Health Stream Literature Summary - Issue 53 - March 2009

Influence of Drinking and/or Cooking with Jinzu River Water on the Development of Itai-Itai Disease.
Kobayashi E, Suwazono Y, Dochi M., Honda R, Kido T and Nakagawa H. (2008) Biological Trace Element Research, 1-12.

There are numerous cadmium (Cd)-polluted regions in Japan, with most caused by irrigation with Cd-polluted river water containing waste discharges from mining. The area most severely polluted is the Jinzu River basin in Toyama Prefecture. In this area there are many inhabitants with renal tubular dysfunction and patients with Itai-itai disease. Itai-itai disease is characterised by renal injury manifested by tubular and glomerular dysfunction and painful bone injury consisting of a combination of osteomalacia and osteoporosis. The influence of Cd intake from rice consumption and renal tubular dysfunction and Itai-itai disease have been previously been investigated, however there have been no studies investigating both Cd-polluted rice consumption and drinking and/or cooking with Jinzu River water on the development of these diseases. This study calculated the amount of lifetime Cd intake from these different sources and evaluated the influence of eating Cd-polluted rice and drinking and/or cooking with Jinzu River water on the development of Itai-itai disease.

There were 38 participants out of 60 with Itai-itai disease admitted for the 1977 and 1978 medical examinations who also agreed to participate in a questionnaire survey. Their medical history was determined by direct questioning in addition to various medical testing. Age at "mild disease onset"; corresponded most frequently to the age at which the patient started to perceive leg/back pain and age at "severe disease onset" when the patent experienced the severest pain associated with for example disturbance of ambulation and/or bone fractures. The questionnaire survey included two questions concerning the use of Jinzu River water for drinking and cooking.

Cumulative intakes of cadmium from food at different stages of disease (mild onset, severe onset and death) were estimated from recorded cadmium levels in rice samples from different hamlets, estimated cadmium intake from other dietary sources and residential history since birth. The mean lifetime Cd intakes in non-users/users of Jinzu River water for drinking and/or cooking were estimated as 3.46-3.60 g/2.58-2.63 g at mild disease onset and 4.24-4.44 g/3.50-3.54 g at severe disease onset. The difference in values was 0.84-0.98 g and 0.70-0.92 g at mild and severe disease onset, respectively. The differences in mean age in non-users/users of river water were calculated as 6.8-8.2 years at mild disease onset and 4.6-5.9 years at severe disease onset, respectively. When river water was used for drinking and/or cooking, age and life time Cd intake differed by 7.6 years and 0.9 g at mild disease onset and 5.9 years and 0.92 g at severe disease onset.

Of the patients with Itai-itai disease in this study, the users of Jinzu River water started to perceive leg/back pain earlier and experience the severest pain earlier, even though their lifetime Cd intake from food was smaller than that of non-users. The influence of not only eating Cd-polluted rice but also drinking and/or cooking with Jinzu River water on the development of Itai-itai disease was highlighted here. However the results suggest that lifetime Cd intake estimated from eating Cd-polluted rice exerted a greater influence on the development of Itai-itai disease than did drinking and/or cooking with Cd-polluted river water.

Comment Itai-itai disease was first described in the early 1900s but the link with cadmium exposure was not elucidated until the late 1950s. Other factors such as malnutrition and poor calcium metabolism are also thought to contribute to development of the disease. The name literally translates to "Ouch-Ouch" disease - referring to the severe pain experienced by sufferers.

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