes in Saudi Adults

“…In workers engaged in the production and formulation of γ-HCH, mean plasma levels ranged from 16–57 µg/L [ 34 ]. In another γ-HCH-producing facility, γ-HCH air levels of 0.004–0.15 mg/m 3 were associated with serum levels of 5–188 µg/L in exposed workers of [ 35 ]. The high serum γ-HCH concentrations in our study in both controls (2.8 ± 0.49 μg/L) and T2DM patients (7.3 ± 0.84) indicate a recent or current exposure to γ-HCH either through diet, drinking water or polluted air.…”