Background Liver diseases have been bound to environmental factors, inclusive of air pollution. The exposure of workers to petrochemicals counts as a possible cause of Liver diseases, whereas results are inconsistent with the previous studies. In this study, a meta-analysis is conducted to assess the pooled risk. Methods and finding A systematic search was performed by related researchers. Correlations are analyzed among petroleum and liver cirrhosis mortality, fatty liver, alanine amino transferase (abbreviated as ALT), aspartate amino transferase (abbreviated as AST). Pooled risk ratios (RR) with 95% confidence interval (CI) and effect size(ES) with 95% confidence interval are calculated. Sensitivity analysis and publication bias are also tested. Data are analyzed from 5 studies involving 296 participants. Results are incorporated through adopting a random effects meta-analysis. Working in a petrochemical plant shall not increase the death risk posed by cirrhosis (RR = 0.44, 95% CI [0.36; 0.54]). Yet the incidence of fatty liver increases (RR = 1.22, 95% CI [1.21; 1.23]). Abnormal incidence of ALT and AST also increases. Conclusions Occupational exposure plays an important role in causing ALT abnormalities and fatty liver among oil workers, but not a risk factor of cirrhosis, AST abnormalities and liver cancer.
