Traffic: The unrelenting polluter near Portland schools

Traffic doesn’t just tie up commuters. Vehicle emissions expose children in dozens of Portland-area schools to air that increases their risk of cancer and other respiratory problems.  

KGW App users: Tap to view

PORTLAND, Ore. – As kids in Portland head back to school this week, many parents are breathing a sigh of relief as the district works to fix lead issues in schools district-wide. But another dangerous health risk lurks near dozens of schools: Road traffic.

An interactive map created by the Seattle-based company Upstream Research shows 78 schools in the Portland metro area are less than 100 meters from major roads such as highways or other main thoroughfares, exposing students to exhaust at levels that increase cancer risk and risk of other respiratory illnesses. Fifty-six of those schools are elementary schools.

Key: Red dots are schools near major roads; blue dots are schools away from major roads. Darker green means greater cancer risk. Click on map to view specific cancer risk by area. 

Tap to view interactive map in new window

Upstream used data from the EPA’s 2011 National Air Toxics Assessment, which analyzed 180 hazardous air pollutants and calculated cancer risk for people if they breathe the air over 70 years – otherwise known as the long-term benchmark for cancer risk. In rural areas, that risk was around 20 cancers per million, which means on average after 70 years, 20 people out of 1 million will get cancer because of the air they breathe.   

That increases to up to 85 cancers per million in the center of downtown Portland. In between, cancer risk hovers between 40 and 80 per million – double to quadruple the risk that rural students face.  




Vehicle exhaust is not the sole hazardous air pollutant in Portland’s air, but vehicle exhaust is responsible for one-fifth of cancer risk from air pollution and one-third of other respiratory health risks, according to the NATA data.  

“On-road traffic is one of the largest sources of hazardous air pollutants,” said Upstream Research Data Scientist Grant Frame.

The threat isn’t limited to schools. Homes across the Portland metro area are exposed to air that increases risk of cancer over time.

The threat to kids is greater than adults face, as children breathe about twice as much air as adults pound-for-pound.

That worries Portland parent and activist Jessica Applegate.

 “I am concerned about how close schools are to major roads and our most vulnerable citizens, our children and future, being exposed to an increased cancer risk,” she said.

Some of the schools with the worst air quality are near Interstate 5 and Interstate 405 in downtown Portland: Le Monde French Immersion Public Charter School, Childpeace Montessori School, St. Marys Academy, the Helen Gordon Child Development Center at PSU, the International School and Capitol Hill Elementary School all have air that increases cancer risk by at least 60 people per million.

The worst spot in Portland for air quality is a census tract downtown, where cancer risk from air pollution is 85 per million. The boundaries of that tract run along Southwest Jefferson and West Burnside, between Southwest 12th avenue and the Willamette River.




In this downtown quadrant, gasoline emissions from cars accounted 34 percent of the cancer risk. Diesel traffic made up about 5 percent of the risk, while the rest was a combination of risk factors such as wood burning, construction and other air pollutants. The heavy local traffic in downtown Portland compounds how much exhaust residents are exposed to in Portland’s busiest sector.

“While the concentration of pollutants increases with population and comes from a variety of sources, we already know that road traffic is by far the largest single contributor for this area,” Frame said. 

Cancer is not the only concern. Schools near major roads and in more densely populated parts of the city are also more at risk of other respiratory health issues such as asthma.

According to the EPA, kids are more at risk for developing asthma and other health problems because their lungs are still developing.




No laws keep schools from being built near major roads, but city of Portland and state officials have singled-out idling cars as one exhaust source that could be culled.

The EPA found elevated levels of toxic pollutants including benzene, formaldehyde and acetaldehyde in the hour parents pick up kids from school.    

The Portland Bureau of Transportation suggests residents limit idling near schools to under 10 seconds.  

Many Portland public schools have “idle-free zone” signs that discourage parents from keeping their engines running while they wait for their kids, according to PPS spokesman Jon Coney. He also said PPS buses run on cleaner-burning propane.

“If any bus at a school is going to be idle for more than five minutes, then they are required to shut off,” he said.

Oregon law prohibits large trucks from idling near schools. It’s also illegal in the state to leave an unattended vehicle parked and running. Police enforce both these laws, according to a DEQ spokesman.

There are no statewide rules or policies for other vehicles idling near schools.

Even with idle-free zones, schools within 100 yards of major roads are still subject to a continuous stream of gasoline and diesel exhaust.

Frame said Upstream Research hopes the maps shed light on a pervasive problem that impacts people throughout the city.

“We mapped the major roads because we know they are dangerous,” he said.  

Are you concerned about vehicle emissions near your child’s school? We want to hear your story. Contact us at


To find out more about Facebook commenting please read the
Conversation Guidelines and FAQs

Leave a Comment