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Alex Bigazzi began to wonder, as he rode his bike each day through Southeast Portland to Portland State University, just how much air pollution he was breathing into his lungs. After all, health was one of the reasons the PSU doctoral student in transportation engineering rode his bicycle in the first place. What if, he wondered, the toxic compounds he was inhaling were offsetting the health benefits of his exercise?
Today, Bigazzi has the beginning of an answer to those questions. Even better, he’s learning on which Portland streets he’s likely to inhale large amounts of toxic chemicals and on which routes he can breathe easier.
He’s also managed to get a doctoral dissertation out of the deal.
You might want to stay off Southeast Powell Boulevard if you’re a bike rider — Bigazzi’s breakthrough data shows biking on Powell leaves a rider with two to three times more volatile organic compounds in their lungs as a ride on a less-trafficked neighborhood bikeway route such as Southeast Clinton or Lincoln streets.
With funding help from the National Science Foundation, Bigazzi rigged up an orange bike with more than $10,000 worth of monitoring equipment and began riding it around Portland. The equipment can measure speed, the rider’s heart rate and breathing, and a second-by-second display of the amount of ambient air pollution. Bigazzi also has a video camera mounted on his bike, so that back in the lab he can compare the pollution readings with what was going on around him.
For instance, recently he noticed a spike in ambient air pollution while riding on Clinton Street. In the lab, he checked the video for the moment the spike occurred and discovered the source — an old Datsun hatchback had stalled right in front of him and then restarted. Bigazzi had ridden right through the exhaust.
But Bigazzi’s true breakthrough data actually comes as a result of the plastic gas-collection bags he carries with him on rides. At five different spots along his route, he stops, exhales into a bag and seals it. Those breath samples — a true representation of what he’s taken into his lungs — are analyzed back in the lab.
The message from those breath samples, Bigazzi says, is that bicyclists should stick to bike-designated streets such as Lincoln whenever possible.
“There are still cars, but you’re looking at 1,000 cars a day compared to Powell, which has 30,000 to 40,000 cars a day,” he says.
Bigazzi’s initial data will be formally presented to the federal Transportation Research Board in January. It shows that biking on an arterial street puts between 20 and 50 percent more air pollution into a rider’s lungs.
Meanwhile, he’s recruiting more bicyclists to take to different Portland streets with his equipment, so he can put together a map showing which streets are most dangerous for riders’ lungs. Bigazzi also is expanding the list of pollutants his equipment measures.
In addition, he is starting to look at how the concentration levels of the 13 compounds he has measured, so far, translate into health effects. Benzene, naphthalene, ethylbenzene and toluene are among the compounds Bigazzi has measured.
Short-term exposure to benzene can cause drowsiness and dizziness. Long-term exposure has been connected with leukemia. Naphthalene is currently classified as a possible carcinogen, and exposure has been associated with eye disease and anemia. Toluene can affect the kidneys, liver and heart and cause brain damage if large enough concentrations are inhaled.
Bigazzi can’t say at this point that bike riding on Powell or other busy streets is directly contributing to those maladies. But he suspects that eventually he will have enough evidence to make riders reconsider their routes.
“There are significant differences,” he says. “I think there will be a measurable cancer risk for arterials, but I don’t think we’ll find one for bikeways.”
Bigazzi also is hoping his research takes a more marketable turn. Having rigged up his expensive pollution-measuring bike, he saw the need for a more accessible way of taking bike-riding measurements. So he has developed what he calls the Portland ACE sensor system — a lower-cost and more portable rig to take air pollution measurements than what is currently available, he says. That might serve future scientists and engineers interested in researching airborne pollutants while moving along city streets.
And, he says, the device, which can be attached to anyone’s bicycle, might even appeal to everyday riders.
“These are dangerous gasses,” Bigazzi says. “People are interested in what they’re exposed to.”