In fact, you are anything between 2.5 to 4.3 times more likely to develop the disease if your career is among the 'deadly dozen'.
The 'at risk' careers are: beauticians, pharmacists, morticians, chemists, laboratory technicians, physicians, veterinarians, dentists, firefighters, photographers, printers and nurses.
The real culprit is the chemical formaldehyde, which scientists have discovered is a major cause of ALS. Scientists originally thought that exposure to most pesticides triggered ALS, but researchers from the Harvard School of Public Health narrowed it down to just one after they tracked 1 million individuals who were regularly exposed to 12 different chemicals.
Over the following 15 years, 1,156 people died from ALS, and the vast majority had had a high exposure to formaldehyde during their working lives.
(Source: Journal of the American Medical Association, 2008; 299: 2375-6).