by Kelly Zito from "San Francisco Chronicle" [http://www.sfgate.com/bayarea/article/Air-quality-Several-Bay-Area-counties-fail-survey-2374211.php]:
Periodic spikes in ozone levels and the choke-inducing fine particle pollution from diesel engines and smokestacks earned several Bay Area jurisdictions poor marks in air quality, according to a nationwide report card released today.
A county-by-county analysis by the American Lung Association in California gave failing marks to Santa Clara, Solano and Contra Costa counties.
But the Bay Area lapses pale in comparison with the persistent, noxious air in places like Los Angeles, Visalia and Bakersfield, which earned the association's title for worst air in the nation.
The 12th annual "State of the Air" report found that despite a drop in the total number of days that Californians breathe smog and diesel fumes, the state remains awash in some of the dirtiest air in the nation.
"Even though we're seeing tremendous improvement in California, the fact is, we still have a significant number of unhealthy air days," said Bonnie Holmes-Gen, senior policy director for the California lung association.
The association analyzed federal data collected between 2007 and 2009 on short-term and annual average concentrations of ozone, or smog - usually generated by car exhaust mixed with heat - and fine particle emissions from diesel trucks, coal-fired power plants and wood-burning fireplaces.
The 177-page report concluded that most of the country - including California - had fewer total days when pollution levels exceeded U.S. Environmental Protection Agency thresholds for unhealthful air compared with a decade ago. The Golden State nevertheless had 11 of the top 15 most smog-filled metropolitan areas. The Los Angeles-Long Beach-Riverside corridor topped the list of ozone offenders, followed by Bakersfield, Visalia (Tulare County), Fresno and Sacramento.
The Bakersfield area ranked worst for fine particle pollution, followed by Los Angeles, Phoenix, Visalia and Hanford (Kings County).
Taking both types of pollution into account for short and long periods, Bakersfield's air ranked worst in the nation, while Honolulu and Sante Fe, N.M., had the best air quality.
Kern County, where Bakersfield is, had about 102 days - more than three months - in which smog contamination reached levels considered particularly harmful to young children, the elderly and those with chronic heart and lung ailments during each year of the study.
Fully 154 million Americans are exposed to unhealthful air each year, the lung association said. Over the longterm, high levels of smog and particulate pollution are associated with asthma, bronchitis, emphysema, lung cancer and other disorders.
In the nationwide "worst of" lists, the San Jose-San Francisco-Oakland metropolitan area showed up only once, tying for 24th with Portland, Ore., and Wheeling, W.Va., for highest levels of particle pollution over a 24-hour period.
The Bay Area counties that received F's each had a number of high ozone or high particle pollution days. Santa Clara, Solano and Contra Costa had more than 10 high ozone days and more than 12 high particle pollution days.
San Francisco County got an A for low ozone days, but a C for five days of particle pollution spikes. Sonoma County, with no high ozone or particulate days, earned all A's.
In contrast, San Bernardino County had a whopping 136 days each year in which ozone topped federal health standards, the worst in the nation in that category.
During a conference call with reporters, representatives of the American Lung Association and the Bay Area Air Quality Management District acknowledged that pollution often accumulates in some regions of the state and not in others because of geography and weather patterns. The Bay Area's cool, coastal climate safeguards the region against some factors that exacerbate pollution, such as high temperatures and stagnant air flow.
What's more, a small portion of Bay Area smog and particulates wafts into the northern Central Valley during summer months - though the reverse is true during winter months, air district officials said.
Wind and topography aside, the report's authors noted that the Bay Area has taken significant steps to cut particle contaminants, especially from wood burning. In 2008, the regional air district passed a sweeping ordinance that bans burning of garbage, requires federally certified stoves or fireplace inserts in new homes and remodels, and prohibits wood burning in fireplaces and stoves when air quality hits harmful levels.
Officials estimate wood smoke accounted for about 30 percent of wintertime particle pollution in the nine-county region.
"The wood smoke rule is really important here. People are heeding the call and burning less," said Lisa Fasano, spokeswoman for the air district.