Although ozone air pollution levels have dropped in recent years, San Luis Obispo County continues to get a failing grade from the American Lung Association.
This week, the association released State of the Air 2013, its annual nationwide report card for particulate and ozone pollution. The report listed San Luis Obispo County as having the 25th worst ozone pollution, resulting in the grade of F.
The ranking is an ongoing annoyance to county air pollution control officials because most of the ozone pollution is found in the far eastern portions of the county where few people live.
While we appreciate the Lung Association report, it seems to misrepresent the air quality the vast majority of people who live, work and play in the county actually experience, said Aeron Arlin-Genet, outreach coordinator with the Air Pollution Control District.
Often called smog, ozone is an odorless and colorless gas that damages the lungs if inhaled. It is formed when carbon emissions interact with sunlight.
Air monitoring stations in the Red Hills near Shandon and the Carrizo Plain account for most of the countys ozone, although Paso Robles and Atascadero can also have elevated levels. Ozone detected at the two east county stations comes from pollutants transported from the Central Valley, Los Angeles and the San Francisco Bay area.
Ozone levels in other parts of the county, including San Luis Obispo, Morro Bay, Grover Beach and Nipomo, are at much lower, background levels.
At the most recent meeting of county Air Pollution Control District board of directors, district staff reported that ozone levels are steadily decreasing in the areas where they are highest and are staying steady in the areas where ambient levels are already low.
This was enough to improve the countys ozone ranking from eighth worst last year to 25th worst this year in the Lung Association report. But that was still enough to give the county a failing grade.
Local improvements in ozone levels mirror a nationwide trend which the Lung Association attributes to stricter air pollution standards for car emissions and other sources. Los Angeles has the nations highest levels of ozone pollution as well as much of the Central Valley from Fresno to Bakersfield.
The Lung Association report does not list particulates as a problem in San Luis Obispo County even though the Nipomo Mesa often has elevated dust levels on windy days from sand blowing off the Oceano Dunes.