Inversion Questions AnsweredMar 13, 2014
We know the air is bad if we can see it. But what’s actually in the air? Kerry Kelly, associate director of the Program for Air Quality, Health, and Society, helps you understand the inversion better by answering questions including what contributes to the air quality, how it affects you, and how you can protect yourself against the inversion. She also talks about the difference between inversion and smog, and if there are any doable solutions for the bad air quality.
Interviewer: The inversion, it seems like this year everybody's saying we have to do something about it. What is that thing that we're going to do? I think the first step is to help you understand it a little better. That's coming up next on The Scope.
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Interviewer: The inversion, from what is in the air to how it affects you and how to protect yourself. To help us examine that is Kelly Kelly, research associate, chemical engineering, and Associate Director of the Program for Air Quality, Health and Society at the University of Utah. Thanks for taking time to talk about this thing that we all are talking about but know little about. What's in the air anyway?
Kelly: Particles in our air are composed of about one-third of things that are emitted directly as particles. Those are things like soot from your diesel engine or your fireplace, emissions from cars that come out as particles. That's about one-third. Then, the other two-thirds are formed by reactions that happen in our air during the winter.
Interviewer: When you say particles, are these like dust particle size? What are they?
Kelly: No. That's a good question. These are fine particles. These are particles that are about one-thirtieth the size of a human hair. They are very easily transported into your lungs.
Interviewer: I want to back up for a second. Is there a difference between inversion and smog? Because I think we all know what smog is.
Kelly: Smog generally means something that you can see.
Interviewer: Yeah, so when we can't see the mountains, it's smog.
Kelly: Right. Inversion means that it's basically the temperatures are inverted. During inversions, cold air sinks into the valley, and there's a layer of warm air that slides in above it trapping that colder layer. That's basically like a toilet bowl that won't flush. During those times, everything we are emitting into our valley stays in our valley.
Interviewer: How does the warm air keep stuff down? I don't quite understand that.
Kelly: Because cold air tends to sink. It's heavier. It's denser. Warm air is less dense. That cold, dense air can't get moving, and we can't get any of this convective air current moving that then gets the pollution to disperse.
Interviewer: Okay. The chemicals, the particulate matter, as you said in the inversion, is it harmful? We all kind of assume that it is, but is it?
Kelly: Yes. The E.P.A. sets national ambient air quality standards, and these are based on sensitive populations.
Interviewer: Who are sensitive populations?
Kelly: This is like the elderly, anyone who is immune compromised, small children, anyone with a compromised especially lung function or cardiac function.
Interviewer: Are there other dangers? You hear people say it affects fertility. You hear people say it might cause other diseases.
Kelly: Yeah, autism. There have been hundreds, thousands of studies linking air pollution to various things. What we don't understand is the mechanisms. We also, then, don't understand how to intervene.
Interviewer: Do we know, is there a link to these other things, though, at this point?
Kelly: There are associations. An association means it's something that's worth looking into more closely.
Interviewer: But we don't know for sure.
Kelly: Yeah, we can't tell you for sure that air quality equals X number of autism cases, for example.
Interviewer: That's kind of where it gets tricky, isn't it?
Kelly: I know, I know, and the people would like to see those numbers.
Interviewer: You sometimes hear air quality reports and they talk about things called P.M. and O3 readings. What are those?
Kelly: Right. Those are basically concentrations. That's the mass of particulate matter per volume of air.
Interviewer: Like mixing sugar in with water sort of a thing.
Kelly: Exactly, yeah.
Interviewer: Where is this inversion, this particulate matter coming from? Is it industry? Is it the cars? Is it fireplace burning?
Kelly: Okay, sure.
Interviewer: I'm going to guess it's industry.
Kelly: Industry contributes about 15% of the pollution that causes our fine particulate matter problem. Transportation, all mobile on road sources and even some of the off-road sources, those are responsible for roughly 60% of the emissions.
Interviewer: Wow, so just us individuals driving around does make a difference.
Kelly: Yeah. The other 25% is what they call area sources. Those are things like home heating, auto body paint shops, and use of consumer products, wood smoke. In fact, you did specifically ask about that. Currently, the state inventory suggests that wood smoke is responsible for about 10% of the particulate matter we see on a filter.
Interviewer: Talking about what we can do to protect ourselves, could a dust mask filter out the particles? I've sometimes seen guys riding their bikes in this cruddy air and they've got that mask on. I'm like, "I don't know."
Kelly: It does turn out that these little surgical masks or these single strip or single attachment masks do nothing. There are certain ones. We have to be very careful about which ones they'll get. They do need to be well fitted, and they do have to say they specifically filter out fine particles. You have to look. They're a little more expensive. You can get those.
Kelly: I should mention if you're trying to address other types of pollutants-gases, volatile organic compounds, or ozone-you would need a mask with some kind of carbon canister in it.
Interviewer: What about the air inside? Is it better than the air outside on these extreme air days?
Kelly: Generally speaking, yes. There are a couple of exceptions. One exception is if there's a smoker in the house, and the other is if someone's burning a lot of candles. For the most part, it's cleaner inside, and that's because two-thirds of the particles that we see are these particles that are formed indirectly. This is the ammonium nitrate, ammonium sulfate . . .
Interviewer: Chemical reactions.
Kelly: Yeah, and these are gases at our ambient temperatures inside. They then become gases, so they don't deposit in our lungs the same way.
Interviewer: Okay. Not as harmful as far as we know.
Kelly: We're not quite sure about that yet.
Kelly: But, we can tell you that the particle concentrations are lower.
Interviewer: What happens when it snows? Is it a bad idea to catch inversion snowflakes on my tongue or eat inversion snow?
Kelly: That's a good question. I'm not sure. I don't think I would recommend doing that.
Interviewer: Okay. Does it actually scrub the pollution out of the air?
Kelly: It depends how big of a snow we get. If we get a big enough precipitation event it does scrub the pollution out of the air. Oftentimes, our precipitation events are also accompanied by wind. That also tends to blow our pollution out of the valley. Yes, it cleans it up. However, we sometimes get light snows that do little to improve our air quality. You have to get enough.
Interviewer: I've sometimes seen those light snows, and I joke well, it's all falling out. Is that pollution falling out of the air at that point?
Kelly: Well, yeah, sometimes there's this sort of grayish precipitation on your car. I think that is. You do see, after these little precipitation events, a small dip in particle concentration, but then it will increase.
Interviewer: Okay. Interesting.
Kelly: I mean, again, as pollution builds up.
Interviewer: Yeah. Is this a solvable problem, or is it just something we're going to have to live with?
Kelly: Air pollution is going to remain a challenge, and we're going to have to keep coming up with better and better solutions as population grows.
Interviewer: What are some of those solutions do you think?
Kelly: I think there are two different ways to look at it. One is what individuals can do and others are sort of broader strategies. I think broader strategies, the first is tier 3 vehicle emissions standards. These tier 3 standards from E.P.A would entail more stringent emission control devices on all of our vehicles, and it would increase the cost of the vehicles by $100 or $200. In addition, cleaner fuel. This cleaner fuel would have lower sulfur content.
The next thing that probably could happen even a little more quickly is to address wood burning. As I said, wood burning appears to be responsible for about 10% of our particles.
Interviewer: That seems like a small percent, though, to be focusing on wood burning. Is it not a small percent?
Kelly: Well, 10% is not a small percent.
Interviewer: Okay, okay.
Kelly: I guess, when you start looking at strategies, if you could reduce 10% of particles in our valley you would reduce the number of days where we exceed the standard.
Interviewer: What about the bigger picture? You talked about a couple of things individuals can do. It sounds like a huge difference if you just watch what you drive, how you drive, when you drive, and wood burning stoves. What about a bigger strategy, statewide perhaps?
Kelly: I guess statewide would be the tier 3 and the wood burning. What individuals can do is, first of all, drive smarter. Avoid cold starts. Use mass transit, carpool, whatever we can do to limit the number of times you're starting that vehicle and driving. The other is don't burn wood. Then, talk to your friends about air quality, because we know that one person's actions don't make a difference, but once thousands and tens of thousands of people start to take action that does make a difference.
Interviewer: Yeah. I'm going to say something here that I think a lot of people think. We look at the refineries around the area, and we think shutting those down might be a good idea. Do you agree with that?
Kelly: The refineries contribute roughly 2% to 3% of our particle emissions. If we worked with the refineries to get tier 3 fuel available in our valley, we might be able to achieve emission reductions that are several times greater than all of the refinery emissions. I think that there might be smarter, more comprehensive ways to look at this than closing down all the refineries.
Interviewer: As a scientist, is this a problem that we absolutely need to address?
Kelly: Yes. It's important for our health because of the health effects that we know about and the health effects that are coming to light. It's also important for continued economic stability.
Interviewer: And, it would be nice when you say how beautiful our view is that when people come to visit, like for Sundance, they could actually see it.
Kelly: I agree. It would be great if we could see the view. It's unfortunate that Sundance occurs when our air quality is very poor.
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