Fierce fires raise concern over major health consequences

Research suggests that children, the elderly and those with existing health problems are the most at risk.

Studies have shown that a short-term exposure to forest fire smoke can aggravate existing asthma and pulmonary disease, leading to treatment in an emergency room or hospitalization.

Increases in physician visits or hospital treatment for respiratory infections, bronchitis and pneumonia in otherwise healthy people have also been observed during and after forest fires.

Some studies have also revealed an increase in the number of emergency room visits for heart attacks and strokes in people with heart disease during days of heavy smoke in previous California fires, echoing research on potential health risks. atmospheric pollution in urban areas.

For most healthy people, exposure to the smoke of a forest fire is simply a nuisance, causing burns to the eyes, an itchy throat or chest discomfort that all disappear when the smoke disappears .

Doctors, scientists and public health officials are concerned, however, that the evolution of forest fires is a much broader health hazard.

"The forest fire season was from June to the end of September. This seems to happen all year long. We need to adapt to that, "said Dr. Wayne Cascio, a cardiologist with the US Environmental Protection Agency this week.

In a survey published earlier this year, Cascio wrote that the increasing frequency of large wildfires, urban expansion in forested areas and the aging of the population all increase the number of people at risk of health problems. by fires.

Wood smoke contains some of the same toxic chemicals as urban air pollution, as well as tiny particles of steam and soot 30 times thinner than a human hair. These can infiltrate the bloodstream, potentially causing inflammation and damage to the blood vessels even in healthy people, a study on urban air pollution has revealed. Studies have linked heart attacks with cancer and long-term exposure to air pollution.

It is not certain that exposure to forest fire smoke carries the same risks, and it may be difficult to determine the damage caused by smog in relation to forest fire smoke. especially when windswept California forest fires spread thick smoke hundreds of kilometers away in polluted large cities.

"That's the big question," said Dr. John Balmes, a professor of medicine at the University of California at San Francisco, who studies air pollution.

"We know very little about the long-term effects of wildfire smoke because it's hard to study populations years after a forest fire," said Balmes.

A decrease in lung function has been observed in healthy firefighters during the fire season. They tend to recover, but federal legislation signed this year will establish a US registry of firefighters and potential risks of various cancers, including lung cancer. Some previous studies have suggested a risk.

Balmes noted that higher rates of lung cancer have been found among women in developing countries who cook on a daily fire.

This type of extreme exposure does not usually occur with wildfires, but experts worry about the damage that firefighters and residents may suffer for their health, as a result of fires if common.

It is not known if this includes more cancer. "We are worried about this," said Balmes.

Regulars breathing all this smoke also worry about risks.

The smoke from the fire that decimated the clouded sky of Paradise, a city in northern California, this week in San Francisco, about 200 km southwest, and the air smelled "as if you camped, "said Michael Northover, an entrepreneur.

He and his 14-year-old son have a first sinus infection that Northover attributes to smoke.

"We are all feeling it," Northover said.

The courses were canceled Thursday in at least six northern California universities, with smoke continuing to cover the nine counties of the Bay Area. Some were closing all buildings, but others, including Cal State East Bay, said libraries, health centers and mess halls would remain open.

At Chico State University, 11 miles from paradise, ash was falling this week and classes were canceled until after Thanksgiving.

"It's a bit odd to see the whole city wearing breathing masks and trying to escape the smoke," said 18-year-old rookie Mason West. "You can see the particles, obviously it's probably not good to breathe that kind of stuff."

West returned home this week in Santa Rosa, badly hit by the fire of the wine country of last year, to finally find him wrapped in smoke in the fire of paradise 100 miles away . West's family had to evacuate last year for a week, but her house was spared.

"It's as bad here as it was in Chico," said West. "It almost seems like you can not escape it."

The smoke was so dense in Santa Rosa that the researchers postponed a door-to-door survey for a study of the health effects of the fire last year.

"We did not think we could justify that our volunteer trainees knock on doors when all the air quality alerts said to stay inside," said Irva Hertz-Picciotto, public health researcher. at the University of California at Davis. The study includes an online survey of households affected by the fire last year, with responses of about 6,000 people so far.

Preliminary data show respiratory problems, eye irritation, anxiety, depression and generalized sleep problems at the time of the fire and months later.

"Conventional thinking is that these fire-related effects are transient, and it's not entirely clear that this is the case," Hertz-Picciotto said.

Researchers will also analyze cord blood and placentas collected from a few dozen pregnant women during the fire, looking for evidence of stress markers or exposure to chemicals containing smoke. .

They hope to continue the study for years, looking for evidence of long-term physical and emotional damage caused by the dismissal of the evacuees and their children.

Other studies have established a link between emotional stress in pregnant women and their children's developmental problems and "it was a considerable stress," said Hertz-Picciotto.

It's a kind of stress that many people need to prepare for as the climate gets warmer and fires increase, "she said.

"Each of us could wake up tomorrow and lose everything we own," she said. "It's pretty scary."

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