Rivers Jinzu

The most severe form of chronic cadmium (Cd) poisoning caused by prolonged oral Cd ingestion is Itai-itai disease, which developed in numerous inhabitants of the Jinzu River basin in Toyama Prefecture, Japan in the 1950s (Figure 20.7). For the first time, cadmium pollution was shown to have severe consequences on human health, particularly in women. The most important effects were softening of the bones and kidney failure. The name of the disease is derived from the painful screams (Japanese /to/) caused by the severe pain in the... 

A classic example of essential metal deficiency resulting from nonessential metal exposure is Itai itai disease. Cadmium pollution in the Jinzu River basin in Japan resulted in severe nephrotoxicity in approximately 184 people. Renal tubule damage caused excessive loss of electrolytes and small proteins from the urine. In severe cases, urinary Ca loss was so severe that bone Ca was mobilized, resulting in osteomalacia. Renal tubular defects persisted for life and induced hypophosphatemia, hyperuricemia, and hyperchloremia, which are characteristic biochemical features of Itai-itai disease (see Section 21.6.1). 

Itai-itai disease was identified in residents of the Jinzu River Basin in Japan in the mid-1940s. A lead and zinc mine polluted the river with high levels of Cd. The river water was used in the irrigation of rice fields and for drinking water. People affected by the disease suffered severe kidney dysfunction and painful skeletal symptoms. In the worst cases, bones would break from slight pressure, even from simply coughing. It is important to note that the worst cases were presented in... 

A follow-up survey on 2,101 inhabitants (1,566 men and 535 women), who participated in a 1967-health survey and had resided in their actual rural community since birth, was conducted to determine the influence of environmental Cd exposure on the mortality of the general population in the Jinzu River basin. The Cox hazard ratios for males and females exposed to Cd concentration in rice >0.30 mg/kg were 1.42 and 1.10, respectively. Especially, this value is statistically significant in men. Since the mean Cd concentration in rice was closely related to the development of renal injury, the Cd-induced renal injury is believed to be the factor underlying the increased mortality observed [89]. 

The relationship between the bone density and renal dysfunction was studied in 85 female inhabitants of the Cd-polluted Jinzu River basin aged 55 to 71 years who had various concentrations of p2-microglobulin in urine [92]. A significant negative correlation between the urinary p2-microglobulin level and indicators of microdensitometry was found. 

Nakano M, Aoshima K, KatohT,Teranishi H, Kasuya M. Urinarytrehalase activity and renal brush-border damage in inhabitants of a cadmium-polluted area (Jinzu River basin). Toxicol Lett 1986 34 159-166. 

Osawa K, Kobayashi E, Okubo Y, Suwazono Y, KidoT, Nogawa K. A retrospective study on the relation between renal dysfunction and cadmium concentration in rice in individual hamlets in the Jinzu River basin, Toyama Prefecture, Japan. Environ Res 2001 86 51-59. 

Aoshima K, Iwata K, Kasuya M. Environmental exposure to cadmium and effects on human health. Part 2. Bone and mineral metabolism In inhabitants of the cadmium-polluted JInzu River basin In Toyama Prefecture. Jpn J Hyg (In Japanese) 1988 43 864-871. 

That cadmium is a toxic and hazardous product of our industrialised society, manifested itself among inhabitants of the Jinzu River basin in Toyama Prefecture, Japan, in the 1950s, in the form of Itai—Itai disease. It remains the... 

Jinzu Valley, Japan. One of the most infamous cases of contaminated land and health occurred in Japan and the effects were most prominent immediately after the Second World War. Around the end of the 19th century, soils in the Jinzu River basin, part of the Toyama prefecture, became contaminated with cadmium as a result of activities upstream at the Kamioka mines. The main activity at this mine was the mining and processing of zinc (cadmium is often associated with zinc ores) with the result that wastewater rich in heavy metals was discharged into the Jinzu River. Contaminants from this industry moved down-stream and caused contamination of soils in paddy fields as a result of abstraction of river water into fields in order to cultivate the local rice crop. Under favourable conditions, cadmium can be a fairly mobile heavy metal, particularly in soils with low pH, and increases in soil cadmium can often result in an increase in the uptake of cadmium by plants. This in turn results in an increase in dietary exposure and the consumption of contaminated agricultural crops can be a major pathway of human exposure. 

This is what happened in the Jinzu River basin as locally grown rice became contaminated with cadmium. Dietary exposure was high as rice was the staple diet of most local people and as a result of chronic exposure to cadmium in the diet many began to suffer bone disease and abnormalities of calcium metabolism and kidney problems, a condition that known locally as itai-itai disease (literally translated as ouch ouch ).38 This disease became most apparent during and immediately after the Second World War with elderly women, particularly women who had given birth to several children, most affected. During this period, food was scarce and the diets of local people became extremely heavily dependent on rice. In addition, the scarcity of food meant that the diet of many people was also deficient in calcium, vitamin D and protein. These factors exacerbated the toxicity of cadmium, and in a relatively small area over two hundred elderly women were severely affected, many of whom eventually died as a result of this condition. It has since been estimated that people in the Jinzu River basin had a... 

The values of indices for both cortical width and bone mineral content were significantly lower in itai-itai disease patients than the Cd-exposed subjects. The Cd-exposed women also showed a decrease in bone density compared with the non-exposed subjects. A significant decrease in bone density was also observed between Cd-exposed men and the non-exposed subjects, although the difference was not as distinct as in women. In other Cd-polluted areas such as the Jinzu River basin or Tsushima Island, a decrease in bone density in Cd-exposed subjects has also been reported using the same method [82, 83]. 

The itai-itai disease, the most infamous case of Cd toxicity to humans, was first reported in the mid 1940s in the Jinzu River basin in Japan. It was a combination of bone and kidney disease. The disease was particularly painful ( itai-itai translates into ouch ouch ) because of the fragility of the bones which could not sustain any pressure. Prolonged exposure to Cd resulted from ingestion of contaminated rice, as rice fields were being irrigated by river water contaminated with the waste from a zinc mine [34,35]. 

An increased risk of osteoporosis correlates with the cadmium burden in different populations, especially for post-menopausal women. Cadmium exposure decreases bone mineral density and thus increases the risk for fractures. These effects on the bones are related to kidney malfunction and poor calcium reabsorption in the nephron, as witnessed by (hyper)calciuria. The consequences of cadmium exposure on the human skeleton were particularly obvious for Japanese living along the Jinzu river basin in the 20th century. Water and rice contaminated by cadmium as a result of zinc-mining activities upstream afflicted the local people with the Itai-Itai disease, a particularly acute and painful form of osteomalacia [44]. 

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