Cadmium Content In Rice Research Articles

Epidemiology of renal tubular dysfunction in the inhabitants of a cadmium-polluted area in the Jinzu River basin in Toyama prefecture.

Urinary beta 2-microglobulin (beta 2-m), alpha 1-microglobulin (alpha 1-m), amino-nitrogen, glucose, calcium, phosphorus, cadmium concentrations, and pH values were analyzed in urine samples from 187 females aged 55-66 years in the Jinzu River basin, which is known to be a cadmium-polluted area, and from 32 controls living in two adjacent reference areas in 1983-1984. Mean urinary beta 2-m, alpha 1-m, amino-nitrogen, glucose, cadmium concentrations and pH values in the inhabitants of the Jinzu River basin were significantly higher than those in the adjacent reference areas. Sixty-four inhabitants in a cadmium-polluted area were found to have renal tubular dysfunction with urinary beta 2-m level exceeding 1 mg/g creatinine and urinary glucose level exceeding 100 mg/g creatinine. The severity of renal tubular dysfunction in several inhabitants were comparable to those of the patients with Itai-itai disease. Mean cadmium concentrations in rice (mean: 0.32-0.57 ppm) which has been daily consumed by the inhabitants of the Jinzu River basin were significantly higher than those in the reference areas (mean: 0.12-0.13 ppm). The close relationship between cadmium exposure and the degree of renal tubular dysfunction was well demonstrated by principal component analysis.

The Prevalence of Itai-itai Disease and the Mean Cadmium Concentration in Rice Produced by Individual Villages

Cadmium concentrations in rice were employed as an index of cadmium exposure. Samples of unpolished rice were collected from 727 households in 40 villages along the cadmium-polluted Jinzu River basin and analyzed for the metal. The prevalence of itai-itai disease was used as the index of the effects of cadmium.A close relationship between cadmium exposure and its effect on health was found when disease patients were stratified according to cadmium concentration per village, demonstrating that doseresponse relationships did in fact exit.

A comparison between cadmium in rice and renal effects among inhabitants of the Jinzu River basin

Inhabitants in a cadium-exposed area (2741) and reference inhabitants (2150) were studied. Unpolished rice samples were collected from 583 households in the same area and analyzed for cadmium. Proteinuria and proteinuria with glucosuria were used as indices of the effects of cadmium on health. Village average rice-cadmium concentration was employed as an index of cadmium exposure. A close relationship between cadmium exposure and health effects was found to exist when the inhabitants were arranged according to their village average rice-cadmium concentrations. Furthermore, the effects of cadmium on health were closely related to residence time in the polluted areas. These facts indicated that village average rice-cadmium concentration was useful as an index of pollution and that the dose-response relationship of cadmium in the polluted area must exist.

Recent results of health examinations on the general population in cadmium-polluted and control areas in Japan.

Health examinations by a revised method aimed at detecting renal tubular dysfunctions more effectively were conducted on the general population aged 50 years and over in cadmium-polluted areas (1826 persons) and control areas (1611 persons) in four prefectures in Japan in 1976. Although detailed analysis of the data is not yet completed, some of the results obtained are described here. The prevalence of glucosuria and low molecular weight proteinuria, frequency of decreased % TRP, and cadmium concentrations in urine are higher in the cadmium-polluted areas than in the controls. Clinically diagnosed cases with tubular dysfunctions seem to follow the same trend as above, though these cases are very few in number and they are limited to the advanced age group. When cadmium concentration in rice is taken as an index, a dose-response relationship is not necessarity explicit in the observations by prefecture. However, suggestive data are obtained in the observation by district in one cadmium-polluted area.

Statistical observations of the dose-response relationships of cadmium based on epidemiological studies in the Kakehashi River basin

Statistical analysis was performed on the results of the epidemiological study for Itai-itai disease carried out in 1974 and 1975 by Ishikawa Prefecture Health Authorities in the cadmium-polluted Kakehashi River basin. As indices of the effects of cadmium on health, we used the urinary excretion of retinol binding protein, of suspected patients, and of tubular dysfunction. As indices of cadmium exposure, village average cadmium concentration in rice and urine were employed. Close dose-response relationships between cadmium exposure and health effects were found to exist and the curves obtained indicated sigmoid lines when the inhabitants were stratified according to their village average rice or urinary cadmium concentrations. When retinol binding protein was employed as the index of the effect on health, significant differences, compared with the control, in inhabitants ages 60 to 69 were observed at the levels of 0.50–0.59 μg/g in rice or 9.0–10.9 μg/liter in urine as village averages and 0.60–0.69 μg/g in rice eaten by inhabitants ages 50 to 59. However, in the inhabitants more than 70 yr of age significant differences in the prevalence of tubular proteinuria were observed between the lowest polluted village and the control ones. This fact indicated that the prevalence of tubular proteinuria in these inhabitants increased continuously from the nonpolluted levels of cadmium. Probit analysis of urinary cadmium concentration and renal effects was performed on 262 inhabitants selected for close examination. Probit linear regression lines were obtained when the inhabitants were arranged according to their urinary cadmium concentrations expressed as micrograms per gram creatinine.

Consideration on Behavior of Cadmium in Soil and Change of Cadmium Content in Rice with Oxidation-Reduction Potential of Soil

Consideration on Behavior of Cadmium in Soil and Change of Cadmium Content in Rice with Oxidation-Reduction Potential of Soil