Concerns about long-term health effects grow since 2017 North Bay wildfires

Catherine de la Cruz, 85, has had asthma since birth, but it’s never interfered with her day-to-day life, whether it was milking cows and cleaning equipment on her family’s Sonoma Valley dairy farm or riding her horse in trail riding competitions well into her 70s.

Even a heart valve replacement in 2015 didn’t slow her down for long. Within months, de la Cruz was back on her horse a couple of times a week at her daughter’s ranch in Potter Valley in Mendocino County.

All that changed after with the Tubbs Fire.

The day before the historic firestorm, de la Cruz, who lives in an apartment complex for seniors off Highway 12, had just celebrated a belated 80th birthday at the Potter Valley ranch, riding the new Missouri Fox Trotter she’d gotten for Mother’s Day.

Two days after the fire started, residents of her apartment building were told to evacuate. De la Cruz spent the next five days in a temporary “hospital ward” at the Santa Rosa Veteran’s Building, connected to oxygen.

The following summer, after the Ranch Fire erupted in July 2018 off Highway 12 near Potter Valley, de la Cruz became stranded at her daughter’s ranch, unable to leave for several days and constantly exposed to dangerous levels of smoke. When she returned to Santa Rosa, her doctor put her on full-time supplemental oxygen.

By January of 2019, de la Cruz was placed on palliative care for management of her severe chronic obstructive pulmonary disease (COPD). She’s had to rely on oxygen treatment since, and she labors to carry on a conversation.

She hasn’t been on a horse in five years.

During a recent phone interview, de la Cruz struggled to catch her breath after about 15 minutes of conversation. As she described her now frequent use of oxygen, her speech became halting, the space between each word growing longer with each sentence.

She finally agreed it would be easier to finish the interview via email.

“My diagnosis is now ‘very severe COPD,’ also known as ‘end stage’ COPD,” de la Cruz wrote in an email. “I am on full-time oxygen with several supplemental inhaler meds plus Prednisone and morphine. I can walk only very short distances, but it leaves me very short of breath.”

If the North Bay is spared from wildfire this fall, it will have been two years since the last urban wildfire ravaged local neighborhoods and darkened skies for extended periods with dangerously unhealthy PM2.5, a term that stands for particulate matter that is 2.5 microns or less in width.

That’s roughly 50 times smaller than the cross section diameter of human hair, and in the age of climate-induced wildfire and urban wildfire it is becoming a growing concern among scientists. Some recent studies suggest that wildfire particulate matter could be more dangerous than the same dose of ambient PM2.5, or typical air pollution.

Because of the relatively short duration of wildfire events, which range from days to weeks, scientists have relied on decades of research on regular air pollution to assess the dangers of wildfire smoke.

But with fires becoming more frequent and more severe, researchers are increasingly zeroing in on the health impact of wildfire smoke, examining such things as respiratory, cardiovascular and asthma-related hospital admissions, as well as the impact of short-term exposure on cognitive ability.

“Particulate matter in wildfire smoke can be very harmful for people who breathe it in,” said Dr. Sundari Mase, the county’s health officer

Mase said a large amount of particles, toxic gases and chemical compounds are produced during a wildfire. It is not clearly known what the long-term exposure means for most people. But she said, “the short-term consequences certainly are exacerbation of underlying pulmonary disorders, like asthma, like COPD ... even exacerbation of underlying heart conditions.”

What’s more, she said, there are carcinogens that could lead to more dire outcomes over time. “We might see even more development of these pulmonary diseases, maybe potentially even, with enough exposure, cancer,” she said.

“Is Santa Rosa going to burn down?”

Dr. Joshua Weil, an emergency physician at Kaiser Permanente Medical Center, recalls the harrowing news he got from a paramedic firefighter just after midnight Oct. 9, about an hour before the Tubbs Fire reached Santa Rosa city limits five years ago. He said he was told every single firefighter and piece of fire equipment in the county had been deployed.

“I got a chill down my spine thought, ‘Oh my god, is Santa Rosa going to burn down tonight?’” said Weil, who was on duty that night. His was one of 4,600 homes destroyed by the Tubbs Fire.

“It just seems so unfathomable and I think that it changed our perception — for me, for people in our community — that fire is real,” said Weil, adding that repeated wildfire, especially in an urban setting, has taken a psychological and emotional toll in addition to the impact on physical health.

“There's a whole mental health aspect that is ongoing and triggering,” he said. “When the wind comes up and it's dry and hot, everybody I know gets nervous, it affects us.”

Weil said the past five years of wildfire have seen an increase in emergency visits for respiratory illnesses throughout the Bay Area that have lasted months. During the 2018 Camp Fire in the town of Paradise, smoke in the Sacramento Valley resulted in a five-day period that saw worst air quality in the world, he said.

Even before the pandemic, he said, the use of N95 masks — a common practice in places like Beijing and Shanghai — was becoming increasingly routine during fire season in after 2017.

“That has become a regular thing for us now in California,” he said. “Every year during fire season, we get days where it’s just demonstrable, palpable smoke and particulate matter.”

Weil said scientists are researching the long-term health effects of wildfire smoke, which, like ambient air pollution, can get deep into people’s lungs and cause significant health problems.

According to the Environmental Protection Agency, there’s growing evidence linking wildfire smoke to increased risk of both cardiovascular- and respiratory-related effects, especially when the intensity of wildfire smoke increases.

How much PM2.5 is dangerous?

Though there are no safe levels for PM2.5, the EPA considers air acceptable when its density or concentration is under 12 micrograms per cubic meter, or 12 ug/m3. For example, last week on Oct. 13, a day of good air quality throughout Sonoma County and the Bay Area, the concentration of PM2.5 at Ridgway Swim Center near Santa Rosa was 3.1 ug/m3 at 6 p.m., according to IQAir, a Swiss air quality technology company.

But when concentrations get to 35 ug/m3 or higher, the air is considered unhealthy, adversely affecting those with existing breathing issues such as asthma. A daily average exposure to PM2.5 of 150.5 ug/m3 or higher is considered “very unhealthy” for both sensitive groups and the general public.

Stephanie Cleland, a research fellow with the EPA, is studying the health impacts, both physical and cognitive, of wildfire.

Her 2020 study found that during the 2017 fires, the daily average concentrations of PM2.5 exceeded 190 ug/m3 just north of the San Francisco Bay, with the highest concentrations occurring on Oct. 10 — two days after North Bay firestorms erupted — as well as Oct. 11 and 13.

Using census tract data, Cleland calculated that 65,466 people were exposed to daily average PM2.5 greater than 150.5 ug/m3 during the fires, with 64,030 exposed on Oct. 13 alone. The study found that an estimated 16 million people across the state on at least one day were exposed to daily average concentrations greater than 35 ug/m3, with Napa and Sonoma counties being disproportionately affected.

Cleland then used that data to examine the health burden of exposure to wildfire smoke in a subsequent study published last year. She found that 2017 fires likely led to a number of excess hospital visits between Oct. 8 and 20 — including 240 respiratory, 68 cardiovascular and 45 asthma hospital admissions. Of these excess visits, 56% occurred in the Bay Area.

The study found that Napa County, which was exposed to some of the highest concentrations of PM2.5 during the North Bay wildfires, had the most respiratory and cardiovascular admissions, 31 and 12, respectively. Sonoma County had 10, three and two excess respiratory, cardiovascular and asthma admissions, respectively.

For a very rough comparison, Cleland said the average rate of respiratory admissions in Sonoma County is 1.6 per 100,000 people. Assuming a population of roughly 500,000, that would mean Sonoma County had an estimated eight respiratory daily admissions or roughly 104 during Oct. 8 to 20, with the fire adding another 10.

Cleland said recent studies have suggested that wildfire PM2.5 may be more toxic to human health than ambient PM2.5, because of its different chemical composition, smaller particle size and co-exposure with other harmful pollutants.

Smoke gets in your brain

In a more recent study, Cleland and a team of researchers examined the impact of wildfire smoke on people’s cognitive performance. The study incorporated user data from a brain-training game called Lost in Migration, where users are shown a flock of five flying birds oriented left, right, up or down, and must correctly identify where the lead bird in the flock is headed.

The study, which examined scores from 10,228 users across the country and 1,809 in the western United States, found wildfire smoke was associated with reduced attention span in adults within hours and days of exposure. The researchers included the use of data from the growing network of PurpleAir air quality monitors to obtain real-time PM2.5 measurements.

The study found that for every increase 10 micrograms per cubic meter of wildfire PM2.5, Lost in Migration scores declined 20 points. Declines in cognitive performance were more pronounced in the western United States. Cleland said air quality networks like PurpleAir have seen an explosion in growth as wildfire and urban wildfire smoke become more prevalent.

“It’s going to be a very valuable thing moving forward when we’re trying to understand the health impacts of wildfires,” Cleland said. “It's really in the last few years of that PurpleAir network has exploded in popularity, especially in California.”

She said increased wildfires have triggered the need to know exactly when the air is healthy or dangerously unhealthy. Though less accurate than higher-quality, sparsely located EPA air monitors, home-based air monitors offer localized information, Cleland said.

“During wildfire events, air quality concentrations can often change quite rapidly over a space, given how smoke plumes work,” she said.

Ana Rappold, a senior EPA researcher who was the senior author in the cognitive performance study and a co-author in Cleland’s paper on health impacts of the 2017 wildfires, said the effects of wildfire smoke depend on the amount of exposure, with lower exposures affecting vulnerable groups.

That includes people with poor health because of chronic medical conditions, people with asthma, children and seniors. “Those are all factors that can increase your risk of adverse outcomes during the exposure,” she said.

Rappold, a longtime researcher into the health impacts of wildfire smoke, said there are several things you can do to prevent poor health outcomes. She said that includes reducing the amount of time spent outdoors during during a wildfire, running a high efficiency particulate air (HEPA) filter and wearing a face mask, which protects against air particles but not gases.

Long-term effects

A year after the 2017 fires, Irva Hertz-Picciotto, an epidemiologist and director of the UC Davis Environmental Health Sciences Center, was leading a team of researchers on a project that had been collecting survey data on health outcomes related to the fires. But when the Camp Fire started in early November 2018, becoming the state’s most destructive and deadly fire, Hertz-Picciotto got back into the field to collect more data.

The results of her team’s study of these fires have yet to be published, she said, delayed in part by pandemic-related studies. Hertz-Picciotto, however, did share some results from a survey of participants responding to questions about the 2017 North Bay fires.

Of 5,000 people surveyed, about 20% reported asthma and wheezing in the first three weeks after the wildfires started. Another 45% reported trouble coughing, with about an equal share complaining of irritated eyes. Just under 10% reported symptoms of bronchitis.

The surveys, which were completed in 2018, also included questions about mental health and open-ended inquiries about people greatest needs. Respondents were asked whether they had experienced such issues as anxiety or stress, trouble sleeping, depressed mood, loss of appetite and alcohol use, among other things.

Nearly 50% reported having some mental health changes, and just over a fifth of respondents reported four or more mental health changes. The largest of the mental health impacts was anxiety or stress, with more than 45% reporting changes in that anxiety or stress between the start of the fire and the time they took the survey.

Nearly 35% reported trouble sleeping or nightmares; more than 30% identified depressed moods; more than 10% had lost appetite; and about 37% had trouble concentrating.

“It’s astounding,” Hertz-Picciotto said of the survey findings. “More than 20% of people had four or more of these symptoms — that’s a lot — if you're having four of these signs of mental health issue, that is debilitating, I would say.”

Mase, the county health officer, said her division is especially concerned about the affect of wildfire smoke on vulnerable populations, particularly children and the elderly. “That’s why the schools are so concerned about exposure to wildfire smoke in school settings,” she said.

The list of underlying conditions that put the elderly at risk when wildfire fills the air with smoke is extensive, she said. It includes asthma, COPD, bronchitis, pneumonia, people with underlying heart disease or even stroke and pregnant people.

Catherine de la Cruz, the former equestrian, said doesn’t know if the past few years of wildfire have led to her COPD but the effects of so much smoke is undeniable.

“Would I have developed COPD without the smoky atmosphere?” she said. “Maybe. But I have no doubt that that contributed to the severity of the disease.”

You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.