A Pilot Study of Bis-perfluoroalkyl Sulfonimides in Dust from E-waste and Urban Regions

Abstract

Following global regulations on traditional per- and polyfluoroalkyl substances (PFAS), alternative PFAS raise emerging concerns. Our study focused on a group of bis-perfluoroalkyl sulfonimides (bis-FASIs) and explored whether electronic waste (e-waste) dismantling and recycling constitute a potential source of bis-FASIs to the environment. The study revealed ubiquitous occurrence of bisperfluoromethane sulfonimide (bis-FMeSI) in dust from e-waste sites, surrounding regions (20-50 km distant from e-waste sites), and urban areas with the levels in a descending order along with the distance from the e-waste sites. The median level of bis-FMeSI was 12 ng/g in e-waste dust, constituting approximately 10% of the total PFAS levels (117 ng/g). The levels dropped to a median of 0.45 ng/g in indoor and outdoor dust from surrounding regions as well as 0.67 and 1.1 ng/g in dust from traffic roads and underground parking lots, respectively, from a megacity located 100 km away from the e-waste sites. Our findings indicate that bis-FASIs appear as an emerging type of PFAS with widespread distribution in the urban environment. Therefore, they should be included into PFAS monitoring networks regionally or globally for a better understanding of their sources, distribution, and fate, as well as human exposure scenarios and associated health risks.