Inversion does not equal air pollution

Here in the Salt Lake Valley, we are no strangers to inversions and air pollution.

We are, unfortunately, so familiar with it that people often think that inversion is the same as air pollution. But they’re not the same—it’s more a matter of circumstance.

Inversion is a weather pattern that can happen in any valley. Inversion occurs when a layer of warmer air sits on top of cold air and acts like a lid, trapping everything below it in, including the pollution that we emit from our cars, buildings and industrial sources.

Our wintertime pollution is known as small particulate matter, or PM2.5. PM2.5 is directly emitted from certain sources and also forms in the air when certain pollutants react with each other. Cars, trucks and heavy-duty vehicles are the largest contributor to PM2.5, making up almost 50% of our wintertime pollution. Area sources— buildings, houses, development projects and wood burning—are the second largest source of emissions. Industrial sources, such as refineries and mines, make up the smallest percentage of emissions.

Unfortunately, when you combine an inversion-prone area with a concentrated, growing population, we get those brown, heavily polluted days during the winter that make people equate “inversion” with “air pollution.” With or without inversions, our emissions and impact on the air remain the same. Inversions just allow the pollution to build until a storm comes through to lift the “lid.”

Does this mean that we have no control over the quality of our air? No!

We have the power to create the change needed to improve our air. All of us are responsible for examining how our own habits impact the air, and can commit to taking action to reduce our personal emissions. They don’t have to be drastic steps; combining multiple errands (“trip-chaining”), turning your car off at drive-throughs to reduce idling, or testing out public transportation to get around town can all help to reduce your personal emissions. Collectively, these efforts can make a big difference and help ensure our air quality improves over time.

—Jessica Reimer, HEAL Utah