食品中カドミウムの曝露評価と健康影響評価

抄録

The major source of exposure to cadmium among Japanese is rice. A half of total dietary cadmium intake comes from rice. Since 2001, we have been investigated in relationship between dietary cadmium exposure and health effects such as renal tubular among 1310 farm housewives in 5 districts in Japan, who have been consumed their rice harvested in their paddy. The geometric means of Cd in the rice(R-Cd)were 0.022, 0.061, 0.054, 0.113, and 0.154 µg/g in district A, B, C, D, and E, respectively. The estimates of total dietary Cd exposure revealed that 0.5 - 2.5% of the participants in district A were exposed to a higher Cd dose than the current Provisional Tolerable Weekly Intake(PTWI),i.e. 4.5 - 20.3% in district B, 6.9 - 22.2% in district C, 24.0 -52.5% in district D, and 35.6 - 66.8% in district E. Creatinin-adjusted urinary Cd(U-Cd)increased age-dependently, and correlated with the degree of Cd contamination in the districts. Renal biomarkers showed statistically significant increases in an age-dependent manner in all the districts, but were correlated with neither U-Cd nor B-Cd, nor R-Cd. Multiple regression analysis depicted no significant increase in the prevalence of renal biomarkers in each district after adjustment for age. In conclusion, this study showed that the prevalence of renal tubular dysfunction remains the same among female farmers exposed to life-long dietary Cd close to or above the current PTWI.