A recent study in the United Kingdom evaluated the impact of traffic-related air pollution on the development of childhood asthma.
Asthma is a chronic condition of the airway passages of the lungs. Asthma sufferers become oversensitive to certain stimuli such as air pollution, dust, and pollen, which can trigger an attack. This causes their airways to become temporarily narrowed and inflamed, leading to symptoms such as coughing, wheezing, and chest tightness. Asthma can develop at any age but is often cited as the most common chronic disease of childhood.
Traffic-related air pollution is thought to be an important factor in the development of childhood asthma, but there has been little research on quantifying its impact. An international group of researchers conducted a study in the United Kingdom (UK) city of Bradford to look at the impact of traffic-related air pollution on childhood asthma. They recently reported their findings in the journal Environment International.
The researchers chose the UK city of Bradford to conduct the study, as it reports higher than average rates of childhood asthma cases. They developed a new approach to assess the impact of exposure to nitrogen oxides in air pollution on the development of childhood asthma. This combined four types of assessment on traffic, emissions, atmospheric dispersion and health impact. This new method allowed them to produce a more accurate assessment of the impact of air pollution and traffic-related air pollution.
Traffic-related air pollution an important contributor to childhood asthma
The results and analysis showed that up to 38% of annual childhood asthma cases in Bradford may be related to air pollution and up to 12% of cases may be specifically related to traffic-related pollution. On further reviewing the results, the researchers concluded that their model may be underestimating the traffic-related portion of air pollution. After adjusting the model using actual measurements of air pollutants, the revised estimate suggested that up to 24% of the annual cases of childhood asthma could be linked to traffic-related air pollution.
Reducing traffic-related air pollution is important in lowering childhood asthma cases
This study provides important quantitative information about the impact of traffic-related air pollution on the development of childhood asthma. Traffic pollution is potentially preventable, and this offers an opportunity to act on one of the root causes of childhood asthma. While current programs such as stopping vehicles from idling their engines outside of schools and providing walking routes away from roads are important, the researchers suggest that more widespread environmental action is needed.
New policies should target traffic-related air pollution at several levels, including controlling traffic volume, exhaust and non-exhaust emissions, pollutant dispersion, and exposure. The researchers propose that future approaches to childhood asthma should move beyond disease-control to include disease-prevention.
Written by Julie McShane, Medical Writer
Reference: Khreis H, de Hoogh K, Nieuwenhuijsen MJ. Full-chain health impact assessment of traffic-related air pollution and childhood asthma. Environment International 2018 doi:10.1016/j.envint.2018.03.008