Children in bike trailers exposed to more pollution than cyclist pedalling, new research shows

New research by the University of Surrey found that air pollution levels in bike trailers on school or nursery runs was between 14 and 18 per cent higher than for the cyclist.

The study, published in the Journal of Hazardous Materials Advances and run by Surrey's Global Centre for Clean Air Research (GCARE) showed that on journeys typical of school or nursery runs the average concentration of coarse air pollution particles was significantly higher than at the cyclist's height.

Researchers found that particle concentration in trailers was 18 per cent higher than at the cyclist's height during afternoons, when parents typically collect children.

Higher concentrations of pollution were also seen during peak morning periods and at traffic lights.

The university took measurements on over 80 school runs, covering 176km, and assessed differences in exposure concentrations in trailers compared to at the cyclist's height.

Use of a bike trailer with a cover reduced children's exposure to pollutants by half during peak morning hours.

Air pollution is a leading cause of death in children under the age of five.

"It is unfortunate that the very people who help minimise pollution by cycling rather than driving can be exposing their children to higher levels of pollution," founding director of GCARE Professor Prashant Kumar said. 

"I would encourage adults pulling bike trailers to use covers in heavy traffic. With the use of electric-assisted cargo bikes growing rapidly in Europe, it's crucial traffic planners ensure road infrastructure is designed to enable safe use of sustainable transport options."

The impact of lockdown measures on air pollution levels was also noted, with a 91 per cent reduction in concentration of fine pollution particles when schools were closed.

Researchers have already committed to trying to secure funding to build a database of bike trailers under diverse traffic and environmental factors.