Subscriber access provided by READING UNIV
Article
Sources of methylmercury to snowpacks of the Alberta Oil Sands Region: A study of in situ methylation and particulates Chelsea E. Willis, Jane L. Kirk, Vincent L. St.Louis, Igor Lehnherr, Parisa A Ariya, and Rodrigo Benjamin Rangel-Alvarado Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b04096 • Publication Date (Web): 03 Dec 2017 Downloaded from http://pubs.acs.org on December 4, 2017
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 29
Environmental Science & Technology
1
Sources of methylmercury to snowpacks of the Alberta Oil Sands
2
Region: A study of in situ methylation and particulates
3
Chelsea E. Willis†, Jane L. Kirk*,‡, Vincent L. St. Louis†, , Igor Lehnherr§, Parisa A. Ariyaǁ,
4
Rodrigo Benjamin Rangel-Alvarado¤
5
†
Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
6
‡
Aquatic Contaminants Research Division, Environment and Climate Change Canada,
7
Burlington, Ontario L7S 1A1, Canada
8
§
9
Canada
Department of Geography, University of Toronto Mississauga, Mississauga, Ontario L5L 1C6,
10
ǁ
Department of Atmospheric & Oceanic Sciences and ¤Department of Chemistry, McGill
11
University, Montréal, Québec H3A 2K6, Canada
12
Methylmercury, snow, Alberta Oil Sands Region, mercury methylation, mercury stable isotopes,
13
particle-bound methylmercury
14 15 16
*
17
ABSTRACT: Snowpacks in the Alberta Oil Sands Region (AOSR) of Canada contain
18
elevated loadings of methylmercury (MeHg; a neurotoxin that biomagnifies through foodwebs)
19
due to oil sands related activities. At sites ranging from 0-134 km from the major AOSR
20
upgrading facilities, we examined sources of MeHg by quantifying potential rates of MeHg
email:
[email protected] ACS Paragon Plus Environment
Environmental Science & Technology
21
production in snowpacks and melted snow using mercury stable isotope tracer experiments, as
22
well as quantifying concentrations of MeHg on particles in snowpacks (pMeHg). At four sites,
23
methylation rate constants were low in snowpacks (km=0.001–0.004 d-1) and non-detectable in
24
melted snow, except at one site (km=0.0007 d-1). The ratio of methylation to demethylation varied
25
between 0.3-1.5, suggesting that the two processes are in balance and that in situ production is
26
unlikely an important net source of MeHg to AOSR snowpacks. pMeHg concentrations
27
increased linearly with distance from the upgraders (R2=0.71, p
