Association between Renal Dysfunction and Mortality among Inhabitants in the Region around the Jinzu River Basin Polluted by Cadmium

Abstract

A follow-up study was conducted on 5725 inhabitants (men 2858, women 2867) in and around the Jinzu River basin to determine the influence of environmental Cd exposure on mortality. In the Jinzu River basin, standardized mortality ratios (SMRs) investigated according to urinary findings (protein, glucose, and protein+glucose) were significantly low in the urinary protein-, glucose-, and protein+glucose-negative groups. SMRs calculated after dividing urinary protein- and glucose-positive status into two levels were lowest in the proteinuria- and glycosuria-negative groups and tended to be high in the higher positive groups. In the Jinzu River basin, Cox's hazard ratios were significantly higher for men and women in the urinary protein, glucose and protein+glucose-positive-groups. In the same analysis where the urinary protein- and glucose-positive subjects were divided into two levels, mortality was demonstrated to be higher in the groups with the greater degrees of proteinuria and glycosuria. In the Jinzu River water system almost all SMRs and Cox's hazard ratios showed statistical significance. This was not the case in the other water systems. Mortality of inhabitants with Cd-induced renal injury is increased in the Jinzu River basin.