Can aluminum cause Alzheimer's disease is a controversial question. Alzheimer's disease is the most common cause of senile brain disease and is a fatal and untreatable condition. It begins with learning memory deficits and progresses to involve all aspects of intellectual activity including judgement, calculation and language.
Post-mortem examinations of humans with Alzheimer's disease show that there are high concentrations of aluminum in the brain. However, aluminum normally is not found in healthy brain tissue and researchers do not know how the metal gets into the brain. Some researchers compared the aluminum concentration on brains of subjects affected by Alzheimer's disease and age-matched controls. They found no differences between the two groups, suggesting that elevated aluminum concentration may be associated with age. Experimentally it is proven that aluminum is toxic to nerves in animals but the neuron degeneration is different from what occurs in humans. For more detailed information please see the chemical profile on aluminum powder.
The animals that respond to aluminum treatment with neuron degeneration are rabbits, cats and dogs. If these animals are injected with aluminum salts directly into the brain they show learning memory deficits, become slower and lose curiosity. This picture resembles remarkably certain features of Alzheimer's disease. But the neuron degeneration is not the same as the one seen in Alzheimer's disease.
In conclusion, the cause of Alzheimer's disease is yet unknown and there is no absolute evidence linking aluminum exposure to Alzheimer's disease.
Workers can be exposed to aluminum during production or processing of this metal and its alloys. In addition to workplace exposure, people can come into contact with aluminum in many other ways.
Aluminum is found in food, drinking water and in some medications. There has been considerable interest and controversy concerning the relationship between aluminum in drinking water and Alzheimer's disease. So far, the results of many studies have been inconclusive and contradictory. It is important to note that the content of this metal in the diet is increased by the use of aluminum and its alloys in the food industry. The cooking and storage of food in aluminum ware might double or even triple the usual daily intake.
In the workplace, the American Conference of Governmental Industrial Hygienists (ACGIH) has assigned an occupational exposure limit based on respirable particle size.
The current ACGIH recommended Threshold Limit Value Time-Weighted Average (TLV-TWA) exposure limit for aluminum in the air is 1 mg/m3 for aluminum metal (CAS number 7429-90-5) and insoluble compounds.
Aluminum metal and insoluble compounds of respirable particle size are also categorized by ACGIH for carcinogenicity as A4 - Not classifiable as a Human Carcinogen; inadequate data on which to classify the substance as a human and/or animal carcinogen.
The TLV-TWA is the time-weighted average airborne concentration for a normal 8-hour workday and a 40-hour workweek to which it is believed that nearly all workers may be exposed repeatedly, day after day, without adverse health effects.
In many Canadian jurisdictions, exposure limits are the same as or similar to the ACGIH TLVs. Since the manner in which exposure limits are established, interpreted and implemented can vary, the appropriate government agency in each jurisdiction should be consulted.
Document last updated on August 5, 2008