Levels of Cadmium, Lead, Mercury and 137caesium in Caribou (<i>Rangifer tarandus</i>) Tissues from Northern Québec

Abstract

Levels of cadmium (Cd), lead (Pb) and total mercury (Hg) were assessed in samples of muscle, kidney, and liver from caribou (Rangifer tarandus; n = 317) harvested in two regions of northern Québec between 1994 and 1996. Levels of 137 caesium ( 137 Cs) were also examined in muscle samples. Log concentration of the three metals varied significantly among tissues and was lowest in diaphragm muscle and highest in kidneys and liver. Mean Cd (wet weight, w.w.) concentration was 0.01 µg • g -1 in muscle, 7.69 µg • g -1 in kidneys and 1.13 µg • g -1 in liver. Levels of Cd exceeded tolerance thresholds for human consumption in nearly all kidney samples and in nearly half the liver samples. Mean Pb concentration (w.w.) was 0.05 µg • g -1 in muscle, 0.26 µg • g -1 in kidneys and 0.95 µg • g -1 in liver, with few samples exceeding consumption thresholds. Mean total Hg concentration (w.w.) in muscle was 0.03 µg • g -1 , 1.26 µg • g -1 in kidneys and 0.67 µg • g -1 in liver, with concentrations exceeding consumption thresholds in most kidney samples and nearly half the liver samples. Regional differences occurred in log concentration of the three metals for most tissues, with the western region consistently showing higher values. Mean log Cd and Pb concentrations increased with age in kidneys, but log Pb decreased with age in muscle samples. Interactions between month of collection and sex and region also occurred for some metals in some tissues. Mean level of 137 Cs in muscle samples was 94.7 Βq • kg -1 , never exceeding the acceptable limit for human consumption.

Liver Parasites and Body Condition in Relation to Environmental Contaminants in Caribou (<i>Rangifer tarandus</i>) from Labrador, Canada

“…Concentrations of mercury, lead, and selenium in kidney of caribou in our study were low and fell within the ranges previously reported in the GRH (Robillard et al, 2002) and other herds in Canada (Elkin and Bethke, 1995). The threshold residue levels in kidney for systemic biological effects of Hg (30 µg/g ww) (Thompson, 1996) and Pb (90 µg/g dry weight; approximately 26 µg/g ww) (Ma, 1996) far exceed even the maximum kidney concentrations found in caribou in our study.…”

“…The geometric mean renal Cd concentration in our study, 6.5 µg/g ww (95% CI: 4.7 -8.9), was consistent with levels found in earlier studies on the GRH. Crête et al (1989) and Robillard et al (2002) found means [SE] ranging from 1.2 [0.1] µg/g ww to 10.7 [0.2] µg/g ww, converted from dry weight, depending on age and season. Similarly Elkin and Bethke (1995) and Larter and Nagy (2000) found means [SE] in caribou in the Northwest Territories and Nunavut, Canada, ranging from 2.0 [0.3] µg/g ww to 8.9 [1.0] µg/g ww, converted from dry weight assuming mean percent moisture of 79.3, depending on region.…”

“…Research programs such as the Northern Contaminants Program and the Arctic Monitoring and Assessment Programme have recently brought attention to the issue of environmental contaminants such as metals, organochlorines (OCs) and radionuclides in northern ecosystems in Canada and worldwide (Fisk et al, 2003;AMAP, 2004AMAP, , 2005. Many studies of environmental contaminants throughout northern Canada have consistently found elevated cadmium concentrations in the kidneys of moose and caribou (Muir et al, 1997;Gamberg et al, 2005), including the GRH caribou (Crête et al, 1989;Robillard et al, 2002).…”

Re-evaluation of blood mercury, lead and cadmium concentrations in the Inuit population of Nunavik (Québec): a cross-sectional study

“…Cadmium is a toxic metal that can cause several health effects [ 29 - 32 ], mainly kidney and bone damage, even in non occupationally exposed populations, and studies indicate health concerns at low dose of exposure either in adults [ 33 - 37 ] or children [ 38 ]. Cadmium is released in the arctic environment from both anthropogenic and natural sources and it accumulates in lichen and vegetation [ 39 , 40 ], which is then eaten by caribou and moose [ 41 ]. Cadmium accumulates in organs rather than in muscle or fat and it is typically higher in kidneys than in the liver [ 41 ], which are part of the traditional diet of several aboriginal people.…”

Santé territoriale, indicateurs de santé animale et vision holistique

“…Cependant, la présence de contaminants dans les écosystèmes et leurs impacts possibles sur la santé des animaux et des humains constituent une préoccupation pour ces communautés. Au cours des dernières décennies, plusieurs études ont porté sur la contamination d'espèces se retrouvant dans l'alimentation traditionnelle des peuples autochtones du Canada (Berti et al 1998 ;Braune et al 1999 ;Braune et al 2005 ;Chan et Receveur 2000 ;Chan et al 2003 ;Houde 2004 ;Kuhnlein et Chan 2000 ;Langlois et Langis 1995 ;Muir et al 2005 ;Robillard et al 2002 ;Rodrigue et al 2007). Certaines des études menées au Québec ont révélé des niveaux de contaminants inquiétants chez diverses espèces de poissons et de mammifères dont se nourrissent les communautés autochtones, suggérant que leur consommation doive faire l'objet de recommandations, compte tenu des risques qu'elle repré sente pour la santé humaine (Houde 2004 ;Langlois et Langis 1995 ;MDDEP 2002).…”