Skeletal pathology and bone mineral density changes in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) inhabiting arsenic polluted areas of Yellowknife, Northwest Territories (Canada): A radiographic densitometry study.

The City of Yellowknife is a known hotspot of arsenic contamination and there is a growing body of evidence suggesting that local wildlife in the vicinity of the abandoned Giant Mine site may be at risk of decreased bone mineralization and various bone disorders. The purpose of this study was to preliminarily measure bone mineral density (BMD) changes and investigate the incidence, pattern, and severity of bone lesions in wild muskrats and red squirrels breeding in three (3) catchment areas at different distances from the Giant Mine Site in Yellowknife, Northwest Territories (Canada): ~2 km (location 1), ~18 km (location 2), and ~40-100 km (location 3). Full femoral bones of 15 muskrats and 15 red squirrels were collected from the three sampling locations (5 from each location) and subjected to radiographic analysis and densitometric measurements.

Comparative study of arsenic toxicosis and ocular pathology in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) breeding in arsenic contaminated areas of Yellowknife, Northwest Territories (Canada).

The Giant Mine is an abandoned gold mine in Yellowknife, Northwest Territories, Canada. Throughout its operation from 1948 to 2004, the Giant Mine released heavy amounts of arsenic trioxide into the environment, thus contaminating the soil and surface water within and around the vicinity of the mine site. Chronic arsenic (As) poisoning negatively impacts wildlife health and can induce multi-organ damages including neurodegeneration and visual dysfunction depending on concentration and duration of exposure.

Neuropathological changes in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) breeding in arsenic endemic areas of Yellowknife, Northwest Territories (Canada): Arsenic and cadmium accumulation in the brain and biomarkers of oxidative stress.

The brain is one of the critical organs particularly susceptible to the damaging effects of chronic arsenic poisoning and there is a growing body of evidence that suggest that oxidative stress plays a key role in the pathogenesis of neurodegenerative disorders. The aim of this present work was to comparatively assess biomarkers of oxidative stress and status of antioxidant enzyme activities in the brains of muskrats and squirrels breeding in arsenic endemic areas, specifically near the vicinity of the abandoned Giant mine site (~2 km radius), and an intermediate location approximately 20 km from the mine area and in reference locations spanning 52-105 km from the city of Yellowknife, Northwest Territories (Canada). Analysis included measurement of total arsenic and cadmium concentration in the nails, brain, and stomach content of muskrats and squirrels, in addition to biochemical evaluation of lipid peroxidation levels and antioxidant enzymes defense: catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the brain tissues.

Altered neurotransmission and neuroimaging biomarkers of chronic arsenic poisoning in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) breeding near the City of Yellowknife, Northwest Territories (Canada).

Chronic arsenic poisoning has been shown to be a risk factor for the development of intellectual disability. Numerous human and animal studies have also confirmed that low-level arsenic exposure has deleterious effects on neurotransmission and brain structures which have been further linked to neurobehavioral disorders. The aim of this present work was to comparatively assess structural brain volume changes and alteration of two (2) neurotransmitters, specifically dopamine (DA) and serotonin (5-HT) in the brains of wild muskrats and squirrels breeding in arsenic endemic areas, near the vicinity of the abandoned Giant mine site in Yellowknife and in reference locations between 52 and 105 km from the city of Yellowknife.