High Levels of PFAA (Subgroup of PFAS) Found in Sea Spray

A new study has found high concentrations of perfluoroalkyl acids, or PFAA, in sea spray. In fact, researchers noted that the levels of PFAAs in sea spray aerosols were even higher than in seawater itself, and the researchers estimated that emissions of PFAAs from sea spray could be even greater than those in the atmosphere from manufacturing sources and other known polluters.

The study looked at PFAAs that are remobilized from seawater into sea spray via field studies of the Atlantic Ocean between the UK and Chile, The Guardian reported. Researchers Bo Sha and Jana Johansson used a sea spray emulator and worked from a ship for two months, according to Sha. They found that PFAA concentrations in the sea spray were over 100,000 times greater than the amount of PFAAs in the water itself. The team of researchers published their findings in the journal Science Advances.

“The common belief is that PFAS drain from the land into the oceans where they stay to be diluted into the deep oceans over the timescale of decades,” Ian Cousins, co-author of the study and professor at the Stockholm University’s Department of Environmental Sciences, said in a statement. “But we’ve now demonstrated in multiple studies that there’s a boomerang effect, and some of the toxic PFAS are re-emitted to air, transported long distances and then deposited back onto land.”

PFAAs are the most-studied subgroup of PFAS and have been previously found in rainwater, a previous study by the same research team found. PFAS (per- and poly-fluoroalkyl substances) are chemical compounds that do not break down in the environment and have been linked to human health risks, including elevated risks of certain types of cancer, as well as potential environmental impacts as they bioaccumulate in wildlife. PFAAs in particular are common in firefighting foams, food packaging and waterproof and stain-repellent materials, as explained by Science Direct. 

Scientists are continuing to try to understand the long-term impacts of PFAS in the atmosphere, so the latest findings of high PFAA concentrations in sea spray provide more information of how PFAA accumulates near the surface of the ocean and then release into the atmosphere from sea spray aerosols. From there, the researchers warned that the PFAAs can be transported back to land, forming a cycle of PFAAs moving from land to sea and back again.

According to the study authors, an estimated 49 tons of PFOA and 26 tons of PFOS are emitted each year from sea spray aerosols, compared to an estimated 1 to 1.4 tons of PFOS emitted into the air annually from industrial sources. The amount of PFOA emissions from sea spray is also comparable to the up to 74 tons of PFOA in the atmosphere from various known emitters as of 2012, the authors wrote in the study.

The scientists noted that these findings raise health concerns for people in coastal regions. They also suggested that their estimates in the study could fall short of the actual amount of PFAAs moving through to coastal regions.

“These findings have implications for human exposure to PFAAs, especially in coastal regions, and this merits further investigation,” the study concluded. “For example, our estimates include neither the contribution of shoreline wave breaking to the atmospheric burden of PFAAs nor the influence of the higher concentrations of PFAAs generally found in coastal regions. As such, our estimates on the deposition of PFAAs to coastal regions following their remobilization through SSA are likely to be conservative.”