It is known that individuals exposed to elevated amounts of airborne pollution are associated with increased rates of lung cancer. However, data analyzing the correlation between fine particulate matter pollutants and head and neck cancers is lacking. In this study, we examine the relationship between incidence of oral cancers in a region with the ambient air pollution levels.
Methods: The Illinois Department of Public Health’s cancer registry was queried to identify cases of oral and pharyngeal cancer diagnosed in each Illinois zip code between 2014 and 2018. The Environmental Protection Agency’s (EPA) Environmental Justice Screening and Mapping Tool (EJScreen) data from 2018 was used to extract ambient air pollution level estimates. Pollutants examined included ozone, particulate mater of less than 2.5 micrometers in diameter (PM2.5), and diesel particulate matter. Air pollutant levels in zip codes within the top quartile of oral/pharyngeal cancer incidence were compared with pollutant levels in the lowest quartile of incidence.
Results: Mean diesel particulate measures were significantly greater in the high incidence group compared to the low incidence group by Student’s t-test (p=0.010). Mean ozone and PM2.5 levels did not vary statistically between the groups (p=0.155 and p=0.157, respectively). The high cancer incidence zip codes did have a greater percentage of population over age 65 (p=0.001). There was no difference between the two groups in the fraction of minority or low-income populations (p=0.466 and p=0.942, respectively). A binary logistic regression found both diesel particulate levels (p<0.001) and percentage of the population over age 65 (p<0.001) to be significant predictors of a zip code belonging to the high vs low incidence group.
Conclusions: Diesel particulate matter levels were found to be associated with oral/pharyngeal cancer incidence. Greater ambient air pollution exposure may be a factor that increases pre-disposition to developing certain head and neck cancers.