Garcia E, et al. - In a cohort of autoworkers, researchers assessed the links between lung cancer mortality and exposure to synthetic metalworking fluid (MWF), as well as to biocides added to water-based fluids to control microbial growth, controlling for the healthy worker survivor effect. Given biocides served as a marker for endotoxin, which has reported antitumour impacts. Biocides were presumed to account for the association shown between reduced lung cancer risk and exposure to synthetic fluids in prior studies. A modest positive association for synthetic MWF with lung cancer mortality was demonstrated. This finding was contrary to the negative links shown in earlier studies. Biocide exposure, however, was found to be inversely related to the risk of lung cancer mortality.