Employee Exposure to Chromium and Plasma Lipid Oxidation

Abstract

Exposure to chromium increases free-radical species in the body, which has an adverse biologic effect. In view of evidence that the oxidation of low-density lipoproteins is important in the pathogenesis of atherosclerosis, the authors measured plasma lipid oxidation and antioxidant levels in 11 welders chronically exposed to chromium and compared them with levels in 15 matched controls. Exposure level was determined by urinalysis. Plasma lipid peroxidation and susceptibility to oxidation were determined by measuring generated thiobarbituric acid reactive substance (TBARS) and lipid peroxides. Total plasma antioxidant status and serum paraoxonase activity were also measured. The Kruskal-Wallis test was used to test for statistical significance. There was no significant difference between the groups with regard to lipid peroxidation, plasma lipid susceptibility to oxidation, total plasma antioxidant status, or serum paraoxonase. Three workers with urinary chromium levels over the biologic exposure index limit (> 10.0 microg/g creatinine) had higher plasma lipid peroxidation and lipid susceptibility to oxidation compared with the rest of the study group. The results suggest that welders exposed to chromium have increased plasma lipid oxidation. The small numbers of subjects and those with elevated urinary chromium limit the power of this preliminary study. Further studies of the association of chromium with plasma lipid oxidation are warranted.