X-rays showed that 6.7 percent of the miners had the potentially life-threatening illness, which results in a build-up of scar tissue in the lungs from years of inhaling silica dust in mining operations.
Researchers say the disease can progress even after miners are no longer exposed to the dust, causing severe breathing problems in its later stages.
The prevalence of silicosis among miners increases with age and years of drilling experience, according to researchers. At age 40, miners faced nearly four times the risk of having the disease, by age 60 they had 10 times the risk, according to researchers.
Controlling dust exposures is critical because there is no effective treatment for silicosis, according to researchers.