Background: Asthma is a common respiratory disease, which is linked to air pollution. However, little is known about the effect of specific air pollution sources on asthma occurrence.

Objective: To assess individual asthma risk in three urban areas in Israel characterized by different primary sources of air pollution: predominantly traffic-related air pollution (Tel Aviv) or predominantly industrial air pollution (Haifa bay area and Hadera). 

Methods: The medical records of 13,875, 16- 19-year-old males, who lived in the affected urban areas prior to their army recruitment and who underwent standard pre-military health examinations during 2012–2014, were examined. Nonparametric tests were applied to compare asthma prevalence, and binary logistic regressions were used to assess the asthma risk attributed to the residential locations of the subjects, controlling for confounders, such as socio-demographic status, body mass index, cognitive abilities, and education.

Results: The asthma rate among young males residing in Tel Aviv was 8.76%, compared to 6.96% in the Haifa bay area and 6.09% in Hadera. However, no statistically significant differences in asthma risk among the three urban areas was found in controlled logistic regressions (P > 0.20). This finding indicates that exposure to both industrial- and traffic-related air pollution is associated with asthma prevalence.

Conclusions: Both industrial- and traffic-related air pollution have a negative effect on asthma risk in young males. Studies evaluating the association between asthma risk and specific air pollutants (e.g., sulfur dioxide, particulate matter, and nitrogen dioxide) are needed to ascertain the effects of individual air pollutants on asthma occurrence.