Smoke from three major fires burning in Southern California have fouled the air in central, southern and coastal Los Angeles County, with the bad air expected to hang around at least through Wednesday afternoon and into Thursday, according to a forecast issued by the South Coast Air Quality Management District.
The areas expected to remain in the unhealthy category — measuring from 151-200 on the Air Quality Index — due to heavy smoke include: Malibu, Pacific Palisades, Altadena, Pasadena and downtown Los Angeles, the SCAQMD reported on Tuesday. In these areas, everyone may experience throat irritation and difficulty breathing, while those with heart disease, children, the elderly or people with asthma should stay indoors.
The less severe category of “Unhealthy for Sensitive Groups” may affect northern and central Orange County as well as western San Bernardino County. The IE areas include Ontario and Rancho Cucamonga, according to the air management district.
The main culprit is soot, ash and even tiny pieces of metal making up very, very small particles, known as PM2.5 or particles carried in the air as small as 2.5 micrometers in diameter that can penetrate deep into the lungs.
“PM2.5 can make respiratory problems like asthma worse,” said Joe Lyou, president and CEO of the nonprofit Coalition For Clean Air who served 12 years on the SCAQMD governing board. “It has been shown to be related to an increase in emergency room visits for heart attacks, and in heart and lung problems in general.”
The good news is that the Santa Ana winds that whipped the Eaton Fire in Altadena and northeast Pasadena on Tuesday night and early Wednesday morning and grew it from 200 acres to 2,200 acres will diminish Wednesday afternoon and Thursday.
“Tonight and tomorrow (Thursday) in the San Gabriel Valley there will be very little wind, less than 10 mph. Basically the San Gabriel Valley is done with winds. We will not see any more winds in that area,” said Mike Wofford, meteorologist with the National Weather Service on Wednesday morning.
Also, winds fanning the Pacific Palisades fire are also decreasing, he said on Wednesday. “We are down to 20 to 40 mph in that area. That is a significant decrease.”
Less wind will help with firefighters fight these voracious fires. But it also means less smoke will be blowing through the region, Lyou said.
Lyou, who monitors wind and weather maps, said some maps showed zero winds in Pasadena and Altadena by Wednesday afternoon. Mostly unhealthful air quality was stretching south of the Eaton Fire, from near South Pasadena, Lincoln Height, Boyle Heights, Downtown Los Angeles, South Los Angeles, to Gardena, according to the Los Angeles Unified School District “Know Your Air Network” site.
The site was created with the help of the Coalition For Clean Air and is used to determine which schools should be closed and which ones should restrict outdoor activity.
Winds have begun shifting to the east, which drove the Eaton fire toward Arcadia and Monrovia early Wednesday morning. Smoke will more likely begin to blow into the eastern San Gabriel Valley, not as much to the south of the fire, Lyou explained. “Arcadia, Duarte and Azusa may see elevated levels (of bad air) from that fire,” he said.
If you see smoke or ash or smell fire in the air, the SCAQMD recommends:
• Stay indoors with windows and doors closed
• Run your air conditioner, which recirculates air from inside and cools it. Also, use a portable HEPA air filter.
• Do not use a whole house fan or a swamp cooler with an outside air intake.
• If outside, wear a N95 or P100 mask and keep it brief, without strenuous activity.