Biologic markers of oxidative stress and nephrotoxicity as studied in biomonitoring of adverse effects of occupational exposure to lead and cadmium.
OBJECTIVE
In this work, we studied impregnation levels of workers occupationally exposed to lead (Pb) and cadmium (Cd), usefulness of early urinary markers of nephrotoxicity, and occurrence of oxidative stress as the underlying mechanism involved in Pb- or Cd-induced adverse effects. Thirty-five men were recruited from a nonferrous metal smelter. Pb and Cd in blood (B-Pb, B-Cd) and urine (U-Pb, U-Cd) were measured. Relations between oxidative stress markers (malondialdehyde, superoxide dismutase, glutathione peroxidase, selenium, glutathione reductase, glutathione status, 8-hydroxy-2'-deoxyguanosine) and exposure levels, on the one hand, and early urinary markers (alpha-1-microprotein, beta-2-microglobulin, retinol binding protein, alpha and pi-glutathione S-transferases) and exposure levels, on the other hand, were evaluated.


RESULTS
Mean exposure levels were moderate (B-Pb = 395.71 microg Pb/L; U-Pb = 95.19 microg Pb/g creatinine; B-Cd = 5.83 microg Cd/L; U-Cd = 4.67 microg Cd/g creatinine). Changes in malondialdehyde, glutathione status, 8-hydroxy-2'-deoxyguanosine, and alpha-glutathione S-transferases were closely correlated with exposure levels and did not depend on tobacco consumption. We showed that these workers showed moderate Pb and Cd exposure levels.


CONCLUSIONS
Taken together, the data suggests the use of alpha-glutathione S-transferases excretion in urine as a hallmark of early changes in the proximal tubular integrity that could later lead to clinical disease if exposure is not reduced.
Garçon
Guillaume
G
Laboratoire de Recherche en Toxicologie Industrielle et Environnementale, Maison de la Recherche en Environnement Industriel de Dunkerque 2, 59140 Dunkerque, France.
Leleu
Bruno
B
Zerimech
Farid
F
Marez
Thierry
T
Haguenoer
Jean-Marie
JM
Furon
Daniel
D
Shirali
Pirouz
P
D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism* / Q000633:toxicity; D004784:Environmental Monitoring; D062665:Epidemiological Monitoring; D005602:France / Q000453:epidemiology; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000453:epidemiology; D007854:Lead / Q000378:metabolism* / Q000633:toxicity; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D016273:Occupational Exposure; D018384:Oxidative Stress; D012044:Regression Analysis; D012907:Smoking / Q000453:epidemiology
D015415:Biomarkers; D002104:Cadmium; D007854:Lead