Cadmium daily intake

Cadmium daily intake levels in most OECD nations have been decreasing steadily since the 1970s and today range from 10 to 20 jig per day, well below any levels of human health concern (International Cadmium Association 1999). These relationships are shown in Figure 6. 

Selenium is readily available in a variety of foods including shrimp, meat, dairy products, and grains, with a recommended daily intake of 55 to 70 jug. It occurs in several forms with Se+6 being biologically most important. Selenium is readily absorbed by the intestine and is widely distributed throughout the tissues of the body, with the highest levels in the liver and kidney. It is active in a variety of cellular functions and interacts with vitamin E. Selenium appears to reduce the toxic effects of metals such as cadmium and mercury and to have anticarcinogenic activity. Selenium produces notable adverse effects both in deficiency and excess thus recommended daily intake for adults is approximately 70 Jg/day but should not exceed 200 pg/day. 

Organization guidelines for drinking water quality (World Health Organization, 1984) include limit values for the organic and toxic substances (see Table 11.6), based on acceptable daily intakes (ADI). These can be adopted direcdy for ground-water protection purposes, but in view of the possible accumulation of certain toxic elements in plants (e.g. cadmium and selenium), the intake of toxic materials... 

Studies on the dietary intake of Cd and Pb carried out in the 1990s in Italy using different methods showed that values were higher than Predicted Tolerable Daily Intake (PTDI) for Pb in two surveys in Modena (641 pg day-1, 220-456 pg day-1) and for Cd in Catania (44-183 pg day-1), Marche (52-138 pg day-1) and Modena (63-151 pgday-1) [22]. Cadmium and Pb daily intake in some European countries have values lower than the PTWI in all European countries, ranging from 17 to 50 percent, of PTWI for Cd and from 8 to 83.5 percent of PTWI for Pb [23]. 

J. P. Buchet, R. Lauwerys, A. Vandevoorde, J. M. Pycke, Oral daily intake of cadmium, lead, manganese, copper, chromium, mercury, calcium, zinc, and arsenic in Belgium duplicate meal study, Food Chem. Toxicol., 21 (1983), 19-24. 

I. F. Rivai, H. Koyama, S. Suzuki, Cadmium content in rice and its daily intake in various countries, Bull. Environ. Contam. Toxicol., 44 (1990), 910-916. 

Llobet, J.M., Falco, G., Casas, C., Teixido, A., Domingo, J.L. Concentrations of arsenic, cadmium, mercury, and lead in common foods and estimated daily intake by children, adolescents, adults, and seniors of Catalonia, Spain. J. Agric. Food Chem. 51, 838-842 (2003)... 

Daily intake of Cd from food is estimated at 35 to 90 /xg. When dietary exposure reaches critical concentrations, estimated to be about 250 to 300 /ug/d, toxicity symptoms are manifested. Cadmium intakes of the Japanese farmers suffering from the widely known "itai-itai" disease were reported to be from 600 to 1000 /xg/d. The disease was caused by ingestion of rice highly contaminated with Cd. The rice paddies received water discharged from upstream Zn mines. Many of the victims died as a result of the disease. 

The diet is the major route of human exposure to cadmium. Contamination of foods with cadmium results from its presence in soil and water. Concentrations of cadmium in foods range widely, and the highest average concentrations are found in mollusks, kidneys, livers, cereals, cocoa, and leafy vegetables. A daily intake of about 60 [tg would be required to reach a concentration of 50 mg/kg in the renal cortex of persons 50 years of age, assuming an absorption ratio of 5%. About 10% of the absorbed daily dose is rapidly excreted (WHO, 1989, 2001). 

Faecal elimination method, again as for lead, confrrmed the daily intake of cadmium obtained by duplicate diet method in Sweden. In Croatia faecal elimination method showed higher values. 

Food and cigarette smoke are the most likely sources of cadmium exposure for the general population. The total daily intake of cadmium from food, water, and air for an adult fiving in North America or Europe is estimated to be between 10 and 40 micrograms (3.53 X 10 and 1.41 X lO ounces). The U.S. Environmental Protection Agency has established oral reference doses for cadmium 0.0005 mg/kg/day (from water) and... 

Sharrett AR, Carter AP, Orheim RM and Feinlieb M (1982a) Daily intake of lead, cadmium, copper, and zinc from drinking water the Seattle study of trace metal exposure. Environ Res 28 456-475. 

The average normal daily intake via food is 10-20 pg in most countries. The highest cadmium concentrations are found in some basic foodstuffs such as wheat, rice, liver, kidney and certain seafoods. Drinking water and atmospheric exposure (1-10 ng/m ) are generally of minor importance. Smoking twenty cigarettes a day has been estimated to result in an inhalation of about 3 pg [67]. 

Human exposure to high concentrations of cadmium are rare and current concern centers around the chronic toxicity caused by long-term exposure to low levels of the metal. Bone disorders are one manifestation of chronic cadmium exposure. Cadmium is present in all tissues of adults, with the most significant amounts found in the liver and kidney, and the concentrations tend to increase with age. The WHO regards a tolerable daily intake of cadmium to be 70pgd for an adult of 70 kg. 

Cadmium oxide can be a colourless, amorphous powder or a red/brown crystal. The natural human intake of cadmium is between 10 to 1000 mg whereas WHO set the safe daily intake as 70 mg. 

TABLE IX Average Daily Intake and Absorption of Cadmium by Americans ... 

Phosphorus fertilizers may contain impurities among those are some heavy metals that are of concern. In particular, cadmium (Cd) has received attention during the past few years. The level of cadmium content in fertilizers has been more or less arbitrarily limited to the concentration of 50 mg Cd/kg of P2O5 [7]. WHO has limited the daily intake of Cd to 1 microgram Ag of body weight per day [7]. The current average intake in Europe is lower than this limit [8]. 

Cadmium is a naturally-occurring environmental contaminant to which humans are continually exposed in food, water, and air. The average daily intake of cadmium... 

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