The bad air of the Californian campfire makes people sick, but for how long?

Respiratory, cardiac and other problems may also occur two to three weeks after the fire has been contained – a late reaction probably due to the cumulative effect of breathing stale air for several days. That's what happened after the deadly fires of last year in the California wine region, said doctors.

The long-term impacts of such exposure, on the other hand, are poorly understood. Few studies have been conducted to monitor the health of the population months and years after exposure to high concentrations of "particulate" pollution. The emissions are similar to the toxic particles released during the burning of fossil fuels. However, fire fumes can pose an additional risk because they include chemicals released from burns in homes and cars – and their insulators, plastics and metals.

From Butte County to Silicon Valley, physicians in some emergency rooms reported a slight increase in the number of patients complaining of sore throats, eye irritation, coughing, and breathing difficulties.

The increases were not evident towards the beginning of the camp fire on November 8, but they were corrected while the fire persisted and there was a "layer of inversion Has settled in most of northern California. This is a meteorological configuration in which high pressure maintains a virtual dome on a given area. Inversions generally trap fog in California valleys, but they also capture smoke after large fires.

For most of the last two weeks, atmospheric stagnation has caused people in the Sacramento Valley to travel to the San Francisco Bay Area as if trapped in a giant brown balloon.

The Bay Area Air Quality Management District has recorded 13 consecutive days of particulate pollution greater than 151 micrograms per cubic meter as of Tuesday. This is the level considered unhealthy for humans. This is the longest consecutive series of consecutive unhealthy air days, in winter, 63 years of history of the air district, which covers nine counties.

Many patients visiting emergency rooms in the area have not associated the smoke with their symptoms, doctors said. They simply reported discomfort.

"You start to realize that if you have 50 people in the emergency room, 25% of them have complaints such as cough, sore throat and heart palpitations," said Ronn Berrol, Medical Director of Alta Bates Emergency Department. Summit Medical Center in Berkeley. "You start thinking that there must be a connection between what is happening in the environment and people exposed to such air quality for seven, eight, nine or ten days. "

According to officials at Sutter Health, the largest hospital chain in northern California and operating from the Berkeley Hospital, it is too early to have gathered data on the apparent increase in respiratory diseases and diseases associated.

Berrol said he hoped he could continue to see patients with respiratory problems even after the departure of the smoke.

"We are gaining experience with these super fires in recent years," said Berrol, "and we tend to find that the inflammatory process of exposure to smoke does not stop not as soon as the smoke goes away … types of conditions will increase over the next two weeks. "

Researchers at the University of California at Davis began last year to recognize how little was known about the long-term effects of wildfire smoke. They have therefore initiated studies on the effects of the Tubbs fire in 2017 in Sonoma County and other outbreaks of giant vineyards that have killed more than 40 people.

Hertz-Piccioto, environmental epidemiologist at UC Davis, collected information from about 6,000 people in 2,000 households. She seeks, beyond breathing problems, other symptoms, including depression, and behavioral changes such as the consumption of alcohol and cigarettes.

"Conventional wisdom is that exposure to short-term smoke will not have a long-term impact on health," said Hertz-Picciotto. "But what is short? And if it's a two-week, but recurring, exhibition once a year? We wonder when and in what group of people this is going to impact ? "

Scientists are also trying to better understand the exact content of smoke from fires at the so-called "wild city interface". When cars and homes burn with trees, it means releasing chemicals that are found in paint, plastics, insulation and metal.

A sample of ashes from last year's fires north of San Francisco Bay revealed 1,947 more chemical compounds in burned suburbs than in areas where there were only trees and trees. brush. Nobody knows what happens when people breathe these compounds.

Another open question concerns the effectiveness of masks in preventing tobacco-related illnesses, said Rebecca Schmidt, professor of public health at UC Davis. Public health officials in northern California prefer that people stay indoors during the worst smoke alarms, but disagree on whether or not to recommend masks.

"They just do not know the answers," said Schmidt. "When we looked at the information, there were not many answers. And that 's one of the reasons why we decided to go ahead. "

Schmidt is studying the effects of fire smoke on the health of pregnant women and their babies before and after birth. She collected samples of hair, placentas, saliva and umbilical cord blood and also interviewed about 200 women exposed to smoke from fires in the vineyards of 2017. The results could be significant not only for mothers in future fire, but also for the general population, "said Schmidt.

Schmidt hopes to obtain the approval to extend the study to women breathing smoke camp fire. It aims to have preliminary results by the beginning of next year.

"We are learning that these fires may become our new standard," Schmidt said. "It's time we started to understand them."