Charcot’s disease: long exposure to diesel exhaust increases the risk

“The greater the exposure to diesel exhaust, the greater the risk of developing amyotrophic lateral sclerosis (ALS).” This is, in summary, what has just proved study Aisha Dickerson (Harvard TH Chan School of Public Health, Boston). “Studies had previously been conducted on the links between exposure to diesel exhaust and ALS, but this is the first time that the link between exposure to diesel exhaust and ALS has been analyzed at the ‘ladder of a lifetime,’ says Aisha Dickerson.

Fatal outcome

ALS, better known as Charcot’s disease, is a serious neurodegenerative disease that results in progressive paralysis of the muscles involved in voluntary motor skills, also affecting speech and swallowing. In the absence of a known treatment, its outcome is fatal after an average of 3 to 5 years, generally via damage to the respiratory muscles.

This new study is based on a panel of 1639 Danish patients all suffering from an ALS diagnosed in 1982 and 2013. The researchers identified the professional path of each, then calculated their level of exposure to diesel engine exhaust. The health status of each person with ALS was then compared to that of 100 people of the same age and sex. Result: Out of 50% of patients who had been exposed to diesel exhaust in their career, 45% were more likely to develop ALS than those who had never been exposed to diesel exhaust during their career.

Personal exhibition

“Exposure to diesel deserves greater attention from the scientific community,” concludes Aisha Dickerson, recalling that while her study does establish a link between exposure to diesel and the development of Charcot’s disease, it does not demonstrate that Exposure to diesel vehicle exhaust alone is the cause of ALS.

Another limitation of the study: the calculation of the exposure to diesel exhaust gases is based only on the occupations of the Danish patients in the panel, leaving aside the possible personal exposure to diesel exhaust gases of the research subjects.