Publication Date:
2022-05-26
Description:
Author Posting. © American Chemical Society, 2019. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Environmental Science and Technology 53(14), (2019):8244-8251, doi:10.1021/acs.est.9b02344.
Description:
Perylene is a frequently abundant, and sometimes the only polycyclic aromatic hydrocarbon (PAH) in aquatic sediments, but its origin has been subject of a longstanding debate in geochemical research and pollutant forensics because its historical record differs markedly from typical anthropogenic PAHs. Here we investigate whether perylene serves as a source-specific molecular marker of fungal activity in forest soils. We use a well-characterized sedimentary record (1735 to 1999) from the anoxic-bottom waters of the Pettaquamscutt River basin, RI, USA to examine mass accumulation rates and isotope records of perylene, and compare them with total organic carbon and the anthropogenic PAH fluoranthene. We support our arguments with radiocarbon (14C) data of higher plant leaf-wax n-alkanoic acids. Isotope-mass balance calculations of perylene and n-alkanoic acids indicate that ~40 % of sedimentary organic matter is of terrestrial origin. Further, both terrestrial markers are pre-aged on millennial time-scales prior to burial in sediments and insensitive to elevated 14C concentrations following nuclear weapons testing in the mid-20th Century. Instead, changes coincide with enhanced erosional flux during urban sprawl. These findings suggest that perylene is definitely a product of soil derived fungi, and a powerful chemical tracer to study spatial and temporal connectivity between terrestrial and aquatic environments.
Description:
We thank John King, Sean Sylva, Brad Hubeny, Peter Sauer, and Jim Broda for their help in sampling; Carl Johnson and Daniel Montluçon for their incessant help with analyses; as well as Mark Yunker for critical discussion on the perils of perylene. Professor Phil Meyers and two anonymous reviewers provided comments that improved the quality of the manuscript. U.M.H. acknowledges the Swiss National Science Foundation for his postdoctoral fellowship and T.I.E. and K.A.H. acknowledges the NSF for research grants CHE-0089172 and OCE-9708478.
Description:
2020-06-19
Repository Name:
Woods Hole Open Access Server
Type:
Article
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