Because of the pervasiveness, persistence, and toxicity of per-and polyfluoroalkyl substances (PFAS), there is growing concern over PFAS contamination, exposures, and health effects. The diversity of potential PFAS is astounding, with nearly 10,000 PFAS catalogued in databases to date (and growing). The ability to detect the thousands of known PFAS, and discover previously uncatalogued PFAS, is necessary to understand the scope of PFAS contamination and to identify appropriate remediation and regulatory solutions. Current non-targeted methods for PFAS analysis require manual curation and are time-consuming, prone to error, and not comprehensive. FluoroMatch Flow 2.0 is the first software to cover all steps of data processing for PFAS discovery in liquid chromatography-high-resolution tandem mass spectrometry samples. These steps include feature detection, feature blank filtering, exact mass matching to catalogued PFAS, mass defect filtering, homologous series detection, retention time pattern analysis, class-based MS/MS screening, fragment screening, and predicted MS/MS from SMILES structures. In addition, a comprehensive confidence level criterion is implemented to help users understand annotation certainty and integrate various layers of evidence to reduce overreporting. Applying the software to aqueous film forming foam analysis, we discovered over one thousand likely PFAS including previously unreported species. Furthermore, we were able to filter out 96% of features which were likely not PFAS. FluoroMatch Flow 2 increased coverage of likely PFAS by over tenfold compared to the previous release. This software will enable researchers to better characterize PFAS in the environment and in biological systems.

Thousands of per-and polyfluoroalkyl substances (PFAS) exist in the environment and pose a potential health hazard. Suspect and non-target screening with liquid chromatography (LC) high-resolution tandem mass spectrometry (HRMS/MS) can be used for comprehensive characterization of PFAS. To date no automated open source PFAS data analysis software exists to mine these extensive datasets. We introduce FluoroMatch, which automates file conversion, chromatographic peak picking, blank feature filtering, PFAS annotation based on precursor and fragment masses, and annotation ranking. The software library currently contains ~7,000 PFAS fragmentation patterns based on rules derived from standards and literature and the software This document is the postprint version of an article published in

Evaluation of cumulative exposure to air pollutant mixtures has been challenged by traditional techniques due to the weight, limited battery life, and cost. The performance of a novel wearable air pollutant sampler, the Fresh Air wristband, to passively concentrate nitrogen dioxide (NO 2 ), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs) was investigated. The Fresh Air Wristband consisted of a commercially-available triethanolaminecoated pad to collect NO 2 and polydimethylsiloxane (PDMS) sorbent bar to sample VOCs and PAHs. Concentrations were measured off-line following the assessment period. The repeatability and rate of VOC and PAHs uptake by the PDMS sorbent bar was evaluated and the Fresh Air wristband was tested as exposure tool. The PDMS sorbent bar achieved reproducible uptake of from ambient air with uptake rates varying from 2 to 5 days across compounds. Higher molecular weight compounds (>180 g/mol) were well retained in the PDMS sorbent bar over multi-day periods. The Fresh Air wristband was demonstrated as a personal exposure tool; exposures of school-aged children were found to differ by sex, asthma status, home kitchen characteristics, and mode of travel to school. The lightweight, wearable Fresh Air wristband will enable future longitudinal air pollutant exposure assessment in vulnerable populations.

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Chemical exposures are a major risk factor for many diseases. Comprehensive characterization of personal exposures is necessary to highlight chemicals of concern and factors that influence these chemical exposure dynamics. For this purpose, wearable passive samplers can be applied to assess longitudinal personal exposures to airborne contaminants. Questions remain regarding the impact of sampler placement at different locations of the body on the exposure profiles observed and how these placements affect the monitoring of seasonal dynamics in exposures. This study assessed personal air contaminant exposure using passive samplers worn in parallel across 32 participant’s wrists, chest, and shoes over 24 h. Samplers were analyzed by thermal desorption gas chromatography high-resolution mass spectrometry. Personal exposure profiles were similar for about one-third of the 275 identified chemicals, irrespective of sampler placement. Signals of certain semivolatile organic compounds (SVOCs) were enhanced in shoes and, to a lesser extent, wrist samplers, as compared to those in chest samplers. Signals of volatile organic compounds were less impacted by sampler placement. Results showed that chest samplers predominantly captured more volatile exposures, as compared to those of particle-bound exposures, which may indicate predominant monitoring of chemicals via the inhalation route of exposure for chest samplers. In contrast, shoe samplers were more sensitive to particle-bound SVOCs. Seventy-one chemicals changed across participants between winter and summer in the same manner for two or more different sampler placements on the body, whereas 122 chemicals were observed to have seasonal differences in only one placement. Hence, the placement in certain cases significantly impacts exposure dynamics observed. This work shows that it is essential in epidemiological studies undertaking exposure assessment to consider the consequence of the placement of exposure monitors.