While summertime can bring fun in the sun, the heat can also usher in poor air quality. Air pollution can have real effects on your health, especially if you have chronic conditions like cardiovascular disease, asthma or COPD (chronic obstructive pulmonary disease, also known as emphysema and chronic bronchitis).
The 2014 State of the Air report from the American Lung Association shows that, thanks to the Clean Air Act, air quality has improved in the United States from the past. But 147.6 million people, or nearly half the nation, still live in areas where air pollution can be unhealthy – including Louisville. In fact, the city ranks in the top 20 in the U.S. for both ozone (also known as smog) and year-round particle pollution, a mix of solid and liquid particles that come from coal-fired plants and vehicle exhaust.
In addition to making chronic lung conditions worse, particle and ozone pollution can increase the risk of heart disease, asthma and COPD exacerbations, and even early death. Children and those over 65 also can be sensitive to the pollution.
This summer has been unseasonably mild in the Louisville area, with few air quality alert days, but when the heat is on, the pollution can be, too. During the summer months, ozone can reach dangerous levels. Heat waves and poor air quality often go hand-in-hand, as lingering high pressure creates a stagnant environment. With light winds and no precipitation, pollutants don’t get cleared from the air, and they build up near ground level.
On days when air quality is expected to reach unhealthy levels, an air quality alert will be issued, and these aren’t something you should ignore.
Air quality affects how well you can breathe, and like the weather, it can change by the day, or even by the hour. When air quality is poor, you may see an acute worsening of your condition, with shortness of breath, a feeling that you can’t catch your breath, a tightening in the chest, a cough from the irritation or even bronchitis.
“If you have any kind of lung condition, the best thing to do is to avoid going outside on alert days,” said Dr. Rodney Folz, a pulmonologist with University of Louisville Physicians.
He said that on those days, air quality may be particularly bad over problematic areas, like downtown or near traffic congestion, where hydrocarbons and diesel exhaust hover in the air.
Symptoms may appear hours or days after exposure. “It really does send a lot of people to the emergency room, and we see an increase in hospital admissions,” Dr. Folz said. “And the longer your exposure, the increased risk you have of developing worsening symptoms.”
If you don’t have any kind of a chronic lung condition, air quality is usually not a concern for short exposure, but if you plan to be active outside, such as exercising or working, you should wait, he said. That’s because when you are active, you’re taking in more air and exposing the lungs to a greater volume of pollution.
Knowing what the air quality is can help you adjust your activities, and Dr. Folz notes there are websites and apps to keep track. The U.S. Environmental Protection Agency’s “AIRNow” and the American Lung Association’s “State of the Air” apps report the air quality index (or AQI), which indicates how clean the air is, and notify you when the air quality is bad.
The Louisville Metro Air Pollution Control District website, also gives a daily air quality forecast, and you can sign up to receive the forecast and alerts sent to you daily via email or text.
How the AQI is calculated
The U.S. Environmental Protection Agency calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide and nitrogen dioxide. For each, the EPA has established national air quality standards to protect public health.