From the mailbag: What are Ozone Action Days and why should we care?

Question: An alert on my smartphone told me today is an Ozone Action Day.  What is that and how does it affect me? – D.E., New York, NY

Answer: An Ozone Action Day is a day when the concentration of ozone gas in a particular area is predicted to be higher than healthy levels. Ozone Action Days generally coincide with high Air Quality Index days.  Ozone is one of the main urban air pollutants that we regulate, due to its potential negative impacts on human health, alone or in combination with other pollutants such as particulate matter.  Ozone can irritate the lungs and cause respiratory symptoms, especially in sensitive groups such as children,  the elderly, and those with respiratory problems such as asthma or COPD.

On Ozone Action Days it is generally a good idea to avoid exercise outdoors if possible.  Children’s outdoor play time should be limited on those days, especially for children with asthma.  You can do your part to help keep ozone levels down on Ozone Action Days by taking measures to reduce your emissions of NOx and volatile organic compounds (VOCs): limit electricity use and use of gasoline vehicles.