Mitigation potential of local traffic interventions on paediatric asthma incidence in EU cities

ISSUE/PROBLEM: Motorised road traffic is a major contributor to Nitrogen Dioxide (NO2) emissions, contributing to the development and worsening of asthma. With a substantial and escalating prevalence of asthma in urban areas worldwide, this is an issue of public health significance. DESCRIPTION OF THE PROBLEM: Deploying methods such as Random Forests and Boosted Regression Trees, this study aims to determine the potential reduction in paediatric asthma incidence in European cities that could be achieved through policy interventions targeting local traffic reductions, such as car-free days. RESULTS: In trafficked areas in European cities such as Brussels and Paris, up to 40% of asthma incidence can be attributed to NO2 exposure. Preliminary results show a potential reduction of 29% [95% CI: 20-34%], 21% [95% CI: 13-25%], and 12% [95% CI: 7-15 %] in paediatric asthma incidence in trafficked areas, central urban areas, and residential areas in Brussels, respectively. In Trafficked and Urban Background Areas in Paris, we found a potential reduction of 17% [95% CI: 11 -19%] and 13% [95% CI: 8-16%] in paediatric asthma incidence respectively. Trends and findings are consistent with several methodologies applied. LESSONS: Using real-world interventions such as car-free days is an innovative way to assess the mitigation potential of diseases associated with traffic. Our study highlights the public health significance of local traffic reduction policies in addressing asthma incidence in urban areas. The recommended public health actions include implementing policy interventions to reduce traffic levels and emissions in urban areas. These findings can be useful for other countries/settings facing similar issues with traffic-related air pollution and asthma incidence. The policy intervention can also positively impact other traffic-related health effects such as physical activity, noise, and availability of green spaces. KEY MESSAGES: • Local traffic reduction policies can significantly reduce (paediatric) asthma incidence in urban areas in large European Cities. • Reducing traffic levels reduces traffic-related air pollution and improves public health via pathways such as promoting physical activity, reducing noise, and increasing green space availability.