Is Commuting Via Bicycle Really Better For You? Fort Collins Study Finds Maybe Not!

General air pollution is a serious health hazard. Being more locally concentrated traffic-related air pollution can be due to even worse for your health and is clearly associated with increased mortality, yet few studies have examined strategies to reduce individual exposure while commuting. Full disclosure I am a bicycle rider. I like many others probably thought that by getting out of a car and instead commuting in a bicycle one would be a lot healthier. However it turns out that things aren't that simple.

Nicholas Good, BSc. PhD. and his team at the Environmental and Radiological Health Sciences Group at Colorado State University decided to study the issue. In 2015 they conducted what has become known as the Fort Collins Commuter Study. They wanted to quantify how choosing between commuting via car or bicycle and the route you take affects personal exposure to air pollutants during commuting. The team analyzed same person differences in exposures to multiple air pollutants including black carbon (BC), carbon monoxide (CO), ultrafine particle number concentration (PNC), and fine particulate matter (PM2.5) during commutes between the home and workplace for 45 participants.

Participants completed 8 days of commuting by car and bicycle on direct and alternative (reduced traffic) routes. What they found is that average same person exposures to BC, PM2.5, and PNC were higher when commuting by bicycling than when driving, but average CO exposure was lower when cycling. Exposures to CO and BC were reduced when commuting along alternative routes. It turns out that when cumulative exposure was considered in the case of CO the benefits from bicycling were greatly reduced or in the case of particulate exposures actually exacerbated. To a large degree this was because of the increased duration of the commute.

Although choice of route can reduce average exposure, the effect of the generally longer route length and duration often offsets these reductions when cumulative exposure is considered. For the fact is that most cities are running bicycle routes on high traffic corridors instead of understanding that park trails, side streets and low vehicular traffic routes are not only safer from a riding perspective but also from a health perspective. The study noted that bicyclists increased breathing rate when cycling may result in a more harmful dose than inhalation of these toxic substances during a regular car commute. For example a 35% increase in average BC exposure when cycling compared to driving a direct route translates to 460% increase in intake!

Last year the results of Dr. Good's study were published in the Journal of Exposure Science and Environmental Epidemiology. Just last week, he presented the results at the American Association of Aerosol Research (AAAR) conference in Raleigh, NC. In addition to Dr. Good's study several other presentations at the AAR conference clearly made the case that particulate matter air pollution is very much a micro-environment problem. Aja Ellis from Carnegie Mellon University noted in her research regarding diesel buses that locating bike lanes near bus lanes did not lead to "effective design for human use."

As Redwood City and other cities nationwide consider urban design plans like the El Camino Real Corridor plan that envisions adding bike lanes along a high traffic corridor and/or near bus transit lanes; they ought to first consider the findings of a lot of recent research. A better understanding of what really can help improve the lives of residents versus what will actually make it worse is imperative. Setting up bicyclists to inhale vehicle and bus emissions clearly isn't the solution.