In late April, The American Lung Association issued its annual air quality grades, including a pretty bad one for Las Vegas (F), pegging it as the ninth-worst-polluted metropolitan area in the country. The Clark County Department of Environment and Sustainability immediately shot back that the area’s air quality is “good, despite the American Lung Association grade,” based on its compliance with all but one (ozone) of the EPA standards for air pollutants.
Meanwhile, there’s the pandemic, which is heightening everyone’s awareness of their respiratory health and, by association, the air they’re breathing. To get the scientific perspective of our local air, and to connect the dots between it and COVID-19, Desert Companion turned to UNLV professor of environmental and occupational health Antony Chen. He reassures with a fact-driven view — and some concrete advice.
The American Lung Association’s annual report looks, broadly, at levels of ozone and particle pollution — or, to use lay terms, smog and soot. Is this a useful way of looking at the healthfulness of the air we breathe?
Basically, they compile all the EPA data for major cities with respect to the air quality. … Ozone and particulate matter (we say “PM”) are the air pollutants the EPA uses to determine air quality for compliance purposes. And it’s real-time data; the EPA posts an air quality index every day. So, yeah, certainly, it’s probably the most official way to look at air quality conditions in a particular area.
But bear in mind, these are just pollutants. If you have high PM concentration, you probably have other problems there, so you have to look into that. There could be something more toxic in the air than PM that’s not regularly measured by the EPA, such as toxic volatile organic compounds.
What do you make of the ALA’s ranking of Las Vegas?
Well, it’s the data, so I don’t argue with that. The air quality in Las Vegas has come a long way since the ’90s, and the population has doubled during that time. So, if you can improve the air quality while growing, it’s an achievement.
That doesn’t mean there isn’t room for improvement. The biggest problem is ozone, which is the same for most of the places that violate the air quality standards. High ozone concentration comes from three things. One, you need to have a source, which, in urban areas, is a high density of traffic emissions. Two, you have to have heat. The more sunlight you have, the more ozone. And three, stagnant air. At times our air is stagnant. Then we have a very long summer, and we have high traffic density. That’s the recipe.
There have been reports that air pollution has decreased in some cities during the pandemic. You watch the data. What are you seeing?
Yes, we’ve had stay-at-home orders reducing traffic. So it’s not surprising to see a decrease in pollution. I don’t have the most recent data on Clark County, because there’s a lag in reporting. But in urban areas, you see a general decrease.
What’s your takeaway from that?
I think it’s temporary. … When we return to full business, (pollution) will come back, but it gives us the opportunity to see how much traffic contributes to air pollution. So, if you can somehow reduce vehicle emissions, you can see what air quality could be like in the future. … The message here is, if you can do a good job reducing vehicle emissions, then you can stop the ozone. So, how can we do that?
How can we do that?
Use more public transportation; reduce the number of vehicles, especially diesel, because they are the biggest emitters of Co2; change from diesel to electric buses; encourage people to buy electric vehicles; and lower our vehicle emissions standards. Those kinds of things can reduce ozone precursors.
Air pollution contributes to some respiratory problems, like asthma. People with respiratory problems are more vulnerable to COVID-19. Does it follow that people in polluted areas are more vulnerable to COVID-19?
It’s a good hypothesis. There was some research published recently by a Harvard group looking at COVID-19 fatality rates, and it found that there were higher fatality rates in areas with poor air quality. It’s not surprising; we know there’s probably some link. The question is, how significant is it? Both (air pollution and COVID-19) impact our respiratory system, so there must be some connection.
The Harvard study is preliminary, but it makes sense. And we find similar examples in other areas, such as mining. It’s been found that if miners, who are exposed to a lot particulate matter, smoke, their chances of cancer increase exponentially. That’s the synergistic effect: You have two things combined that multiply the risk enormously.
And then, you add poverty, and …?
Locally, we did a study with students that showed there are higher rates of asthma in areas with higher pollution in Las Vegas. Pollution does increase asthma rates. We then measured where are those areas. They’re areas where, if you have a chance, if you have the money, you’ll move somewhere else. But people have no choice but to live in places where there are bad conditions, including poor air quality.
I don’t know if that has anything to do with incidence rates of COVID-19, because there are other factors. People living in poorer areas may not have the resources to work from home. They may have to go out to do their jobs. They have to go out more often to interact with people, which increases their exposure to the virus. If you have poor air quality on top of that, you could get that synergistic effect. Conversely, if you improve the air quality, then you could reduce people’s risk during pandemics.
So, your team’s work links asthma and air pollution, but not necessarily asthma and poverty?
Not directly, but it’s related. … One big area we haven’t touched on is indoor air quality. It’s difficult to measure, but in poor communities, there tend to be poor ventilation systems, so auto pollution can easily penetrate indoors, and there’s no way to remove that. Personal behaviors, such as smoking, can make it worse. And some appliances and furniture can actually emit pollutants, depending on what kind of chemicals are used to clean and finish them. Poor-quality construction materials can produce air pollution indoors. If you have good housing with good filtration, chances are you have good indoor air quality, you have high-quality building materials and furnishings. But if you’re poor, you don’t have a choice. Most people spend more time indoors, so that’s a concern.
What thought would you like to leave people with?
Before this pandemic, if someone asked me, I’d say, we know there’s poor air quality outdoors, especially when there’s a wildfire. The county will issue a warning, people can check the air quality on their website, and they know not to go outside — or, if they need to go outside, they can wear a mask for protection. It’s a similar thing now with COVID-19. Watch the news. Know when to go out. If you really have to go out, then reduce your contact with people, wash your hands, and use a mask when you can. That’s the kind of thing everybody should do to protect themselves and their children.