Lessons learned during environmental forensic investigation of chemical manufacturing and use of PFAS by nontargeted analysis
Citation:
Strynar, M. Lessons learned during environmental forensic investigation of chemical manufacturing and use of PFAS by nontargeted analysis. SETAC Focus Topic Meeting: Nontarget Analysis for Environmental Risk Assessment, Durham, NC, May 22 - 26, 2022.
Impact/Purpose:
Environmental screening is necessary to identify new and emerging chemical contaminants. Through partnerships with state and regional EPA offices we have obtained contaminated waste and groundwater impacted by industrial manufacturing and examined itusing mass spectrometry techniques. this consistently enables the detection and quantification of legacy PFAS contaminants, as well as novel PFAS associated with different manufacturing chemistries. Long-term, the detected compounds are of interest for local biomonitoring efforts and toxicity/exposure modeling as PFAS of concern for similarly affected regions.
Description:
Industrial producers and users of per- and polyfluorinated alkyl substances (PFAS) are a major source of chemical contamination to nearby communities due to historical releases of legacy PFAS. Following the general phase-out of legacy PFAS such as PFOA/PFOS, industrial usage has shifted to alternative PFAS chemicals and it has been the domain of non-targeted analysis (NTA) to identify replacement species. Knowledge of emerging chemical contaminants is of significant environmental and human health impact due to the potential for widespread release, persistence, and bioaccumulation of PFAS species, along with their concomitant toxicological effects, which are frequently understudied. Over the past several years we have obtained samples of industrial effluent and contaminated ground and wastewater from numerous state and regional EPA offices for investigation into the presence of legacy and emerging PFAS chemistries. NTA using high-resolution mass spectrometry was used to examine the chemical identities of PFAS within these samples and compare the abundances of legacy and emerging chemical contaminants. Non-targeted analysis has been able to identify legacy contaminants of use, as well as elucidate replacement chemistries used by a variety of chemical manufacturers. These include previously identified family of chlorinated perfluoropolyethers (ClPFPECAs), polyfluorinated side products of polyfluorovinylidine (PVDF), as well as several other novel PFAS fluoroether species exhibiting ether linkages and acid head groups. Several of these families have been reported as components of fluoropolymer manufacturing in multiple locations in the United States, while some are novel to specific active sites. Measurements indicate the presence of effluent derived contaminants in localized groundwater and recirculation through processes that are “non-contact” is common, and that both intentionally added processing aids and polymeric production byproducts are frequent PFAS sources. This presentation will discuss case studies of recent work by EPA ORD in multiple PFAS site investigations.