Having never been west of New York, I pondered what Salt Lake City would look like as our plane flew closer to Utah from New York City. It clearly wasn’t going to look like New York City. In fact it didn’t look like any other city I had been to up until that point. Salt Lake City sits in the middle of The Great Salt Lake, The Wasatch and The Oquirrh mountain ranges. The tallest building in Salt Lake City is just slightly over 400 feet, which may make one think there isn’t a very picturesque skyline, but with the mountainous backdrop, it’s actually quite breathtaking. That is, if you can see it. Inversion is becoming a more and more serious problem for residents of Salt Lake City and the first few days I was there I experienced it first hand.
Driving from Salt Lake City through the canyon up to Park City, Utah where I’d be staying was like coming out of a cloud. It was very difficult to see any of Salt Lake City because it was full of pretty thick smog that distorted visibility for anything further than a mile away. The city of Salt Lake experiences air inversion due mainly to its location in the mountains. During air inversion, cooler air gets pinned down by warmer air from above, which causes pollutants to get trapped in the cooler air below. An article in The New York Times states, “When heavy winter storms sweep through the area, they leave snow on the Salt Lake Valley floor. But intermittent warm high-pressure systems trap the cold air, creating the effect of a lid on a soup bowl and keeping dirty air from car emissions and other pollutants from escaping. (Frosch A15). The toxicity of the pollutants can be detrimental to human health at long exposures. The textbook Chemistry in Context tells us, “Toxicity is the intrinsic health hazard of a substance and exposure is the amount of the substance encountered.” (Anderson, Bentley, Cann, Ellis, Keller and Middlecamp 24) The United States Environmental Protection agency or EPA has determined the standards for ambient air, which is the outside air surrounding us. The table shows us how much of the pollutant is normal to be exposed to for an hour and an eight hour average. Anything rising above these standards can be dangerous to our health.
Pollutant Standard (ppm) Approximate Equivalent Concentration (μg/m3)
PM10 annual average
PM10 24-hr average
PM2.5 annual average
PM2.5 24-hr average
*PM10 refers to all airborne particles 10 μm in diameter or less. PM2.5 refers to particles 2.5 μm in diameter or less.
-The unit of ppm is not applicable to particulates.
tPM2.5 standards are likely to be revised after 2011.