Cadmium is discharged into rivers from metal processing, plating and chemical industry operations and can also be dissolved from plumbing. It can produce high blood pressure but of more concern is the fact that cadmium is a cumulative poison with the main target organs being the liver and kidneys.
In Japan the toxic effects of cadmium were highlighted when people developed “ouch ouch” disease which had the symptoms of lumbago, and resulted in death by kidney failure.
The World Health Organisation (WHO) recommends a maximum intake of 0.4 mg to 0.5 mg per week of cadmium. This is a very low level and therefore, the maximum level for cadmium in drinking water is reflective of this. Cadmium is also present in tobacco; smoking 20 cigarettes per day corresponds to about half the WHO limit for one week.