INLAND EMPIRE – (INT) – Although not of its own doing, the San Bernardino Valley was the smoggiest location in the 4-county South Coast Air Basin this summer.

Monitoring stations at Redlands, San Bernardino and Crestline reported the most days and peak ozone readings of any location in Southern California, according to the South Coast Air Quality Management District (SCAQMD).

As of October 3rd, there were 122 days this year that the 8-hour ozone standard was exceeded. Redlands claimed 105 of those days followed by Crestline with 99 and San Bernardino 94.

Redlands had the 1-hour peak ozone concentration.

Prevailing air currents carry pollutants generated by stationary and mobile sources in more densely populated areas to the Inland Empire.

The result is a combination of emissions from the nation’s second largest urban area, meteorological conditions adverse to the dispersion of those emissions, and mountainous terrain surrounding the Basin that traps pollutants as they are pushed inland with the sea breeze.

Wildfires contributed to the air pollution this year with the AQMD issuing eight smoke advisories.

Although there have been significant reductions in smog over the past few decades, the AQMD says there are additional challenges to attain clean air standards by federal deadlines.

Story Date: October 23, 2019