New research shows that hemp may be able to pull toxic perfluoroalkyl and polyfluoroalkyl substances, also called PFAS or “forever chemicals,” from the soil. The study, which has been underway since 2019, involved cleaning up contaminated land given to an Indigenous tribe in Maine.
What are PFAS?
PFAS are a group of human-made chemicals that can cause a variety of health risks, including cancer. They were originally created by 3M for products like Teflon and Scotchguard. Today they are in a wide variety of products including nonstick cookware, fast food wrappers, stain-resistant fabrics, carpets, surgical gowns, commercial aircraft and low-emissions vehicles. They are also used in the manufacturing process for creating phones, tablets and semi-conductors.
PFAS are referred to as “forever chemicals” because they do not break down in the environment or human bodies. Today, these forever chemicals are found in soil, groundwater and bodies across the United States.
'Protecting the land is part of the Micmac beliefs'
In addition to all of the other uses, PFAs are also used in firefighting foam. The Loring Air Force Base in Maine served as a firefighting testing ground where this foam was commonly used. The U.S. Airforce reportedly detected concerning levels of PFAS in the groundwater there, but did not try to remedy the problem.
Now, some of the former Loring Airforce Base land belongs to the Micmac Nation, an Indigenous tribe that is very concerned about the site’s contamination. The Micmac tribe is made up of about 1,500 people in Aroostook County, Maine.
“Protecting the land is part of the Micmac beliefs,” said Chief E. PeterPaul of the Micmac Nation in a statement. “Anything we can do to contribute to making the environment better, we want to be a part of.”
Cleaning up the land required collaboration
In 2019, a group scientists, activist and Indigenous volunteers teamed up to test different ways to remove PFAS from the soil at the former Loring Air Force Base after portions of that land was given back to the Aroostook Band of Micmacs in 2018.
While the researchers conducted the testing themselves, problems like lack of funding and pandemic-related travel restrictions meant that the project had to be a collaborative one. Local Micmac Nation volunteers collected the field samples for the study and the activist group Upland Grassroots helped develop the methodology for planting the hemp and collecting soil samples to help ensure that it was scientifically sound.
Fiber hemp successfully pulled the chemicals out of the soil
So far, the research seems to be a success. In the study, small fields of fiber hemp reportedly removed a primary type of PFAS from the soil.
A plant’s ability to remove contaminants from the soil is called phytoremediation, and hemp is “versatile in extracting many different kinds of chemicals from the soil,” said Chelli Stanley, a member of Upland Grassroots, in a statement.
“Hemp phytoremediation has been previously used for other types of soil contaminants — mainly metals,” Sara L. Nelson reportedly told media. Nelson is a scientist with the Connecticut Agricultural Experiment station and one of the lead researchers on the project.
“The primary contaminant at the study site is PFOS (perfuorooctane sulfonic acid), which we have found at up to 150 ppb in the soil, but many other PFAS are present as well,” Nason said in a statement. “[I]n our 2020 field test, PFOS soil concentrations decreased in both hemp growth plots. Earlier data from 2019 showed that several PFAS were accumulated in hemp tissue, and that the shorter-chain compounds showed greater bioaccumulation than long chain, similar to what has been reported in other literature.”
Nelson reportedly pointed out that hemp has been grown in several sites with large amounts of contamination, such as Chernobyl. However, there hasn’t been much previous research on hemp’s ability to specifically remove PFAS.
Research from the hemp/PFAS project in Maine was published in 2020, but it has not yet been peer-reviewed. The group also published a commentary of their work on July 13, 2021.