Inorganic lead exposure does not effect lymphocyte micronuclei in car radiator repair workers

Abstract

Eighteen individuals exposed to lead in their work with repair and reconditioning of car radiators were investigated regarding blood lead levels and frequencies of lymphocyte micronuclei. The micronuclei werc analyzed in cells with preserved cytoplasm. The lead-exposed group was compared with 12 white-collar workers with no occupational lead exposure. The mean blood lead levels were 2.3 (range 1.50-3.30) and 0.42 (range 0.20-1.05) Kmolil, respectively, with no overlapping of exposed subjects and controls. There was no effect of lead exposure when the influences of age, smoking and drug intake were allowed for in a multivariate analysis. On the other hand, there was a striking effect of age on the frequency of micronuclei. Benkr Hiigstedf, Department of Occupational Medicine, Central Hospital, S-30185 Halmsrad, SwedenThe possible mutagenicicarcinogenic effect of inorganic lead exposure has been discussed for a long time. Inorganic lead does not seem to have any mutagenic effect neither in bacterial test systems, nor in mammalian cells in vitro, with the exception of lead chromate (NESTMAN et al. 1979; DOUGLAS et a1.1980), in which the effect possibly is due to the chromate ion.There are contradictory results of cytogenetic studies in lead-exposed workers (for review and references see MAKI-PAAKKANEN et al. 1981, and. The differences may be due either to the culturing conditions or confounding exposures to other metals such as arsen and cadmium, and to polyaromatic hydrocarbons (WANG et al. 1978;HOGSTEDT et al. 1979HOGSTEDT et al. ,1981. In addition, in most of the earlier investigations the statistical methods used have not permitted the separation of the effects of age, smoking habits, and other life-style factors from the occupational exposure.Micronuclei are formed by a damage either directly to the chromosomes (agentric fragments) or to the spindle apparatus (lagging chromosomes). The micronucleus method applied to cultured lymphocytes with preservation of the cytoplasm has proven to be a rapid and sensitive way of measuring cytogenetic damage in individuals exposed to mutagens such as styrene (HOGSTEDT et al. 1983; Hoc-STEDT 1984). The method has not been used previously in individuals exposed to lead in their occupation.The aim of the present investigation was to study the effect of exposure to fairly pure lead on the frequency of micronuclei in lymphocytes by means of a statistical analysis of the multivariate type to allow for multiple background factors. Material and methodsIndividuals investigated.-The lead-exposed group consisted of eighteen males who had been working with repair and reconditioning of motor vehicle radiators for 2 to 45 (mean 17.8) years. They were 18 to 64 (mean 41) years of age. Eight of them were smokers. Two of them took beta-blocking drugs for hypertension. One had been radiographed within a year before the investigation. One individual had a mild proteinuria since childhood. Otherwise, all were quite healthy and showed no sign of acute or chronic lead intoxication. Their main ex...

Elevated blood lead levels and cytogenetic markers in buccal epithelial cells of painters in India

“…Our findings are consistent with the above reports. However insignificant increase in MN in cultured peripheral blood lymphocytes of shipbreaking workers and car radiator repair workers was reported (Hoffmann et al 1984;O'Riordan and Evans 1974). Moreover, (Pelelova et al 1997) could not detect a significant increase in structural aberrations in 22 workers from a lead battery plant; the negative response observed in the above reports was in contrast to the positive data obtained in our study.…”

“…Presently, most of genotoxic studies on the effect of occupational lead exposure in humans are limited and controversial (Duydu et al 2001;Fracasso et al 2002;Hoffmann et al 1984;O'Riordan and Evans 1974). (Forni et al 1980) studied 18 females occupationally exposed to lead in the manufacture of storage batteries.…”

Usefulness of biomarkers as intermediate endpoints in health risks posed by occupational lead exposure

“…The vast majority of researchers have demonstrated an increase in MN rate in exposed individuals compared with control groups, consequently highlighting the possible role of MN assay as a stable indicator of chronic lead exposure [21,26,40,42,[47][48][49][50][51][52][53][54][55][56][57][58]. The only study that have not found any genotoxic effect using MN assay was that conducted by Hoffmann et al [59].…”

“…They have investigated the effect of lead on the genetic material in a group of car repair and radiator reconditioning workers reporting an insignificant increase in MN in cultured peripheral blood lymphocytes of workers who were exposed to lead [59].…”