Effects on the nervous system in different groups of workers exposed to aluminium.

OBJECTIVE: To investigate possible neurotoxic effects in groups of aluminium pot room and foundry workers, aluminium welders, and a small group of workers exposed to aluminium in the production of flake powder. METHODS: Exposure to aluminium was evaluated with aluminium concentrations in blood and urine as well as a questionnaire. The groups exposed to aluminium were compared with a group of mild steel welders. Neurotoxic effects were studied with mood and symptom questionnaires and several psychological and neurophysiological tests. RESULTS: The pot room and foundry workers showed very low aluminium uptake as their aluminium concentrations in blood and urine were close to normal, and no effects on the nervous system were detected. The group of workers exposed to flake powder had high concentrations of aluminium in blood and urine, even higher than those of the aluminium welders. However, aluminium could not be shown to affect the functioning of the nervous system in flake powder producers. Although significant effects could not be shown in the present analysis of the data on welders, the performance of the welders exposed to high concentrations of aluminium was affected according to the analyses in the original paper from this group. CONCLUSIONS: For the pot room and foundry workers no effects related to the exposure to aluminium could be found. For the group of flake powder producers exposed for a short term no effects on the nervous systems were evident despite high levels of exposure. Due to the high concentrations of aluminium in the biological samples of this group, measures to reduce the exposure to aluminium are recommended, as effects on the central nervous system might develop after protracted exposures. However, this assumption needs to be verified in further studies.

A follow-up study of five cases of aluminosis.

Five men were investigated after having pulmonary aluminosis due to exposure to aluminium pyrotechnic flake powder during the late 1940s. Two of the men had died 6 years and 20 years after exposure respectively, due to their lung disease. One man had died from heart failure 34 years after the end of exposure. Today, more than 40 years after exposure, two men were available for investigation. They had no respiratory symptoms and their vital lung capacities had not deteriorated during these years. One of the two survivors had developed a dementia with motor disturbances, which is not consistent with Alzheimer's dementia. This man had a very high concentration of aluminium in his cerebrospinal fluid. The other survivor had a normal concentration and was not demented.

Blood and urine concentrations of aluminium among workers exposed to aluminium flake powders.

In a group of workers exposed to aluminium flake powders, blood and urine concentrations of aluminium were assessed before and after vacation. Another group was investigated after retirement. Workers currently exposed to aluminium flake powders had urinary concentrations of the metal 80-90 times higher than those in occupationally non-exposed referents. The calculated half life for concentrations of aluminium in urine was five to six weeks based on four to five weeks of non-exposure. Among the retired workers the half lives varied from less than one up to eight years and were related to the number of years since retirement. These results indicate that aluminium is retained and stored in several compartments of the body and eliminated from these compartments at different rates.