Such threshold estimates
may be conservative, and in a study of
90 workers exposed to cadmium dusts
for up to 20 years (average 7.5 years) of
whom 75 were smokers, a mean urinary
excretion of cadmium of 23 mg/g creatinine
(50 times that of the NHANES III
smokers) was not associated with any
excess proteinuria compared with unexposed
controls