Although working outdoors has frequently been considered more healthful than working indoors, a growing literature suggests that outdoor air exposures increase the risk for a variety of diseases, such as asthma, heart disease, and lung cancer.^1,2 Consistent with these epidemiological studies are reports using the ³²P-postlabelling assay for stable DNA adducts showing that outdoor air causes DNA damage,³ which is a prerequisite for most mutation and cancer. Supporting these observations are hundreds of studies using primarily the Salmonella mutagenicity assay showing that the particulate and volatile fractions of outdoor air are mutagenic.⁴

As reviewed by Tovalin and colleagues⁵ in this issue of OEM, a few studies have used the single cell gel electrophoresis (comet) assay to assess DNA damage associated with outdoor air pollution. However, unlike many of the studies using the ³²P-postlabelling assay, studies using the comet assay have not included the personal monitoring of pollutants in order to link the …