The excretion of urinary glycosaminoglycans by five occupationally exposed men with urinary cadmium levels of 1 to 6.5 micrograms/g creatinine did not differ significantly from that of six age-matched non-exposed controls (2.8 +/- 1.8 mg/mmol creatinine vs. 2.3 +/- 1.6 mg/mmol creatinine, +/- S.D.) as analyzed in random urine samples. However, there was a cadmium concentration-dependent increase in the excretion of 50 kD proteoglycan as analyzed by polyacrylamide electrophoresis of the isolated proteoglycan fraction in the same urine samples. This may represent the early dose-dependent effect of cadmium on renal tubules which leads to decrease in the renal cell sialic acid content and protein excretion at higher exposure levels.