Roundup is being sprayed in national forests. Here’s what PCT hikers need to know

tThe U.S. Forest Service is spraying increasing amounts of the herbicide glyphosate in California’s national forests, report says report published in the May/June issue of Mother Jones.

The report focuses largely on Northern California’s Lassen National Forest, where, as author Nate Halverson points out, the Pacific Crest Trail passes directly.

Research on the safety of glyphosate-based herbicides like Roundup is controversial, with some studies pointing to possible health and environmental risks. Should hikers be worried?

Why is the Forest Service’s spraying raid in the first place?

Halverson’s report, based on more than 5 million spraying reports in California dating back to 1990, shows that glyphosate spraying in the state’s national forests has increased dramatically. And that’s just California, which has stricter public reporting requirements than most states on herbicide application.

The PCT passes through 15 national forests in California alone.

Glyphosate-based herbicides are most commonly associated with agricultural use and weed control. However, land managers, including the U.S. Forest Service, also spray forests. Roundup is effective in suppressing invasive species, but also native species that may compete with commercially valuable conifers, which are less susceptible to the herbicide than broadleaf trees. Fumigation is often done in areas that have recently been logged or burned in wildfires.

«We sometimes use herbicides with forest-specific formulations for things like invasive plant control and reforestation, but only a small portion of Forest Service lands in California, Oregon and Washington receive herbicide applications,» a Forest Service Region 5 (California) spokesperson told Trek via email.

Backpacker Concerns

“PCTA is concerned about how pesticide use may impact the landscape and, in particular, the water sources that PCT hikers and horseback riders depend on,” the organization said. Photo: J Taylor Bell

The report has raised concerns from at least one major trails organization. “The PCTA is concerned about how pesticide use may impact the landscape and, in particular, the water sources that PCT hikers and horseback riders rely on as they travel along the PCT,” the Pacific Crest Trail Association (PCTA) said in an email to Trek. «We are reviewing some prior National Environmental Policy Act (NEPA) documents to determine how glyphosate fumigation and potential related environmental effects could impact PCT users.»

Meanwhile, the Forest Service spokesperson told Trek that the public is given sufficient warning before entering sprayed areas. «Signs are posted at public access points to any treatment area at the time of application and remain in place until a specified interval of restricted entry. Posted signs include herbicides being used, application dates, and the required period during which entry is prohibited,» the agency said.

According to the National Pesticide Information Center glyphosate fact sheetThe half-life of the herbicide can vary from a few days to more than six months, depending on the medium and conditions:

• Between 2 and 197 days on the ground
• Between “a few days” and 91 days in the water
• One study found an average half-life of 8 to 9 days in red alder and salmon litter.

Higher levels of microbial activity and, to a lesser extent, sunlight, cause glyphosate to break down more quickly.

Is glyphosate safe?

The PCT passes through 15 national forests in California alone. Photo: Theo Crazzolara

He World Health OrganizationThe International Agency for Research on Cancer has classified glyphosate as a probable human carcinogen based on a review of approximately 1,000 studies. In contrast, the US Environmental Protection Agency (EPA; among others) says it is safe, based on its own review of research.

However, Halverson questions the reliability of some studies that both the EPA and the Forest Service have relied on to show that the substance is safe, including a key study that was recently retracted.

“Monsanto (the company that created Roundup, later acquired by Bayer) “He orchestrated, funded, and even authored studies that were published in peer-reviewed scientific journals under the names of supposedly independent researchers, articles that state and federal agencies have relied on to justify the copious spraying of Roundup,” Halverson wrote in Mother Jones.

Still, the Forest Service has maintained that it takes sufficient precautions before conducting forest spraying. «The decision to use any herbicide, including glyphosate, is made with careful consideration. Before applying herbicides, the Forest Service undergoes a rigorous, multidisciplinary evaluation of each chemical and its potential project-specific impacts to comply with state and federal laws. Herbicides cannot be applied on national forests without biological review and expert agreement that data show that herbicide application is the best tool to achieve forest health or restoration,» the board said. Region 5 press.

As mentioned above, California’s reporting requirements for herbicide applications are among the most stringent in the country. It is largely unknown how much spraying is taking place in other states.

Featured image: A burned section of the PCT near Belden, California, in 2022. Photo: Sibley

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