Earth’s crust contains about 8.13% aluminium which happens to be the third most abundant element on earth’s surface.
It is next only to iron in order of industrial importance and use in modem society. The mineral, bauxite (Al2O3 3H2O), is the chief source of aluminium of which adequate deposits, estimated to be around 150-200 million tons, occur in India. Important reserves of aluminium are found in Bihar, Madhya Pradesh, Maharashtra, Orissa and Tamil Nadu.
Aluminium is extensively used as canning and packaging material for foodstuffs and a number of other items, in making pans and utencils for cooking and keeping edible materials, in electrical appliances, as building material etc. all over the world. Due to its light weight and low cost, it is fast replacing iron and other metals in a number of articles and appliances.
Persons occupationally involved with mining, processing, manufacture of aluminium and other products are usually exposed to higher levels of aluminium. Indiscriminate disposal of aluminium products, the metal or its salts, usually causes contamination of the environment. Plenty of aluminium is present in foodstuffs and water, has been estimated that a normal individual ingests about 80.5 mg of this element per day. However this quantity may be as high as 160 mg per day if the entire food is prepared in aluminium utensils
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Aluminium levels as high as 50-60 times the average daily intake do not appear to cause any interference in the metabolism of the human body. Higher levels of aluminium, however, may interfere with phosphate metabolism, inhibit absorption of fluorides, calcium and iron compounds. Pulmot effects of aluminium follow inhalation of bauxite aerosols. Both restrictive and obstructive pulmot diseases develop as a sequel to fibrosis in tissues of lung (Schaver, 1948).
Aluminium compounds dissolved in water are much more injurious than as particulates in suspended state. Aluminum content higher than 1.5 per ml may cause anorexia, decreased activity and gill hyperplasia in fishes. To plants the injuring action of aluminium is enhanced under acidic conditions (pH 5 of lower). Roots become thick, lack finer branches and are unable to absorb water and nutrients efficiently.
Plants become stunted, stubby and brittle. Usually young seedlings are more susceptible to the toxic effects of aluminium than older plants. There is still no need for much concern about raised levels of aluminium. However, in view of the environmentally prevalent nature of aluminium compounds its levels should be closely monitored to avoid any likelihood of toxicity caused by this metal.