New data from the Oregon Department of Environmental Quality found six toxic air pollutants were above average in urban and rural areas throughout the state.

The agency monitored 109 pollutants at six locations, including spots in The Dalles, La Grande, and four sites in the Portland metro area. Of those tested, none were found to pose an immediate health risk to the public but six air toxic pollutants – including arsenic and benzene – were found at above what researchers call their “ambient benchmark concentration average” at all monitoring locations.

According to the report, average levels of arsenic were higher in the Portland area sites compared to The Dalles and La Grande. Arsenic can come from vehicle emissions or certain kinds of industry.

“The ambient benchmark concentrations are goals that we set that we hope we can achieve, but they are goals that are fairly conservative standards that are definitely protective of people, even sensitive populations,” DEQ’s Tom Roick said.

The report shows concentration levels of pollutants in ambient air, meaning they can come from a variety of sources in the community and are not necessarily specific to any facility or source. DEQ researchers will use the information and data collected to track and implement new strategies for reducing pollutants throughout the state.

The report also found no real significant difference in pollution levels between rural and urban areas.

Some of the other air pollutants that tested above average included benzene, carbon tetrachloride, naphthalene, acetaldehyde and formaldehyde.

“Benzene very commonly comes from vehicle emissions, it’s a component of gasoline,” Roick said. “We also see benzene associated with woodsmoke; it’s an artifact of burning of organic matter.”

He said vehicle emissions and woodsmoke are the biggest contributors for these air toxic pollutants.

Wildfire smoke was also shown to increase average concentrations in at least four of the pollutants which include, benzene, carbon tetrachloride, acetaldehyde and formaldehyde. But according to Roick, the agency is seeing some decreases in toxic metal concentrations over the last four years.

“This is helping us assess how well our program, such as the vehicle inspection program and other programs that are trying to reduce air toxics, how well they’re working,” he said. “It’s suggesting they are having impacts in terms of air toxics declining over time.”

DEQ programs such as Cleaner Air Oregon, which monitors the air quality at industrial facilities, is helping reduce pollutants. DEQ also offers a woodstove change out program which helps homeowners switch to cleaner energy systems.

By March, the DEQ will have air toxic monitors in Eugene, Medford, Bend, Hillsboro and Tualatin. 

OPB Reporter Cassandra Profita contributed to this story.