Metal accumulation in cattle raised in a serpentine-soil area: relationship between metal concentrations in soil, forage and animal tissues

A critical review on the ecotoxicity of heavy metal on multispecies in global context: A bibliometric analysis

Heavy metals (HMs) have become a significant concern in the current era, with deleterious effects on diverse living organisms when exposed beyond threshold concentrations. Both nature and human beings have been constantly casting out HMs into environmental matrices through various activities. Innumerable cases of threatened diseases such as cancer, respiratory ailments, reproductive defects, skin diseases, and several others have been a cause of significant concern for humans as the number of instances has been increasing with each decade. HMs migrates via several pathways to infiltrate biological organisms and amass within them. Even though numerous treatment approaches are available for remediating HM pollution, however, they are expensive, along with other setbacks. Due to such constraints, combating HM contamination requires environmentally conscious strategies like bioremediation, which employs an array of biological systems to remove HMs from the environment. Nonetheless, to address the current global HM pollution situation, it is critical to comprehend not only how these hazardous HMs cause toxicity in various living organisms but also the knowledge gaps that currently exist concerning the subject of HM ecotoxicity. In the present investigation, data was extracted from Google Scholar using software program called Harzing's Publish or Perish. The collected information has been subsequently displayed as a network file using the VOSViewer software tool. Thus, the current review presents a significant insight with the inclusion of a readily accessible bibliometric analysis to comprehend the present status of HMs research, global research trends, existing knowledge discrepancies, and research challenges. Further, it also provides an in-depth review of HMs ecotoxicity, with a focus on arsenic (As), cadmium (Cd), and lead (Pb). Thus, as indicated by the bibliometric study, the present review will assist future investigators studying HMs ecotoxicity by providing baseline data concerning a wide range of living organisms and by addressing research gaps.

Serpentine Overburden Products-Nature-Inspired Materials for Metal Detoxification in Industrially Polluted Soil

The possibility of plants growing on serpentine soils and the ability of serpentine minerals to accumulate significant amounts of metals was the basis for developing a method for using serpentine-containing materials to restore vegetation in areas with a high level of metal pollution. Serpentine-containing products obtained from phlogopite mining overburden (Kovdor, Murmansk region, Russia) with and without thermal activation were used in a field experiment on the remediation of industrially polluted peat soil. According to the geochemical mobility of the components, one of four fractions was allocated depending on the acidic (HCl) concentration of the solution used for the material treatment: readily mobile (0.001 mol/L), mobile (0.01 mol/L), potentially mobile (0.1 mol/L), and acid-soluble (1.0 mol/L). This study showed that the addition of serpentinites to peat soil changed the fraction composition. The most significant changes were noted for serpentinite components such as Ca and Mg: their concentrations increased 2-3 times even in the smallest portion of serpentine material. On the contrary, the contents of metals in the readily mobile fraction decreased 3-18, 3-23, 5-26, and 2-42 times for Cu, Ni, Fe, and Al, respectively. The main factor causing the decrease in metal mobility was the pH rise due to the release of Ca and Mg compounds into the soil solution. This study showed that the addition of serpentine-containing material at 25 vol.% to peat soil was sufficient to create a geochemical barrier with a stable-functioning vegetation cover. All serpentine-containing materials are recommended for the remediation of large industrially polluted areas.

Seasonal Assessment of some Potentially Toxic Elements with Possible Animal Health Risks in Atriplex canescens (Pursh) Nutt

In the present investigation Br (Bromine), Cr (Chromium) and Pb (Lead) concentrations were assessed employing X-ray florescence spectrometry to evaluate seasonal variation of these elements in the xero-halophyte Atriplex canescens (Pursh) Nutt., a shrub with high pastoral value. The results showed that A. canescens and its surrounding soil have similar accumulation patterns for Br and Pb across seasons, but Cr concentrations in shrubs are higher in spring than other seasons. The seasonal mean contents of trace elements in A. canescens descend in the following order: Cr (8.33 µg g^- 1) > Br (5.34 µg g^- 1) > Pb (0.24 µg g^- 1). The maximum element transfer factor (ETF) of Cr and Pb was recorded in summer and autumn. However, no significant difference between seasons was found for Br. Principle component analysis (PCA) showed that Br, Cr and Pb were associated negatively with soil during all seasons. In contrast, A. canescens was only associated to Cr contents in the spring. Results provide evidence also that the levels of Br, Cr and Pb were within the safety-limits recommended by the National Research Council (NRC) guidelines for animal nutrition.

Carcinogenic Risk of Pb, Cd, Ni, and Cr and Critical Ecological Risk of Cd and Cu in Soil and Groundwater around the Municipal Solid Waste Open Dump in Central Thailand

Several consequences of health effects from municipal solid waste caused by carcinogenic and noncarcinogenic metals have been recognized. The water quality index ( $\text{WQI}$ ) in the groundwater around this landfill is 2945.58, which is unacceptable for consumption. The contaminated groundwater mainly appears within a 1 km radius around the landfill. The metal pollution levels in the soil in descending order were Cu > Cd > Zn=Cr > Pb > Ni. The pollution degree (ER) of Cd was 2898.88, and the potential ecological risk index (RI) was 2945.58, indicating that the risk level was very high. Surprisingly, the hazard index (HI) of Pb (2.05) and Fe (1.59) in children was higher than 1. This indicated that the chronic risk and cancer risk caused by Pb and Fe for children were at a medium level. Carcinogenic risk by oral (CR oral) consumption of Ni, Cd, and Cr in children was 1.4E − 04, 2.5E − 04, and 1.8E − 04, respectively, while the lifetime carcinogenic risk (LCR) of Ni, Cd, and Cr in children was 1.5E − 04, 2.8E − 04, and 2.0E − 04, respectively. In adults, CR oral of Ni and Cr were 1.6E − 03 and 3.0E − 04, respectively, while LCR of Ni and Cr were 1.6E − 03 and 3.4E − 04, respectively, which exceeded the carcinogenic risks limits. Our study indicated a lifetime carcinogenic risk to humans. Environmental surveillance should focus on reducing health risks such as continuous monitoring of the groundwater, soil, and leachate treatment process.

Metal transfer and related human health risk assessment through milk from cattle grazing at an industrial discharge area

The water bodies within industrial areas are often used for the disposal of effluents leading to metal contamination in water, soil, and vegetation. However, the impact of metal enrichment in the food grown in these areas has not been much explored. The present study investigates the food chain contamination of eight metals (Al, Cd, Cr, Cu, Fe, Mn, Pb, and Zn) in the milk from the cattle grazing on a shallow lake bed within the industrial town of Ranipet, India, and associated health risk from the consumption by adults and children. It also considers the possible sources of metals into the cattle from water, forage, and soil. The total number of cattle grazing in the study area was identified, along with their average daily intakes. The total milk yield from these cattle and the milk consumption rates were identified from surveys conducted among cattle owners and milk buyers. The primary sources of all the metals, except Al are forage; whereas for Al, it is the soil. The projected milk consumption pattern indicates that 531 children and 1279 adults drinking contaminated milk are at considerable risk. The hazard indices ranged from 0.86 to 2.74 for children, and 0.35 to 1.13 for adults. The Cancer Risk values for Cd and Cr were above 10^-4 for adults and children, signify serious health risk. The analyses of tail switch hair samples indicated that cattle are also environmentally exposed to metals indicating their subclinical effect. Hence, the study substantiates that soil can be a potential source of metals in the food chain, and apprises stringent quality control and monitoring food chain contamination from milk in industrial belts.

Heavy metal phytoremediation potential of the roadside forage Chloris barbata Sw. (swollen windmill grass) and the risk assessment of the forage-cattle-human food system

This study presents the assessment of the risks incidental to the growth of the common tropical grass species Chloris barbata Sw. (swollen windmill grass) on road margins contaminated with Pb and Cd. Pot experiments were first carried out to quantify the Pb and Cd accumulation potential of the plant species in various plant parts as a function of the metal concentration in soil. C. barbata was found to be a hyperaccumulator for Cd (BCF>1, for aerial parts) and an excluder of Pb (BCF<1, for aerial parts). As the plant was found to accumulate Pb in its roots with TF<1, it can be considered a phytostabilizer of Pb. The mathematical relationship developed between soil concentrations of Pb and Cd and their corresponding concentrations in aerial parts were used in combination with the concentrations of these heavy metals reported in roadside soils to obtain estimates of their accumulation in the forage and consequently in the animal organs. Risk to the consumers of offal was estimated. It was found that the consumption of kidney meat was riskier than the consumption of liver meat. Furthermore, it was seen that despite the nearly two order less concentrations of Cd in roadside soils compared to Pb, it was posing a higher risk. For the median concentrations of Pb reported in roadside soils and cattle feeding exclusively on C. barbata growing on roadside soils, the HQ exceeded 1 for weekly consumption of kidney meat above 650 g. For median Cd concentrations, consumption of kidney meat above 230 g/week resulted in HQ>1. The scenario considered for risk assessment is significant for India, where stray grazing of cattle on road margins is common and offal offers a cheap source of animal protein for the economically poor.

Bioassimilation of lead and zinc in rabbits fed on spinach grown on contaminated soil

Accumulation of heavy metals in the environment can pose a potential risk to living organisms. Ingestion of leafy vegetables, containing heavy metals, is one of the main routes through which these elements enter the human body. The present study was conducted to assess the accumulation of lead (Pb) and zinc (Zn) in spinach grown on metal contaminated soil, and to examine the bioassimilation of these metals in spinach-fed rabbits. Spinach grown in the fields spiked with Pb (1000 mg kg-1 soil) and Zn (150 mg kg-1 soil), was fed to the rabbits for 14 days. Concentrations of Pb and Zn in the leaves of spinach were 39.1 and 113 mg kg-1, respectively. For the assessment of Pb and Zn concentration, blood samples were collected after 24 h, 7 days and 14 days of feeding, while the essential organs, i.e. liver and kidneys of rabbits were collected at the end of feeding trials. Concentrations (mg L-1) of Pb (3.28) and Zn (7.10) increased in blood after 24 h compared to control treatment and then decreased (Pb 1.12; Zn 3.32) to a steady state with the passage of time after 7 days. A significant increase in the concentrations of Pb (1.20%, 3.95% and 5.58%) and Zn (10.7%, 6.89% and 18.4%) as compared to control treatment was also found in liver, kidney and bones of the rabbits, respectively, which was further confirmed by multivariate analysis. The highest significant values of correlation coefficient (r) were observed for blood and bones, i.e. 0.992 followed by blood and liver, i.e. 0.989. The bioassimilation of Pb in the body of rabbits was in the order of bone > kidney > liver > blood, while for Zn the order was bone > liver > kidney > blood. The bioassimilation of Pb and Zn in the blood, essential organs and bones depicted the serious health risks associated by consuming the metal contaminated vegetable.

Heavy metal (PTE) ecotoxicology, data review: Traditional vs. a compositional approach

Potentially Toxic Elements (PTEs) otherwise known as heavy metals are ubiquitous in soils and can have a range of negative health and environmental impacts. In terrestrial systems understanding how PTEs move in the environment is made challenging by the complex interactions within soil and the wider environment and the compositional nature of PTEs. PTEs are compositional because data of individual PTEs within in a sample are ratios which may be under a sum constraint, where individual components sum up to a whole. In this study three different scenarios were considered, one using the centred log ratio transformation (clr) a compositional transformation, the more "traditional" log10 transformation (log10) and untransformed data acting as a comparison (unt) were applied to four different datasets. Three were the Liver, Muscle and Kidney tissue of Eurasian Badgers (Meles meles) and the fourth was soil and data were extracted from a regional geospatial survey. Cluster analysis demonstrated that the clr and log10 transformation were able to resolve compositional trends at the point of the individual sample, whilst unt could not and did not meet the preconditions for the next phase of analysis. At the level of compositional trends between PTEs complex heatmaps demonstrated that clr was able to isolate PTE relationships and highlight commonalities between different datasets, whilst log10 could not. In the final phase, principal component analysis (PCA) of the clr transformation showed similarities between the signals in the soft tissues and the disparities they had with soil, whilst the log10 transformation was unable to achieve this. Overall, the clr transformation was shown to perform more consistently under a variety of analytical scenarios and the compositional approach will provide more realistic interpretations about PTEs in both soil and animal soft tissue than the log10 or unt conditions.

Potentially toxic element accumulation in badgers (Meles meles): a compositional approach

Potentially Toxic Elements (PTEs) in Badgers (Meles meles), otherwise known as heavy metals, are unique amongst environmental pollutants occurring, both naturally and anthropogenically. PTEs have a broad range of negative health and environmental effects, therefore identifying their sources and pathways through the environment is imperative for public health policy. This is difficult in terrestrial systems due to the compositional nature of soil geochemistry. In this study, a compositional statistical approach was used to identify how PTEs accumulate in a terrestrial carnivorous mammal, Eurasian Badgers (Meles meles). Compositional principal component analysis (PCA) was used on geochemical data from the Tellus survey, the soil baseline and badger tissue data to map geo-spatial patterns of PTEs and show accumulative trends measured in time. Mapping PCs identified distinct regions of PTE presence in soil and PTE accumulation in badger tissues in Northern Ireland. PTEs were most elevated in liver, kidney and then muscle tissues. Liver and kidney showed the most distinct geo-spatial patterns of accumulation and muscle was the most depleted. PC1 and 2 for each type were modelled using generalised additive mixed models (GAMM) to identify trends through time. PC1 for the liver and muscle were associated with rainfall and ∂N15 in the liver, showing a link to diet and a bioaccumulation pathway, whilst PC2 for both tissues was associated with mean temperature, showing a link to seasonal activity and a bioaccessibility pathway. However, in kidney tissue these trends are reversed and PC1 was associated with bioaccessibility and PC2 with bioaccumulation. Combined these techniques can elucidate both geo-spatial trends in PTEs and the mechanisms by which they move in environment and in future may be an effective tool for assessing PTE bioavailability in environmental health surveys.

Ultramafic geoecosystems as a natural source of Ni, Cr, and Co to the environment: A review

Ultramafic soils are in equal parts fascinating and dangerous. Developed on rocks derived predominately from the Earth's mantle and metamorphosed at the ocean floors, ultramafic soils form in the places where tectonic forces brought these rocks from mantle depths to the surface. As it is common in nature, both ultramafic rocks and soils are site-specific, and vary in character and composition; however, they have one thing in common, they are enriched in certain elements and three metals in particular form an "ultramafic" triad: Ni, Cr, and Co. These three metals are far from being human-friendly and strict legislative limits are established for maximum allowable concentrations of these metals in soils, but mostly in the case when the metals are of anthropogenic origin. However, ultramafic soils are a natural phenomenon where increased metal content is not the result of pollution, but rather referred as a peculiar geochemical background, therefore there is no reason for their remediation. At the same time, it is not that easy to actually find an ultramafic soil that does not overstep the limits (for the sake of this paper we use median world Regulatory Guidance Values - RGVs). Often, mobile Ni and Co concentrations are above the guidelines when doing tests to estimate the bioavailable fraction (EDTA and DTPA), and high concentrations of Ni are also commonly present in excluder plants (also edible ones). Also waters in ultramafic areas often exceed Ni and Cr(VI) limits. It is therefore expected that the ultramafic metals are present in the food chain and they might constitute a potential health risk. Thus, there is a need for additional research focused on assessment of the potential health consequences of chronic high exposure on naturally occurring Ni, Cr, and Co.

Discrimination of mutton from different sources (regions, feeding patterns and species) by mineral elements in Inner Mongolia, China

The traceability of mineral element fingerprints to mutton in a small area of China was studied. The element data of 104 sheep and 24 goat samples from Inner Mongolia were measured, and the data were analyzed by multivariate statistical analysis from different origins, species and feeding patterns. The results shows that 11 elements (Mg, Al, K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, Ba) in sheep meat had significant differences between different regions (P < 0.05), and the results of linear discriminant analysis (LDA) showed that the accuracy of the original classification rate was 95.2%, and the cross-validation rate was 85.9%. Goat meat and sheep meat samples from Alxa League were also clearly identified with LDA results showing that the cross-validation accuracy of the two species was 70.2%. Then the feeding patterns of sheep meat were effectively classified. The results showed that the multi-element analysis has certain potential as a method to distinguish mutton in a small area.

Occurrence, behaviour, and human exposure pathways and health risks of toxic geogenic contaminants in serpentinitic ultramafic geological environments (SUGEs): A medical geology perspective

Serpentinitic ultramafic geological environments (SUGEs) contain toxic geogenic contaminants (TGCs). Yet comprehensive reviews on the medical geology of SUGEs are still lacking. The current paper posits that TGCs occur widely in SUGEs, and pose human health risks. The objectives of the review are to: (1) highlight the nature, occurrence and behaviour of TGCs associated with SUGEs; (2) discuss the human intake pathways and health risks of TGCs; (4) identify the key risk factors predisposing human health to TGCs particularly in Africa; and (5) highlight key knowledge gaps and future research directions. TGCs of human health concern in SUGEs include chrysotile asbestos, toxic metals (Fe, Cr, Ni, Mn, Zn, Co), and rare earth elements. Human intake of TGCs occur via inhalation, and ingestion of contaminated drinking water, wild foods, medicinal plants, animal foods, and geophagic earths. Occupational exposure may occur in the mining, milling, sculpturing, engraving, and carving industries. African populations are particularly at high risk due to: (1) widespread consumption of wild foods, medicinal plants, untreated drinking water, and geophagic earths; (2) weak and poorly enforced environmental, occupational, and public health regulations; and (3) lack of human health surveillance systems. Human health risks of chrysotile include asbestosis, cancers, and mesothelioma. Toxic metals are redox active, thus generate reactive oxygen species causing oxidative stress. Dietary intake of iron and geophagy may increase the iron overload among native Africans who are genetically predisposed to such health risks. Synergistic interactions among TGCs particularly chrysotile and toxic metals may have adverse human health effects. The occurrence of SUGEs, coupled with the several risk factors in Africa, provides a unique and ideal setting for investigating the relationships between TGCs and human health risks. A conceptual framework for human health risk assessment and mitigation, and future research direction are highlighted.

Titanium and Chromium Determination in Feedstuffs Using ICP-AES Technique

The present study represents the determination of Ti and Cr in dry animal feeds using wet acid digestion and inductively coupled plasma–atomic emission spectrometry (ICP-AES), in order to use these metals as digestibility markers. A radiofrequency power of 1350 W and a nebulizer argon flow of 0.8 L/min was selected. The limits of detection were between 11.4 and 16.1 μg/g for titanium and between 10.7 and 38.2 μg/g for chromium. The recovery values for the aqueous solutions were 89.5–103.9% (titanium) and 85.3–104.2% (chromium), with relative standard deviations (RSD%) under 2.1% and standard errors under 2.32%, demonstrating that the method offered good accuracy and repeatability. Six different samples of commercially available feedstuffs (two cat foods, two dog foods, and two poultry foods) were analyzed and the levels of investigated metals were found to be in the ranges of 0.10 g/kg and <LOD for chromium and titanium, respectively (dog foods); 0.10–0.18 g/kg, 0.70 g/kg for chromium and titanium, respectively (cat foods); and 0.07 g/kg, 0.82–1.35 g/kg for chromium and titanium, respectively (poultry foods).

Relationships between Pb, As, Cr, and Cd in individual cows' milk and milk composition and heavy metal contents in water, silage, and soil

Various industrial activities lead to environmental pollution by heavy metals. Toxic heavy metals enter the food chain of dairy cows through feed and water, then transferred into milk. This study investigated the correlations of heavy metal contents between individual cows' milk, water, silage and soil. The relationships between heavy metal contents in individual cows' milk with milk protein, fat, lactose, solid nonfat (SNF), and total solids (TS) were analysed. Concentrations of Pb, As, Cr, and Cd in milk, silage and water were measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Lead, Cr, and Cd in soil were measured by Atomic Absorption Spectrometry (AAS), and As was detected by Atomic Fluorescence Spectrometry (AFS). One-way non-parametric tests and Spearman correlation analyses were performed using SAS 9.4 software. Levels of Pb and Cd in milk from the unpolluted area were significantly lower (P < 0.01) than those from industrial area. Significantly higher (P < 0.01) As residue was recorded in milk from unpolluted area. Positive correlation of Pb was observed between milk and silage, and As in milk was positively correlated with As in water. Content of As in milk was slightly (r = 0.09) correlated with As in silage, even though strong positive correlation (r = 0.78) was observed between silage and water. Positive correlations were observed for Cr and Cd between milk and silage, as well as milk and soil. Positive correlations were observed in Pb-protein, Cr-protein, and Cd-lactose; other positive correlation coefficients were nearly equal to zero. The results suggest that industrial activities lead to possible Pb and Cd contamination in milk. Drinking water could be the main source of As contamination in cows. No clear relationship was found between milk composition and heavy metals contents in milk. Water and soil on the farm had a partial contribution to heavy metal contamination in milk.

Occurrence and cycling of trace elements in ultramafic soils and their impacts on human health: A critical review

The transformation of trace metals (TMs) in natural environmental systems has created significant concerns in recent decades. Ultramafic environments lead to potential risks to the agricultural products and, subsequently, to human health. This unique review presents geochemistry of ultramafic soils, TM fractionation (i.e. sequential and single extraction techniques), TM uptake and accumulation mechanisms of ultramafic flora, and ultramafic-associated health risks to human and agricultural crops. Ultramafic soils contain high levels of TMs (i.e. Cr, Ni, Mn, and Co) and have a low Ca:Mg ratio together with deficiencies in essential macronutrients required for the growth of crops. Even though a higher portion of TMs bind with the residual fraction of ultramafic soils, environmental changes (i.e. natural or anthropogenic) may increase the levels of TMs in the bioavailable or extractable fractions of ultramafic soils. Extremophile plants that have evolved to thrive in ultramafic soils present clear examples of evolutionary adaptations to TM resistance. The release of TMs into water sources and accumulation in food crops in and around ultramafic localities increases health risks for humans. Therefore, more focused investigations need to be implemented to understand the mechanisms related to the mobility and bioavailability of TMs in different ultramafic environments. Research gaps and directions for future studies are also discussed in this review. Lastly, we consider the importance of characterizing terrestrial ultramafic soil and its effect on crop plants in the context of multi-decadal plans by NASA and other space agencies to establish human colonies on Mars.

Alkaline Mineral Soil Amendment: A Climate Change ‘Stabilization Wedge’?

Extreme climate change due to heat-trapping gases, especially carbon dioxide, necessitates its mitigation. In this context, the carbon dioxide sequestration technology of enhanced weathering has for years been investigated, with a possible implementation strategy via alkaline mineral soil amendment being more recently proposed. Candidate materials for enhanced weathering include calcium and magnesium silicates, most notably those belonging to the olivine, pyroxene and serpentine groups of minerals, given their reactivity with CO2 and global availability. When these finely crushed silicate rocks are applied to the soil, the alkaline earth metal cations released during mineral weathering gradually react with carbonate anions and results in the formation of pedogenic carbonates, which, over time, and under the right conditions, can accumulate in the soil. This review paper critically reviews the available literature on alkaline mineral soil amendments and its potential to sequester enough CO2 to be considered a climate change ‘stabilization wedge’. Firstly, evidence of how agricultural soil can serve as a carbon sink in discussed, based on the observed accumulation of inorganic carbon in alkaline mineral-amended soils. Secondly, the impact of alkaline minerals on agricultural soil and crops, and the factors determining the rate of the weathering process are assessed. Lastly, the CO2 sequestration potential via alkaline mineral soil amendment is quantified according to an idealized shrinking core model, which shows that it has the potential to serve as a climate change stabilization wedge.

Levels of trace elements and potential toxic elements in bovine livers: A trend analysis from 2007 to 2018

Trace elements and potential toxic elements were analyzed in bovine livers submitted for autopsy in the Netherlands during the years 2007 to 2018. The age of each animal was recorded. In total, 1544 livers were analyzed for cadmium, cobalt, chromium, copper, iron, molybdenum, nickel, lead, selenium and zinc. Less than 2% of the liver samples were from veal calves. Young animals had significantly higher concentrations of iron and zinc in their livers compared to animals older than one year, while older animals had significantly higher levels of cadmium and molybdenum in their livers. Animals aged 1 to 2 years had the lowest copper and selenium levels. There was a tendency for lower chromium and nickel levels during the last years of the testing period, while copper showed an increase. Lead intoxication was only seen in the youngest group of cattle, while copper intoxication, defined as a liver copper of more than 1000 mg/kg dry matter, occurred in older animals, mainly in animals of 3 to 4 years old. This trend analysis of trace elements in bovine livers of cattle over time in recent years, and the relation of liver element concentrations with age of the animal, provides insight in the uptake and storage of these elements by cattle in The Netherlands. Possible reasons for observed trends and age-related patterns are discussed.

Zinc, copper, cadmium, and lead levels in cattle tissues in relation to different metal levels in ground water and soil

The objective of the present study was to investigate the interaction between environmental (water and soil) levels of zinc, copper, cadmium, and lead levels, as well as their content in Hereford beef cattle tissues in five districts (D₁-western area, D₂ and D₃-central area, D₄ and D₅-eastern area) of the Orenburg region. Soil metal levels were assessed using atomic emission spectrometry, whereas water and tissue (liver, kidney, muscle, heart) metal content was studied using inductively coupled plasma-mass spectrometry. The obtained data demonstrate that the highest levels Zn in soil and water (p < 0.001), as well as cattle muscle, liver, and kidney (p < 0.05) were observed in D₄ and D₅ (eastern area), exceeding the maximum permissible concentration levels (MPCL) for drinking water and muscle for all regions. Similar associations were found for Cu levels. The highest soil and water Cd and Pb content were observed in D₂ (central area) and D₅ (eastern area), respectively. At the same time, cattle tissue Cd and Pb content did not correspond to the respective environmental levels. Correlation analysis demonstrated that water and soil Zn and Cu content directly correlated with muscle, liver, and kidney, but not heart metal content. At the same time, water Cd levels were negatively interrelated with muscle cadmium content but correlated directly with hepatic metal content. Both water and soil Pb levels positively correlated with renal metal levels in cattle. In turn, soil lead content was inversely associated with muscle metal levels. Regression analysis also demonstrated a significant association between environmental and tissue levels of Zn and Cu. The models adjusted for all studied elements demonstrated a significant effect of metal interaction on tissue metal levels. Hypothetically, excessive environmental Zn, and possibly Cu, levels may affect the uptake of heavy metals including Cd and Pb from the environment.

Determination of Heavy Metal Residues in Slaughtered Camels at Sokoto and Gusau Modern Abattoirs, Nigeria

BACKGROUND

Heavy metals can pose health risks to both animals and humans. Objectives. To determine the concentrations of lead (Pb), cadmium (Cd), and chromium (Cr) in samples taken from the kidney, liver, muscle, hide, and blood of camels slaughtered at both Sokoto and Gusau modern abattoirs.

METHODS

The concentrations of Pb, Cd, and Cr in tissues and organs of camels slaughtered at both Sokoto and Gusau modern abattoirs were determined using atomic absorption spectrophotometry. A total of 120 samples were collected.

RESULTS

All the samples collected tested positive for Pb, Cd and Cr. The overall mean concentrations of Pb, Cd and Cr in tissues and organs of slaughtered camels at Sokoto modern abattoir ranged from 0.11 mg/kg to 0.35 mg/kg, 0.05 to 0.8 mg/kg and 0.41 to 0.59 mg/kg, respectively, while at Gusau modern abattoir, the overall mean concentrations of Pb, Cd and Cr ranged from 0.20 mg/kg to 1.17 mg/kg, 0.01 to 0.14 mg/kg and 0.13 to 0.51 mg/kg, respectively.

DISCUSSION

The concentration of Pb in the tissues and organs of camels slaughtered at Gusau modern abattoir was high compared to in camels slaughtered at Sokoto modern abattoir, while the concentrations of Cd and Cr in the tissues and organs of camels slaughtered at Sokoto modern abattoir were high compared to those in tissues and organs of camels slaughtered at Gusau modern abattoir. There were significant differences (P<0.05) in the concentration of Pb, Cd, and Cr in samples taken from the kidney, liver, muscle, hide, and blood of slaughtered camels at both Sokoto and Gusau.

CONCLUSIONS

Camels slaughtered at both Sokoto and Gusau modern abattoirs were exposed to Pb, Cd, and Cr.The tissues and organs of camels slaughtered at both Sokoto and Gusau contain Pb, Cd, and Cr. Prolonged exposure through consumption of these tissues and organs should be avoided.

COMPETING INTERESTS

The authors declare no competing financial interests.

Trace Element Concentrations in Beef Cattle Related to the Breed Aptitude

Animal feed has traditionally been supplemented with trace elements at dietary concentrations well above physiological needs. However, environmental concerns have led to calls for better adjustment of mineral supplementation to actual physiological needs and, in this context, consideration of breed-related differences in trace element requirements. The aim of this study was to analyze trace element concentrations in the main breeds used for intensive beef production in northern Spain (Holstein-Friesian [HF], Galician Blonde [GB], and GB × HF cross). Samples of blood, internal organs, and muscle were obtained at slaughter from 10 HF, GB, and GB × HF cross calves in the same feedlot. Overall, trace element concentrations in serum and internal organs were within adequate ranges and did not differ between those of breeds, suggesting that trace mineral supplementation was adequate in all groups. The only exception to this was copper, and hepatic copper concentrations were above adequate levels in all calves. This was particularly evident in the HF calves, and the maximum recommended level for human consumption was exceeded in 90% of these animals. Copper, iron, manganese, selenium, and zinc concentrations in muscle were significantly higher in the HF than those in the GB calves, with intermediate values for the crosses. These breed-related differences in trace element concentrations in the muscle may be related to lower muscle mass and/or higher hepatic activity in the HF (dairy) calves than in GB (beef) calves. As meat is an essential source of highly available trace elements in human diets, breed-related differences in trace element concentrations in meat deserve further investigation.

Plant and Soil Metal Concentrations in Serpentine Soils and Their Influence on the Diet of Extensive Livestock Animals

Background:

Grazing circuits and resources consumed differ strongly throughout the year and within a territory. For this reason, animals’ diet composition, as well as their exposure to metals, is variable. No studies have been performed on how habitat use affects the metal concentrations to which sheep and goats reared in serpentine soil areas are exposed.

Objective:

The aim of the present study was to investigate the metal exposure of grazing animals raised in a serpentine soil area of the north-east of Portugal, taking into account the spatial distribution of metal concentrations in soils and plants.

Methods:

The habitat use and foraging behaviour of six flocks of sheep and goats were studied. The concentrations of Ca, Mg, Mn, Cr and Ni were determined in the soils and plant species most consumed by those animals.

Results:

The highest Mg, Mn, Cr and Ni concentrations were found in the soils of the ultramafic complex. Ni concentrations above the recommended threshold for agricultural soils (30 μg/g) were found in some sites. A positive correlation between Ni concentration in soils and plants was found (0.634). Ni concentrations higher than 10 µg/g were found in some samples of the following plant species:Sorghum × drummondii(Steud.) Millsp. & Chase,Quercus rotundifoliaLam.,Cytisus multiflorus(L’Hér.) Sweet,Cistus ladaniferL. andErica scopariaL. Significant differences (p ≤ 0.05) in metal concentrations of the plants most consumed by each flock were observed.

Conclusion:

Grazing circuits have an important role in the metal exposure of animals raised in this serpentine soil area.

Heavy metal contamination in sandy beach macrofauna communities from the Rio de Janeiro coast, Southeastern Brazil

We evaluated concentrations of eight heavy metals Cr, Zn, Pb, Ni, Cu, Cd, Co and V, in tissues of representative macrofauna species from 68 sandy beaches from the coast of Rio de Janeiro state. The links between contamination levels and community descriptors such as diversity, evenness, density and biomass, were also investigated. Metal concentrations from macrofaunal tissues were compared to maximum permissible limits for human ingestion stipulated by the Brazilian regulatory agency (ANVISA). Generalized linear models (GLM's) were used to investigate the variability in macrofauna density, richness, eveness and biomass in the seven different regions. A non-metric multidimensional scaling analysis (n-MDS) was used to investigate the spatial pattern of heavy metal concentrations along the seven regions of Rio de Janeiro coast. Variation partitioning was applied to evaluate the variance in the community assemblage explained by the environmental variables and the heavy metal concentrations. Our data suggested high spatial variation in the concentration of heavy metals in macrofauna species from the beaches of Rio de Janeiro. This result highlighted a diffuse source of contamination along the coast. Most of the metals concentrations were under the limits established by ANVISA. The variability in community descriptors was related to morphodynamic variables, but not with metal contamination values, indicating the lack of direct relationships at the community level. Concentration levels of eight heavy metals in macrofauna species from 68 sandy beaches on Rio de Janeiro coast (Brazil) were spatially correlated with anthropogenic activities such as industrialization and urbanization.

Seasonal variations in the blood concentration of selected heavy metals in sheep and their effects on the biochemical and hematological parameters

The main objective of this study was to assess the concentration of various heavy metals (Cd, Pb, Zn, Cu, Hg) in the blood of sheep, followed by biochemical and hematological analysis in order to reveal possible associations. Blood was collected in two different seasons: winter (fed by fodder) and spring (grazing animals). The higher concentrations of Pb (p < 0.01), Cu (p < 0.05) and Hg, but lower of Cd and Zn were found in spring. Evaluation of the biochemical and hematological parameters during different seasons showed a possible environmental effect on the health of animals. A statistically significant increase of Ca (p < 0.001), Mg (p < 0.05), urea (p < 0.001), TP (p < 0.05), glucose (p < 0.01), AST (p < 0.001), ALT (p < 0.001), ALP (p < 0.01), cholesterol (p < 0.001), bilirubin (p < 0.05), triglycerides (p < 0.001) and a decrease of P (p < 0.05), HGB (p < 0.05), MCHC (p < 0.05) and RDWc (p < 0.05) in spring was detected. The results of this study showed statistically significant correlations between Pb and ALP (r = 0.53) level in winter and between Pb and Ca (r = -0.73) in the spring. The hematological analysis revealed a significant correlation between Zn and RBC (r = 0.61), MCV (r = -0.74), MCH (r = -0.71) and between Pb and MCH (r = -0.55), PCT (r = -0.66), PDWC (r = -0.55) in the winter. A high positive significant correlations were found between Cd and RDWC (r = 0.77) and Cu and RDWC (r = 0.75). The significance of this work is the use the data in the preventive diagnosis of metabolic and production diseases. The collected data may serve as a control indicator to detect toxic hazards related to the heavy metal occurrence on animal health status.

Transfer of heavy metals through terrestrial food webs: a review

Heavy metals are released into the environment by both anthropogenic and natural sources. Highly reactive and often toxic at low concentrations, they may enter soils and groundwater, bioaccumulate in food webs, and adversely affect biota. Heavy metals also may remain in the environment for years, posing long-term risks to life well after point sources of heavy metal pollution have been removed. In this review, we compile studies of the community-level effects of heavy metal pollution, including heavy metal transfer from soils to plants, microbes, invertebrates, and to both small and large mammals (including humans). Many factors contribute to heavy metal accumulation in animals including behavior, physiology, and diet. Biotic effects of heavy metals are often quite different for essential and non-essential heavy metals, and vary depending on the specific metal involved. They also differ for adapted organisms, including metallophyte plants and heavy metal-tolerant insects, which occur in naturally high-metal habitats (such as serpentine soils) and have adaptations that allow them to tolerate exposure to relatively high concentrations of some heavy metals. Some metallophyte plants are hyperaccumulators of certain heavy metals and new technologies using them to clean metal-contaminated soil (phytoextraction) may offer economically attractive solutions to some metal pollution challenges. These new technologies provide incentive to catalog and protect the unique biodiversity of habitats that have naturally high levels of heavy metals.

Lead and cadmium levels in cattle muscle and edible tissues collected from a slaughter slab in Nigeria

Contamination levels of lead (Pb) and cadmium (Cd) in muscles, liver and kidney of 50 randomly selected, freshly slaughtered cattle in Ogun State, Nigeria were assessed using an official procedure and atomic absorption spectrophotometry. Results showed that Pb and Cd were present in all of the tested samples. Mean Pb concentrations were 0.721 ± 0.180 mg kg(-1), 0.809 ± 0.220 mg kg(-1) and 0.908 ± 0.422 mg kg(-1) in muscle, liver and kidney tissues, respectively. Mean Cd concentrations were 0.157 ± 0.049 mg kg(-1), 0.172 ± 0.071 mg kg(-1) and 0.197 ± 0.070 mg kg(-1) in muscle, liver and kidney tissues, respectively. Pb and Cd levels in muscle versus kidney tissues and also in liver versus kidney samples were significantly different (p < 0.05). Mean Pb concentrations in all tested tissues were significantly higher than the International Standards while the mean Cd concentrations in liver and kidney samples were within the limits of these standards.

Olivine weathering in soil, and its effects on growth and nutrient uptake in Ryegrass (Lolium perenne L.): a pot experiment

Mineral carbonation of basic silicate minerals regulates atmospheric CO(2) on geological time scales by locking up carbon. Mining and spreading onto the earth's surface of fast-weathering silicates, such as olivine, has been proposed to speed up this natural CO(2) sequestration ('enhanced weathering'). While agriculture may offer an existing infrastructure, weathering rate and impacts on soil and plant are largely unknown. Our objectives were to assess weathering of olivine in soil, and its effects on plant growth and nutrient uptake. In a pot experiment with perennial ryegrass (Lolium perenne L.), weathering during 32 weeks was inferred from bioavailability of magnesium (Mg) in soil and plant. Olivine doses were equivalent to 1630 (OLIV1), 8150, 40700 and 204000 (OLIV4) kg ha(-1). Alternatively, the soluble Mg salt kieserite was applied for reference. Olivine increased plant growth (+15.6%) and plant K concentration (+16.5%) in OLIV4. At all doses, olivine increased bioavailability of Mg and Ni in soil, as well as uptake of Mg, Si and Ni in plants. Olivine suppressed Ca uptake. Weathering estimated from a Mg balance was equivalent to 240 kg ha(-1) (14.8% of dose, OLIV1) to 2240 kg ha(-1) (1.1%, OLIV4). This corresponds to gross CO(2) sequestration of 290 to 2690 kg ha(-1) (29 10(3) to 269 10(3) kg km(-2).) Alternatively, weathering estimated from similarity with kieserite treatments ranged from 13% to 58% for OLIV1. The Olsen model for olivine carbonation predicted 4.0% to 9.0% weathering for our case, independent of olivine dose. Our % values observed at high doses were smaller than this, suggesting negative feedbacks in soil. Yet, weathering appears fast enough to support the 'enhanced weathering' concept. In agriculture, olivine doses must remain within limits to avoid imbalances in plant nutrition, notably at low Ca availability; and to avoid Ni accumulation in soil and crop.

Soil-plant-animal transfer models to improve soil protection guidelines: a case study from Portugal

Food chain models are essential tools to assess risks of soil contamination in view of product quality including fodder crops and animal products. Here we link soil to plant transfer (SPT) models for potentially toxic elements (PTEs) including As, Ba, Cd, Co, Cu, Hg, Ni, Pb, Sb, U and Zn with models describing accumulation in animal organs. Current EU standards for food products and acceptable daily intake levels (ADI) for humans were used as critical limits. The combined model is used to assess the impact of soil contamination on animal health, product quality and human health using data from 100 arable fields. Results indicate that 42 existing arable fields near industrial and mining sites are unsuitable for animal grazing in view of food safety due to elevated intake of Cd, Cu, Hg and Pb by cows and sheep. At 10 sites daily intake levels of As by cows exceeded threshold concentrations regarding the quality of animal products. The food chain model also was used inversely to derive soil threshold concentrations in view of EU fodder standards. Calculated threshold levels in soil for As, Cd, Cu, Pb, Hg and Zn appear to be in line with those proposed or used in other EU countries. As such the approach applied here can form a conceptual basis for a more harmonized risk assessment strategy regarding the protection of animal and human health.

Concentrations of selected trace elements in organs and tissues of livestock from a polluted area

The occurrence of cadmium (Cd), nickel (Ni) and lead (Pb) from industrial emissions were determined in the muscle and liver of cattle from agricultural farms near an industrial plant in Eastern Slovakia. In this study cows (n = 25) were slaughtered and the concentrations of Cd, Ni, Pb were analyzed with a the atomic absorption spectrophotometer. Levels reaching the highest permissible hygiene limits for toxic metals Cd, Pb and Ni were determined in 50 samples. The maximum levels of Cd, Pb and Ni were recorded in the liver (0.865; 2.324; 1.140 mg/kg, respectively) and muscle (0.300; 0.854; 0.700 mg/kg, respectively). It was concluded that the exposure to an industrial plant significantly increases the levels of contaminants in the muscle and organs of cattle, as the most susceptible livestock.

Effect of type of muscle and Cu supplementation on trace element concentrations in cattle meat

Considering that meat is an important source of metals exposure to humans it is important to explore trace element concentrations in different types of muscles. Because of the demonstrated effect of Cu-supplementation on mineral status, the influence of Cu-supplementation was also evaluated. Samples of four different muscles (diaphragm, cardiac, semitendinous and pectoral, n=120) from beef calves receiving typical commercial diets Cu-supplemented (15 mg Cu(2)SO(4)/kg DM) and non-supplemented were taken and acid digested. The levels of non-essential (As, Cd, Hg, Pb and Sn) and essential (Co, Cr, Fe, Mn, Mo, Ni, Se and Zn) elements were analyzed by ICP-MS. The statistical analyzes included two way Anova, post hoc DHS Tukey and Spearman correlations. The most active and less fat containing muscles showed in general the highest essential and the lowest non-essential trace element accumulation. As and Hg muscular residues are indicative of animal exposure, however, in situations of an adequate mineral status, essential trace element concentrations in muscle are irrespective of the mineral status of the animal and could be possibly related to their own particular muscular metabolism. Cu-supplementation significantly reduced As but caused a significant decrease of Se, which could have significance for the animal's health.