Americans with lower incomes and educational attainment often live shorter, sicker lives than their wealthier, more educated counterparts. Contributors to these disparities can include access to care, hazardous living conditions, nutrition in early childhood, and personal behaviors. But what about workplace conditions? Do certain groups of people get sorted into jobs that exacerbate inequalities in life expectancy?

That’s the question a study published in this month’s issue of Health Affairs confronted. The researchers noted that while previous research shows that a “variety of working conditions — such as job insecurity, work-family conflict, low job control, high demands at work and long hours — have important health consequences,” their study may be the first to examine the effect of workplace exposures on racial and educational disparities in life expectancy.

To conduct the study, researchers analyzed General Social Survey data and considered 10 workplace conditions and practices (defined in the study as “workplace exposures”): unemployment and layoffs; lack of health insurance; shift work; long working hours; job insecurity; work-family conflict; low job control; high job demands; low social support at work; and low organizational fairness.

Study authors Joel Goh, Jeffrey Pfeffer and Stefanos Zenios write:

Our analysis is based on two premises. The first is that these exposures affect health outcomes, a result that is well established. The second is that people who have less education and lower socioeconomic status are more likely to hold jobs that have a higher prevalence of these unhealthy workplace practices, compared to people who are better educated and have higher socioeconomic status. Therefore, it is reasonable to argue that the differential exposure to workplace conditions across socioeconomic strata may be an important factor in accounting for the observed differences in life expectancy across demographic groups.

Ultimately, the researchers found that 10 percent to 38 percent of the difference in life expectancy across demographic groups could be explained by different job conditions. In particular, the study found that people with the highest educational attainment had only 5 percent to 10 percent of their mortality associated with workplace exposures. In contrast, people with the least formal education had 12 percent to 19 percent of their mortality associated with workplace conditions. Those with the highest education levels experienced workplace-attributable losses in life expectancy of between 0.31 years to 1.02 years; those with the least education experienced losses that were two to three times higher, between 1.4 years and 2.77 years.

Across all demographic groups, the combination of unemployment and layoffs and lack of health insurance contributed the most toward life span inequalities. The next most important factor was low job control among both men and women, followed by job insecurity among men and shift work among women. Overall, the study found that people with the least formal education tend to have jobs with more harmful workplace exposures.

In discussing their results, the authors noted that policy interventions could make a difference. They write: “The results suggest that policies to encourage healthier psychosocial work environments, especially for jobs likely to be held by the most disadvantaged demographic groups, should be seriously considered as part of any comprehensive strategy that aims to reduce the extent of these health inequalities.”

To request a full copy of the study, visit Health Affairs.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.