Environmental contamination by heavy metals is a common fact in Central Asia. In the present study two sampling procedures were achieved: (i) Sampling of fodder, camel raw milk and shubat (fermented camel milk) in 8 farms closed to pollution sources from the South of Kazakhstan for copper, iron, manganese, zinc, arsenic and lead analysis, (ii) sampling of camel milk in 4 regions of Kazakhstan (63 samples) analyzed for lead, chrome and zinc contamination. In first sampling, camel milk contained 0.07 ± 0.04, 1.48 ± 0.53, 0.08 ± 0.03, 5.16 ± 2.17, <0.1 and 0.025 ± 0.02 ppm respectively for Cu, Fe, Mn, Zn, As and Pb. In shubat (fermented milk) the mean content was 0.163 ± 0.164, 1.57 ± 0.46, 0.088 ± 0.02, 7.217 ± 2.55 and 0.007 ppm respectively. Arsenic was detected in some samples of milk and shubat only. The trace elements concentration increase in shubat compared to milk but lead concentration decreased. No clear correlation was observed with fodder composition. In second sampling, the lead content was on average 250 ± 56 ppb in the camel milk with no significant differences between regions. The maximum value was observed at Atyrau (532 ppb). Zinc content in milk (5.42 ± 0.2 ppm) did not change significantly between regions. In reverse, chrome (59.5 ± 45.4 ppb) was higher in Shymkent region compared to others. These values were discussed according to the proximity of pollution sources. Specially, higher concentrations were experienced in fodder from pastures close to some industrial sites or high traffic road. (Résumé d'auteur)

While long-term organic fertilizer (OF) applications tend to decrease copper (Cu) and zinc (Zn) availability in agricultural soils, earthworm bioturbation has been reported to have the opposite effect. Thus, the consequences of OF amendments in earthworm-inhabited soils on Cu and Zn bioavailability to earthworms are still under debate. Here, we assessed the effect of a decade of agronomically realistic OF applications on Cu and Zn availability in earthworm-inhabited soils and the consequences on Cu and Zn bioavailability to earthworms. An epi-endogeic species (Dichogaster saliens) was exposed in microcosms to three field-collected soils that had received either no, mineral, or organic fertilization for a decade. Dissolved organic matter (DOM) properties (i.e., concentration, aromaticity, and binding properties toward Cu), pH, and Cu and Zn availability (i.e., total concentration and free ionic activity) were determined in the solution of the soil containing earthworms. Cu and Zn bioavailability was assessed by measuring the net accumulation (ng) and concentration of Cu and Zn in earthworms (mg kg−1). Despite soil Cu and Zn contamination induced by a decade of OF applications, organic fertilization induced an increase in soil pH and DOM properties that drove the reduction of Cu and Zn availability in earthworm-inhabited soils, while bioturbation had little effect on soil pH, DOM properties, and Cu and Zn availability. Consistently, Cu and Zn bioavailability to earthworms did not increase with OF applications. From an ecotoxicological perspective, our results suggest that agronomically realistic applications of OF for a decade should not pose a risk to earthworms in terms of Cu and Zn net accumulation, but further studies have to be undertaken to understand consequent long-term toxicity after exposure.

In Kazakhstan, camel milk is mainly consumed after fermentation process. The fermented camel milk, named shubat, is generally home-made by the traditional process. The changes in mineral composition of camel milk during the fermentation process were rarely studied especially for heavy metals. The present study aimed to assess the change in heavy metals and trace-elements contents during the fermentation process. Samples of milk and shubat were collected in eight farms of Southern Kazakhstan in order to determine copper, iron, manganese, zinc, arsenic and lead. In camel milk mean content of these heavy metals was respectively of 0.065 ± 0.04, 1.478 ± 0.53, 0.084 ± 0.03, 5.163 ± 2.17, <0.1 and 0.025 ± 0.02 ppm. In shubat, the mean content was 0.163 ± 0.164, 1.57 ± 0.46, 0.088 ± 0.02, 7.217 ± 2.55, and 0.007 ppm respectively. Arsenic was detected in some samples of milk and shubat only. A relationship between heavy metals in raw milk and shubat at the farm level was observed. (Résumé d'auteur)

In the desert, camel rearing is an important cultural fact. In the present paper, 240 Arabian camels from Emirates were sampled for the determination of trace elements and different heavy metals. The following elements were tested: copper, zinc, iron, aluminium, arsenic, boron, barium, cobalt, chromium, cadmium, manganese, molybdenum, nickel, selenium, strontium and lead. The variation factors included age, sex and physiological status. On the average, the mineral contents were 190.3 µg/100 ml (iron), 60.1 µg/100 ml (copper), 44.0 µg/100 ml (strontium), 22.5 µg/100 ml (arsenic), 20.0 µg/100 ml (zinc), 19.7 µg/100 ml (selenium), 19.3 µg/100 ml (boron) and 14.6 µg/100 ml (barium). Other minerals like aluminium (3.7 µg/100 ml), molybdenum (2.9 µg/100 ml), chromium (2.0 µg/100 ml), nickel (1.8 µg/100 ml), lead (1.5 µg/100 ml), manganese (0.16 µg/100 ml), cobalt (0.08 µg/100 ml) and cadmium (0.07 µg/100 ml) were in very small concentration. Age, sex and physiological effects were assessed for some parameters. According to the lack of references in camel species, it is difficult to link those results to polluting context. But those data could contribute to understand the heavy metal status in camel confronted to pollution. (Résumé d'auteur)

Since its independence in 1991, Kazakhstan is in a state of "ecological crises", due to the specific place for nuclear test by soviet government for long time, and to the development of irrigation for field cottons linked with decreasing Aral Sea level. In addition the manufacturing of metals and the minerals had some impact on environmental contamination. In the South of Kazakhstan, eight farms were sampled close to probable pollution sources. Samples of camel milk, fodder and water were collected in each farm and analyzed for copper, iron, manganese, zinc, arsenic and lead. The mean content in fodder of Cu, Fe, Mn, Zn, As and Pb was 10.40 ± 2.93, 793.69 ± 630.48, 62.38 ± 20.67, 32.95 ± 27.15, 1.03 ± 0.49 and 4.28 ± 9.60 ppm respectively. In camel milk mean content of these heavy metals was respectively of 0.07 ± 0.04, 1.48 ± 0.53, 0.08 ± 0.03, 5.16 ± 2.17, <0.1, and 0.025 ± 0.02 ppm respectively. No heavy metals were detected in samples of water with the analytical methods used. The relationships between heavy metals in water, forages and milk were not clear. Some information's are lacking. We need to extend sampling at more areas where camels, cows, goat and sheep farms are closed to pollution areas, and analyzed other heavy metals suspected in pollution process.

In four regions of Kazakhstan (Atyrau, Aralsk, Shymkent and Almaty), a survey on camel farms was achieved in order to study the variability of the physico-chemical composition of camel milk both in dromedary (Camelus dromedarius) and Bactrian (Camelus bactrianus) camel as well as their hybrids. As the whole, 163 milk samples were analyzed for calcium, phosphorus and iron determination. In order to maximize the variance, the samples were done in four different seasons which expressed the feeding change and the physiological stage changes as the calving season was concentrated in few months. The mean values were respectively 1.232 ± 0.292 g/l, 1.003 ± 0.217 g/l and 2.02 ± 1.24 mg/l for calcium, phosphorus and iron. No species, season or region effect was observed on iron content in the milk. Calcium and phosphorus change significantly according to season and species, but only phosphorus was linked to region effect. Especially phosphorus content is high in Aralsk region (1.156 ± 0.279 g/l). Globally, it is noticeable to observe the high level of phosphorus in the camel milk of Kazakhstan compared to the literature's results. (Résumé d'auteur)