These planes can release a tankful of bright pink flame retardant over a roaring flame in just 20 seconds. They have long been considered essential in fighting wildfires.
but new research The millions of gallons of flame retardant sprayed onto landscapes each year to quell wildfires carry a toxic burden, as they contain heavy metals and other chemicals that are harmful to human health and the environment. The research team showed.
This toxicity poses a serious dilemma. These tankers and their cargo are powerful tools for putting out deadly fires. But as wildfires become more intense and more frequent in the era of climate change, firefighters are using them more frequently, releasing more harmful chemicals into the environment in the process.
Some environmental groups question the effectiveness and potential harm of retardants. Because flame retardants are one of the intensive firefighting tactics used during large fires, their effectiveness has been difficult to measure. Once the flames are extinguished, it’s hard to take credit.
In recent years, the frequency and severity of wildfires has increased, particularly in the western United States. Scientists also found that fires across the region are growing faster than in recent decades.
There are also long-term health effects from exposure to wildfire smoke, which can penetrate the lungs and heart and cause illness. a Recent global research A study of the health effects of air pollution from wildfires found that exposure to wildfire smoke has increased by 77% since 2002 in the United States. Wildfire smoke is estimated worldwide. take responsibility to 675,000 premature deaths Year by year.
Flame retardants pose a “very troubling trade-off,” adding to the burden on health and the environment, said Daniel McCurry, an assistant professor of civil and environmental engineering at the University of Southern California who led recent research on flame retardants. he said. -Metal content.
The U.S. Forest Service said Thursday that nine large retardant spray planes and 20 water cannon helicopters are being used to battle Southern California fires that have displaced tens of thousands of people. Several “water scooper” amphibious aircraft are also in use, which can skim the surface of oceans and other bodies of water to fill tanks.
Two large DC-10 aircraft, dubbed “super-large air tankers” and capable of transporting up to 9,400 gallons of retardant, will also soon join the force, said Stanton, a spokesman for the National Interagency Fire Center in Boise, Idaho.・Mr. Florea said. It coordinates national wildland firefighting efforts throughout the West.
Florea said flame retardant sprayed before a fire coats the plants and prevents oxygen from burning them. (Red dye is added so firefighters can see the flame retardant against the landscape.) And flame retardants, which are typically made with salts such as ammonium polyphosphate, “last longer. . It doesn’t evaporate like a drop of water,” he said.
But a new study by Dr. McCurry and colleagues shows that at least four heavy metals, including chromium and cadmium, in a common type of flame retardant used by firefighters exceed California’s hazardous waste requirements. It turned out that.
Federal data shows more than 440 million gallons of flame retardants were applied on federal, state, and private lands between 2009 and 2021. Using that figure, researchers estimated that more than 400 tonnes of heavy metals were released into rivers between 2009 and 2021. The environment due to firefighting efforts is one-third the size of Southern California.
Both the federal government and the flame retardant manufacturer, Perimeter Solutions, dispute the analysis, saying the researchers evaluated different versions of the flame retardant. Perimeter spokesman Dan Green said the flame retardants used in aviation firefighting have passed “extensive testing to ensure they meet rigorous standards for aquatic life and mammal safety.” He said there was.
Still, the findings help explain why heavy metal concentrations tend to spike in rivers and streams after wildfires. hundreds of times more. As fire extinguishing agents come under increased scrutiny, the Forest Service has established buffer zones around lakes and rivers. proprietary data This shows that flame retardants are still inadvertently drifting into these waters.
In 2022, the environmental nonprofit Forest Service Employees for Environmental Ethics sued the government in federal court in Montana, demanding that the Forest Service obtain a permit under the Clean Water Act to cover accidental spraying into waterways. Ta.
The judge ruled that the agency must actually obtain a permit. However, the use of flame retardants was authorized to continue to protect life and property.
