Public health
Pharmaceutical uses of aluminium
Aluminium hydroxide is widely used as an antacid to relieve gastric irritation and assist in the healing of peptic ulcers. It has good acid neutralising capacity and also has the ability to absorb and reduce the activity of pepsin.
Soluble aluminium compounds have been used for many years as antiperspirants. Aluminium chloride was the first compound used as an antiperspirant although currently aluminium chlorohydrate, which is much less acidic, is the major antiperspirant compound. The mechanism of action is still under investigation but it may achieve its effect by forming a plug of aluminium hydroxide within the sweat duct.
In 1926 alum-precipitation diphtheria toxoid was discovered to have greater antigenic properties (stimulate the production of antibodies) than the toxoid alone. The enhancement of diphtheria toxoid by the adjuvant (beneficial additive) aluminium hydroxide is typical of the use of an aluminium salt to increase the level and duration of immunity afforded by a vaccine. Aluminium salts are the most widely used type of adjuvant due to its reputation for safety in humans.
When used in blister packs for medicines, aluminium protects from tampering, maintains sterility and facilitates easy use.
Aluminium in water
Aluminium performs a valuable role in the treatment of water. In particular, aluminium sulphate (alum) is widely used in the purification of water from rivers, lakes and reservoirs as well as in the treatment of waste water. It is a flocculating agent with the capacity to coagulate and trap solid matter, which may be floating in the water - algae and other organic and non-organic matter.
During the water treatment process a fine precipitate is formed which removes many contaminants, including the spores of dangerous pathogens. Before leaving the treatment plant the water is filtered to remove the flocculant and the vast majority of the aluminium.
At present there is a World Health Organization (WHO) guideline for the maximum level of aluminium in drinking water of 0.2mg total aluminium per litre. This is essentially set for the visual effect and taste. No health-based criteria have been proposed for aluminium levels in drinking water by the WHO.
Aluminium in Packaging:
The use of aluminium in food packaging applications decreases potential health risks through its excellent barrier and heat and cold transfer properties – allowing the material to undergo faster sterilization through heating as well as through more rapid fast freezing.