Railway-Associated Attractants as Potential Contaminants for Wildlife

• Published in: Environmental management (New York) Vol. 66; no. 1; pp. 16 - 29
• Main Authors: Pollock, Sonya Zoey, St. Clair, Colleen Cassady
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2020; Springer Nature B.V
• Subjects: Animal feed; Animals; Anthropogenic factors; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Attractants; Bears; Canada; Chromium; Collars; Contaminants; Earth and Environmental Science; Ecology; Environment; Environmental Management; Environmental Monitoring; Exposure; Feeds; Forestry Management; Global positioning systems; GPS; Grizzly bears; Hair; Heavy metals; Hills; Humans; Infrastructure; Male; Metal concentrations; Metals, Heavy - analysis; Metals, Heavy - toxicity; Mountains; Mycotoxins; Nature Conservation; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Polycyclic Aromatic Hydrocarbons - toxicity; Principal components analysis; Protected areas; Railroad cars; Railroads; Railway stations; Soil; Soil contamination; Ursidae; Waste Water Technology; Water Management; Water Pollution Control; Wildlife; Canada; Train-spilled grain; Polycyclic aromatic hydrocarbons; Grizzly bear; Metals; Railway-associated vegetation
• ISSN: 0364-152X; 1432-1009
• DOI: 10.1007/s00267-020-01277-6

Grizzly bears ( Ursus arctos ) appear to be attracted to natural and anthropogenic forage along railways, which may increase collision vulnerability, but also potentially causes exposure to contaminants associated with railway infrastructure. We assessed contaminant exposure for a vulnerable population of grizzly bears in the Canadian Rocky Mountains by determining if (1) dandelions ( Taraxacum officinale ) growing adjacent to a railway and grain spilled from hopper cars contain heavy metals, polycyclic aromatic hydrocarbons (PAHs), and mycotoxins and (2) metal concentrations from hair samples of individual bears correlates with use of the railway or other anthropogenic features. We used principle components analysis to represent 10 heavy metals and 16 PAHs and then compared their concentrations in railway-associated sources of grain and dandelions to reference samples that we purchased (grain) or sampled from nearby sites (dandelions). We also measured metal concentrations in the hair of bears that were captured and fitted with GPS collars. We found significantly higher concentrations in railway-associated samples of dandelion and grain for both metals (particularly lead, iron, and chromium), and the sum of 16 PAHs. Several metals and PAHs in railway-associated samples exceeded regulatory standards for soil or animal feed. Mycotoxins were detectable in grain samples, but occurred well below permissible standards. Metal concentrations in bear hair were not predicted by railway use, but higher metal concentrations occurred in male bears and two individuals that used ski hills during fall. As mitigation to reduce wildlife exposure to contaminants, particularly in protected areas, we encourage removal of railway grain deposits, regular maintenance of railway infrastructure, such as lubricating stations, and investigation of contaminants associated with other human infrastructures, such as ski hills.