Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that have been used in a wide range of products, including nonstick cookware, waterproof clothing, and fire-fighting foam. PFAS are persistent in the environment and can accumulate in the human body, where they have been linked to a range of health problems, including cancer, birth defects, and immune system dysfunction.
PFAS can enter the environment from a variety of sources, including industrial discharge, wastewater treatment plants, and landfills. Once in the environment, PFAS can travel through groundwater and surface water, where they can be ingested by humans and animals.
A new study published in the journal Environmental Science & Technology has shed light on how PFAS travel in groundwater. The study, conducted by researchers at the University of California, Berkeley, found that PFAS can travel through groundwater in a variety of ways, including:
* Advection: This is the process by which PFAS are transported by the flow of groundwater. PFAS can be advected through groundwater at a rate that is determined by the hydraulic gradient, which is the difference in water pressure between two points.
* Dispersion: This is the process by which PFAS are spread out as they travel through groundwater. Dispersion is caused by a variety of factors, including the heterogeneity of the aquifer (the material through which groundwater flows) and the rate of groundwater flow.
* Diffusion: This is the process by which PFAS move from areas of high concentration to areas of low concentration. Diffusion is caused by the Brownian motion of molecules, which is the random movement of molecules due to thermal energy.
The study found that the rate at which PFAS travel through groundwater depends on a number of factors, including the type of PFAS, the concentration of PFAS, and the properties of the aquifer. The study also found that PFAS can travel through groundwater over long distances, and that they can persist in groundwater for many years.
The findings of this study have implications for the management of PFAS contamination. The study suggests that PFAS can travel through groundwater more easily than previously thought, and that they can persist in groundwater for a long time. This means that it is important to take steps to prevent PFAS from entering the environment, and to clean up PFAS contamination when it occurs.
References:
* Hu, X., Brusseau, M. L., & Rao, P. S. C. (2021). Transport of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in groundwater: A review. Environmental Science & Technology, 55(12), 7573-7591.
