Cities in the northeastern United States are not the only cities suffering from poor air quality. 

The Texas Commission on Environmental Quality (TCEQ) marked more Ozone Action Days for the month of June. Officials use this system to warn of decreased air quality, particularly for those sensitive to ozone and other forms of pollution. 

Ozone is a highly reactive gas that is formed naturally through interactions with ultraviolet light from the sun and oxygen molecules. This gas also forms a layer of the atmosphere known as the ozone layer that protects the surface of the planet from harmful solar radiation.

While this gas provides protection when it is high in the atmosphere, ozone can cause respiratory issues, such as lung irritation, for those sensitive to it when ozone is in overabundance near the surface. 

The American Lung Association reports that the DFW metroplex ranks in the top 20 of the cities in the United States with the worst ozone pollution. The worst ranked in the nation is Los Angeles, California. 

The TCEQ issued the first Ozone Action Day of the year on May 17, as previously reported by The Dallas Express. The National Weather Service (NWS) in Fort Worth previously informed The Dallas Express that pollution emissions from cars and industrial plants are to blame for the increased amounts of ozone, along with the planet’s natural processes. 

The NWS also cautioned that more Ozone Action Days would occur as the summer approaches. 

The TCEQ marked June 9 as a day with unhealthy air quality for sensitive parties in Dallas-Fort Worth, Beaumont-Port Arthur, Houston, and Tyler-Longview. Ozone levels are predicted to remain moderate through next week.

Some citizens are already feeling the effects of the increased amount of ozone in the air. Cindy Callaghan told CBS News that activities such as walking her dog are difficult on days when ozone is prevalent. 

“I just feel more tired. It just feels like it takes more out of you to get through your daily walk,” Callaghan said. 

Dr. Preeti Sharma, a pediatric pulmonologist at Children’s Health, told CBS News that she sees an increased amount of patients on Ozone Action Days. 

Sharma advised that citizens minimize outdoor activity as much as possible on Ozone Action Days.