Distribution and dry deposition of alternative and legacy perfluoroalkyl and polyfluoroalkyl substances in the air above the Bohai and Yellow Seas, China

Abstract

A total of 26 alternative and legacy perfluoroalkyl and polyfluoroalkyl substances (PFASs) were investigated in air collected above the Bohai and Yellow Seas during a research cruise between June 28 and July 15, 2016. ∑PFAS concentrations ranged from 70 pg m −3 to 430 pg m −3 (mean 230 ± 100 pg m −3 ). Trifluoroacetic acid (TFA, mean 120 ± 80 pg m −3 ) and 8:2 fluorotelomer alcohol (8:2 FTOH, mean 34 ± 46 pg m −3 ) were the predominating compounds of ionizable PFASs (i-PFASs) and neutral PFASs (n-PFASs), respectively. The contributions of C 4 and C 6 i-PFASs were higher than those of C 8 i-PFASs. Alternative substances, such as chlorinated 6:2 polyfluoroalkyl ether sulfonic acids (Cl-6:2 PFESA, mean 1.6 ± 1.2 pg m −3 ) and diPAPs (mean 1.6 ± 1.3 pg m −3 ), were only detected on the filter. The distribution coefficient of 10:2 FTOH was higher than 8:2 FTOH, which could be explained by the length of the carbon chain. The gas phase dry deposition velocities were simulated, and the values ranged from 0.08 ± 0.12 cm s −1 to 0.85 ± 0.28 cm s −1 . For i-PFASs and diPAPs, the estimated fluxes of the particle phase were higher than those of the gas phase. For n-PFASs and TFA, the gas phase deposition played a key role. The ∑PFASs dry deposition fluxes were 11-290 ng (m 2 d) −1 (mean 72 ± 67 ng (m 2 d) −1 ). The measurement of the concentrations in the gas and particle phases simultaneously provided a more comprehensive understanding of PFAS behaviours in air.

Emerging and legacy per- and polyfluoroalkyl substances in water, sediment, and air of the Bohai Sea and its surrounding rivers

“…8:2 FTOH was the predominant compound and its concentrations ranged from 60.7 to 368 pg/m 3 (191 ± 111 pg/m 3 ). Compared to previous studies, 8:2 FTOH concentrations in 2017 were comparable to those in 2012 (55e429 pg/m 3 , 182 ± 166 pg/ m 3 ) (Fang et al, 2018). Backward air trajectories showed that air masses with higher concentrations (A4, A5, and A6) originated from Shandong, Liaoning, and Jiangsu provinces and air masses with lower concentrations (A1, A2, and A3) from the eastern coastal provinces of China, Mongolia, and Russia (Fig.…”

“…Liaodong, Bohai, and Laizhou bays. Extremely high PFAS concentrations have been detected in adjacent inland and coastal waters because of emission from fluorochemical industrial parks and the contaminants are transported to the Bohai Sea not only by various rivers but also via deposition from the air (Fang et al, 2018;Li et al, 2011;Regnery and Püttmann, 2010;Wang et al, 2014a;Wang et al, 2013a;Zhou et al, 2018). Simultaneous field investigation of PFASs in air, water, and sediment in the semiclosed Bohai Sea are still needed to get a more comprehensive understanding about the PFAS behaviors in the environment.…”

Investigation of the Production of Trifluoroacetic Acid from Two Halocarbons, HFC-134a and HFO-1234yf and Its Fates Using a Global Three-Dimensional Chemical Transport Model

“…Moving forward, dry deposition fluxes of TFA were modeled as an upper limit to investigate the impact of this loss mechanism on tropospheric TFA levels under the future emission scenario for HFO-1234yf. A dry deposition velocity of 0.43 cm s −1 , extracted from Fang et al, 51 was employed in these simulations, hereafter referred to as "STO-HFC-SCI-DD and STO-HFO-SCI-DD". The global budgets of TFA from these simulations are shown in the Supporting Information (see Table S3).…”

Perfluoroalkyl acids in dust on residential indoor/outdoor window glass in Chinese cities: occurrence, composition, and toddler exposure

“…The instrument analysis employed Agilent 1290 series liquid chromatograph interfaced with an Agilent 6460 triple quadrupole mass spectrometer (HPLC-MS/MS, Agilent Technologies, USA). The detailed information of instrument analysis could be found in previous studies (Fang et al, 2018, Zhao et al, 2020.…”

“…Indoor surfaces might be in uenced by human activities which could result in particles falling off, while outdoor surfaces might be highly in uenced by wet deposition (Wu et al, 2008). Unlike other semi-volatile organic compounds, PFAA are hydrophilic and mainly distributed in particle phase (Fang et al, 2018). PFAA could adsorb on glass materials, which is an unique behavior.…”