|Budget Amount *help
¥4,900,000 (Direct Cost : ¥4,900,000)
Fiscal Year 1995 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1994 : ¥4,100,000 (Direct Cost : ¥4,100,000)
1.A follow-up study on mortality for 11 years was carried out on 341 inhabitants of the cadmium (Cd) -polluted Jinzu River basin (B-L) and on 69 inhabitants of the two adjacent reference districts (A and M) in Toyama prefecture, Japan. All female inhabitants of the target areas of A-G whose year of birth was between 1918 and 1927, and of the areas of H-M whose year of birth between 1914 and 1929 were followed from January 1983 to March 1994 and from May 1984 to March 1995, respectively. Increases of SMRs according to all causes of death in the inhabitants of districts of B-G and H-L were found compared with those of the reference districts (A and M) or the overall female population in Toyama.
2.(1) The means of urinary excretions of beta_2-microglobulin, alpha_1-microglobulin, glucose and total protein in inhabitants of districts of B-G and H-L in 1994 or 1995 were significantly higher than those detected in 1983 or 1984, respectively. No significant changes were found in inhabitants of areas of A and M for 11 years. These results showed that renal tubular dysfunction caused by environmental Cd was developed in inhabitants of the Jinzu River basin.
(2) Prevalence of renal tubular dysfunction was increased in the districts of B-G and H-L during the observation periods. Nine new cases were found in the district of B-G and 26 in H-L districts for 11 years, amounting to an incidence was 16% in B-G and 30% in H-L,respectively. No significant correlation was found between incidence of renal tubular dysfunction and the degree of restoration of paddy fields by covering with nonpolluted soil in each B-L district.
(2)尿中β_2-マイクログロブリン1mg/g creatinine以上,グルコース150mg/g creatinine以上のとき尿細管障害と判定すると,汚染地区では11年後の有病率が高く,H〜L地区では有意であった。11年間にB〜G地区9名,H〜L地区26名が新たに尿細管障害を発症した。11年間の罹患率は,B〜G地区1.5/100人/年,H〜L地区2.7/100人/年となった。A地区は罹患率ゼロ,M地区は0.75/100人/年であった。各地区の土壌復元状況(水田土壌復元率)と尿細管障害罹患率との間に関連はみられず,環境改善事業の効果はみられなかった。