Why Knozone Days Matter For Your Health

You may have seen the Knozone Action Days or Air Quality Action Days alerts on a highway sign or the local news. But these high ozone alert days serve more than an environmental notice; these weather conditions can put your respiratory health at risk as well.

What Is A Knozone Action Day?

Knozone Action Days are also known as Air Pollution Action Days, Air Quality Action Days or Ozone Action Days. These summertime alert days note that the combination of the high temperatures, light winds, and other factors, are expected to produce conditions where high levels of ozone emissions may exceed federally mandated standards.

Knozone Action Days are issued when ozone or fine particulate matter (PM2.5) levels rise to a level that makes the air quality unhealthy for sensitive individuals.

Air pollutants like ozone and particulate matter pose a public health issue as they can cause increased hospitalizations, asthma, bronchitis, heart attacks, chronic obstructive pulmonary disease (COPD), and premature death, according to the American Public Health Association.

Particle pollution comes from diesel engines and other sources. These microscopic particles can trigger asthma attacks, heart attacks, strokes and cause lung cancer. Research has also tied particle pollution to other serious diseases, such as asthma and dementia, and to worse COVID-19 outcomes.

On a Knozone Action Day, vulnerable groups, especially active children, the elderly, and anyone suffering from lung disease or other serious health problems, should avoid spending much time outdoors.

Why Is The Combination Of Heat And High Ozone Levels Dangerous For Breathing?

“Ozone at lower level of atmosphere is synthesized by photochemical reaction between different air pollutants. Hot weather potentiates this process of ozone generation,” said Franciscan Health Indianapolis pulmonologist Faisal Khan, MD. “Hot weather can be associated with increased humidity due to water evaporation making air heavier. Heavy air requires more effort to draw in for each breath. The combination of high ozone levels and humidity in hot weather therefore results in risk of breathing problems, especially in people with underlying lung disease.”

How Does Ozone Impact Breathing?

“Inhaling ground level ozone can impact breathing in different ways,” Dr. Khan said. “It can directly irritate the upper and lower airways and can result in symptoms like throat irritation, cough, wheezing, chest discomfort, chest tightness and shortness of breath.”

Ground-level ozone can cause respiratory problems for anyone; however, certain groups of people will generally experience more serious health effects. These include:

• Young children, who have smaller lung capacity and airways
• The elderly
• People with respiratory conditions like asthma, chronic bronchitis, emphysema or other lung diseases

“Ozone inhalation can reduce ability to breathe deeper thereby reducing effective lung capacity,” Dr. Khan said. “It is also shown to cause inflammation in the airways resulting in increased chances of having asthma and COPD flare ups and increased mucus production.”

Why Are Seniors More At Risk During High Ozone Days?

Several factors put seniors at a higher health risk during high ozone days, Dr. Khan said. These include:

• A natural decline in lung capacity
• A decline in the strength of respiratory muscles
• Being overweight, which reduces lung capacity and has shown to be more sensitive to ozone effects.
• Weaker immune responses and local defense mechanisms in airways

How Should People Protect Their Health On Knozone Days?

Dr. Khan recommends taking these four steps to protect your respiratory health on Knozone Action Days:

1. Be knowledgeable about Knozone days and air quality reports. An Air Quality Index (AQI) of >100 is considered to be unhealthy.
2. Plan to stay indoors in well ventilated and/or air-conditioned areas.
3. Reduce time spent outdoors and reduce level and duration of outdoor activities.  
4. Pay attention to any potential respiratory symptoms during these days and seek medical advice if any concerns.

What Can I Do To Help Reduce Ozone Emissions?

You can help reduce ozone-forming emissions by:

• Refueling vehicles in the evening. When you pump gasoline into your car tank or a gas can, some gasoline escapes as fumes. On hot summer days, these emissions can react with sunlight and heat to form ground level ozone. Refueling after 7 p.m. prevents emissions from escaping during the hottest hours of the day when they’re most likely to form ozone.
• Don't let your vehicle idle. Letting your car idle for longer 10 seconds releases more emissions than simply restarting. Avoid heavy traffic times, drive-thru lanes, and any other idling on Knozone Action Days.
• Combine errands. You’ll save emissions and time.
• Walk, bike, carpool or use public transportation.
• Conserve energy by turning off lights or setting the air conditioner to 75 degrees or above.
• Delay using garden, household or workshop chemicals until the air has returned to healthy levels.