Drinking water containing cadmium

Hundreds of people in Japan suffered from a degenerative bone disease called itai-itai because they drank water containing cadmium.9 They lived downstream from a mine and smelter that produced zinc and cadmium. In West Bengal, India, where 800,000 people drink well water containing over 50 /a/L arsenic, 200,000 people developed skin lesions from drinking the water.10 In Bangladesh, 70 million people drink well water containing arsenic.11 The problem... 

Electroanalytical application of hemispherical [35,36], cylindrical [37,38] and ring microelectrodes [39] has been described. A hemispherical iridium-based mercury ultramicroelectrode was formed by coulometric deposition at -0.2 V vs. SSCE in solution containing 8 x 10 M Hg(II) and 0.1M HCIO4 [35]. The radius of the iridium wire was 6.5 pm. The electrode was used for anodic stripping SWV determination of cadmium, lead and copper in unmodified drinking water, without any added electrolyte, deoxygenation, or forced convection. The effects of finite volume and sphericity of mercury drop elecPode in square-wave voltammetiy have been also studied [36]. 

Other cadmium sources can include solder, galvanized pipes and metal fittings, pollution from disposal of cadmium-containing materials and from mining operations (see Chapter 7). However, concentrations of cadmium in drinking-water above the guideline value are unusual. 

Some advanced industrial nations have established strict guidelines for water supply facilities to protect their citizens from the adverse effects of toxicity and hazardous materials. Some countries have set up maximum contaminant levels (MCLs) beyond which the drinking water is considered unhealthy. The MCL established by the United States for lead is 0.05 mg/L and for cadmium is 0.01 mg/L. The United States has not defined an MCL for nickel. Specific detailed on adverse effects of lead, cadmium, mercury, nickel, and their compounds are well documented in the U.S. Environmental Protection Agency list. This list contains the Toxic Release Inventory (TRI) for chemicals, and the list is updated every five years. 

Due to its use in industry, cadmium containing solid waste disposal is regulated in many industrialized countries. These countries also have regulated the acceptable levels of cadmium in drinking water and wastewater. 

The TCLP specifically requires analyzing a liquid waste extract to determine whether it contains unacceptably high concentrations (Table 12) of any of eight toxic metal constituents identified in the USEPA National Interim Primary Drinking Water Standards. These are arsenic, barium, cadmium, chromium, lead, mercury, selenium, and silver. Some states have added copper, nickel, and zinc to this list. 

Human exposure mainly arises from combustion of fuels, plants, and waste, and consumption of adventitious cadmium present in food and water [83]. Humans and animals breathe cadmium-containing particles (mainly the oxide) and ingest cadmium complexes with their food and drinks. Cigarette smoking is a major route of uptake, whereas skin contact is not widespread owing to the natural dilution of cadmium, except for occupational settings. Dietary cadmium is more concentrated in some food items such as shellfish, offal, grains, and seeds. Some crops, such as rice, soybeans, or wheat, are more likely to accumulate cadmium firom polluted soils than others. 

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