Cadmium transfer from whole milk to cream, rennet, or lactic curds was studied before and following a repeated oral cadmium administration to three lactating ewes and one cow. Before cadmium administration, the cadmium levels in milk were around 0.4 microg/L in ewes and less than 0.2 microg/L in cow. Throughout cadmium administration the mean cadmium levels in milk were 3.3+/-1.4 microg/L in ewes and 2.5+/-1 microg/L in cow. During cadmium administration, 86% of cadmium in ewe milk was dispersed in the skimmed milk and 17% in the cream, whereas only 72% was dispersed in the cow skimmed milk and 27% in the cow cream. Most of milk cadmium was associated with casein fractions. About 70% of milk cadmium was transferred to the rennet or lactic curds of ewe. The remaining cadmium present in whole milk, about 9%, was transferred to the rennet or lactic curd whey. In cow, the proportion of cadmium associated with rennet or lactic curds, rennet curd whey, and lactic curd whey was, respectively, 60%, 56%, 14% and 12% of total milk cadmium. The fraction of total cadmium transferred from milk to its milk products, whatever the species, ranged from 94% to 103%. The factor of concentration of cadmium from whole milk to milk products ranged from three to six. We suggest that the excretion of cadmium into milk is mainly achieved via the milk casein secretion. This is, to our knowledge, the first in vivo study where the cadmium transfer from milk to its milk products after repeated cadmium oral administration to ewe and cow has been studied.
This study sought to assess sediment contamination by trace metals (cadmium, chromium, cobalt, copper, manganese, nickel, lead and zinc), to localize contaminated sites and to identify environmental risk for aquatic organisms in Wadis of Kebir Rhumel basin in the Northeast of Algeria. Water and surficial sediments (0-5 cm) were sampled in winter, spring, summer and autumn from 37 sites along permanent Wadis of the Kebir Rhumel basin. Sediment trace metal contents were measured by Flame Atomic Absorption Spectroscopy. Trace metals median concentrations in sediments followed a decreasing order: Mn > Zn > Pb > Cr > Cu > Ni > Co > Cd. Extreme values (dry weights) of the trace metals are as follows: 0.6-3.4 microg/g for Cd, 10-216 microg/g for Cr, 9-446 microg/g for Cu, 3-20 microg/g for Co, 105-576 microg/g for Mn, 10-46 microg/g for Ni, 11-167 microg/g for Pb, and 38-641 microg/g for Zn. According to world natural concentrations, all sediments collected were considered as contaminated by one or more elements. Comparing measured concentrations with American guidelines (Threshold Effect Level: TEL and Probable Effect Level: PEL) showed that biological effects could be occasionally observed for cadmium, chromium, lead and nickel levels but frequently observed for copper and zinc levels. Sediment quality was shown to be excellent for cobalt and manganese but medium to bad for cadmium, chromium, copper, lead, nickel and zinc regardless of sites.
SUMMARYThe aim of this article is to assess the level of trace metal contamination of sediment and to evaluate the environmental water quality based on the distribution of benthic organisms at stations along the Rhumel river and its principal tributary Boumerzoug river selected in urban areas (Constantine, Algeria). Fresh sediment samples and benthic organisms were collected from 10 sites on three occasions (December 2000, February 2001 and April 2001. Four trace metals-manganese (Mn), lead (Pb), chrome (Cr), and cadmium (Cd)-were measured in surface sediment and in the fauna using a flame or flameless atomic absorption spectrophotometer. In addition, chemical water parameters, pH, dissolved oxygen (DO), conductivity (EC) and sediment variables, pH, loss on ignition (LOI) and grain size were determined. The differences in species composition of the benthic community and the biotic index variation were used to reveal disturbance in watercourses.Principal component analysis (PCA) was used to identify the relationship between the sediment variables, water chemistry and distribution of benthic invertebrate communities. The results of PCA indicate that there are several significant correlations between trace metals which suggest their common origin (anthropogenic or natural sources). Besides, the PCA results suggest the following trend: the biotic index, communities' distribution of macroinvertebrates and dissolved oxygen were unconnected to from both sediment and fauna trace metals concentrations.
Transfer of cadmium from ewe milk to cream and to rennet and lactic curds. Milks from control ewes and from cvvcs fed with a diet containing added cadmium were skimmed and then transformed into cheese curds either hy rennet coagulation or hy lactic acidification with a culture of Lactococcufi lactix. Cadmium contents ranged from less than 0.2 to 0.5 pg-L~' in the control milk and from 4.8 to 21.4 Mg'L"1 in the contaminated milk. Cadmium contents were always higher in the cream than in the whole milk: the concentration factor was 3.0 ± 1.1 in the treated ewes'milk. In the rennet curds obtained from (he skim-milk of the treated ewes, the cadmium levels were 3.6 to 7.6 times higher than in the original milk. For the lactic curds, the concentration factor ranged from 2.1 and 3.1. The fresh curd cadmium contents reached 4.7 ± 2.1 fig-kg ~' when obtained from control milks, which suggested a contamination hy the cadmium during the cheese making. © Inra/Elsevier, Paris. cadmium / ewe / milk / cream / curd Resume-Des laits provcnant de brebis temoins el de hrebis ayanl re^u line alimentation enrichie en cadmium ontete ccremesel transformed ensuite en cailles par la presure on par acidification lactique a Paide d'une culture de Lactococcus Itictix. l-es laits temoins avaicnl des leneurs en cadmium variant de moins dc 0.2 a 0,5 pg-L"1. Les laits provcnanl des brehis traitees avaient des leneurs comprises entre 4,8 et 21,4 pg-L~'. Les leneurs en cadmium dc la crcme elaicnt toujours plus elevees que celles du lait eniier: Ie facteur de concentration ctail de 3,0 ±1,1 pour les laits provenant des animaux ayant rec.u du cadmium. Les « cailles presure » frais oblenus avec cc tail avaicnl des tencurs en cad-* Correspondance el tires a part.
L’objectif de la présente étude est d’évaluer la distribution de quatre éléments traces métalliques (ETM), cadmium, cuivre, nickel et zinc, dans les différentes parties anatomiques (racines et feuilles) d’une chénopodiacée Spinacia oleracea (L.), en lien avec le niveau de contamination des sédiments où elle pousse, de l’oued Boumerzoug et ses affluents. Localisé dans le Constantinois au nord-est de l’Algérie, l’oued draine un bassin versant de 1 832 km2 avec ses zones urbaines et industrielles. Cette étude inclut 14 stations, 5 situées sur l’oued Boumerzoug et 9 sur ses affluents, sélectionnées en des lieux stratégiques et échantillonnées cinq fois au mois de mai, septembre et décembre 2016, ainsi qu’en mars et juillet 2017. Les teneurs moyennes des ETM des sédiments sont de 0,44 ± 0,30 mg∙kg-1 (masse sèche) pour Cd, 43,61 ± 36,45 mg∙kg-1 (ms) pour Cu, 35,16 ± 9,85 mg∙kg-1 (ms) pour Ni et 181,33 ± 115,12 mg∙kg-1 (ms) pour Zn. Le transfert des ETM a été étudié chez l’épinard S. oleracea dont les différentes parties accumulent différemment les métaux. Les concentrations des ETM dans les sédiments et la chénopodiacée sont très variables aussi bien dans l’espace que dans le temps. Nos résultats montrent que la chénopodiacée séquestre dans ses racines le Cd, le Cu et le Ni, alors que le Zn est transloqué vers les feuilles. La hiérarchie des teneurs moyennes en métaux dans les épinards (Zn > Cu > Ni > Cd) est similaire à celle des sédiments.
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