Think Chico’s bad? Try Riverside

Summer is the worst time for air pollution, and the air in California’s Central Valley is some of the dirtiest in the country. So how’s the air in Butte County? Are we cutting time off our lives with every breath?

The American Lung Association’s annual report, released just as summer was beginning, gives Butte County an “F” for ozone pollution and a barely passing “D” for particulate matter, the two categories in which the county has pollution problems.

That’s not good, said Bob McLaughlin, assistant air pollution control officer with the county Air Quality Management District. But it’s not terrible, either.

“We’ve gotten ‘unhealthy for sensitive groups’ on a few days,” he said. In the three years encompassed by the ALA report, there were 24 days on which ozone levels rose sufficiently to be unhealthful for sensitive groups. On such days, the district advises, “active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion.”

Ozone pollution is a bigger problem in summer months, while particulate matter—smoke, especially—is troublesome in the fall and winter.

Ozone, or heavy oxygen, is an oxidant that can be harmful to the lungs and cause pain while breathing, but this summer levels in Chico haven’t gotten high enough to warrant warnings, McLaughlin said. For the most part Chico summers have poor ozone levels, but “we’ve been hanging out in the ‘moderate zone’ lately.”

Ozone levels increase due to many factors, including winds that blow up pollution from the San Joaquin Valley and the Sacramento area, but most of the problem is caused by local vehicle use, he said, especially older vehicles with poor emissions control.

“At one point they were estimating 70 percent of the emissions were coming from gross polluting vehicles,” McLaughlin said.

It should be noted that the ALA report is based on limited data. If only one of the county’s several monitors reports high ozone levels, it goes into the record for the entire county. Butte County’s ozone grade was based primarily on readings from the Paradise monitor; the Chico monitor indicated only two days of unhealthful ozone readings in the three-year period.

By the same token, areas like Butte County with only a few days of unhealthful air received the same “F” grades as areas with more than 200 bad days. The BCAQMD recommends that people look at an area’s weighted average rather than the letter grade.

Butte County’s weighted average for ozone is 8.0. In comparison, Sacramento’s is 25.2, Los Angeles’ 85.8 and Riverside’s 93.2.

Particulate matter becomes a problem when fires start raging around September and through the winter months. Butte County’s “D” grade was the result of six days on which PM levels were considered unhealthful for sensitive groups and one day on which they were unhealthful, period. All of the readings were from the Chico air quality monitor.

Again, the district urges people to consider the county’s weighted scores: Butte County’s is 2.5, which Sacramento’s is 15.2, L.A.'s 39.7 and Riverside’s 54.8.

“We’re better than most [counties], but we still have work to do,” McLaughlin said. “We need to look at what we can do locally.”

Pollution from vehicle exhausts is regulated by the state, so BCAQMD’s focus is on expanding the use of such alternatives as car-pooling, bicycling and public transportation. Otherwise its focus is on controlling PM pollution. This includes restrictions on residential and agricultural burning, emission controls on boilers and stationary engines, and dust control measures.