We examine whether the job characteristics of physical demands and environmental conditions affect individual's health. Five-year cumulative measures of these job characteristics are used to reflect findings in the biological and physiological literature that indicate that cumulative exposure to hazards and stresses harms health. To create our analytic sample, we merge job characteristics from the Dictionary of Occupational Titles with the PSID data set. We control for early and also lagged health measures and a set of pre-determined characteristics to try to address concerns that individuals self-select into jobs. Our results indicate that individuals who work in jobs with the ‘worst’ conditions experience declines in their health, though this effect varies by demographic group. We also find some evidence that job characteristics are more detrimental to the health of females and older workers. Finally, we report suggestive evidence that earned income, a job characteristic, partially cushions the health impact of physical demands and harsh environmental conditions for workers. These results are robust to inclusion of occupation fixed effects. Copyright © 2010 John Wiley & Sons, Ltd.