Cadmium water contamination level

The evaluation of risk has underlined the possible adverse effects both on human health after the exposure to drinking water contaminated by landfill leachate and on small rodents and aquatic species at the hypothesized condition for humans, the estimated toxic effects of the raw leachate are mainly due to the levels of ammonia and cadmium and carcinogenic effects are induced by arsenic first and then by PCBs and PCDD/Fs while ecological potential risk is mainly attributable to the concentration of inorganic compounds, in particular ammonia for small rodents, cadmium, ammonia, and heavy metals for fishes. 

Inza, B., F. Ribeyre, R. Maury-Brachet, and A. Boudou. 1997. Tissue distribution of inorganic mercury, methylmercury and cadmium in the Asiatic clam (Corbicula fluminea) in relation to the contamination levels of the water column and sediment. Chemosphere 35 2817-2836. 

Although lead and cadmium sulfate are both soluble, a body of water contaminated with these toxicants in the presence of sulfate and biodegradable organic matter shows very low concentrations of dissolved lead and cadmium, although levels are relatively high in the sediments of the body of water. Explain. 

The metals have the tendency to form compounds of low solubility with the major divalent cations (Pb, Cd being found in natural water. Hydroxide, carbonate, sulfide, and, more rarely, sulfate may act as solubility controls in precipitating metal ions from water. A significant fraction of lead and, to a greater extent, cadmium carried by river water is expected to be in an undissolved form. This can consist of colloidal particles or larger undissolved particles of lead carbonate, lead oxide, lead hydroxide, or other lead compounds incorporated in other components of surface particulate matter from runoff. The ratio of lead in suspended solids to lead in dissolved form has been found to vary from 4 1 in rural streams to 27 1 in urban streams. The US Environmental Protection Agency (USEPA) has reported Maximum Contaminant Levels in water that are permissible to be 0.005 m L for cadmium and 0.015 mg/L of lead. ... 

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. 

Industries are constantly dumping heavy metal ions into lakes, rivers and reservoirs, thereby polluting them. Heavy metals are broadly defined as materials whose density is above 5 g/cm (Barakat 2011). Conmion heavy metals present in aqueous streams include chromium, mercury, lead and cadmium (Bailey et al. 1999). Table 2.1 (Kumiawan et al. 2006a) shown below describes the maximum contaminant level of heavy metals in surface water and their toxicides. 

Chronic exposure to high levels of cadmium in food has caused bone disorders including osteoporosis and osteomalacia. Long-term ingestion of water, beans, and rice contaminated with cadmium by a Japanese population was associated with a crippling condition, Itai-Itai disease. The affliction is characterized by pain in the back and joints, osteomalacia, bone fractures, and occasional renal failure, and it most often affected women with multiple risk factors such as multiparity and poor nutrition. ... 

Cadmium TT a simple microcosm experiment associating two biotic levels conducted in a Petri dish allows measurement of reproduction effects on daphnids following Cd contamination of either their food source (algae) or of their water medium. I (Janati-Idrissi et ah, 2001)... 

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