A study published in the July issue of the American Journal of Industrial Medicine shows that a variety of jobs are associated with an increased risk of death from several forms of brain degeneration, namely Alzheimer’s and Parkinson’s disease, early-onset dementia and motor neuron disease.

Many of the associations had been seen in earlier research and could potentially be explained by on-the-job exposures to the chemicals that farmers, welders and hairdressers routinely use or inhale. Other findings, however, such as the elevated disease risks among teachers, clergy and bank tellers, are not easily explained, according to the researchers, led by Robert M. Park of the National Institute for Occupational Safety and Health, Cincinnati, Ohio.

These neurodevelopmental diseases are marked by progressive, irreversible damage to cells of the central nervous system. It is thought that genes influence susceptibility to the conditions, but growing evidence also points to environmental factors, including some on-the-job exposures.

For example, farmers exposed to pesticides have been shown in some studies to have a higher-than-average risk of Parkinson’s disease, as have welders exposed to fumes containing the mineral manganese. Both of these occupations were associated with Parkinson’s in the current study as well. Hairdressers exposed to hair dyes, solvents or other chemicals used in salons were at increased risk of death from Alzheimer’s disease, presenile dementia and motor neuron disease.

 Link to European Agency for Safety and Health at Work