AUSTIN, Texas — The National Weather Service offices from Dallas to San Antonio have issued a special air quality alert.
For Wednesday, they are calling for an Ozone Action Day, in order to try and offset the amount of ozone being produced.
Ozone in the upper atmosphere is a good thing. It helps provide a layer of protection between the Earth and harmful ultraviolet rays from the sun. However, when it is present in high concentrations at the surface, it is harmful to humans.
According to the Air Central Texas website, the Environmental Protection Agency "considers anything over 70 ppb (parts per billion) to be unhealthy for human health and welfare."
Tuesday's measures of surface-level ozone over the Interstate 35 corridor are not far below the 70 ppb threshold in Austin and are expected to rise for Wednesday, per the air quality alert.
This is partly due to the uptick in temperatures and sunny days that we are expecting this week. Sunlight causes ozone to be produced when it passes through common manmade chemical pollutants, like nitrogen oxides, carbon monoxide and hydrocarbons. The stronger and more widespread the UV light is on a given day, the greater chance for harmful ozone at the surface.
Ozone causes harm to the respiratory systems of humans and animals. Asthma sufferers and those with chronic lung infections are the most sensitive to high surface-level ozone. According to the EPA, the most common side effects are shortness of breath and a sore or scratchy throat.
Below is a list of actions you can take in order to reduce your ozone output on Wednesday. Another Ozone Action Day may be issued Wednesday afternoon, as the forecast continues to call for sunny stagnant air through the majority of the week.