Code Orange

Just in time for the holiday weekend: The Air Quality Partnership of the Delaware Valley has declared the first Code Orange of the year.

Date: Friday, May 25, 2007
Action Day?: Yes
Forecast Discussion: Friday will be an Air Quality Action Day with high concentrations of ozone expected. Light winds, warm temperatures and sunny skies will allow ozone concentrations to reach the Code Orange range on Friday. PM concentrations will increase Friday but remain within the moderate range.

Even though I'm a generally healthy guy, I fall in the sensitive group on the scale because of a sinus infection. The AQP describes why we should be concerned about ozone:

Ozone in the upper atmosphere protects us from the sun’s harmful rays where it plays an important role protecting life on earth (good ozone). At ground level, where we breathe, ozone can be harmful to our lungs and the environment. In the summer, sunlight and heat can "bake" pollutants to form ground-level ozone, also known as smog (bad ozone). Inhaling high levels of ground-level ozone damages your lungs and may feel like a sunburn on your lungs.

PM 2.5 refers to particulate matter, which is a year round problem.