Friday, July 22, 2016

Let’s Talk Science: Gearing up for the Tri-Cities Ozone Study

Ground-level ozone, not to be confused with “good” ozone in the earth’s upper atmosphere that shields us from harmful ultraviolet radiation, is toxic to human health.

Exposure to ozone irritates the eyes, nose, throat and the respiratory system. It is especially bad for people with chronic heart and lung disease, pregnant women as well as the very young and elderly.

Air quality specialists here at Ecology monitor air quality across the state to ensure we’re meeting federal health-based standards. Recent monitoring data collected in partnership with Benton Clean Air Agency indicate levels of ozone are higher than we’d like in the Tri-Cities. Ozone readings in Kennewick are about as high as those downwind of the Seattle area.

Because of the health risks associated with ground-level ozone pollution, we need to figure out how to manage it – and are launching a study of sources in the Tri-Cities area of south central Washington.

How ozone forms

Ozone forms in the air when certain gases from individual sources react together on hot summer
days. These gases are known as ozone precursors.

Nitrogen oxide (NOx), a combination of oxygen and nitrogen, is a common air pollutant in the recipe for ground-level ozone. Also in the mix are volatile organic compounds (VOCs), a large group of carbon-based chemicals that easily evaporate at room temperature and come from a variety of natural and manmade sources.

The hot weather, in particular sunlight, bakes the ingredients of NOx and VOC, creating the harmful ozone pollutant.

Let’s fix the problem

Before we can control ozone, we need to know where the ozone precursors are coming from.

We’re taking a team approach. For three weeks in July and August, we hope to quantify compounds such as ozone, carbon monoxide, and nitrogen oxide in the air by taking several high-tech measurements.

Washington State University and RJ Lee Group Inc. are on contract to complete a majority of the work. We will also conduct some measurements as part of the study. Our friends south of the border in Oregon are also concerned about an ozone buildup in Hermiston. So the Oregon Department of Environmental Quality is conducting field monitoring that coincides with our study.

What happens next?

These measurements will tell us where VOCs and NOx are coming from and potentially what is causing high levels of ozone in the area.

Please stay tuned. Study results are expected around mid- 2017. We will share the results and next steps and looking for input from the local Tri-Cities community.

Meanwhile, we all can take important steps to reduce ozone pollution in our communities.

If you have questions about the study, email

By Ranil Dhammapala, atmospheric scientist

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