PFAS in California Groundwater: Distribution, Facility Sources, and Environmental Factors Correlations
Abstract
Poly- and perfluoroalkyl substances (PFAS) have been widely used since the 1940s. They are ubiquitous and have posed a threat to human health. Because of that, researchers have shown high interest in PFAS contamination in the environment and are trying to find effective ways for PFAS removal, primarily focusing on specific compounds like perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The limited understanding of PFAS presence in groundwater, along with the diverse subclasses of PFAS and their occurrence after the discharge from various industrial facilities, has significantly challenged our ability to assess risks. These complexities hinder the thorough evaluation of PFAS subclasses' impact on groundwater quality after the related facilities discharge. 38 PFAS in California groundwater from 2016 to 2022 were analyzed in this study. Statistical and spatial analyses were performed to visualize the distribution of groundwater PFAS in California and examine the relationship between PFAS and the facilities and environmental factors such as weather, soil, and air quality. I found that airports in California contributed significantly to PFAS groundwater contamination and then came bulk fuel terminal/ refinery and cleanup program sites. In addition, I identified the three highest concentration PFAS of each industrial facility. These analyses demonstrate the Greater Los Angeles Area is a hotspot for PFAS-contaminated groundwater. PFOS is the most frequently occurring PFAS in all the facility types. Also, this research summarizes all the environmental factors associated with PFAS and the top three highest concentrations of PFAS in all the facilities.I compared the results of this study with those of other researchers regarding PFAS in groundwater at airports and landfills, which exhibit similar trends. The recognition of PFAS subclasses provides a new understanding of PFAS contamination in California caused by industry. It aims to offer targeted approaches to the removal of specific PFAS for future study.