Association of Traffic-Related Air Pollution (TRAP) with DNA Damage and Respiratory Health Symptoms among Primary School Children in Selangor

Exposure to Traffic-Related Air Pollution (TRAP) is a public health concern accountable for several health problems each year in Malaysia. Several studies globally have shown that children in schools near high traffic roads have increased risks for Deoxyribonucleic Acid (DNA) damage due to higher exposure to TRAP. The study aimed to determine the association between TRAP exposure with DNA damage and respiratory symptoms among school children in Selangor state. PM2.5, PM10, Ultrafine Particle (UFP), Carbon Monoxide (CO), Carbon Dioxide (CO2), Nitrogen Dioxide (NO2) and Sulphur Dioxide (SO2) were measured as TRAP. A cross-sectional comparative study was carried out among children in Kajang as exposed group (n=52) and Hulu Langat as comparative group (n=52). A set of standardized and validated questionnaires were used to determine respiratory symptoms and history of exposure. Measurements of indoor and outdoor air pollutants were conducted in schools. Buccal mucosa cells were collected, which then followed by investigation of DNA damage using a comet assay. All pollutants were significantly associated with reported cough and wheezing at p<0.05. Meanwhile, PM2.5, PM10 and UFP were significantly associated with comet tail length at p<0.05. Additionally, comet tail length in the exposed group was significantly higher (35.95±7.93 μm) than those in the comparative group (30.32±8.358 μm), and the difference was significantly different (t=3.450, p=0.001). Children were more likely to have genotoxicity of buccal mucosa if they were exposed to higher levels of ultrafine particles (UFP). This study demonstrated that children in schools near heavy traffic roads have an increased risk for respiratory symptoms and DNA damage due to higher exposure to TRAP. Therefore, this study supports its importance as a risk factor in associations documented between TRAP and respiratory health among children.