ORIGINAL ARTICLE

Synergistic effect of hepatitis virus infection and occupational exposures to vinyl chloride monomer and ethylene dichloride on serum aminotransferase activity

H-I Hsieh¹, J-D Wang², P-C Chen², T-J Cheng²

¹ Department of Family Medicine, Cathay General Hospital, Taipei, Taiwan
² Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan

Correspondence to:
Correspondence to:
Dr T-J Cheng
Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, Taipei, Taiwan 10018; tcheng{at}ha.mc.ntu.edu.tw

Aims: To study the synergistic effect of occupational chemical exposure and hepatitis virus infection on serum aminotransferase activity.

Methods: A total of 568 male workers who were employed in five polyvinyl chloride (PVC) or four vinyl chloride monomer (VCM) manufacturing factories were studied. Information relating to current job title, alcohol consumption, and cigarette smoking was obtained. Exposure level of chemical mixtures was classified by hygienic effect (a summation of personal time weighted average/reference permissible exposure level of each chemical) into high, moderate, and low exposure groups. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and anti-hepatitis C antibody were assayed.

Results: Hepatitis virus infection and increased body mass index were associated with abnormal serum aminotransferase activity. In workers with hepatitis virus infection, those with high exposure had a higher prevalence of abnormal AST and ALT compared to low exposure; among those without hepatitis virus infection, the differences of prevalence of abnormal AST and ALT were not significant between different chemical exposure groups. There was a significant trend of increasing risks of increased AST and ALT in moderate and high exposure groups with hepatitis virus infection. Such a synergistic effect was more prominent among HBeAg-positive workers.

Conclusions: Mixed exposures to 1,2-ethylene dichloride and VCM have a positive synergistic effect with hepatitis virus infection on liver damage. Assessment of fitness for work should be considered in workers with hepatitis B and C infection, when they have potential exposure to hepatotoxins in the workplace.

Keywords: serum aminotransferase; hepatitis virus infection; occupational chemical exposure

Abbreviations: anti-HCV, anti-hepatitis C antibody; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; EDC, 1,2-ethylene dichloride; GSH, glutathione; HBeAg, hepatitis B e antigen; HBsAg, hepatitis B surface antigen; PEL, permissible exposure level; PVC, polyvinyl chloride; TWA, time weighted average; VCM, vinyl chloride monomer

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?