Beyond fires, the deadly dangers of smoke are increasing

It kills more people every year than car accidents, war, or drugs. This invisible killer is air pollution from sources such as cars, trucks or factory smokestacks.

But as wildfires become more intense and more frequent in a warming world, smoke from these fires is emerging as a new and deadly source of pollution, health experts say. By some estimates, wildfire smoke — which contains a mixture of dangerous air pollutants such as particulate matter, nitrogen dioxide, ozone and lead — actually causes Up to 675,000 premature deaths Years around the world, as well as a group of Respiratory, heart and other diseases.

Research shows that wildfire smoke is beginning to appear The erosion of progress in the world In cleaning pollution from exhausts and chimneys, While climate change leads to an increase in fires.

“It’s heartbreaking, it really is,” said Dr. Afif Al-Hassan, a pediatrician who specializes in asthma care at Kaiser Permanente in Southern California and a board director for the American Lung Association. Dr. Al-Hassan said that forest fires “put our homes at risk, but they also put our health at risk, and it will get worse.”

These health concerns came to the fore this week as wildfires swept through the Los Angeles area. Residents They began to return to their neighborhoodsBurning ash and debris were scattered over many of them to survey the damage. Air pollution levels It remained high in many parts of the cityIncluding on the northwest Los Angeles coast, where the air quality index has risen to “hazardous” levels.

Carlos F. said: Gould, an expert on the health effects of air pollution at the University of California, San Diego, said Los Angeles, in particular, has seen air pollution at levels that can raise its daily death rate by 5 to 15 percent.

He added that this means that the current death numbers, “while tragic, are likely significantly underestimates.” People with underlying health problems, as well as the elderly and children, are particularly at risk.

The rapid spread of this week’s fires through crowded neighborhoods, where they have burned homes, furniture, cars, electronics and materials such as paint and plastic, has made the smoke more dangerous, said Dr. Lisa Patel, a pediatrician in the San Francisco Bay Area and WHO. Executive Director of Medical Community Consortium on Climate and Health.

A recent study found that even for homes that escaped destruction, smoke and fly ash inside can stick to carpets, sofas and drywall. Creating health risks Which can last for several months. “We’re breathing this toxic mixture of VOCs, polycyclic aromatic hydrocarbons and hexavalent chromium,” Dr. Patel said. “It’s all harmful.”

At the same time, increasing and frequent fires are undermining experts’ understanding of the health effects of smoke. “Wildfire season is no longer a season,” said Colleen Reed, who researches the health effects of air pollution caused by wildfires at the University of Colorado Boulder. “We have fires all year round that repeatedly affect the same population.”

“The health effects are not the same as if you were exposed to it once and then not again for 10 years,” she said. “The implications of that are something we still don’t really know.”

A United Nations report released in 2022 concluded that the risk of devastating wildfires around the world will rise in the coming decades. Heating and drying caused by climate change, coupled with development in fire-prone places, is expected to intensify…Global forest fire crisisThe report said. Both the frequency and severity of severe wildfires It has more than doubled over the past two decades. In the United States, the average Burning cultivated areas in the year It has risen since the 1990s.

Now, pollution from wildfires is reversing what had been a decades-long improvement in air quality as a result of clean cars and power generation. Since at least 2016, in nearly three-quarters of states on the U.S. mainland, wildfire smoke has eroded about 25 percent of the progress made in reducing concentrations of a type of particulate matter called PM 2.5, Study of nature In 2023 found.

In California, the effect of wildfire smoke on air quality Offsets public health gains It was caused by a decline in air pollution from cars and factories, state health officials found. (By releasing carbon dioxide and other greenhouse gases into the atmosphere, wildfires are themselves a major contributor to climate change: Wildfires to sweep through Canada’s boreal forests in 2023 Produced more greenhouse gases from burning fossil fuels in all but three countries.)

“It’s not a pretty picture,” said Dr. Gould of the University of California, San Diego, who was involved in the nature study. If greenhouse gas emissions continue at current levels, “we have some work that suggests deaths from wildfire smoke in the United States could rise by 50 percent,” he said.

One silver lining is that the Santa Ana winds that have fanned the fires so intensely in recent days are pushing some smoke toward the ocean. This contrasts with the smoke from the 2023 Canadian wildfires Which drifted to New York And other US states are hundreds of miles away, causing significant spikes Emergency room visits for asthma.

At one point that year, more than a third of Americans, from the East Coast to the Midwest, were under air quality alerts due to smoke from Canadian wildfires. “We are seeing new and heightened threats in places we are not accustomed to,” said Dr. Patel, a pediatrician.

Dr. Patel said the new normal is bringing changes to healthcare. More health systems are sending air quality alerts to at-risk patients. At the small community hospital where she works, “I talk to every child who comes in with wheezing or asthma about how air pollution is being made worse by wildfires and climate change,” she said.

“I teach them how to look for air quality, and I tell them they should ask for an air purifier,” Dr. Patel added. It also warns that children should not participate in clean-up after wildfires.

Scientists are still trying to understand the full range of health effects of wildfire smoke. One big question is how much what researchers know about car exhaust and other forms of air pollution applies to wildfire smoke, said Mark R. Miller, a researcher at the Center for Cardiovascular Science at the University of Edinburgh, who led the study. Recent global survey From climate change, air pollution and forest fires.

For example, he said, exhaust particles “are so small that when we inhale them, they go deep into our lungs and are actually small enough that they can move from our lungs into our blood.” “Once it’s in our blood, we can carry it around our bodies and it starts to accumulate.”

This means that air pollution affects the entire body, he said. He added: “It has effects on people with diabetes, it has effects on the liver and kidneys, it has effects on the brain, and on pregnancy.” What remains unclear is whether pollution from wildfires has the same effects. “But it’s possible,” he said.

Experts have a set of tips for people who live in areas where there is a lot of smoke. Monitor air quality alerts and follow evacuation orders. Stay indoors as much as possible, and use air purifiers. When you venture outside, Wear N95 masks. Do not do strenuous exercise in bad air. Keep children, the elderly and other vulnerable groups away from the worst types of smoke.

Dr. Al-Hassan of the American Lung Association said that addressing climate change and reducing all types of air pollution is ultimately the way to reduce the overall burden on health. “Can you imagine how much worse things would be if we didn’t start cleaning up emissions from our cars?” He said. “I try to think, and the glass is half full, but it breaks my heart and worries me.”