Simi Registers High Pollution Levels

Air pollution in Simi Valley on Friday reached unhealthful levels for the second consecutive day, officials with the Ventura County Air Pollution Control District said.

Ozone pollutant readings registered 113 on Thursday and 114 on Friday, officials said. A pollutant standard index of 100 or above is considered unhealthful.

Air quality in the county’s smoggiest region was expected to improve slightly today to about 100, officials said. Ozone, a colorless gas that forms when hydrocarbons and nitrogen oxides bake in sunlight, can impair respiratory function and prematurely age lungs, experts say.

A high-pressure weather system responsible for hot temperatures also was credited with trapping pollutants in the valley, according to meteorologist James McCutcheon of Weather Data Inc.

That system will be breaking up over the next few days, McCutcheon said. “So I would expect to see a break in pollution levels associated with it,” he said.