Environmental exposure to cadmium and renal function of elderly women living in cadmium-polluted areas of the Federal Republic of Germany

Summary An epidemiological study was performed to assess whether environmental pollution by cadmium as found in cadmium-polluted areas of the Federal Republic of Germany is associated with an increased prevalence of biological signs of kidney dysfunction in population groups non-occupationally exposed to heavy metals. The study was run in two industrial areas known to be highly contaminated by cadmium, lead and other heavy metals, viz. Stolberg and Duisburg. Dusseldorf was selected as a reference area. As a study population we selected 65- and 66-year-old women (n = 286) who had spent the major part of their lives in one of these areas. The average cadmium levels in blood (CdB) and urine (CdU) revealed significant differences in exposure to cadmium in the order Stolberg > Duisburg > Düsseldorf. Serum creatinine levels were, on average, significantly higher in the Stolberg group than in the Duisburg and Düsseldorf groups. However, with respect to the urinary excretion of low molecular weight proteins (₂-microglobulin, retinol-binding protein), albuminuria, total proteinuria, aminoaciduria, phosphaturia and some other biological findings, no significant differences between the study populations were noted. Similarly, the prevalence of clinically-confirmed hypertension as well as the relative frequency of hypertensive subjects (systolic 160 and/or diastolic 95 mm Hg) did not differ significantly among the three study groups. There was no exposure-reponse relationship between CdU and tubular proteinuria in the range of the CdU-levels found (0.1 to 5.2 g/g creatinine). However, albuminuria tended to be increased at CdU levels > 2 g/g creatinine.