Latest status of cadmium accumulation and its effects on kidneys, bone, and erythropoiesis in inhabitants of the formerly cadmium-polluted Jinzu River Basin in Toyama, Japan, after restoration of rice paddies.
OBJECTIVE
The cadmium-polluted Jinzu River Basin in Toyama, Japan, where nephropathy and itai-itai disease were endemic among resident farmers decades ago, has been almost completely restored. The aim of this study is to investigate whether inhabitants there would still exhibit cadmium accumulation and its effects on kidneys, bones, and erythropoiesis.


METHODS
We performed a cross-sectional study of 150 subjects from the polluted area and 144 controls from the same prefecture. Participants included female inhabitants from 34 to 74 years of age who underwent examinations to gather anthropometrical and medical information, obtain rice, blood and urine samples, and measure bone mineral density.


RESULTS
Cadmium concentration in rice from the polluted area was lower than the level in the control area. Blood and urinary cadmium and urinary β(2)-microglobulin levels were higher in subjects from the polluted area than controls, and the urinary β(2)-microglobulin was independently affected by urinary cadmium. Bone mineral density did not differ between the two areas, but it was affected by renal tubular function in subjects from the polluted area. Serum bone alkaline phosphatase was lower in subjects from the polluted area compared to controls. We detected three cases of cadmium nephropathy among the subjects. One of them suffered from a renal anemia type of itai-itai disease.


CONCLUSIONS
Inhabitants in the formerly polluted area still had high cadmium accumulations and showed a characteristic natural history of chronic cadmium toxicity, indicating that the risk remains for developing nephropathy or itai-itai disease in the future.
Division of Environmental Medicine, Center for Community Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan. hhyogo@jichi.ac.jp
Hyogo
H
Horiguchi
Keiko
K
Aoshima
Etsuko
E
Oguma
Satoshi
S
Sasaki
Kayoko
K
Miyamoto
Yoko
Y
Hosoi
Terutaka
T
Katoh
Fujio
F
Kayama
D000328:Adult; D017677:Age Distribution; D000368:Aged; D015519:Bone Density; D001842:Bone and Bones / Q000737:chemistry*; D002104:Cadmium / Q000097:blood* / Q000652:urine*; D002105:Cadmium Poisoning / Q000097:blood / Q000453:epidemiology / Q000652:urine; D003430:Cross-Sectional Studies; D004920:Erythropoiesis; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000737:chemistry*; D007674:Kidney Diseases / Q000139:chemically induced / Q000453:epidemiology / Q000652:urine; D008593:Menopause / Q000097:blood / Q000652:urine; D008875:Middle Aged; D012275:Oryza / Q000737:chemistry; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D014874:Water Pollutants, Chemical / Q000097:blood* / Q000652:urine*; D001613:beta 2-Microglobulin / Q000652:urine
D014874:Water Pollutants, Chemical; D001613:beta 2-Microglobulin; D002104:Cadmium