Skip to Content
Streetsblog California home
Streetsblog California home
Log In

How's this for poetic justice: People who drive end up being exposed to more pollution from their cars than people who ride bikes or walk, a new report found.

To conduct its experiment, the BBC asked families to drive, walk, and ride bikes along the same route to school in the northern England city of Sheffield — and then monitored the level of atmospheric toxins around them.

It turns out that drivers inhaled the highest levels of PM2, a tiny particle — 44 percent higher than the World Health Organization set as a baseline. Meanwhile, pedestrians consumed PM2 at 40.1 percent above The Who limit, and cyclists were 28.1 percent over the limit.

"I'm quite surprised by the result actually," one Sheffield mother quipped. "I thought in the car you'd have a bit more protection from the pollution."

In fact, air that enters through a car's front grille includes regular air, plus the exhaust fumes of the vehicles in front. The result is a toxic greenhouse for you and your family.

Other studies, including one at Leeds University on ambient air quality last year, confirmed the results that cyclists have far less exposure to air pollution than drivers while traveling through traffic.

“On more congested routes, the cyclist would come out with the lowest inhaled dose. Cycle lanes mean you can skip past traffic,” University of Leeds Institute for Transport Studies professor James Tate told The Guardian. Tate, who wrote the study, noted that bike lanes separated from traffic by several feet would cut particle exposure by a quarter more.

Some transportation experts even compared the dangers of driving with that of second-hand smoking when it comes to children's health.

“Children sitting in the backseat of vehicles are likely to be exposed to dangerous levels [of air pollution],” former UK Government Chief Scientific Adviser Sir David King told The Guardian. “You may be driving a cleaner vehicle, but your children are sitting in a box collecting toxic gases from all the vehicles around you.”

Research has shown that consistent exposure to air pollution can stunt the growth of children's lungs and can lead to asthma and other respiratory ailments, as well as reduce their ability to learn, concentrate, and pay attention. Worse, a California study found that prolonged exposure to hydrocarbons in the air can shorten children's DNA and affect their immune system. Hydrocarbons are formed from the burning of oil and gas.

King has warned drivers to "leave our cars behind" in order to protect the health of their children.

“It’s been shown that the health benefits of walking and cycling far outweigh the costs of breathing in pollution," King said. "If more drivers knew the damage they could be doing to their children, they’d think twice about getting in the car.”

Stay in touch

Sign up for our free newsletter

More from Streetsblog California

Thursday’s Headlines

Posted from the Oakland airport. I don't have any more travel until the end of the year so we'll be on a "normal schedule" until 2026.

November 20, 2025

Talking Headways Podcast: Emotional Consumption in China

High-speed rail has completely transformed the country. Think about that sentence: "High-speed rail has completely transformed the country." When was the last time something positive like that happened here?

November 20, 2025

Want Vancouver Skytrain in San Diego? Support People Mover to the Airport.

Vancouver is not alone in running people movers on urban rail networks. Copenhagen built its entire 26.9-mile metro using the same technology used on a Saudi Arabian university’s APM.

November 20, 2025

Cutting Federal Transit Funding Won’t Close Budget Gaps — But Will Make Transportation Less Affordable

The Trump administration's proposal to eliminate the mass transit account of the Highway Trust Fund would be short-sighted, ineffective, and ruinous, a new analysis finds.

November 19, 2025

Driver Kills Cyclist at Alemany and Naglee

Wide, high-speed street with painted bike lanes and no protection leads to inevitable outcome. This was not an accident.

November 19, 2025

Pomona North Metro Station to get Protected Bike Connection

The two-way cycle track will run a little under two miles, and also link with bike facilities in Claremont.

November 19, 2025
See all posts