The effects of arsenic contaminated drinking water of livestock on its total levels in milk samples of different cattle: Risk assessment in children

A review on arsenic in the environment: bio-accumulation, remediation, and disposal

Arsenic is a widespread serious environmental pollutant as a food chain contaminant and non-threshold carcinogen. Arsenic transfer through the crops-soil-water system and animals is one of the most important pathways of human exposure and a measure of phytoremediation. Exposure occurs primarily from the consumption of contaminated water and foods. Various chemical technologies are utilized for As removal from contaminated water and soil, but they are very costly and difficult for large-scale cleaning of water and soil. In contrast, phytoremediation utilizes green plants to remove As from a contaminated environment. A large number of terrestrial and aquatic weed flora have been identified so far for their hyper metal removal capacity. In the panorama presented herein, the latest state of the art on methods of bioaccumulation, transfer mechanism of As through plants and animals, and remediation that encompass the use of physicochemical and biological processes, i.e., microbes, mosses, lichens, ferns, algae, and macrophytes have been assessed. Since these bioremediation approaches for the clean-up of this contaminant are still at the initial experimental stages, some have not been recognized at full scale. Nonetheless, extensive research on these primitive plants as bio-accumulators can be instrumental in controlling arsenic exposure and rehabilitation and may result in major progress to solve the problem on a worldwide scale.

Heavy metal levels in milk and dairy products and health risk assessment: A systematic review of studies in China

Previous studies have indicated that heavy metal levels in milk vary partly depending on environmental metal concentrations. Given the increasing consumption of milk in China, it is essential to pay attention to milk safety. We performed a systematic review of relevant published studies to evaluate the heavy metal levels in milk and dairy products and the associated health risks, discuss environmental sources of heavy metals, and propose future research directions. A literature search was implemented in the Web of Science Core Collection and PubMed using multiple keywords such as "metal," "milk," "dairy products," and "China". A total of 16 published studies that analyzed metal levels in milk and dairy products in 20 provincial administrative regions were included. Most studies detected toxic heavy metals in milk and dairy products samples, including mercury, lead, cadmium, chromium, and arsenic. The lead concentration in milk from these studies did not exceed the Chinese standard for milk. However, three studies detected relatively high lead levels in both commercial and raw milk, exceeding the European Commission standard. The polluted environment surrounding the farm, feed, and packaging materials are likely sources of metals in milk and dairy products. The hazard index for the 11 analyzed metal elements in milk and dairy products was lower than 1, indicating negligible non-carcinogenic health risks from exposure to these metals. Children are at a higher risk than adults. This review illustrates that research in this field is limited to China. More research should be conducted in the future, such as evaluating the contribution of each environmental source of metal in milk and dairy products.

The Occurrence, Pathways, and Risk Assessment of Heavy Metals in Raw Milk from Industrial Areas in China

This study evaluated chromium (Cr), arsenic (As), cadmium (Cd), and lead (Pb) contamination in raw milk from industrial areas in China, identified the possible pathways of heavy metals from the environment to raw milk, and made a risk assessment of the consumption of heavy metals from milk consumption. The Cr, As, Cd, and Pb concentrations in raw milk, water and silage were analyzed using inductively coupled plasma mass spectrometry. The Cr and As in soil were analyzed by flame atomic absorption spectrometry and atomic fluorescence spectrometry, respectively. Cd and Pb in soil were determined by a Graphite furnace atomic absorption spectrophotometer. The Cr and As concentrations in milk from industrial areas were 2.41 ± 2.12 and 0.44 ± 0.31 μg/kg, respectively, which were significantly higher (p < 0.01) than those from non-industrial areas, which had levels of 1.10 ± 0.15 and 0.25 ± 0.09 μg/kg, respectively. Chromium was mainly transferred through the soil-silage-milk pathway, As was transferred through the water-silage-milk pathway, while Cd was mainly transferred through the soil (water)-silage-milk pathway. The contributions of each metal to the overall hazard index (HI) followed a descending order of As, Cr, Pb, and Cd, with values of 46.64%, 25.54%, 24.30%, and 3.52%, respectively. Children were at higher risk than adults.

Health effect and risk assessment of the populations exposed to different arsenic levels in drinking water and foodstuffs from four villages in arsenic endemic Gaighata block, West Bengal, India

Health exposure and perception of risk assessment have been evaluated on the populations exposed to different arsenic levels in drinking water (615, 301, 48, 20 µg/l), rice grain (792, 487, 588, 569 µg/kg) and vegetables (283, 187, 238, 300 µg/kg) from four villages in arsenic endemic Gaighata block, West Bengal. Dietary arsenic intake rates for the studied populations from extremely highly, highly, moderately, and mild arsenic-exposed areas were 56.03, 28.73, 11.30, and 9.13 μg/kg bw/day, respectively. Acute and chronic effects of arsenic toxicity were observed in ascending order from mild to extremely highly exposed populations. Statistical interpretation using 'ANOVA' proves a significant relationship between drinking water and biomarkers, whereas "two-tailed paired t test" justifies that the consumption of arsenic-contaminated dietary intakes is the considerable pathway of health risk exposure. According to the risk thermometer (SAMOE), drinking water belongs to risk class 5 (extremely highly and highly exposed area) and 4 (moderately and mild exposed area) category, whereas rice grain and vegetables belong to risk class 5 and 4, respectively, for all the differently exposed populations. The carcinogenic (ILCR) and non-carcinogenic risks (HQ) through dietary intakes for adults were much higher than the recommended threshold level, compared to the children. Supplementation of arsenic-safe drinking water and nutritional food is strictly recommended to overcome the severe arsenic crisis.

Arsenic toxicity in livestock growing in arsenic endemic and control sites of West Bengal: risk for human and environment

The present study aims to estimate geochemical arsenic toxicity in the domestic livestock and possible risk for human and environment caused by them. Daily dietary arsenic intake of an exposed adult cow or bull is nearly 4.56 times higher than control populace and about 3.65 times higher than exposed goats. Arsenic toxicity is well exhibited in all the biomarkers through different statistical interpretations. Arsenic bioconcentration is faster through water compared to paddy straw and mostly manifested in faeces and tail hair in cattle. Cow dung and tail hair are the most pronounced pathways of arsenic biotransformation into environment. A considerable amount of arsenic has been observed in animal proteins such as cow milk, boiled egg yolk, albumen, liver and meat from the exposed livestock. Cow milk arsenic is mostly accumulated in casein (83%) due to the presence of phosphoserine units. SAMOE-risk thermometer, calculated for the most regularly consumed foodstuffs in the area, shows the human health risk in a distinct order: drinking water > rice grain > cow milk > chicken > egg > mutton ranging from class 5 to 1. USEPA health risk assessment model reveals more risk in adults than in children, subsisting severe cancer risk from the foodstuffs where the edible animal proteins cannot be ignored. Therefore, the domestic livestock should be urgently treated with surface water, while provision of both arsenic-free drinking water and nutritional supplements is mandatory for the affected human population to overcome the severe arsenic crisis situation.

Risk assessment of heavy metals in milk from cows reared around industrial areas in India

This study assessed the health risk associated with exposure to heavy metals through consumption of milk from cows reared around industrial areas in India. Heavy metals, namely Cu, Zn, Cr, Pb, and Cd, were determined in water and forage from four locations as well as in milk produced by dairy cattle raised in these locations, using inductively coupled plasma-mass spectrometry. A quantitative risk assessment using probabilistic approaches was performed to assess the exposure of adults and children to the heavy metals via milk consumption. In milk samples, the highest levels of Cd and Pb were 0.18 mg L^-1 and 0.37 mg L^-1, respectively, which were above the international permissible levels. Possible sources of Pb in the milk could be the industrial by-products and wastes or automobiles exhaust gas. Significant (P < 0.05) positive relationships were found between the concentration of Cu, Cr, Pb, and Cd in milk and in the environmental samples (water or forage). Exposure assessment showed that milk consumers were mostly exposed to Zn, Cd, and Pb, with 63.7%, 51.2%, and 41.2% of children exposed to a dose greater than the references dose for these metals, respectively. Our results suggest that industrial activities lead to possible transfer of heavy metals to cows from their rearing environment (water, plant), which can be accumulated and cause potential health risks to milk consumers. The outcome of this study can be used by policy makers to manage the potential health risk.

Arsenite induce neurotoxicity of common carp: Involvement of blood brain barrier, apoptosis and autophagy, and subsequently relieved by zinc (Ⅱ) supplementation

Arsenic pollution is a common threat to aquatic ecosystems. The effects of chronic exposure to arsenite on the brains of aquatic organisms are unknown. This study was designed to evaluate arsenic-induced brain damage in common carp (Cyprinus carpio) and the ameliorating effects of divalent zinc ion (Zn2+) supplementation from the aspects of oxidative stress (OxS), tight junction (TJ), apoptosis and autophagy. After arsenite exposure (2.83 mg/L) for 30 days, oxidative damage to the brain was determined, as indicated by inhibited antioxidants system (catalase-superoxide dismutase system, and glutathione system) and elevated levels of biomacromolecule peroxidation (malondialdehyde and 8-hydroxydeoxyguanosine). Moreover, we also found functional damage to the brain as suggested by injuries to the blood-brain barrier (decreases in tight junction) and nerve conduction (depletion of AChE). Mechanisticly, apoptotic and autophagic cell death were indicated by typical morphologies including karyopyknosis and autophagosome, accompanying by key bio-indicators (Bcl-2, caspase and autophagy related gene family proteins). In contrast, the coadministration of Zn2+ (1 mg/L) with arsenite effectively alleviated this damage as suggested by the recovery of the aforementioned bioindicators. This study provides new insight into the brain toxicity caused by arsenite and suggests the application of zinc preparations in the aquatic pollution of arsenic.

Zinc offers splenic protection through suppressing PERK/IRE1-driven apoptosis pathway in common carp (Cyprinus carpio) under arsenic stress

Arsenic (As) occurs naturally and concentrations in water bodies can reach high levels, leading to accumulation in vital organs like the spleen. Being an important organ in immune response and blood development processes, toxic effects of As on the spleen could compromise immunity and cause associated disorders in affected individuals. Splenic detoxification is key to improving the chances of survival but relatively little is known about the mechanisms involved. Essential trace elements like zinc have shown immune-modulatory effects humans and livestock. This study aimed to investigate the mechanisms involved in As-induced splenic toxicity in the common carp (Cyprinus carpio), and the protective effects of zinc (Zn). Our findings suggest that environmental exposure to As caused severe histological injuries and Ca²⁺ accumulation in the spleen of common carp. Additionally, transcriptional and translational profiles of endoplasmic reticulum stress, apoptosis and autophagy-related genes of the spleen showed upward trends under As toxicity. Treatment with Zn appears to offer protection against As-induced splenic injury in common carp and the pathologic changes above were alleviated. Our results provide additional insight into the mechanism of As toxicity in common carp while elucidating the role of Zn, a natural immune-modulator, as a potential antidote against As poisoning.

Toxicity in Goats Exposed to Arsenic in the Region Lagunera, Northern Mexico

The Region Lagunera, a region in northeast Mexico, is undergoing significant problems with the quality of its groundwater, which exceeds the permissible limits of contaminants and/or heavy metals stipulated in Mexican legislation. The present study evaluated chronic toxicity in male goats exposed to arsenic via one ex situ Group 1 (n = 5) and one in situ female goats Group 3 (n = 10). The treatment in Group 1 was carried out in the La Laguna experimental field of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), located in Matamoros, Coahuila, Mexico. Sodium arsenite (2 mg/kg) was orally administered for 84 days to five male Creole goats, aged between four and five years old and weighing between 60 and 70 kg, in order to determine its effect on urine toxicity, libido, and physiological condition, an untreated group (n = 5) was included (Group 2). The experiment in group 3 was conducted on ten female Creole goats, aged between four and six years old and weighing between 40 and 49 kg, in both the contaminated sampling area in the rural community of El Venado and the control sampling area in the rural community of Nuevo Reynosa (Group 4 (n = 5)), in which the arsenic levels were measured in the urine of the exposed goats, as was their physiological condition. Significant differences (p < 0.01) between the groups were found in both the arsenic concentration in the urine and the physiological condition observed in both experimental groups.

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.

Hepatoprotective effects of zinc (II) via cytochrome P-450/reactive oxygen species and canonical apoptosis pathways after arsenite waterborne exposure in common carp

Chronic arsenicosis has threatened the survival of aquatic animals with molecular mechanisms yet clear. In the present study, liver damage was evident by fluctuated activities of transaminases and declined ATPases in common carp under arsenic (As) exposure for 30 days. Mechanically, As significantly decreased cytochrome P-1A (CYP1A) activity and increased reactive oxygen species (ROS) content, which corroborated mitochondrial dysfunction in the hepatocytes. This hypothesis was further suggested by Caspase-3-executed apoptosis by death receptor pathway (Fas, TNF-α and Caspase-8) and mitochondrial pathway (Bax, Bcl-2 and Caspase-9). The above results indicated that As-elicited oxidative damage lead to apoptotic hepatic injury in carp. On the contrary, zinc (Zn) exerted an ROS scavenger and an antidote to As in the present model evidenced by alleviated liver injury and restored liver function index. Moreover, Zn and As co-administration displayed partially recovered CYPs enzyme system and quenched apoptotic positive cells compared As treated alone. These outcomes could be applied to develop counter practices based on Zn preparations to decrease the biotoxicity of As.

Assessing the feasibility of using a closed landfill for agricultural graze land

Once landfills are closed and maintained according to the US Environmental Protection Agency's standards and regulations, they are potential sites for revitalization efforts, particularly via agricultural activities. This project was commissioned by the City of Tucson Environmental Services Department as part of an effort to explore ways to reuse one or more of the 16 landfills the department manages in the Tucson metropolitan area. The objective of this project was to assess the feasibility of using a closed landfill to support safe goat browsing. A site history and investigation was conducted at the Harrison Landfill in Tucson, Arizona, to characterize the soil quality and uptake of deleterious metals by the following plants observed at the landfill: Pennisetum ciliare (buffel grass), Baccharis sarothroides (desert broom), Salsola tragus L. (Russian thistle), Larrea tridentata (creosote), Tamarix ramosissima (salt cedar), and Atriplex canescens (fourwing saltbush). Site characterization data were combined with known goat browsing and plant consumption patterns to determine exposure risks. It was observed that soil concentrations of metals (Al, Ag, As, Be, Ba, Fe, Co, Cu, Cr, Cd, Fe, Mn, Ni, V, Se, Mo, Sn, Sb, Pb) did not exceed Arizona Department of Environmental Quality's soil remediation levels. Tamarix ramosissima, Baccharis salicifolia (willow baccharis), Pennisetum ciliare, Salsola tragus L., Baccharis sarothroides, Larrea tridentata, and Atriplex canescens contained metal concentrations that fell well within maximum tolerable levels. In general, this project determined that after soil and plant assessment, urban, arid landfills may be used effectively for economic development through agricultural grazing ventures.

Interplay between elemental imbalance-related PI3K/Akt/mTOR-regulated apoptosis and autophagy in arsenic (III)-induced jejunum toxicity of chicken

Arsenic trioxide (As₂O₃), the most toxic form of arsenic found in foodstuffs, is considered a carcinogen for human and animal. But many of the events that occur during its passage through the gastrointestinal tract are uncharted in birds. This study assesses the toxic effect on the jejunum of chicken which subchronically exposed to diets that contain As₂O₃ (0, 0.625, 1.25, 2.5 mg/kg body weight) for 90 days. Electron microscopy, TdT-mediated dUTP nick-end labeling (TUNEL), qPCR, and Western blot were performed. The results showed that mitochondrial fusion and apoptosis inhibiting genes had degressive trends, whereas mitochondrial fission and apoptosis activating genes presented heightened expressions in the treatment group compared with the control (P < 0.05). Subsequently, significant inhibition in PI3K/AKT/mTOR signaling was observed. Moreover, the expression of autophagy markers (LC3-II/LC3-I, Beclin-1) increased time and dose-dependently. Additionally, metabolic disorders of trace elements were detected evidenced by their significant decreases (aluminum, silicon, calcium, manganese, strontium, titanium, lithium, boron, cobalt, mercury, chromium) and increases (arsenic, cadmium, selenium, lead, nickel) on 90 days using inductively coupled plasma mass spectrometer (ICP-MS). It is possible that the changes of trace elements have a hand in the come on and development of arsenism. Taken together, we conjectured that, in chicken jejunum, arsenic led to redistribution of trace elements, promoting apoptosis via regulating mitochondrial dynamics, leading to autophagy through PI3K/AKT/mTOR signal pathways.