Investigating the atmospheric sources and sinks of Perfluorooctanoic acid using a global chemistry transport model

Rayne Holland, M. A. H. Khan, Rabi Chhantyal Pun, Andrew J Orr-Ewing, Carl Percival, Craig A Taatjes, Dudley E Shallcross*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

23 Downloads (Pure)

Abstract

Perfluorooctanoic acid, PFOA, is one of the many concerning pollutants in our atmosphere; it is highly resistant to environmental degradation processes which enables it to accumulate biologically. With direct routes of this chemical to the environment decreasing, as a consequence of the industrial phase out of PFOA, it has become more important to model accurately the effects of indirect production routes like environmental degradation of precursors, e.g. fluorotelomer alcohols (FTOHs). The study reported here investigates the chemistry, physical loss and transport of PFOA and its precursors, FTOHs, throughout the troposphere using a 3D global chemical transport model, STOCHEM-CRI. Moreover, this investigation includes an important loss process of PFOA in the atmosphere via the addition of the stabilised Criegee Intermediates, hereby referred to as the ‘Criegee Field’. Whilst reaction with Criegee intermediates is a significant atmospheric loss process of PFOA, it does not result in its permanent removal from the atmosphere. The atmospheric fate of the resultant hydroperoxide product from the reaction of PFOA and Criegee intermediates resulted in a ~0.04 Gg yr-1 increase in the production flux of PFOA. Furthermore, the physical loss of the hydroperoxide product from the atmosphere (i.e. deposition), whilst decreasing the atmospheric concentration, is also likely to result in the reformation of PFOA in environmental aqueous phases such as clouds, precipitation, oceans and lakes. As such, removal facilitated by the ‘Criegee Field’ is likely to simply result in the acceleration of PFOA transfer to the surface (with an expected decrease in PFOA atmospheric lifetime of ~ 10 hours, on average from ca. 79 hours without Criegee loss to 69 hours with Criegee loss).
Original languageEnglish
Article number407
Number of pages13
JournalAtmosphere
Volume11
Issue number4
DOIs
Publication statusPublished - 19 Apr 2020

Keywords

  • Criegee intermediates
  • Perfluorooctanoic acid (PFOA)
  • global budget
  • atmospheric lifetime

Fingerprint Dive into the research topics of 'Investigating the atmospheric sources and sinks of Perfluorooctanoic acid using a global chemistry transport model'. Together they form a unique fingerprint.

  • Projects

    Cite this