What's at stake:
Breathing in wildfire smoke can damage your health, but experts agree that taking some steps can limit impact. In short: buy filters, N95 masks, and follow PurpleAir.
The Garnet fire near the Kings River has scorched more than 30,000 acres of the Sierra National Forest and remains just 12% contained, sending thick smoke across the region that is expected to affect air quality in Fresno late Thursday morning.
Smoke is expected to roll into Fresno by 10 AM, according to NOAA Wildfire Smoke Forecast System.
“I would say it’s fairly serious,” said Emily Wilson, a National Weather Service meteorologist. “I would definitely not recommend outdoor activity.”
“Older adults and children should avoid any kind of strenuous exertion outside,” said Wilson, who’s based in the NWS Hanford office. “I would recommend staying indoors as much as you can and keeping the windows closed as well, just to keep out that smoke.”
The Valley Air District, alongside the National Weather Service, issued an air quality alert Wednesday afternoon.
Here’s what you need to know to stay safe and prepare for poor air quality.
What Are the Health Impacts of Wildfire Smoke?
Wildfire smoke contains PM2.5 particles, which include chemicals that cause damage to every organ in the human body. Breathing PM2.5 pollution is linked to brain inflammation, impaired cognitive functioning, emergency-room visits, early-onset Alzheimer’s and premature death.
A study estimated that wildfire pollution is 10 times more toxic than regular air pollution, and even short-term exposure to smoke was found to cause hard-to-reverse changes to how DNA is expressed in young adults.
Breathing in wildfire smoke can also make you more vulnerable to other ailments and diseases. For example, a recent study from Science, one of the world’s top science journals, estimates that 2020’s Creek fire caused a 45% increase in COVID deaths in Fresno because wildfire smoke stresses and weakens the body’s immune system.
Pregnant women and children are especially sensitive to the toxic effects of wildfire smoke and should take protective measures whenever possible.
Due to their higher exposures and developing bodies, children suffer lifelong consequences from PM2.5 pollution, including altered brain structure, increased risk for autism, depression, schizophrenia and suicide later in life, obesity, and asthma. Even small increases in PM2.5 exposure can increase children’s risk for self-harm by 42% later in life.
Brain health is also impacted by wildfire smoke than regular air pollution. A study by the California Air Resources Board also found that in addition to PM2.5, wildfire smoke contains other toxic chemicals such as high levels of lead, which is catastrophic for the brain development of babies and children.
Pregnant women benefit from every protective measure against wildfire smoke exposure. Maternal exposure to toxic air has serious health impacts on the fetus. The tiny particles in PM2.5 pollution have been found to sediment in the placenta and increase the risk for fetal death.
Women who breathe high pollution levels during pregnancy give birth to children with higher rates of health problems like pediatric leukemia, kidney cancer, eye tumors, and heart malformations.
Each increase of 1 µg/m3 in the trimester-average wildfire smoke PM2.5 over the second trimester is associated with a 13.2% increase in odds of preterm birth. A study from 2017 found that high pollution levels in the year a baby is born create detriments for a child’s ability to earn high wages when they reach adulthood.
How To Protect Yourself From Wildfire Smoke
Reducing the amount of smoke you breathe is the main goal of any protective measure. This can be done through three actions:
1. Indoor Air Filters
Air filters are rated by so-called MERV levels. A MERV-13 filter, for instance, captures more pollutants than a MERV-11.
According to experiments conducted over the last year by the Central California Asthma Collaborative, your filter should be rated at least a MERV-11. “Any filter rated under a MERV-11 is simply not going to keep you safe from wildfire smoke in your home,” said Kevin Hamilton, co-director of the Central California Asthma Collaborative.
While MERV-11 filters are OK at filtering wildfire smoke, Hamilton says MERV-13/14 filters offer superior protection.
Replace these filters once a month during wildfire season.
- If your AC motor is older than 10-15 years old, buy a MERV-11 filter.
- If your AC motor is less than 10 years old, buy a MERV-13/14 filter.
Adding a HEPA filter to your car can be helpful too. Replace every three months. Run AC on recirculate.
2. N95 Masks
When you have to go outside when smoke is in the air, wearing a well-fitting N95 mask is essential.
Fresnoland recommends N95 masks that cost between 70 cents and $1.10 per mask. (The second one, the N95 Aura, is the mask Fresnoland’s environment reporter Gregory Weaver prefers to wear.) Replace your N95 mask once a week during wildfire season.
To make sure the mask is sealed on your face, see here.
3. Outdoor Activity
Avoid outdoor activity when the AQI is greater than 80-100 or when the PM2.5 concentration is over 25. People under the age of 18 should avoid sports and recess when the AQI is over 80.
Check PurpleAir (AQI) or SJVAir (PM2.5 concentration) for real-time air quality information in Fresno before going outside.
Family Buying Guide
Assuming wildfire season goes from August to November, keeping your family safe from wildfire smoke will cost between $160 and $240 for N95 masks and AC filters. Add an additional $100-600 if you want the extra protection of a HEPA filter.
$ — $40/month + $100 upfront
Adult Mask: 3M vFlex $6/month (assumes two adults, using one mask each per week)
Child Mask: Savewo Small KN94 (2-6), Dr. Puri Sm. KN94 (6-9), Savewo Lrg KN94 (7-13) $19 / month (assumes two kids, using two masks each per week.)
AC Filter: MERV-11 filter 1 / month $15/month
HEPA for bedroom/living room: Medify Air or Dreo Air.
$$ — $50/month + $200 upfront
Adult Mask: 3M Aura $9/month (assumes two adults, using one mask each per week)
Child Mask: Savewo Small KN94 (2-6), Dr. Puri Sm. KN94 (6-9), Savewo Lrg KN94 (7-13) $19 / month (assumes two kids, using two masks each per week)
AC Filter: MERV-13 filter: 1x month $20/month
HEPA filter for living room: Winnix 5500-2
$$$ — $60/month + $800 upfront
Adult Masks: Flomask $180 upfront, $8/month for filters
Child Masks: Savewo Small KN94 (2-6), Dr. Puri Sm. KN94 (6-9), Savewo Lrg KN94 (7-13) $19 / month (assumes two kids, using two masks each per week.)
AC Filter: MERV-14 filter 1 / month $30/month
HEPA filter for living room: Medify air MA-112 or BlueAir 680i
