Researchers from the University of Arizona conducted a study to find how per and polyfluoroalkyl (PFAS) chemicals are moving through soil.
PFAS chemicals can contaminate groundwater sources and cause harm. (Source: Unsplash)
There is a growing health crisis due to synthetic chemicals in groundwater and it is starting to gain attention. The team reported levels of PFAS are just the tip of the iceberg because they found that chemicals are moving slowly through the soil.
There are 3,000 chemicals that belong to the PFAS class. PFAS chemicals have been used since the 1940s in food packaging, water-resistant fabrics, non-stick products, pizza boxes, paints and more. These chemicals don’t break down in the environment or in the human body. The model works for any PFAS chemical, but for the study, the researchers focused on perfluorooctanesulfonate or PFOS.
Past research has shown that PFAS contamination in water sources is widespread in the U.S. Exposure to PFAS is harmful, but treatment plants are not equipped to treat PFAS compounds. Because of this, the chemicals stay in the water and get put through the recycling process, and PFAS end up in biosoils.
The team created a mathematical model to simulate complex processes that affect the transport and retention of PFAS. This helps the team understand how chemicals mitigate through the vadose zone.
The model found that the majority of PFAS chemicals accumulate in places where air meets the surface of water and end up trapped in the soil. This slows down the chemicals' path to the groundwater. PFAS are moving through coarse-grain soil much slower than previously thought, creating a ticking time bomb of chemicals. The model proves that the research focus should be on the soil rather than the water.
The team believes that the model could one day be used by policymakers, regulators and environmental consultants to do assessments.
A paper on the model was published in Water Resources Research.
