But a new study by researchers at USC has found that a popular variety is laden with toxic metals, and estimates retardant use has released 850,000 pounds of these chemicals into the environment since 2009. Each contained at least eight heavy metals. The findings offer a new clue to a phenomenon geochemists have documented for years: heavy metal concentrations in streams and rivers tend to spike after nearby wildfires. A Forest Service report said it could not rule out potential heavy metal impurities in retardant, which was hosed down from firefighting planes. “We’re adding a potentially significant amount of toxic heavy metals when we dump retardant, no matter where we dump it in the watershed,” he said.

Source: Los Angeles Times November 23, 2024 17:39 UTC