Air quality studies

We sometimes conduct special studies to better understand air quality issues in a specific location and identify ways to improve air quality. When we develop these studies, we often partner with research facilities such as Washington State University.

The Yakima skyline with a snow-capped mountain in the background that is a little hazy from air pollution. — A hazy Mount Rainier as seen from Yakima.

Ozone studies

Ozone high in the atmosphere protects people from the sun's harmful radiation. But ground-level ozone harms people and plants. It forms when nitrogen oxides and volatile organic compounds react with each other in sunlight and hot temperatures. This air pollution comes from vehicles, industry, and other sources. It creates smog.

Although Washington currently meets the national ozone standards, we continue to watch these areas closely:

Western foothills of Cascade Mountains
Tri-Cities area (Kennewick, Pasco, and Richland)

View this map in full screen with more functions.

Tri-Cities ozone precursor study

In Summer 2016, we partnered with Washington State University and Benton Clean Air Agency to conduct the Tri-Cities ozone precursor study. This study measured precursors of ozone, including nitrogen and volatile organic compounds at two sites in the Tri-Cities, as well as from a mobile platform that drove throughout the region.

What happens next

We're partnering with Benton Clean Air Agency to identify and implement reduction measures and raise public awareness. Find out what you can do to reduce ozone.

More information

Tri-Cities Ozone Precursor Study Report (long)
Studying ozone in the Tri-Cities (short)
StoryMap (web map)

Particulate matter studies

One of the air quality issues facing Washington is particle pollution, especially those particles that are 2.5 micrometers (PM_2.5) in diameter or smaller. These particles can pass through the throat and nose into the lungs.

People with heart or lung diseases, children, and adults 65 and older are more likely to be irritated by particle pollution exposure. These particles can harm health by causing:

Earlier death in people with heart or lung disease
Higher chance of heart attacks
Airway irritation, coughing, difficulty breathing, and increased asthma symptoms

Read about the studies we have conducted.

When routine air testing showed that higher-than-usual nitrate levels were detected in the Yakima area, we asked researchers from Washington State University (WSU) and Central Washington University (CWU) to find out what was causing the elevated levels.

About 25 percent of Yakima’s wintertime particle pollution (PM_2.5) is made up of nitrate in the air. These nitrate levels were higher than anywhere else in the state. Researchers monitored Yakima’s air quality over three weeks in January 2013 to better understand the high nitrate levels. The most likely cause of high nitrate levels was determined to be the interaction of:

Ammonia from agricultural activities
Oxides of nitrogen from vehicles
The right weather conditions

The solution to reduce nitrate particles in Yakima has not been determined and requires a detailed air quality modeling study.

In December 2010, EPA revised the monitoring requirements for measuring lead in the air. The amendments required eight states to conduct one-year monitoring studies at airports with lead emissions between 0.50 and 1.0 tons per year. EPA identified two airports in Washington that met the study criteria: Auburn Municipal Airport and Harvey Field in Snohomish.

2012 Airport Lead Study: Auburn Municipal Airport and Harvey Field

In December 2009, EPA classified the Tacoma-Pierce County area as a nonattainment area (not meeting an air quality standard) because fine particle (PM_2.5) pollution levels did not meet healthy limits from 2006 – 2008. We were required to develop an air quality plan called a State Implementation Plan (SIP) showing what actions would be taken to control air pollution in the area. Wood smoke was found to contribute more than half of the PM_2.5 measured during the winter. Fine particles from wood smoke and industry have gone down every year since 2006.

Sources of Fine Particles in the Tacoma-Pierce County PM_2.5 Nonattainment Area

Contact information

Beth Friedman
Atmospheric Scientist
beth.friedman@ecy.wa.gov
360-515-6728