The Air Quality Index, a method of air quality reporting and forecasting, rose as high as 226 in Sacramento this week. While the AQI was higher in 2018 from the Camp Fire, Sacramento County's current bad air quality still poses serious health threats.
"It is concerning because we are exposed to higher pollutant concentrations," said Dr. Juan Aguilera, an allergy and asthma research scientist at Stanford University.
Closer to the wildfires up North, the AQI levels are even starker. Just Thursday, the AQI soared as high as 353 in Berry Creek, 308 in Pollock Pines and 239 in Placerville.
California tops the charts of cities with the worst air pollution, according to the American Lung Association's recent "State of the Air 2019" report. While wildfires are only one part of the equation for California's poor air quality, the report shows that frequent and severe wildfires contribute to the state ranking consistently as the most polluted state for dangerous particulate matter in the air.
Over 90 percent of California residents "breathe unhealthy levels of one or more air pollutants during some part of the year," according to the California Air Resources Board.
Air pollution from wildfires includes both gases and burned materials, but exposure to fine particles known as PM2.5 has caused the most fatalities. These particles can easily enter the deepest parts of the respiratory tract, into the delicate tissues, according to Dr. Kent Pinkerton, a professor of Pediatrics at the UC Davis School of Medicine.
"They can easily enter into the respiratory system down into your lungs, where they can be deposited along the airways or within the regions of your lung where gas exchange occurs," Pinkerton said.
AQI focuses on short-term health effects that can be experienced within hours or days after exposure, according to Dr. Helene Margolis, an associate adjunct professor at the UC Davis School of Medicine.
The higher the AQI value, the greater the level of pollution and the higher the health concern. The severity of impacts varies from person to person depending on the amount of exposure, the weather conditions and an individual's sensitivity to negative air quality, Pinkerton said.
"We may not have the same kind of symptoms or conditions that lead to an emergency room visit, but [bad air quality] is something that we really should avoid," Pinkerton said.
More at-risk individuals include those with a heart or lung disease, the elderly, pregnant women, children and those with asthma, according to Aguilera. In AQI standards, these individuals are defined as "sensitive groups."
To protect themselves from exposure to higher pollutant concentrations, people should stay inside and invest in air purifiers if they can. If people must go outside, they should wear N95 masks and avoid physical exercise, Pinkerton said.
Experts and doctors say it's important to review local air quality levels daily to understand the risks of certain activities. Websites such as AirNow offer current and forecasted air quality data and maps.
How harmful is the air during wildfires?
With more mega-fires hitting the West Coast each year, air quality issues may be here to stay. The cumulative effects of repeated exposures to wildfire smoke are a big concern to researchers right now, Pinkerton said. Researchers know that repeated exposures to poor air quality can exacerbate or trigger respiratory effects.
With the frequency of wildfires increasing, these impacts could get worse.
"If this continues over the years, then we will definitely start seeing people that are more vulnerable being wildly affected by some of those symptoms — in particular, people that are from an elderly population or have lung or heart disease," Aguilera said.
A major concern with wildfire smoke is the burning of plastics, paints and other toxic materials involved in the destruction of buildings, appliances and vehicles. These fires generate a unique profile of particles into the air that is "potentially even more toxic," Pinkerton said.
A Napa County report on wildfire exposure and cancer from 2018 highlighted how smoke and debris from major fires can include asbestos, lead and heavy metals, which are known carcinogens.
The report found that inhaling particulate matter and carbon monoxide from smoke worsen existing respiratory and cardiovascular conditions, but that inhaling pollutants from wildfires has "not been found to cause cancer for the general public."
The National Foundation for Cancer Research also has said, "More data is required to determine the correlation of cancer risk with short-term exposure" to wildfire smoke and dangerous particulates.
The California Air Resources Board, which studied the air quality from the Camp Fire, found elevated levels of lead detected in Chico that lasted for about a day.
While a short amount of time, "these numbers are still concerning," the report said, "since lead is considered a toxic air contaminant and any increased exposure can be harmful. ... Infants and young children are especially sensitive to low levels of lead that are known to cause behavioral changes and learning deficits."
Long-term exposure to PM2.5 is linked to respiratory and heart-related illnesses and hospitalizations, adverse brain effects, depression, memory loss, learning disorders, reduced lung function growth in children and premature death, the CARB report said.
A number of traffic exposure studies show that children who grow up in areas with more polluted air, don't attain the maximum potential level of lung functions, Margolis said.
Aside from respiratory effects, the psychosocial effects are likely also quite significant, resulting from the trauma and stress of relocating and evacuating from wildfires and losing a home. More research needs to be done to understand them, said Dr. Angela Haczku, a professor at the UC Davis School of Medicine.
"There are just guesses [as to] what long-term problems might arise," Haczku said.
However, among all the experts, one thing remains clear: to prevent negative impacts of wildfires, reduce your smoke and particulate matter exposure by staying inside or masking up with N95s.
"Perhaps it's just logical that people would realize this, but when the air quality is bad and when we have wildfire smoke in the air, we should not be going outside," Pinkerton said.
AQI between 0 to 100: Good to moderate
Between 0 and 50 AQI, air quality is considered satisfactory and poses little to no health risks, Margolis said.
Between 51 and 100 AQI levels, air quality is acceptable. However, it poses some risks for those "unusually sensitive to air pollution." The majority of California is currently in the moderate AQI category, including most parts of Sacramento County.
AQI between 101 to 150: Unhealthy for sensitive groups
Above 100 AQI, air quality is unhealthiest for more sensitive groups, but it also poses slight risks for the entire population, Pinkerton said. Sensitive groups should limit exposure in this range, and the general public will likely be affected in this range as well.
"For those who are really susceptible, an AQI that goes above 100 should be the indicator to stay indoors," Pinkerton said.
AQI between 151 to 200: Unhealthy
At this level of air quality, members of sensitive groups may experience more serious health effects if exposed to these levels of air quality, however regardless of one's health or age, everyone is still at risk.
At this level, tiny PM2.5 particles are being generated, which can easily enter into the respiratory system deep into the lungs. After inhaling too much smoke at this level, people begin noticing eye irritation, a runny nose, a sore throat, coughing spells, wheezing, difficulty breathing or a rapid heartbeat, Pinkerton said.
"Those are all signs that whatever we're breathing in the air is having an effect on our respiratory system, and also can have an effect on our heart as well," Pinkerton said.
For sensitive groups, the impacts are only more severe and they may end up with the emergency department if they become too exposed, Margolis said. At these levels, it should be "a signal for everyone to stay indoors," Pinkerton said.
Most of the most Northern parts of California are currently ranked in these AQI levels. For some countries, pollution this high is in their normal air quality range. In 2020, Bangladesh ranked first for the worst air quality, with an average AQI of 162. Pakistan and India trailed closely behind with 153 and 141.
AQI between 201 to 300: Very Unhealthy
At this AQI, the risk of health effects increases for all groups. At levels this high, people are at risk of serious respiratory complications. More individuals can end up in hospitals as a result of smoke conditions this severe.
"Once the symptoms reach a certain threshold, people could get into severe respiratory failure, and end up being in emergency units in hospitals," said Dr. Angela Haczku, a professor of medicine at the UC Davis School of Medicine.
AQI 301 and higher: Hazardous
At these levels, there is a health warning of emergency conditions and all groups are likely to be harmed, Margolis said. People should avoid any kind of exposure at these levels.
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