More than half of former construction workers have experienced hearing loss, and certain factors can exacerbate the condition, according to a recent study by the Center for Construction Research and Training (also known as CPWR).

Researchers looked at Building Trades Medical Screening Program data from more than 19,000 workers previously employed at Department of Energy nuclear power sites. The team used hearing test results and, after reviewing work history interviews, developed “qualitative exposure metrics” for noise and solvents. The study group was compared to an internal reference group with lower exposures and an external sample of workers who experienced low noise exposure.

The researchers found that 58 percent of the former construction workers had some form of hearing loss and, overall, had “significantly increased risk of hearing loss compared to reference populations.” In addition, those who worked for more than 30 years were nearly four times more likely to experience hearing loss than workers with fewer than 10 years on the job.

Other findings:

Smokers were 18 percent more likely than nonsmokers to experience hearing loss.
Workers with the highest amount of solvent exposure were 15 percent more likely than workers with the lowest exposure rates to experience hearing loss.

The researchers recommend that prevention efforts center on reducing worker exposure to noise, solvents and smoking.

Article originally appeared on Safety + Health