Cai Y, Aoshima K, Katoh T, Teranishi H, Kasuya M
Department of Pharmaceutical University, Sugitani, Toyama, Japan.
J Epidemiol. 2001 Jul;11(4):180-9. doi: 10.2188/jea.11.180.
An eleven-year follow-up study was carried out to elucidate the changes in the level of environmental exposure to cadmium (Cd) from rice after soil replacement of polluted paddy fields and these effects on urinary excretion of Cd in male inhabitants of a Cd-polluted area in Toyama, Japan. In addition, the prevalence of renal tubular dysfunction (RTD) was examined to clarify the progress of Cd-induced RTD. One hundred and twenty-seven male inhabitants born between 1914 and 1929 in 11 districts of the Cd-polluted Jinzu River basin and 31 reference subjects in 2 adjacent districts were examined twice in 1985-86 and 1996-97. The geometric means of Cd concentrations in polished rice (Cd-R) in the Cd-polluted areas were 0.18 ppm in 1985 and 0.21 ppm in 1986; these values were significantly higher than those of the reference areas (0.13 ppm in 1985 and 0.12 ppm in 1986). After 11 years, the Cd-R levels were significantly decreased to approximately half (0.08 ppm in 1996, 0.12 ppm in 1997) due to soil replacement of polluted paddy fields, which has been carried out since 1980. The mean Cd levels in urine (Cd-U) were significantly reduced from 7.9 and 9.5 microg/g creatinine in the initial study to 6.9 and 6.8 microg/g creatinine in the follow-up study. However, the prevalence of RTD, which was determined by urinary beta2-microglobulin exceeding 1 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine, increased from 18 and 23% in the 1985-86 study to 25 and 32% in the 1996-97 study, and a total of 12 new cases (12%) of RTD were found. Whereas, only one subject (4%) in the reference control areas was identified as RTD. Cd-induced RTD was prevalent, progressive and irreversible for male inhabitants of the Cd-polluted Jinzu River basin, although the environmental exposure to Cd through rice was significantly reduced by soil replacement of polluted paddy fields.
开展了一项为期11年的随访研究，以阐明在日本富山镉污染地区对受污染稻田进行土壤置换后，大米中镉（Cd）的环境暴露水平变化及其对男性居民尿镉排泄的影响。此外，还对肾小管功能障碍（RTD）的患病率进行了检查，以明确镉诱导的RTD的进展情况。对1914年至1929年出生在镉污染的神通川流域11个地区的127名男性居民以及相邻2个地区的31名对照对象，在1985 - 1986年和1996 - 1997年进行了两次检查。镉污染地区精米中镉浓度（Cd - R）的几何平均值在1985年为0.18 ppm，1986年为0.21 ppm；这些值显著高于对照地区（1985年为0.13 ppm，1986年为0.12 ppm）。11年后，由于自1980年以来对受污染稻田进行了土壤置换，Cd - R水平显著下降至约一半（1996年为0.08 ppm，1997年为0.12 ppm）。尿镉（Cd - U）的平均水平从初始研究时的7.9和9.5微克/克肌酐显著降至随访研究时的6.9和6.8微克/克肌酐。然而，由尿β2 - 微球蛋白超过1毫克/克肌酐和尿葡萄糖超过150毫克/克肌酐所确定的RTD患病率，从1985 - 1986年研究中的18%和23%增至1996 - 1997年研究中的25%和32%，共发现12例新的RTD病例（12%）。而对照地区仅1名对象（4%）被认定为RTD。对于镉污染的神通川流域男性居民，尽管通过对受污染稻田进行土壤置换，通过大米的镉环境暴露显著减少，但镉诱导的RTD仍普遍存在、呈进行性且不可逆转。
