Uptake of Aluminium

Aluminium is one of the most abundant elements in the earth s crust, amounting to about 8% it is the third most abundant element. Aluminium is ubiquitous in soil, clay, rocks, and even in water. It occurs in the form of chemical compounds (in the oxidation state A1 (111+)), but never as an unoxidised metal (oxidation state 0). 

Because of its high concentration in the earth s crust, aluminium is necessarily found in the air and water. It thus penetrates into the food chain and is found in plants and all animals, as well as in humans (30-50 mg for a body weight of 70 kg). Exposure to aluminium through natural foodstuffs is thus daily and unavoidable. The ingested quantity is estimated at 10 mg per day, and its origin can be broken down as follows [1]  

The aluminium content of many foodstuffs has been evaluated by the US Food and Drug Agency (FDA) [2]. In general, vegetables contain more aluminium than meat. For example, small peas contain 0.6 mg of aluminium per 100 g of foodstuff, while chicken contains only 0.5 g of aluminium per 100 g of meat. Tea is particularly high in 

The daily aluminium uptake varies from one country to another, because it depends on both eating habits and food additives (generally aluminium salts) used as preservatives, fermenting agents and emulsifiers in the food industry. For example, in the United States, the daily aluminium uptake is estimated at 2-35 mg, compared to 2.5-6.8 mg in Italy. 

Aluminium sulphate is widely used for the treatment of drinking water, in order to flocculate organic matter in suspension. The aluminium concentration of treated water is generally below 200 

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Direct entry of alumina adjuvants through the skin may occur by the use of therapeutic vaccines, with a resultant transient uptake of aluminium in the brain (Redhead et al., 1992). The injection of talc (magnesium silicate)-containing drugs intended for oral consumption has been shown to induce progressive pulmonary fibrosis in drug abusers (Pare etal., 1989). 

Perl, D.P. and Good, P.F. (1987). Uptake of aluminium into central nervous system along nasal-olfactory pathways. Lancet i, 1028. 

Z. Rengel, Uptake of aluminium by plant cells. New Pliyiol. 734 389 (1996). 

Aluminium is the third most abundant element in the earth s crust and is used widely in the manufacture of construction materials, wiring, packaging materials and cookware. The metal and its compounds are used in the paper, glass and textile industries as well as in food additives. Despite the abundance of the metal, its chemical nature effectively excludes it from normal metabolic processes. This is due largely to the low solubility of aluminium silicates, phosphates and oxides that result in the aluminium being chemically unavailable. However, it can cause toxic effects when there are raised concentrations of aluminium in water used for renal dialysis. These effects are not seen when aluminium is at the concentrations usually present in drinking water. There is currently much activity to examine the factors that influence uptake of aluminium from the diet. 

Smans KA, D Haese PC, Van Landeghem GF, Andries LJ, Lamberts LV, Elendy GN, De Broe ME. Transferrin-mediated uptake of aluminium by human parathyroid cells results in reduced parathyroid hormone secretion. Nephrol Dial Transplant 2000 15 1328-1336. 

Studies of the interaction of hydroxyapatite with the acid washings from glass-ionomer cements show that fluoride is taken up readily by the mineral phase, despite the initial state of fluoride as a complex ion or covalent species [106]. There was no concomitant uptake of aluminium by the hydroxyapatite, suggesting that any complexes formed are dissociated by the mineral phase, allowing only fluoride to be taken up. 

Pesticide contamination in humans and in the environment Pollution in a mining context Green chemistry Environmental pollution in soils Heavy metal and groundwater issues Biological uptake of aluminium... 

Most farm crops will not grow satisfactorily if the soil is veiy acidic. In acid conditions aluminium, iron and manganese become more readily available. Excessive uptake of aluminium in add conditions can severally affect crop growth. Some crops are more affected than others. This can be remedied by applying one of the commonly nsed liming materials. 

Treatments of diseases such as osteoporosis, rickets and osteomalacia, in which there is a disturbance of phosphate levels, is complicated by the interdependence of calcium metabolism. This topic has recently been discussed in relation to clinical medicine21. There is the further difficulty that absorption of phosphate from the bowel can be decreased in the presence of calcium or aluminium salts because of the formation of their insoluble phosphates. Uptake of phosphate by bone is exploited in the treatment of polycythaemia vera by intravenous injection of 32P as sodium phosphate. The resulting irradiation of the neighbouring red bone marrow diminishes the production of red cells. 

In a further study of autophobicity by Blake and Wade (1971), adsoiption isotherms were determined for water vapour and the first five n-aliphatic alcohols on the surface of oxidized aluminium foil. The results were very similar to those obtained for a-Al203. A Type II water isotherm was obtained, the initial steep slope being indicative of a high affinity of adsorption. The residual uptake of water was... 

Ma, J. F. Hiradate, S. (2000). Form of aluminium for uptake and translocation in buckwheat (Fagopyrum esculentum Moench). Planta, 211, 355-60. 

Surveys have shown a general correlation between the pH and fish status in lakes, and the physiological response of fish to acidic water is now well known ( ). Acid water affects the uptake of sodium and chloride ions through the cell membranes in the gills, and leads to a disturbance of the electrolyte balance ( ). The concentration of reactive (uncomplexed) aluminium ions in acidified waters is particularly detrimental (30), apparently because this interferes with the metabolic uptake of electrolytes from the water, while calcium ions have an ameliorating effect (31) ... 

RufyUdri, G., Dufey, J.E., Nootens, D., Delvaux, B., 2001. Effect of aluminium on bananas Musa spp.) cultivated in acid solutions. II. Water and nutrient uptake. Fruits 56, 3-14. 

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