Health effects of environmental exposure to cadmium in a population study.

The Cadmibel Study is a cross-sectional population study, which investigated the hypothesis that environmental exposure of the population to cadmium would result in health effects. The 2,327 participants constituted a random sample of the population of four Belgian districts, chosen to provide a wide range of environmental exposure to cadmium. The urinary cadmium excretion, a measure of lifetime exposure, averaged 9.3 nmol/24h in men (range 0.4-325 nmol/24h) and 7.2 nmol (0.1-71 nmol/24h) in women. The Cadmibel Study refuted the hypothesis that exposure to cadmium would lead to an increase in BP and in the prevalence of hypertension and other cardiovascular diseases. Serum alkaline phosphatase activity and the urinary excretion of calcium correlated significantly and positively with urinary cadmium in both sexes. These findings suggest that the calcium metabolism is gradually affected, as cadmium accumulates in the body. Furthermore, several markers of renal tubular function (urinary excretion of retinol binding protein, N-acetyl-beta-glucosaminidase, beta 2-microglobulin and aminoacids) were significantly and positively associated with urinary cadmium. There was a 10% probability of abnormal values of these markers of tubular function when urinary cadmium exceeded +/- 20 nmol/24h. However, the morbidity associated with the functional changes, observed in the Cadmibel Study, remains presently unknown and requires further investigation, preferably in a longitudinal population studies.