Density of truck traffic on residential streets and the impact on asthma and asthma-like symptoms in childhood

Abstract

Background: Conflicting results have been reported, mostly in developed countries, on the relationship between traffic exposure and asthma. The aim of this study was to examine the impact of truck traffic exposure on childhood asthma in The Republic of Macedonia, as a developing country with a moderate rate of high truck traffic exposure, high dietary antioxidants intake, and previously reported low prevalence of asthma. Methods: Parental-reported data was used, obtained through standardized surveys in winter 2015-16. There were 1945 children aged 5-15 years from randomly selected schools in Skopje, the capital of Macedonia, who took part. The association between truck traffic density on residential streets on weekdays with wheeze 'ever', current wheeze, current exercise-induced wheeze, current dry night cough apart from a cold and doctor-diagnosed asthma was investigated after adjusting for potential confounders using binary multiple logistic regression. Results: Truck traffic density exposure almost the whole day was found to be 9.6%, frequently through the day 30.2%, seldom 47.7% and never 11.9%. The exposure almost the whole day increased the risk of current wheeze (aOR: 2.84; 1.20-6.70; p=0.017), wheeze 'ever' (aOR: 1.55; 0.98-2.45; p=0.061), exercise-induced wheeze (aOR: 4.19; 0.85-20.62; p=0.078) and dry night cough (aOR: 1.78; 0.96-3.33; p=0.068). There was no association with the other investigated variables, including diagnosed asthma. Conclusion: The findings suggest an adverse effect of high truck traffic exposure on asthma-like symptoms, but not on asthma, which support the hypothesis that components of air pollution act as non-specific respiratory irritants.