Liver fibrosis in asymptomatic polyvinyl chloride workers.

This study was designed to determine whether vinyl chloride monomer (VCM) exposure is associated with liver fibrosis. A total of 347 workers with occupational exposure to VCM were systemically examined using liver ultrasonography and routine liver function tests. Vinyl chloride monomer cumulative dose (ppm-month) was estimated by summing the products of air VCM concentration levels and months of employment. Liver fibrosis was defined in subjects with precirrhosis and cirrhosis of liver diagnosed using ultrasonography. Significantly increased risks of developing liver fibrosis were found in workers who had history of high exposure jobs (odds ratio 5.5, 95% confidence interval 1.7-25.4) when compared with workers who did not have history of high exposure jobs. We concluded that there was an increased risk of developing liver fibrosis in PVC workers who had high exposure to VCM.