Transfer of cadmium, lead, mercury and arsenic from feed into milk and various tissues of dairy cows: chemical and pathological data.

Abstract

In the 1st trial, lasting 3 months, 24 cows in 2 groups were given daily 15 kg roughage and 3 kg concentrates without (control) or with soluble compounds of heavy metals (including As2O5) added to the concentrates to give Cd, Pb, Hg and As at 2, 50, 0.2 and 3.4 (control) and 152, 200, 1.7 and 33 mg/day (treatment) resp. In the 2nd trial, lasting 2-3 lactations, 32 cows in 4 groups were kept indoors and given daily 10 kg roughage and 10-11 kg concentrates without or with soluble compounds (including As2O3), harbour sludge or sewage sludge. Intakes of Cd, Pb, Hg and As by control cows were the same as those in the 1st trial, but for cows in the 3 treatment groups daily intakes averaged: Cd 32, 10 and 6 mg; Pb 200, 164 and 168 mg; Hg 1.7, 3.1 and 1.2 mg; and As 33, 21 and 6.8 mg. In neither trial did increased intakes of Cd, Pb, Hg or As lead to significantly increased concn. in milk or blood, and only As given in soluble compounds was increased in muscle from slaughtered cows (4/group in trial 1 and 1-2/group in trial 2). Concentrations of Cd, Pb, Hg and As in liver and kidney were all increased by the treatments, and particularly by soluble compounds, with concn. in kidney exceeding those in liver in all but 1 case. Cd also accumulated in spleen and thymus, Pb in bone, Hg in spleen, and As in heart, thymus, spleen and brain. Results are compared with those obtained in other carry-over studies. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Transfer of Cadmium and Mercury to Sheep Tissues

“…The relatively high degree of Cd accumulation in liver and kidney as observed in the present study has previously been reported for many species including ruminants (13,14,16,31,32). The activity concentrations of 203 Hg in important food chain tissues were in the order muscle < liver < kidney.…”

Raccoons (Procyon lotor) as Sentinels of Trace Element Contamination and Physiological Effects of Exposure to Coal Fly Ash

“…The lack of significant tissue pathology or changes in body size was likely due to the relatively low levels of trace elements accumulated in raccoons in this study. Although we found significantly greater concentrations of Cu, As, Se, and Pb in animals from the contaminated site than in the reference site, the reported values were well below values associated with ex situ studies whose aims were to determine the physiological impairments resulting from toxic concentrations of Cu in sheep (1900 ppm) (Eisler 1998 ), As in domestic livestock (5–10 ppm) (Vreman et al 1986 ), and Se in horse (44 ppm) (Eisler 1985 ).…”

L’épandage de matières fertilisantes d’origine résiduaire sur les prairies comporte-t-il des risques en termes de transfert de polluants organiques et inorganiques vers la chaîne alimentaire ?

“…Pour le Zn, des concentrations généralement équivalentes entre le muscle et le foie ont pu être observées (Bertrand et al 1981, Lisk et al 1982, Bruce et al 2003, Cai et al 2009. Sur le long terme, le Pb est connu pour être séquestré dans les os et peut être remobilisé (par exemple lorsque une femelle est en gestation ou allaite son petit) pour être redistribué contrairement au Cd qui reste majoritairement séquestré au niveau des reins (Pattee 1984, Vreman et al 1986, Scheuhammer 1996, Wilkinson et al 2003b, Khalafalla et al 2011, Abduljaleel et Shuhaimi-Othman 2013.…”

“…La concentration en Cd dans les reins du porc serait également 2 à 3 fois supérieure que dans le foie (Sharma et al 1979) Giulio et Scanlon 1984). Cependant ces résultats doivent être interprétés avec précaution car il semblerait que les concentrations puissent être soumises à un effet dilution entre le foie et le rein et dépendre de la taille des organes (Vreman et al 1986). Laurent et al (2005) ont synthétisé les données de différents travaux et calculé les FBC pour différents éléments.…”