California wildfire toxic smoke may cause long-term health effects

November 26, 2018 GMT

Cellphones, computers, refrigerators and cars these are just some of the objects that have been vaporized in California’s deadly wildfires, and the chemicals and particles from the melted objects have blanketed the northern part of the state in endless smoke this month.

“It literally felt like you were living in a cloud of fog, but it was not fog, it was smoke from the fire,” said James Steele, a realtor in San Francisco who described nearly two weeks unrelenting air pollution even being over 150 miles south of Butte County, the center of the Camp Fire, the deadliest fire in the state’s history.


The California Department of Forestry and Fire Protection this weekend said that the Northern California fire was has been nearly extinguished after several days of rain. Since its start on Nov. 9, the Camp Fire has left at least 84 people dead (and 475 others missing), charred 240 square miles and destroyed 19,000 buildings, mostly homes.

Almost all of Northern California is under a poor air quality advisory, with residents from Redding to San Francisco donning industrial-grade face masks to filter polluted air. Emergency room visits for asthma, heart attacks, stroke and other cardiovascular maladies are known to increase after a wildfire, but less is known about the long-term consequences on public health.

For people who are generally healthy, headaches, burning and itching eyes, and difficulty breathing are the most commonly reported symptoms.

“While it definitely it felt very difficult to breathe and exist up [here],” Mr. Steele said, “just keeping in perspective, I don’t think we’re that worried about it long-term. I think our concerns are the people just north of us.”

While lung cancer is associated with long-term exposure to particle pollution and wood-fire smoke, it’s unclear how short-term exposure to such smoke, increasingly burning up residential areas, will affect people.

Few studies have examined exposure to wildfire smoke and long-term health effects, Rebecca Schmidt, an assistant professor in the Department of Public Health Sciences at the University of California, Davis, told The Washington Times.

Ms. Schmidt and other researchers from UC-Davis have embarked on a fast-paced research effort to collect as much data about the current wildfires to analyze health effects.

“The things we’re actually exposed to are a little bit unknown at this point,” she said. “It is likely very different than just traffic-related air pollution or ambient air pollution that’s been better studied.”


The California Department of Public Health lists a toxic combination of chemicals likely present in smoke that can be a risk factor for heart disease, cancer and neurological problems.

Ms. Schmidt is leading a research team evaluating the impact of smoke exposure and the stress of the wildfire emergencies on women who were pregnant during the fires in 2017, which were similarly destructive to residential communities in Northern California.

Called the Wine Country Fires, the most devastating ones occurred in Napa and Sonoma counties, burning almost 37,000 acres and destroying more than 5,600 structures. A total of 44 people died in at least five fires that burned from October to December.

Ms. Schmidt has enrolled about 200 pregnant women and collected data on thousands of compounds detected in their hair, blood and urine samples, as well as testing the placenta and umbilical cord. Researchers also are collecting data on air pollution on specific days and chemicals in the soil, among other methods.

“We’re casting a broad net and collecting as much as we can ... because we really just don’t know that much and this is a way to narrow it down to what might be of most concern,” Ms. Schmidt said.

A colleague, UC-Davis environmental epidemiologist Irva Hertz-Picciotto, is helping lead a study on general population health related to wildfire smoke exposure.

“This has become a question too with these wildfires they’re different, they have different things in their mix,” Ms. Schmidt said. “There’s particulate matter, but then there’s all these other things, like, when a refrigerator melts and releases gasses and all the furniture and building materials and tar and all of these things being vaporized and put into the air.”

‘Complex, complicated condition’

Toxic chemicals are one concern, but fine particulate matter is another. Microscopic solid materials are inhaled and absorbed in the lungs and enter the blood stream, threatening to trigger an immune response or add to blockage buildup in arteries.

“We know that to some extent they seem to behave in the body much like the way cigarette smoke does in terms of promoting hardening of the arteries and cardiovascular risk over the longer run,” said Patrick Kinney, professor of environmental health at Boston University.

“But certainly I am a little concerned that there could be something with a mix of extra toxic pollutants to come from all the things, plastics ... things that get burned up when a house burns compared to when just a forest burns,” he said, adding that researchers “haven’t, unfortunately, really observed or studied so much.”

Mr. Kinney noted the long-term effects for firefighters, first responders and civilians in ground zero of the Sept. 11 attacks on the World Trade Center in New York.

“The exposure level there in California would be far less than what the firefighters several weeks and months working in the debris and getting really exposed to high levels,” he said.

Ms. Schmidt was cautious to compare the two events but said trauma and stress can harm the body and exacerbate health issues.

Kent Pinkerton, a professor of pediatrics and in the school of veterinary medicine from UC-Davis, echoed Ms. Schmitt’s assessment that trauma and stress can be an added layer to whatever long-term consequences may occur.

“In fact, even the trauma and psychological issues that you have to go through are far greater than anything you could be breathing,” he said. “It’s a very complex, complicated condition that people are facing who have had this kind of devastating event in their lives.”

Both Ms. Schmidt and Mr. Pinkerton can be counted among the cohort of their subjects their university closed for more than two weeks because of poor air quality. In the areas of Northern California down to the Bay Area of San Francisco, the air quality index has rated above 100 or 150 over that time period, unhealthy levels that at points were worse than air quality in China and India.

“I don’t think we’ve ever seen this long period of exposure to this high level of particles,” Mr. Pinkerton said. “That is what makes it so unusual.”

Rain over the coming days is expected to break up the smoke and wash away some of the larger particles clouding the atmosphere, although ultra fine particles, Mr. Pinkerton said, can remain.

“Rain cannot capture those,” he said, adding that it “could be an issue for concern that ultra fine particles may remain in the atmosphere within an area, or transported and being present for a fairly long period of time.”

The concern is mostly for the most vulnerable populations pregnant women, newborns, children, elderly and those with compromised immune systems and the general, healthy population are likely to recover, said Cindy Pak, chief of pulmonology at Kaiser Permanente in West Los Angeles.

“For the vast majority of the healthy population and the short term of acute smoke inhalation, which may or may not cause symptoms in these people, it will probably resolve on its own,” Dr. Pak said. “Our bodies are built with pretty robust immune systems that would take care of that.”