TITLE:
Polychlorinated Biphenyls in Whole-Body Field Mice Collected Upgradient and Downgradient of a Sediment Retention Structure in Los Alamos Canyon, Los Alamos National Laboratory, New Mexico, USA
AUTHORS:
Philip R. Fresquez
KEYWORDS:
Polychlorinated Biphenyl Congeners; Deer Mice; Peromyscus; Biomonitoring; Rio Grande; Southwest; New Mexico
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.2,
February
26,
2014
ABSTRACT:
Polychlorinated biphenyl (PCBs)
congeners were measured in (unwashed) whole-body field (deer) mice (Peromyscus maniculaltus) collected
directly upgradient from a sediment retention structure (weir) within Los
Alamos Canyon (LAC), Los Alamos National Laboratory (LANL), New Mexico, USA,
from 2007 through 2013. Samples were also collected approximately 8 km
downgradient of the retention structure in 2009 and 2013. LAC, a major drainage
that crosses LANL lands, contains legacy waste, including PCBs, and
occasionally discharges storm water and snowmelt flows to the Rio Grande approximately 8.8 km away from
the weir. The Rio Grande is the major waterway that flows southward across the
state. The weir was constructed across the channel on the northeastern boundary of LANL
in late 2000 to help contain sediments mobilized by floodwaters as a result of
a large wildfire in early 2000 that burned forest lands west and adjacent to
LANL. Total PCBs in field mice directly upgradient of the sediment retention structure from 2007 through 2012 were
significantly greater (p 0.05) than in field
mice collected from background locations but decreased in concentration over
time; by 2013 the levels were statistically similar (p > 0.05) to background. The highest mean
total PCB concentration in field mice was below the levels that may negatively
impact field mice population attributes. Total PCBs in field mice collected 8 km below the sediment retention
structure in 2009 were lower than field mice collected from behind the weir and
decreased over time; also by 2013, the amount of PCBs in field mice 8 km below
the sediment retention structure were not significantly different (p > 0.05) from background. The rank order
of concentrations of ICES 7 PCB congeners in upgradient and downgradient field
mice were: No. 153 > 180 > 138 > 118 > 28 > 101 > 52 and No. 153 > 180 > 138 > 52 > 101 > 118 > 28, respectively. Based on the PCB
homolog distribution, the major formulation detected in field mice was
Aroclor-1260. Overall, the reduction of PCBs in whole-body field mice from both
sites over time was attributed, in part, to sediment control practices.