Summertime . . . and the Air is Nasty

By Jack Hurty, SLCgreen intern

We’re all used to winter smog here along the Wasatch Front, with brown haze moving in and obscuring the mountains. But there is another pollutant in the valley, invisible but no less dangerous — ozone.

What is Ozone?

Ozone, a molecule consisting of three oxygen atoms, is created when nitrogen oxide (NOx) and volatile organic compounds (VOCs) mix and are heated by the sunlight.

NOx and VOCs are typically emitted by motor vehicles, but they can come from consumer products as well as industrial sources. (Read more about how ozone forms.)

Ozone is often found in the Earth’s stratosphere, where it plays a beneficial role by protecting us from damaging rays. But when ozone sits in the atmosphere where we can breathe it in, it can be very damaging to our health.

Photo courtesy of MPCA Photos on Flickr. Creative Commons license.

Effects of Ozone

In low levels, ozone is generally benign. However, as the concentration begins to rise, it can affect those with a sensitivity to poor air quality, such as people with pre-existing respiratory conditions, children, and the elderly. Higher concentrations, as well as long term exposure to ozone can be permanently damaging to the lungs, and can even cause a heightened risk of heart disease, even in healthy adults. And unlike particulate matter, ozone can’t necessarily be escaped by going to higher altitudes. 

Ozone on the Wasatch Front

Unfortunately, Salt Lake Valley is a hot spot for ozone pollution. According to the state Department of Air Quality, Salt Lake City violated the federal ozone standard of 70 parts per billion at least 20 times in 2017. On May 2, 2018, the EPA formally designated the Wasatch Front as a marginal nonattainment area, giving the state of Utah three years to come up with a plan to reduce ozone pollution to sustainable and healthy levels.

Source: Utah Division of Air Quality

There are several new policies being put in place designed to limit and eliminate sources of the compounds that react to form ozone. Most notably, new vehicle and fuel standards were recently finalized by the EPA that will help.

The Tier 3 standards, as they are known, will reduce the emission of NOx and VOCs by as much as 80% and particulate matter by 70% in new motor vehicles. Even if you don’t drive a Tier 3 car, new Tier 3 standards for fuel can clean out an older car’s pollution removal systems, so after a few weeks even Tier 2 cars using Tier 3 fuel could be cleaner by up to 14%.

Avoiding and Reducing Ozone

Fortunately, there are several simple steps we can take every day to avoid inhaling high concentrations of ozone and keep your lungs healthy:

• Enjoy the majority of your recreation in the morning, and reduce outdoor activity during the middle of the day, when the sun’s rays are strongest. Ozone is created by UV radiation from the sun, so levels of ozone cycle up and down throughout the day as the sun rises and sets.
• Drive less by walking, riding a bike, or taking public transit. If you have to drive, make sure you don’t idle. Idling is a major culprit when it comes to unnecessary emissions, as just 2 minutes of idling is the equivalent of driving a mile. Just 10 seconds of idling uses more fuel than it would take to turn off and restart the engine. Every year, idling wastes approximately 6 billion gallons of fuels. So when you’re waiting to pick the kids up from school or going through a drive thru, turn the key, and protect the air
• Purchase products that qualify for the EPA’s Design for Environment (DfE) certification to ensure you’re limiting your VOC output. Many consumer products, like solvents, air fresheners, and adhesives can emit great quantities of VOCs. See a list of those products here.
• Avoid using gas-powered household tools on high ozone days – or better yet, opt for electric ones. The gas motors found in tools like lawnmowers and weed whackers are extremely inefficient and dirty. In fact, the EPA found that a new four-stroke lawnmower running for an hour produced the same level of emissions as 11 new cars driving for the same period. It is estimated that lawn equipment is responsible for up to 5% of the country’s air pollution and 17 million gallons of spilled fuel every year. Both emissions and spillage are sources of NOx and VOCs, the key components of ozone. Electric and push mowers are much better for the air (and they have the added benefit of being much quieter).

Ozone is a big problem for Salt Lake Valley, but with these few simple changes, we can all be part of the solution for reducing this “summertime scourge.”

Helpful Links and Tools

• Watch a Utah DEQ video about ozone: https://youtu.be/cvr5vraYY4o
• Plan your low emission commute: https://travelwise.utah.gov/
• Calculate your car’s idling efficiency: https://www.ucair.org/calculators/
• Learn more about the Tier 3 emission standard: https://www.epa.gov/vehicles-and-engines
• Check current air quality: https://air.utah.gov/
• Download the UtahAir app: Android   iOS
• See near-real time local air quality sensors: here and here