However, prolonged exposure to organic solvents such as toluene and xylene may represent a risk factor for liver cancer. ?? 2001 Wiley-Liss, Inc.Abbreviations:CI, confidence intervals; ELISA, enzyme-linked immunosorbent assay; HBsAg: hepatitis B surface antigen; HBV, hepatitis B virus; HCC, hepatocellular carcinoma; HCV, hepatitis C virus; HCVAb, hepatitis C virus antibodies; IARC, International A