SMOKE CAUSES BREATHING HAZARD AIR PARTICULATE LEVELS INCREASE.

Byline: Charles F. Bostwick and Karen Maeshiro Staff Writers

PALMDALE - Thousands of schoolchildren were kept off playgrounds, air tankers fighting wildfires were grounded and mail carriers halted their deliveries Wednesday as a pall of smoke descended on Antelope Valley.

After days of blue skies and 50-mile visibility while Southern Californians in other areas choked, a change in the wind patterns blew in wildfire smoke that measured high in particulate pollution.

At midday, motorists in the valley were turning on their headlights.

``You can almost look at the sun. It's so gray and brown, brown from the dust and gray from the smoke,'' said Rod Van Norman, superintendent of Southern Kern Unified School District in Rosamond, where children were kept inside classrooms at recess.

Particulate pollution levels measured in ``snapshot'' readings - readings that are not averaged out over an hour to fit federal standards - were as high as 250 to 350 micrograms per cubic meter, a spokesman of the Antelope Valley Air Quality Management District said.

By comparison, particulate measurements in Victorville, which is directly downwind of the San Bernardino Mountain fires, reached up to 1,000 micrograms per cubic meter.

``Whenever we have fires, the readings always become elevated. We are seeing higher than normal levels over other fires we've had,'' said Violette Roberts of the Antelope Valley Air Pollution Control District.

Levels of 255 to 354 are considered unhealthy. Up to 424 is considered very unhealthy, and beyond that is hazardous.

At Kaiser Permanente clinics in Lancaster and Palmdale, workers reported an increase in patients because of the smoke.

``Generally they're asthma patients who come in for breathing treatments,'' said Ken Murtishaw, a Kaiser administrator. ``We definitely have seen an increase.''

At Fox Airfield in Lancaster, low visibility plus poor conditions over the wildfires kept tankers on the ground for part of Wednesday, an air traffic controller said. Twelve tankers took off within 40 minutes after conditions changed in early afternoon.

At Edwards Air Force Base, visibility went from 90 miles Tuesday to two miles Thursday afternoon. A base spokesman said the smoke did not halt flying.

``We're doing business as usual. We're flying like normal,'' Lt. Dan Bernath said.

The U.S. Postal Service announced that mail would not be delivered to homes and businesses from Acton to California City, or picked up from collection boxes on streets, to protect mail carriers from the pollution.

Some schools reported higher than normal traffic at their health offices, with pupils experiencing coughing, burning eyes, headaches and episodes of asthma.

``There are students who are sensitive to smoke and other pollutants,'' said Julie Ferebee, Palmdale School District's director of health services.

In some areas, winds topping 30 mph kicked up dust that combined with the smoky haze. At Esperanza School in west Palmdale, where the cafeteria is under construction, students ate lunch in their classrooms rather than outside under the big tent they usually use.

The Antelope Valley Air Pollution District issued an advisory Wednesday warning residents of the pollution hazard and warning them to stay indoors if possible.

If the smoke persists, air pollution officials advised people with respiratory ailments like asthma to avoid moderate or heavy exertion. Everyone else, especially children and the elderly, should limit prolonged exertion, pollution officials said.

People were also advised to keep their doors and windows closed when possible and to set air conditioners to they do not draw in outside air, if possible.

Charles F. Bostwick, [phone]

chuck.bostwick(at)dailynews.com

Karen Maeshiro, [phone]

karen.maeshiro(at)dailynews.com

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Photo:

(1 -- color) A Sierra Highway motorist in Rosamond passes thr ough the smoky haze that cut visibility Wednesday. An air pollution advisory was issued.

(2 -- color) Smoke from the Southland wildfires combines with the cloud cover, obscuring the horizon in this view of the California aqueduct shot from Godde Hill Road in Palmdale. On Wednesday the air particulate readings, from 250 to 350 micrograms per cubic meter, were unhealthy.

Jeff Goldwater/Staff Photographer