Rising unemployment rates could lead to an increase in morbidity and mortality rates even for workers who keep their jobs.

Researchers at the Integrated Benefits Institute, San Francisco, have come up with estimates of the possible impact based on risk factor survey data from the U.S. Centers for Disease Control and Prevention’s National Health Interview Survey.

IBI researchers analyzed the correlation between employed adults’ use of tobacco, alcohol and exercise, and the quarterly unemployment rates for those adults’ industries.

“Employees tend to smoke more, drink more, and exercise less at higher rates of unemployment,” the IBI says.

The researchers’ analysis suggests that the increase in the U.S. unemployment rate from 4.5% in April 2008 to 8.9% in April 2009 probably increased the percentage of employees who smoke each day by 25%, and the percentage who could be classified as moderate to heavy drinkers by 20%.

The doubling of the unemployment rate probably caused the percentage of employees who exercise at least 8 hours per week to fall 15%, the researchers warn.