Layers of smoke hung over the South Bay on Friday morning after a fast-growing wildfire exploded overnight in the mountains to the east.
The Border 2 Fire, which flared to life yesterday afternoon near Otay Mountain, has now grown to over 5,000 acres. The wildfire has triggered a ripple of evacuation warnings and orders and is continuing to pour smoke into the air above parts of Tijuana and San Diego County.
As firefighters work to slow the blaze, South Bay residents are raising growing concerns about the worsening air quality. Fourteen schools across Chula Vista announced they would be closed on Friday. Others switched to rainy day protocols, keeping their students indoors.
The region’s air quality has cleared up significantly since yesterday, according to the U.S. Environmental Protection Agency. This morning, their air quality tracker showed a plume of unhealthy air spreading south from Otay Mountain across Tijuana. But at noon, the tracker updated to show mostly moderate air quality.
Still, residents of east Chula Vista said the skies remained hazy Friday afternoon.
Chula Vista resident Juan Escorcia was one of the parents whose kids were home from school today. From his backyard in Eastlake Greens, he said he could see the fire burning over the hills and spilling smoke into the sky.
“I can see ashes flying around,” Escorcia told KPBS early Friday afternoon. “You can extend your arm out and catch ashes on your hand.”
KPBS spoke with Tarik Benmarhnia, an environmental epidemiologist at the Scripps Institute of Oceanography, about how you can stay safe until the skies clear.
Why is wildfire smoke harmful?
Wildfire smoke is harmful because the burning reaction produces tiny particles, known as PM 2.5, Benmarhnia said.
Those particles are small enough to breach the oxygen-absorbing tissues in a person’s lungs and enter the bloodstream. There, they can cause inflammation and complicate other conditions like asthma.
The particles that wildfires produce are also especially toxic because these types of fires burn at such intensely hot temperatures, he said. That means smoke from wildfires is harmful, regardless of whether the fire is burning buildings or vegetation.
Benmarnhia said researchers are also currently studying whether wildfire smoke can carry other harmful materials like microorganisms, fungi or heavy metals.
Who should be careful?
Pregnant people should be especially careful around wildfire smoke, Benmarhnia said. Some studies have found that pregnant women exposed to particulate matter can face a higher risk of preterm births.
Young children should also take special precautions. At an early age, he said, a person’s lungs are still developing and they inhale more air than an adult, which makes them more susceptible to the risks of smoke.
Benmarhnia also warned that people with asthma, diabetes and other cardiovascular conditions should take extra care too, along with people who are isolated from others and people with mental health conditions.
What can I do to stay safe?
When it comes to staying safe around wildfire smoke, Benmarhnia emphasized that there are many steps you can take to minimize the health risks.
- Get ready to evacuate. First and foremost, he said everyone living close to a wildfire should be ready to leave if necessary.
- Wear a mask. Masks used to protect against Covid-19 are highly effective at filtering the harmful particles in wildfire smoke. Benmarhnia recommends using one that meets the FFP2 standard, like an N95.
- Monitor local air quality. Benmarhnia recommends monitoring sites like IQAir or the U.S. EPA’s AirNow site.
- Reduce your physical activity. If you can, keep running or other outdoor physical activities to a minimum while the air quality is poor.
- Remove dust at home. Before smoke from a wildfire arrives, Benmarhnia said vacuuming up dust at home can prevent the particles from spreading indoors. If the air is already smoky, he said, use a wet sponge or towel instead so you don’t kick up particles into the air.
- Turn on your home air filter. If you have one, Benmarhnia said, a home air filter can help keep indoors clear of harmful particles.
- Check in with a physician. If you have any serious health conditions, he said, you should try to check in with a doctor about specific medications or other precautions to take.
