title: Terrestrial ecosystem recovery following removal of a PCB point source at a former pole vault line radar station in Northern Labrador.
abstract: Saglek Bay (LAB-2), located on the northeast coast of Labrador is a former Polevault station that was operated by the U.S. Air Force from 1953 to 1971 when it was abandoned. An environmental assessment carried out in 1996 determined that the site was contaminated with polychlorinated biphenyls (PCBs) with concentrations in soils far exceeding the Canadian Environmental Protection Agency (CEPA) regulation of 50 μg/g in three areas of the site (Beach, Site Summit, Antenna Hill). This led to remediation work carried out between 1999 and 2004 to remove and/or isolate all PCB-contaminated soil exceeding 50 μg/g and to further remediate parts of the site to <5 μg/g PCBs. In this study, spatial and temporal trends of PCB concentrations in soil, vegetation (Betula glandulosa and Salix spp.), and deer mice (Peromyscus maniculatus) were investigated over a period of fourteen (1997-2011) years in an effort to track ecosystem recovery following the removal of the PCB point sources. The data collected shows that PCB levels in vegetation samples are approximately four times lower in 2011 than pre-remediation in 1997. Similarly, PCB concentrations in deer mice in 2011 are approximately three times lower than those measured in 1997/98. Spatial trends in vegetation and deer mice continue to demonstrate that areas close to the former point sources of PCBs have higher PCB concentrations than those further away (and higher than background levels) and these residual PCB levels are not likely to decrease in the foreseeable future given the persistent nature of PCBs in general in the environment, and in particular in cold climates.
authors.affiliation: Environmental Sciences Group, Royal Military College of Canada, P.O. Box 17000 Stn Forces, Kingston, ON K7K 7B4, Canada.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Ficko
authors.forename: Carol
authors.initials: C
authors.lastname: Luttmer
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Zeeb
authors.forename: Kenneth
authors.initials: K
authors.lastname: Reimer
mesh_terms: D000818:Animals; D001140:Aroclors; D029662:Betula / Q000378:metabolism; D017753:Ecosystem; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000493:pharmacokinetics* / Q000633:toxicity; D052918:Environmental Restoration and Remediation / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D009523:Newfoundland and Labrador; D010542:Peromyscus / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics* / Q000633:toxicity; D011825:Radar; D032108:Salix / Q000378:metabolism
chemical_list: D001140:Aroclors; D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
keywords: Birch; Deer mice; Ecosystem recovery; Long-term monitoring; Polychlorinated biphenyls; Willow