Understanding Cache Valley's air pollution -- and what we can do about it

By Todd Stewart

December 20, 2004 | Old man winter is back and he has brought his inversions to the valley again. Just a month ago the valley air was back under scrutiny for poor air quality. After Thanksgiving, snow storms dumped in the mountains and valleys while colder than normal temperatures lingered into Cache Valley.

The snow on the ground can make it harder for the valley to warm up during the winter months while an inversion will move in and trap the pollutants. The snow reflects the suns rays that are needed to break up the inversion.

Monitors have been set up to help detect the pollution in Cache Valley with two in Idaho, and one on each end of Cache County. Prevention is necessary in keeping air quality healthy. Grant Koford, who is a scientist for the Bear River Health Department said, "That's our big push this year, to get ahead of it and predict it."

Hearing the word inversion and understanding what it does is important to know. An inversion is a meteorological phenomenon that occurs when warm air becomes trapped above cold, reversing normal atmospheric conditions and preventing air circulation. Inversion is most commonly created by a warm air mass moving over a colder air mass, keeping the cooler air trapped below. When inversions occur, air quality suffers because air pollution stays at ground level where it is most hazardous to breathe.

What kinds of pollutants become trapped in the air that makes it so unhealthy for us? The main problem with an inversion is that it traps particle matter (PM). Particle matter is composed of soot, dust, and emissions from vehicles. It is the fine matter that we cannot see that harms us. Particle matter is measured in microns.

The most common particle matter talked about are PM 10 and PM 2.5. This means that particle matter is 10 microns or less in diameter or one-tenth the diameter of a human hair. The particle matter can be seen in valleys as a grayish brown haze that hover above the valley floor. Other pollutants include carbon dioxide and sulpher dioxide.

Majority of the pollution in Cache Valley is linked to vehicles, factories and animal stock, while along the Wasatch Front, 60 percent of particulate matter and 70 percent of carbon monoxide emissions come from vehicles.

The Utah Department of Environmental Quality issues wood-burning bans to counties that become in high risk of unhealthy pollutants in the air. A green light means that it is OK to use your wood burning stove or fireplace. A yellow light warns that pollution levels are beginning to build up and a red light indicates that pollution levels are high and burning is not allowed.

On Dec.6, the Cache Valley Air Quality Task Force submitted its report to a committee at the Bear River Health Department. It reported that 10 percent of the vehicles within the valley cause 45 percent of the nitrogen oxide pollution during the inversions in the winter.

The committee established three general goals: to predict temperature inversions before they happen; to prevent elevated levels of air pollution during inversions; and to protect "at risk" people during inversions. To reach those goals they will follow the following six programs.

1. Cut driving in half during inversions.

2. Reduce air pollution for "at risk" people.

3. Continuation of county's smoking car program.

4. Continuation of county's wood burning regulations.

5. An extensive public education program.

6. Development of vehicle emissions inspection program for the winter of 2005-2006.

As the air quality decreases in this valley during the winter months ahead the EPA will be increasing its watch. Cache County is close to exceeding federal air quality standards for the number of high PM 2.5 readings over a three-year span. If it has even one day of serious pollution this winter, the Environmental Protection Agency likely will mandate vehicle emission testing. Last winter, the county had 17 days of seriously polluted air.

Logan Mayor Doug Thompson wants the residents to remember to car pool, ride buses or walk to keep air quality healthier in the valley. Although it may seem hard, it might be worth it a few times a year so vehicle inspections won't have to be mandated through the EPA.

Koford says there is need to educate the public on reducing emissions but lacks money within the department to raise the awareness needed.

Ed Redd, medical director of the BRHD said, "If people don't voluntarily limit their driving, we're going to have the EPA down our throats."

The problem with the pollutants in the valley is they become hazardous to all that inhale them. Particulate matter, carbon monoxide, and sulfur dioxide affect breathing and respiratory function. The tiny PM 2.5 particles can penetrate deeply into the lungs, causing difficult breathing, asthma attacks, heart attacks and stroke.

When carbon monoxide enters the bloodstream, it too reduces the delivery of oxygen to the body's organs and tissues. Some studies indicate that particulate matter decreases the heart's ability to respond to physical stress. When the heart cannot adapt well to changes in the heart rate, its oxygen-carrying capacity in the blood is reduced.

The EPA's standard for very unhealthy air is measured at 60 micrograms. On Dec. 6, the valley hit 61. There are ways to prevent pollution but educating the population takes time. Click the link for 50 steps you can take to choose clean air.

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