Ozone: The Silent Killer Coming from China

By Sydney Johnson

Breathing in “ozone can cause serious health effects,” claims the Environmental Protection Agency (EPA). Exposure to ozone pollution can lead to problems with your respiratory system, aggravate asthma (especially in children), damage lungs, and is even linked to 150,000 premature deaths. Both short-term and long-term exposure to ozone pollution has serious consequences, and children are one of the main groups considered most at risk from ozone exposure!

There are two types of ozone – one is good ozone and one is bad ozone. The good ozone is in the stratosphere, which is the higher layer of the atmosphere. The bad ozone is in the troposphere, which is the lowest layer of the atmosphere. Ozone that is in the troposphere is the most harmful to humans because it is the air we breath. Tropospheric ozone is formed from nitrogen oxide (NOx) (which is from transportation and other industries), and volatile organic compounds (VOCs) (which is from household products like paint), reacting with sunlight. This creates the harmful ozone that is a gas and traps the air in the troposphere.

According to the EPA, breathing in ozone can irritate the respiratory system, which then reduces lung function, making it a lot harder to breath. As the shortness of breath, wheezing, coughing, and chest pain begin, difficulty breathing isn’t the only problem from inhaling ozone pollution. The EPA also found that exposure to ozone and premature deaths has expanded since reviews in 2008, causing an even greater awareness of the harm ozone pollution has on humans, especially children. One in every 12 children in the U.S. already suffer from asthma, which is a serious side effect of ozone pollution.

Recent studies show that while ozone levels have declined nationwide in the United States, they are still high on the west coast. These constant high levels are due to polluted air coming over from China’s recent industrial boom. Dr. Owen Cooper, who is a research scientist with the Cooperative Institute of Research in Environmental Science, has confirmed that although the amount of ozone pollution coming from Asia is rather small, it has been rising quite steadily since 1995. This polluted air from China is being blown over by the westerly winds. These molecules move across the Pacific and travel in the troposphere. Ozone pollution in the troposphere is the most harmful because that is the ozone human’s breath! Dr. Owen Cooper also stated that ozone pollution that is being “[Transported] from Asia to the western US can occur in under 5 days if the westerly winds are strong…” therefore stressing the increase in ozone pollution on the west coast and Pacific Northwest.

Dan Jaffe, a professor of atmospheric and environmental chemistry at the University of Washington – Bothell, supports Dr. Owen Cooper’s evidence. After gathering data from his observatory on top of Bachelor Butte in Oregon, Jaffe states that this study is largely the first link between atmospheric ozone pollution over the U.S. and Asian pollution. Jaffe also states that the rise of pollution coming over from Asia is a result of their booming economy, which has led to an increase in burning more coal and oil.

As consistent levels of ozone pollution increase on the west coast, we see an increase in poor air quality for that same region. The relationship of ozone level and its effect on air quality can be seen within and around urban areas, and even in areas that are downwind of combustion, like here on the west coast from China’s industrial boom. The two figures to the right demonstrate how constant ozone levels can effect air quality. Figure A shows us the air quality for Fresno, CA, and Figure B shows us the air quality for Seattle, WA. Both figures, from AQICN.org website, show us the real-time air quality index of the cities. Fresno, CA and Seattle, WA are cities on the west coast whose air quality is unhealthy. With spring and summer just around the corner, rising temperatures in these major metropolitan cities will contribute to an increase in smog levels and ozone pollution for these areas.

These increases in ozone levels aren’t just effecting air quality, but also contributing to climate change. Unfortunately, ozone is a big contributor to global warming, especially when it is in the troposphere. In Hannah Hoag’s article, Air Quality to Suffer with Global Warming, she talks about a recent study on air quality and its relation to global warming that was published in the Nature Climate Change. This study suggests that the effects of climate change will slow air circulation around the world.

The increase in worsening air quality is due to an increase in stagnation days. During these stagnation days’ soot, dust, and ozone build up and accumulate in the troposphere. Stagnation days are days with light wind, a stable lower atmosphere, and little or no precipitation to wash away pollution.

Hannah Hoag also states that the study published by Nature Climate Change says that in high greenhouse gas emissions scenario “… researchers factored in current population size to quantify human exposure to daily stagnation events and air pollution. The impacts are especially intense in India, Mexico and the western United States.” In areas like the Pacific Northwest, key ingredients to ozone production (e.g. temperature, urbanization, and emissions from industrial development) are increasing. Increases in ozone production, combined with more future stagnation days, will only magnify the effects of ozone pollution here in the Pacific Northwest.

So with spring and summer just around the corner, rising temperatures in major metropolitan cities like Seattle will contribute to an increase in smog levels and ozone pollution for this area. In order to help reduce the negative health impacts this could have on individuals here in Seattle, especially children, and the climate, Dr. Owen Cooper gives us the top two solutions that’ll help reduce ozone pollution. One is reducing the combusting of fossil fuels or biomass, and the other is reducing emissions of methane. While it might be hard to change our entire way of life, the faster we change to renewable forms of energy the faster we can begin to reduce ozone. Switching to renewable forms of energy not only decreases the threat of global warming, but also increases future air quality! 


Sydney JohnsonRaised in Seattle, Sydney Johnson is a senior at UW Bothell majoring in Global Studies. Why does she care about the air we breathe? “It's a pressing issue... we breathe this air no matter what.”