Oregon DEQ releases 2019 – 2021 Air Toxics Summary Report

Chris Modderman (left) and Peter Husted (center) record data in an air quality monitoring shed.

Oregon DEQ has released its 2019 – 2021 Air Toxics Summary, which provides data on air toxics that were monitored in nine locations across the state, including Bend, Eugene, La Grande, Medford and Portland. The goal is to measure air toxics across Oregon where people live, work and play. That way, DEQ and communities can make better informed decisions on how to track and reduce pollution and lessen exposure to harmful effects to protect public health.   

DEQ’s Lab measured 107 air toxics, including metals (PM10), volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at each monitoring site, which included all 60 priority Hazardous Air Pollutants in the National Air Toxics Trends Station Program. These pollutants were identified by the U.S. Environmental Agency because they have the greatest impact on public health and the environment in urban areas, and because cost-efficient measurement methods exist. The other 47 air toxics are measured because the field and analytical methods used have no additional costs. Also, our Lab sampled for the metal hexavalent chromium, using a specially designated instrument to improve sample detection.

DEQ follows the schedule for a sampling set by the EPA NATTS program. A sample is taken once every six days and the results are summarized over the course of 365 days. A dataset for a year is expected to have approximately 60 samples, but may have fewer due to instrument malfunctions, quality assurance or quality control requirements or other reasons that may invalidate a sample. DEQ used three main monitoring networks, each with its own goals. These are the EPA-funded NATTS sites, Oregon trend sites and rotating annual sites. 

Map of the 2019 – 2021 Air Toxics Monitoring Network.

The nine locations monitored, and their networks are as follows:

  • Amazon Park (Eugene)
  • Bend Senior High School (Bend)
  • Cully Helensview School (Portland-metro)
  • Highway 99 (Eugene)
  • Hillsboro Hare Field (Portland-metro))
  • Humboldt School (Portland-metro)
  • N. Hall St. & E. North Ave. (La Grande)
  • Welch & Jackson Streets (Medford)
  • Tualatin Bradbury Court (Portland-metro)

Oregon sets targets to reduce air toxics in ambient air. Our goal is to reduce levels of each pollutant down to be equal to one or less than the ambient benchmark concentration. The data and statistics from monitoring sites inform progress toward these targets. As one of DEQ’s key performance measures, DEQ selected five representative air toxics – benzene, acetaldehyde, formaldehyde, arsenic and cadmium – to track over time as an indicator of overall trends.

You will note, the ambient benchmark concentrations are designed to protect the health of the most sensitive individuals in our communities and serve as clean air targets. They are not regulatory standards. Industry regulation falls under EPA’s National Emission Standards for Hazardous Air Pollutants Program and air quality permits.   

The Results

For air toxics with the potential to increase cancer risk, DEQ sets Ambient Benchmark Concentrations at levels that would not pose more than one-in-a-million excess lifetime cancer risk if a person breathed air at that level every day for an entire lifetime. For air toxics that have the potential to cause health effects other than cancer, DEQ sets ABCs at concentrations that would not be expected to harm anyone’s health even if they breathed that air every day for a lifetime.

Additional details include the following:

  • Results of monitoring show that Oregon’s air is consistent with national averages for air toxics levels. The health/cancer risk for these air toxics is considered low. 
  • While some pollutants in our air are present at levels exceeding health benchmarks, the overall risk to individuals is relatively low, particularly for cancer risk.
  • Our data shows an excess lifetime risk of developing or dying from cancer as less than 100 in a million, or 0.01%. This is considered low compared to the background rate of 400,000 in a population of a million, or 40%, lifetime risk of developing or dying from cancer as determined by the American Cancer Society. All monitoring locations show levels that are well below 100 excess cancer risk when combining cancer risk of all pollutants measured.
  • Intense wildfire smoke skewed data at some sites. The report identifies cases where the annual average concentrations of a pollutant were reduced to below the chronic cancer ABC when wildfire-impacted samples were removed from the dataset. These occurred at the Portland’s Cully Helensview School and La Grande’s N. Hall St. & E. North Ave. locations.
  • Acetaldehyde, arsenic, benzene, formaldehyde and naphthalene were above their ABCs at most monitoring locations. This indicates their presence is widespread and not unique to individual communities, even though levels vary between sites. EPA’s website hosts the Health Effects Notebook for Hazardous Air Pollutants for more information.

So, the good news is the data showed no air toxics were found at levels posing an immediate health risk to communities. For specific results and graphs, it is best to read the report thoroughly.

We believe many pollutants were below their benchmarks due to the following:

DEQ selects annual air toxics monitoring locations based on several factors, including sources of pollution, number of pollutants, relative toxicity, lack of information, community and environmental justice factors and agency program and regional needs. Air toxics data collection for the 2022 – 2024 monitoring report is currently underway.

To view Oregon DEQ’s 2019 – 2021 Oregon Air Toxics Monitoring Summary, go to www.ordeq.org/ATSummary2019_2021.

By Susan C. Mills, public affairs specialist, and Peter Husted, LEAD Air Toxics Monitoring program manager

Published by Oregon Department of Environmental Quality

DEQ’s mission is to be a leader in restoring, maintaining and enhancing the quality of Oregon’s air, land and water.