Twenty-Two-Year Observation on Urinary Cadmium and ß 2 -Microglobulin in Inhabitants after Cessation of Cadmium-Exposure in Japan

Abstract

Objective: This is an epidemiological survey that was conducted for 22 years to investigate the physical effects on inhabitants who had been exposed to cadmium (Cd) from processing of remnants discharged at the time of copper refinement. It was possible to obtain findings on physical effects 27 years after Cd exposure. Materials and Methods: Of the inhabitants who were 50 years old or younger in 1981 and who were living in the most contaminated area in the Kakehashi River basin, 68 (32 males and 36 females) who underwent all of the 5 screenings during the 22-year period were extracted as subjects. Early morning urine was collected for urinalysis, and Cd and ß2-MG concentrations were determined. Results: 27 years after cessation of Cd exposure, it was shown that urinary Cd concentrations were significantly decreased and urinary ß2-MG concentrations were significantly increased. Conclusion: Once exposed to Cd, it takes about 30 years for the Cd that remains in the body to decrease by half. Once renal tubular dysfunction occurs after Cd exposure, irreversible aggravation is inevitable.