Scientists have discovered that a soil microbe commonly found in New Jersey wetlands can break down one of the toughest class of pollutants, known as per- and polyfluoroalkyl substances, or PFAS. Often referred to as “forever chemicals,” PFAS are found in household products from non-stick pans, to dental floss, to water-repellant fabric.
These pollutants are extremely long-lasting and difficult to clean up, and can be found extensively in U.S. waterways and soil. They also move through the food chain, accumulating in humans at levels that scientists say can cause adverse health effects, including higher cholesterol levels, cancer, thyroid disruption, and low infant birth weights. The problem has gotten so widespread that the U.S. Environmental Protection Agency recently started a research initiative into the pollutants’ impact on drinking water.
The reason PFAS are so difficult to get rid of is because of their carbon-fluorine covalent bonds, one of the strongest in organic chemistry. Scientists Shan Huang and Peter Jaffe at Princeton University had been studying a process known as Feammox in which ammonium breaks down in acidic, iron-rich soils in New Jersey wetlands and similar locations. They found that this reaction occurred in the presence of the bacterium Acidimicrobium A6, and when they sequenced the microbe’s genome, they found that it held certain characteristics that could help break carbon-fluorine bonds, and therefore break down PFAS.
“We knew this was a big environmental challenge, to find an organism that could degrade these perfluorinated organics,” Jaffe said in a statement.
The researchers sealed the microbe in soil samples containing PFAS. After 100 days, Acidimicrobium A6 had removed up to 60 percent of the pollutants from the soil samples. They published their findings in the journal Environmental Science and Technology. Huang, Jaffe, and their colleagues are now testing the bacterium’s effectiveness over different timespans in lab conditions, before testing it in the field.