Episode 13: Some Ozone On a Hot Summer Day

Summer has just begun here in New York, and we've already received several ozone advisories. What does this mean and should you be concerned? In this episode, I want all of us to be informed on what ozone air pollution is and why it seems to show up every summer. 

Transcript

Hey everyone and welcome back! My name is Carmen, and I am your Brooklyn-based host for this podcast. Here, I talk about and present air quality issues so that you have the information you need to make the best decisions for you and your family. At the time of recording this episode, the temperature in Brooklyn, NY is 92 degrees F, with a feels-like temp of 101, and our current AQI is 111.

Before I dive in, I want to make sure that you understand that yes, you heard that right regarding our local AQI. Right now the entire state of NY is experiencing elevated levels of ozone, with the NYC metro area and Long Island under an air quality alert due to the high levels. Summer just started and we've already experienced several ozone action days here in the New York City area. I’ve been posting about it online and got quite a few great questions about it, which is what inspires today’s topic.

When most people hear the word "ozone," they might think about the ozone layer protecting us from harmful ultraviolet radiation from the sun. It’s something far away from our reach and is there to protect versus harm us. And yes that's true, but today we're talking about a different kind of ozone. When we’re talking about ozone air pollution, our focus is at ground level, right where we live, work, walk, bike, and of course breathe. Unlike the ozone layer in the atmosphere, ground-level ozone is a dangerous air pollutant. In fact, it's one of the most common reasons we receive air quality advisories here throughout the summer.

In this episode, I want all of us to be informed on what ozone air pollution is, why it seems to show up every summer, and why it’s a big deal. Let's dive in.

One of the most surprising things about ozone pollution is that ozone its not something that is directly emitted into the air. Here, the ozone air pollution is created through a chemical reaction from our everyday, existing pollution. It is a hot mess, ya’ll.

A primary example of our everyday pollution is vehicle exhaust. So cars, trucks, buses. Factories and power plants also create air pollution. These, and other sources, release gases called nitrogen oxides, often abbreviated as NOx, and volatile organic compounds, or VOCs. Bright sunlight and heat create a chemical reaction that results in ground-level ozone. In other words, ozone pollution is literally created on hot sunny days.

What makes it worse is that often these hot sunny days also have relatively stagnant wind patterns. This means there's not much wind to disperse pollutants, causing ground ozone levels to build up throughout the day.


So now let's talk specifically about New York City and what’s going on. Why do we experience ozone problems here?

The answer is a combination of population, transportation, weather, and geography. These four things are intimately intertwined and directly affect how the air pollution is disproportionately experienced. Straight off the bat, we have a lot of people.

More than eight million people live in New York City, and millions more commute into the region every day. That means a lot of vehicles, fuel combustion, and emissions. This includes public, private, and commercial vehicles.

Second, ozone doesn't stay where it's created. Pollution from neighboring communities and even states can be carried into our region by wind and weather patterns. Something to consider is that some of the ozone problems we experience here in New York are partially influenced by emissions generated hundreds of miles away, closer to Ohio, for example.

Third, urban environments tend to be warmer than surrounding areas due to something called the Urban Heat Island Effect. The very materials our city is built on: concrete, brick, and asphalt, for example, absorb and retain heat throughout the day. This creates warmer temperatures in some communities, and this can help promote the formation of ozone air pollution.

So now that we have that background information, let’s explore what ozone does to the human body? Should you be concerned?

The easiest way to understand the health effects of ozone is to think of it as a lung irritant. When you breathe ozone in, it can irritate and inflame your respiratory system. For some people, this irritation may be mild and might feel like a dry, raspy throat. For others, this exposure can have significant health effects that include chest tightness or heaviness, shortness of breath, difficulty catching your breath, having difficulty exercising outdoors, or a feeling like  your lungs are having to work harder than usual.

Here's the important thing: you don't need to have asthma or another preexisting health condition to be affected. Healthy adults can experience symptoms during elevated ozone events. If you’re a runner and you've ever gone out on a hot summer afternoon and felt unusually winded, ozone may have been part of the reason. It’s not just the heat.

Of course, certain groups are particularly vulnerable, which is why its important to stay up-to-date with local AQI information. Children are a group whose risk we underestimate. They’re vulnerable because their lungs are still developing and they tend to spend more time outdoors being active. This means they’re breathing more of the polluted air for longer periods of time.

Older adults in general are often more sensitive to respiratory stressors. Generally speaking, all people with asthma, COPD, or other respiratory conditions can experience worsening symptoms during high ozone days. Often overlooked as a vulnerable group are outdoor workers. They often spend hours breathing elevated ozone concentrations throughout the day, with no reprieve.

Let’s start tying together what we know, but talking about AQI, the air quality index. When ground ozone levels rise, they can push the Air Quality Index into the yellow or orange categories. Based on how air quality has been presented to the public, a lot of people might see a yellow reading and think, "That doesn't sound too bad." And for many healthy individuals, occasional exposure isn't a big deal and isn’t likely to cause major problems.

But ozone exposure is cumulative.

If ozone levels remain elevated for multiple days, (just at the yellow level) the effects build up and healthy people may begin to notice symptoms. By the time we reach the orange category, health officials consider the air unhealthy for sensitive groups and issue an advisory or alert. These public notifications aren't meant to scare people, they’re meant to help people make informed decisions.

Maybe you postpone that afternoon run, or schedule outdoor activities earlier in the morning. Maybe a person with asthma will have their rescue inhaler nearby.

The goals are education and prevention.

One interesting thing about ozone is that levels are often lower in the morning and higher in the afternoon. Keep that in mind as you plan your days over the summer. Remember those sunlight-driven chemical reactions I talked about earlier? Those reactions need time to occur. As the day progresses and there’s more sunlight, this becomes fuel for ozone production. This often causes air pollution concentrations to rise.

If you're planning outdoor exercise on an ozone alert day, morning is usually the better choice.

So…. is there anything we do about ozone pollution? The short answer is yes!

Impactful solutions can happen at the individual level. Reducing private vehicle use when possible and using public transportation instead are two easy ways. You can also refuel your car during cooler evening hours when ozone formation is less likely.

But realistically speaking, many solutions require larger-scale action. We need cleaner and more reliable transportation systems, stronger emissions standards, modernized infrastructure, and an investment in renewable energy that includes expanding green space. Ozone pollution is an environmental and public health issue, but it's also a policy issue.

The good news is that ozone levels in many parts of the United States are significantly lower than they were decades ago thanks to regulations and cleaner technology. The challenge is that climate change may make ozone management more difficult because hotter temperatures generally favor ozone formation. This is why continued progress remains important. We could easily just go around in circles and make things worse again.

That was a lot, so let’s hone in on the key takeaway:

Ground-level ozone is an invisible pollutant created when sunlight reacts with emissions from vehicles, power plants, and other sources. It's one of the primary reasons we receive summer air quality advisories and alerts here in New York City.

Ozone can irritate the lungs, worsen asthma, reduce exercise performance, and affect even healthy individuals. Because ozone is invisible, you can't rely on your eyes or your nose to know when it's present. That's why checking the AQI is so important.

I hope you’ve found this helpful and that the next time you see an ozone advisory, you'll know exactly what it means and why it's important to your health.
Thanks so much for listening. If you found this episode helpful, consider sharing it with a friend or family member. You can also follow me on Instagram or Facebook at CarmenTalksAir. Here I post about air quality news, advisories, health alerts, and more.

Until next time, stay informed and remember: no matter where you live on this planet, we're all breathing the same air. This is Carmen signing off….



REFERENCES:
American Lung Association. Ozone. https://www.lung.org/clean-air/outdoors/what-makes-air-unhealthy/ozone

Environmental Protection Agency. What Is Ozone? https://www.epa.gov/ozone-pollution-and-your-patients-health/what-ozone

Joseph, G. (n.d.). Summertime Air Quality in NYC: Risks and Strategies to Reduce Exposure. Environmental Health and Safety. https://ehs.weill.cornell.edu/summertime-air-quality-nyc-risks-and-strategies-reduce-exposure

Kheirbek I, Wheeler K, Walters S, Kass D, Matte T. PM2.5 and Ozone Health Impacts and Disparities in New York City: Sensitivity to Spatial and Temporal Resolution. Air Qual Atmos Health. 2013 Jun;6(2):473-486. doi: 10.1007/s11869-012-0185-4. Epub 2012 Oct 12. PMID: 23710262; PMCID: PMC3661920.

NYC Health. Outdoor Air Quality. https://www.nyc.gov/site/doh/health/health-topics/air-quality-air-pollution-protection.page

New York State Department of Health. Ozone. https://health.ny.gov/environmental/outdoors/air/ozone.htm