5 July 2005
A new Taiwanese study published in Occupational and Environmental Medicine reports evidence of increased levels of DNA damage among female motorway toll-booth operators, when compared with a similar group of female office workers. Researchers from Taiwan's National Defence Medical Center measured levels of 8-hydroxydeoxyguanosine (8-OhdG) in the urine, and of nitric oxide (NO) in the blood of both groups as indicators of the levels of oxidative DNA damage (that is, damage induced by reactive oxygen intermediates, or ROIs). When smokers were excluded from analyses, because tobacco smoke has a significant effect on urinary 8-OHdG levels, 8-OHdG levels were found to be around 90% higher, and NO levels 30% higher, among the toll-booth operators than they were among the office workers (see BBC news report).
Although the study size was very small (47 subjects and 27 controls) and the researchers themselves note that they did not take into account other genetic and environmental factors that can influence 8-OHdG metabolism, they nevertheless propose that exposure to traffic fumes can induce DNA damage via increased levels of ROI activity. Since this could in turn increase the risk of cancer, they call for increased control of traffic pollution in order to protect the health of people exposed to traffic fumes [Lai CH et al. (2005) Occup Environ Med. 62, 216-222]. Further studies will be required to investigate the genotoxic effect of such fumes more reliably.