Concentrations of toxic metals and essential elements in raw cow milk from areas with potentially undisturbed and highly disturbed environment in Slovakia

Abstract

Dietary composition and husbandry practices largely determine the essential trace element status and the toxic metal exposure of livestock and consequently their concentrations in animal products. The main objective of this study was to determine the real contamination of selected areas of Slovakia compared with existing Environmental regionalization of the Slovak Republic (SR) created by the Ministry of the Environment SR. Another aim of this study was to determine the content of essential and toxic metals in feed and milk of dairy cows on selected farms in Slovakia referred to the suitability of the use of milk from these areas to other food processing. This article deals with the analysis of the content of selected elements in feed and milk of dairy cows in the area of Novoť (Northern Slovakia; area with undisturbed environment) and Čečejovce (Eastern Slovakia; highly disturbed environment). Eleven elements have been analyzed (essential elements: calcium, zinc, magnesium, selenium, iron, copper; toxic elements: arsenic, cadmium, mercury, lead, nickel). Samples of feed and milk were collected five times during the spring season and five times during the autumn season in 2016. Analysis of samples was performed in Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by atomic absorption spectroscopy and atomic emission spectrometry. The obtained values of the individual elements in the feed and milk were evaluated by Student's t test. Significantly higher contents of essential elements Ca, Zn, Fe, Mg, and Cu were found in the feed of dairy cows in Čečejovce (P < 0.001). Significantly higher (P < 0.001) As and Ni content in feed in Čečejovce in autumn season was also recorded. However, the content of these elements in feed did not affect their milk content. The content of Ca, Zn, and Mg in milk was significantly (P < 0.001) higher in Novoť in both investigated seasons. Some essential elements and toxic elements in feed and milk were below the LOQ (limit of quantification). Reduced content of Ca and Zn in milk in both farms compared with optimal limits, decreased Ca and Mg content in feed in Novoť, and a significant increase of Ca and Mg in feed in Čečejovce in autumn season were found. It can be concluded, due to the low content of toxic elements on these farms, that the use of milk of dairy cows from these areas for direct use or for dairy product processing is appropriate and poses no health risk to the consumers.

Disorders of the Reproductive Health of Cattle as a Response to Exposure to Toxic Metals

“…To diagnose cattle poisoning with toxic metals, milk can be tested, which is an indirect indicator of environmental pollution. These metals, mainly arsenic, cadmium, nickel, and lead, enter into animal organisms in feed and water, and then are excreted into cow’s milk [ 18 ].…”

“…According to Bonnet et al (2018) [2], the average global meat consumption increased by 60% between 1990 and 2009, and this increase is continuing. In Europe, as one of the largest meat consumers, there is also an increase in areas, near steel mills and mines [18]. The source of contamination can be containers of milk, feed, or the animal environment [15].…”

“…The toxic metals in milk pose a danger to humans and the contamination of the milk is an important issue. These toxic metals enter into the milk through contaminated feed and water, most often in industrialized areas, near steel mills and mines [ 18 ]. The source of contamination can be containers of milk, feed, or the animal environment [ 15 ].…”

Concentrations of toxic elements (As, Cd, Hg and Pb) in cow milk: A review of the recent scientific literature

“…Recently, also in various zones of Slovakia, Pšenková et al . (2020) measured the concentrations of As, Cd, Pb, Hg and Ni and the essential elements (Ca, Mg, Fe, Se, Cu, Zn) in feed and milk samples. For the toxic elements, all mean levels were below the respective limits of quantification: As, <0.030 mg/kg, Hg, <0.002 mg/kg, Pb and Ni, <0.10 mg/kg and Cd < 0.0040 mg/kg.…”

Insights into the nutritional properties and microbiome diversity in sweet and sour yogurt manufactured in Bangladesh

“…Like milk and other dairy products, yogurt has been reported to be a unique source of trace minerals Na, K, Ca, Mg, Fe, Zn and Cu 22,23 . The content of trace elements in dairy milk and products has begun to be more widely studied, particularly in industrialized and polluted regions, since it is considered a good bioindicator of pollution of the agricultural environment 24–26 .…”