A Centers for Disease Control and Prevention (CDC) study of more than 12 million people who died in the U.S. between 1985 and 2011 found that deaths from Parkinson’s disease and ALS (amyotrophic lateral sclerosis) occurred more often in people in higher socioeconomic status (SES) occupations.
Findings from the study were reported in the article, “Mortality from Amyotrophic Lateral Sclerosis and Parkinson’s Disease Among Different Occupation Groups — United States, 1985–2011,” that appeared recently in the Morbidity and Mortality Weekly Report.
The analysis included 26,917 ALS deaths, 115,262 Parkinson’s disease deaths, and 158,618 deaths from chronic disease of the endocardium (used as a control) out of about 12.1 million deaths in people whose occupations were categorized into 26 groups in the CDC’s National Institute for Occupational Safety and Health (NIOSH) National Occupational Mortality Surveillance (NOMS).
The NOMS surveillance system includes deaths from 30 U.S. states. The 26 categories were roughly arranged from high SES occupations, such as management, to low SES, such as transportation and mining.
The risk factors for Parkinson’s disease include increasing age, male gender, and pesticide exposure. Smoking and caffeine consumption are lower in people with Parkinson’s disease. In this study, as expected, deaths from Parkinson’s disease occurred in people who were older and were more common among males and whites.
Deaths from Parkinson’s were significantly higher than the norm in 13 of the 26 job categories, in higher SES occupations such as white collar positions. But the authors emphasize that cause and effect relationships cannot be made based on these results and that additional studies into causes are needed.
“Most previous studies of occupation and ALS and Parkinson’s disease have focused on exposures to toxicants (e.g., pesticides, solvents, lead, welding fumes, and electromagnetic fields) that occur more frequently in lower SES occupations (e.g., farming, construction, production, and military service),” the authors reported. “This study, however, did not find positive associations between lower SES occupations and ALS and Parkinson’s disease mortality.”
Instead, the researchers report that people at higher socioeconomic status were significantly more likely to die from ALS or Parkinson’s. In particular, people included in the occupation categories of computer and mathematical, architecture and engineering, legal, or education training, and library, had at least a 50 percent higher chance of dying from the diseases compared to the norm.
“This study identified higher ALS and Parkinson’s disease mortality among workers in higher SES occupations, but was unable to identify occupational or nonoccupational factors that might explain these findings,” they continued.
“Future studies of workers in higher SES occupations are needed to assess the consistency of these findings and identify factors that might explain elevated ALS and Parkinson’s disease mortality, using study designs that provide evidence for causality,” the researchers wrote.