A Study of Lung Epithelial Atypia in Regard to the Effect of Smoking and Traffic-Related Air Pollution in Sudan

Background: Lung cancer risk in association with smoking was well established, but its association with traffic- related air pollution still unclear. To determine the relationship between exposure to smoking and air pollutants and lung epithelial atypia, we assessed using cytological method; cytological changes in sputum specimens. Methods: Sputum specimens were obtained from 300 apparently healthy volunteers, living in the city of Khartoum. Of the 300 study subjects, 150 were Traffic policemen (they were exposed to traffic-related air pollution (ascertained as Cases)) and 150 were non-exposed (ascertained as Controls). Results: Dysplasia was detected in nine individuals, of whom seven were cases and two were controls. All the nine individuals with dysplasia were smokers. Consequently, the risk of dysplasia associated with smoking was found to be statistically significant (P<0.02). Notably, there were 84 individuals with metaplasia, of whom, 58(69%) were identified among cases and the remaining 26(31%) were among controls. As a result, the risk of metaplasia associated with smoking and traffic-related air pollution was found to be statistically significant (P<0.001). In respect to the duration of exposure to traffic-related-air pollution among cases, metaplasia increases with the increasing of exposure (P<0001). Conclusion: Exposure to traffic was also associated with borderline elevated risks for developing dysplasia and high risks of development of metaplasia. Sputum cytology may provide a useful method in the assessment of lung atypical changes.