Persistent ethanol drinking increases liver injury induced by trinitrotoluene exposure: an in-plant case-control...

On the basis of a general survey conducted in a munitions plant, a case-control study was made on the various risk factors of liver damage induced by trinitrotoluene (TNT) exposure in the plant. One-hundred male cases with occupational TNT liver damage were paired with 100 male controls, one-by-one, for occupation, age and duration (years) of employment. A total of 55 possible risk factors were statistically analysed with a single factor analysis. On the basis of the single analysis, nine factors including drinking, smoking and education were further analysed with a conditional logistic regression model. A calculation was made on the odds ratio (OR) of each factor selected into the model. According to the estimated parameter of the established logistic model, the relative risk of the risk factors could be worked out. Finally, two factors, the amount of ethanol drunk on each occasion and the frequency of drinking every week were selected into the model at the level of a = 0.05. The result showed that these two factors have a dose-response relationship with their OR of occupational TNT liver damage, but there is no connection between smoking and occupational TNT liver damage and no interaction between drinking and smoking. The above results have revealed that people exposed to TNT and with a long history of heavy drinking, have a greater risk of suffering from chronic liver impairment than those that do not drink.