PFAS are a group of chemicals made by man. You might not be very familiar with this type of chemicals; however, they start affecting the water sources. Their level is increasing in the groundwater. These human-made chemicals are being used in food packaging, water-resistant fabrics, non-stick products, pizza boxes, paints, firefighting foams, and so many other similar industrial products. A new study raises red flags on this specific subject and brings to attention the PFAS contamination in water sources, especially in the United States. This high level of PFAS chemicals is harming people's health. The PFAS contamination process "Because PFAS are in a lot of consumer and industrial products, they can get into wastewater. Treatment plants are not designed to treat these compounds, so these chemicals just stay in that water to get reused. It's sprayed on soccer fields or used to recharge aquifers, for example," said Mark Brusseau, professor of environmental science. "PFAS can also get into the biosolids, which are land-applied as fertilizer, so there are all these sources, which means they could have entered the environment at many different time periods and repeatedly." Computer simulations Researchers of the University of Arizona have done a computer simulation with the help of a mathematical model that they created. The simulation helps them understand the process of transportation of the PFAS chemical from the soil between the ground surface and groundwater. "This means that the majority of PFAS are still in the soil, and they are migrating down slowly in a way similar to a ticking time bomb," said Guo, University of Arizona assistant professor of hydrology and atmospheric sciences as well as study's lead author. The scope of the study "One of our objectives in the future would be to apply the model to different sites," said, Brusseau, who co-authored the study with Guo and Jicai Zeng, a postdoctoral researcher in Guo's group. "Then hopefully it will be useful for policymakers, regulators, environmental consultants to do assessments."