Accumulation patterns and risk assessment of metals and metalloid in muscle and offal of free-range chickens, cattle and goat in Benin City, Nigeria

Markers for meat provenance and authenticity with an account of its defining factors and quality characteristics - a review

Provenance is becoming increasingly important in meat supply chains as it lends products higher perceived quality. However, its precise definition and interpretation along with its associated characteristics factors have remained somewhat elusive. This review meticulously defines meat provenance while dissecting the essential factors and associated quality attributes that constitute its essence and are subsequently employed to establish pertinent markers for provenance. Meat provenance emerges as a multi-dimensional construct stemming from the adept management of a constellation of factors relating to geographical origin, farm production system, traceability, and authenticity. Through intricate interactions, these factors unveil innate originality that not only forges a distinct reputation but also imparts a unique typicity to the meat product. Gaining insights into a meat product's provenance becomes attainable by scrutinizing its pertinent composition and organoleptic quality traits. Trace elements and stable isotopes stand out as provenance markers, forging a direct connection to both geographical origin and dietary sources. While somewhat less direct in linkage, other markers such as plant biomarkers, fatty acid composition, pH levels, flavour and aromatic compounds along with organoleptic characteristics contribute to the overall understanding of provenance. Additionally, the identification of animal species and breeds serves as key markers, particularly in the context of protected geographical indications. The study findings are useful for the various stakeholders of how the information for meat provenance can be linked with intrinsic and extrinsic factors for meat quality and protecting the integrity of the supply chain with special reference to traceability and authenticity. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Health effects of heavy metals in meat and poultry consumption in Noakhali, Bangladesh

This study examined the quantities of heavy metals (Cd, Cr, Pb, Ni, Fe, and Cu) in commercially available meat, poultry, and game products in Noakhali, Bangladesh, and their potential health effects, as heavy metal contamination poses a significant food safety risk to human health Atomic Absorption Spectrophotometry was used to analyze heavy metals, and the health risk assessment was based on Estimated Daily Intake (EDI), Targeted Hazard Quotient (THQ), Total THQ, and Total Carcinogenic Risk (TCR). Most samples exceeded Maximum Allowable Concentrations (MAC) for heavy metals. The EDI value of Cd, Pb, and Cr for duck liver, goat liver, and pigeon brain, were higher than the Maximum Tolerable Dietary Intake (MTDI). Children had 1.28 times higher HI values than an adult. The calculation of THQ of all elements in adults and children was in the order of Cu; Pb; Ni; Cr; Cd; and Fe. The calculated TTHQ values were in the range of 0.051 to 1.988 and 0.047 to 3.975 for adults and children, respectively. The TCR values for Cd in poultry liver, brain, and meat, Sonali chicken, cow, pigeon, duck, and goat liver were higher than the reference value for adults and children, suggesting a potential cancer risk. The average exposure to lead leads to an increase in blood pressure by 0.47 mmHg and a decrease in IQ score by 1.94 points. The present study reveals the need to determine strong relationships between heavy metal exposure and food supply.

Occurrence of microplastics in edible tissues of livestock (cow and sheep)

Plastic contamination is widely recognized as a major environmental concern due to the entry of small plastic particles into the food chain, thereby posing potential hazards to human health. However, the current understanding of microplastic (MP; < 5 mm) particles in livestock, which serve as an important food source, is limited. This study aims to investigate the concentration and characteristics of MPs in edible tissues of cow and sheep, namely liver, meat, and tripe, obtained from butcher shops in five areas of Bushehr port, Iran. The mean concentration of MPs in different tissues of cow and sheep were 0.14 and 0.13 items/g, respectively. Among the examined tissues, cow meat exhibited the highest concentration of MPs, with a concentration of 0.19 items/g. Nylon and fiber were identified as the predominant polymer types and shapes of MPs found in cow and sheep tissues, respectively. Furthermore, no statistically significant difference was observed in MP concentration across different tissues of cow and sheep. Significantly, this study highlights the elevated hazards associated with exposure to MPs through the consumption of edible cow and sheep tissues, particularly for children who consume meat. The results underscore the potential transfer of MPs from the environment to livestock bodies through their food, contamination during meat processing, and subsequent health hazards for consumers.

An Investigation of Heavy Metal Concentrations in the Sera of Cattle Grazed in Different Locations in the Kars Province of Türkiye

The aim of this study was to investigate the effects of exposure of cattle to low levels of environmental pollution on trace metal metabolism. The assessment of heavy metal concentrations in blood samples is essential to evaluate the potential effects of pollutants on cattle production and to measure the uptake of pollutants by animals. For this purpose, cattle raised in villages at varying distances to the center of the Kars province were sampled for blood, and heavy metal concentrations were measured in the extracted sera. In total 150 blood samples were collected from 4-to 5-year-old cattle from 15 regions. Sera were extracted from the blood samples from the selected foci and analyzed with an inductively coupled plasma-optical emission spectrometry (ICP-OES) device for essential (Co, Cr, Cu, Fe, Mn, Ni and Zn, Se, V) and non-essential (Pb, Cd and Hg, As, Al, Sn) heavy metals. Heavy metals were detected in the serum samples in the following order: Sn > Fe > Al > Zn > Cu > Pb > Cr > As > V > Ni > Mn > Hg. A confidence interval of 95% was used to evaluate all tests. Differences between the villages were insignificant for the Cu, Pb, Cd, Hg, Se, Al, Co concentrations (p > 0.05), whereas differences between the villages were significant for the Fe, As, Ni, Mn (p < 0.05), Zn, Cr (p < 0.01), V and Sn (p < 0.001) concentrations. The results of this study show that heavy metals detected in bovine sera from the sampling area do not exceed the maximum permissible limits, suggesting limited exposure to heavy metals and no associated health risk to animals in the region.

Heavy metal toxicity in poultry: a comprehensive review

Arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg) have been recognized as most toxic heavy metals that are continuously released into the environment, both from natural sources and from anthropogenic production of fertilizers, industrial activities, and waste disposal. Therefore, As, Cd, Hg, and Pb are found in increasing concentrations in bodies of water, fodder, feed, and in the tissues of livestock, including poultry, in the surroundings of industrial areas, leading to metabolic, structural, and functional abnormalities in various organs in all animals. In poultry, bioaccumulation of As, Pb, Cd, and Hg occurs in many organs (mainly in the kidneys, liver, reproductive organs, and lungs) as a result of continuous exposure to heavy metals. Consumption of Cd lowers the efficiency of feed conversion, egg production, and growth in poultry. Chronic exposure to As, Pb, Cd, and Hg at low doses can change the microscopic structure of tissues (mainly in the brain, liver, kidneys, and reproductive organs) as a result of the increased content of these heavy metals in these tissues. Histopathological changes occurring in the kidneys, liver, and reproductive organs are reflected in their negative impact on enzyme activity and serum biochemical parameters. Metal toxicity is determined by route of exposure, length of exposure, and absorbed dosage, whether chronic and acute. This review presents a discussion of bioaccumulation of As, Cd, Pb, and Hg in poultry and the associated histopathological changes and toxic concentrations in different tissues.

Health risk assessment of metals in chicken meat and liver in Egypt

This study aimed to evaluate the concentration of metals such as aluminum (Al), cadmium (Cd), lead (Pb), barium (Ba), bismuth (Bi), cobalt (Co), nickel (Ni), chromium (Cr), iron (Fe), copper (Cu), zinc (Zn), and selenium (Se) in 360 samples of poultry meat and liver from six brands (A, B, C, D, E, and F) in Assiut, Egypt; compare these concentrations with Egyptian and world permissible limits; and determine their safety for human consumption according to health risk assessment. Chest, thigh muscles, and liver were collected randomly from Assiut city markets, and the concentration of heavy metals was measured in the central laboratory of the faculty of agriculture at Assiut University using inductively coupled plasma mass spectrometry (ICP-MS). All the analyzed samples were positive for the tested metals and were far below the allowed maximum permissible limits except for Pb and Fe, which exceeded the Egyptian Organization for Standardization (EOS) permissible limits with 33% and 67%, respectively, as well as Pb and Cd, which exceeded FAO/WHO permissible limits with 94% and 17%, respectively. Health risk assessment revealed the safety and minimum health risk for human consumption of metal residues in poultry tissues and liver using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TR). Even though the THQ and HI values were significantly lower than 1.0 during our study, heavy metal monitoring in poultry products and byproducts is required for human security and safety.

Towards a Standardized Approach for the Geographical Traceability of Plant Foods Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Principal Component Analysis (PCA)

This paper presents a systematic literature review focused on the use of inductively coupled plasma mass spectrometry (ICP-MS) combined with PCA, a multivariate technique, for determining the geographical origin of plant foods. Recent studies selected and applied the ICP-MS analytical method and PCA in plant food geographical traceability. The collected results from many previous studies indicate that ICP-MS with PCA is a useful tool and is widely used for authenticating and certifying the geographic origin of plant food. The review encourages scientists and managers to discuss the possibility of introducing an international standard for plant food traceability using ICP-MS combined with PCA. The use of a standard method will reduce the time and cost of analysis and improve the efficiency of trade and circulation of goods. Furthermore, the main steps needed to establish the standard for this traceability method are reported, including the development of guidelines and quality control measures, which play a pivotal role in providing authentic product information through each stage of production, processing, and distribution for consumers and authority agencies. This might be the basis for establishing the standards for examination and controlling the quality of foods in the markets, ensuring safety for consumers.

The Distribution of Selected Toxic Elements in Sauced Chicken during Their Feeding, Processing, and Storage Stages

Sauced chicken is popular food worldwide. However, the elemental pollution of poultry industrialization has led to an increasing health risk concern. In this study, four typical toxic elements, including chromium (Cr), arsenic (As), lead (Pb), and cadmium (Cd), were selected and detected in whole industry chains of sauced chicken preparation by inductively coupled plasma-mass spectrometry. The detection method was optimized and verified with an average recovery of 93.96% to 107.0%. Cr has the highest proportion among the elements during the three stages, while the content of Cd was the least. In the feeding stages, elements were at the highest level in the starter broiler, and the grower broiler was considered to have a good metabolic capacity of them. In addition, the elements were mainly distributed in the chicken kidney, gizzard, liver, leg, wing, and lung. In the processing stage, the elements continued to accumulate from the scalding to the sterilization process. The elements were mainly distributed in the chicken wing, leg, head, and breast. In the storage stage, the elements almost kept constant in the polyamide and polyethylene packaging, while it showed irregular small-range fluctuations in the other two packages. This study provides beneficial references for the toxic element risk management in the whole industry chain.

Heavy Metals Levels in Soil, Water and Feed and Relation to Slaughtered Camels’ Tissues (Camelus dromedarius) from Five Districts in Saudi Arabia during Spring

Soil, water, and forage contaminated with toxic heavy metals such as Pb, Cd, and Co can affect the meat and liver quality of camels raised in this area which affect human health. This study aimed to determine the concentrations of Pb, Cd and Co in soil, water, feed and young camels’ carcass tissues (meat, liver, whole blood, rumen fluid and rumen tissue) from five districts in Saudi Arabia during the spring. All samples were wet-digested and analyzed by ICP-OES for heavy metals. In the liver, a significantly higher (p < 0.05) concentration of Pb and Co was observed in camels reared in the central and southern districts, while Cd was found significantly higher in the western and northern districts. The concentration of Pb, Cd and Co in meat of camels in the northern district was significantly higher (p < 0.05), and the meat of camels in the west had a higher (p < 0.05) concentration of Co. In addition, the Cd and Co concentrations in rumen fluid samples from camels in the eastern district were significantly higher than in the central district. A negative correlation between the concentration of Pb and Cd in rumen fluid and rumen tissue was reported. The accumulation of Cd, Pb, and Co in meat and liver was below the recommended maximum limit. Therefore, the harmful risk of human consumption of camel meat and liver is not possible.

Human health risk assessment of edible body parts of chicken through heavy metals and trace elements quantitative analysis

Food safety and security have now been regarded as a significant emerging area within the food supply chain leading to scientific and public health concerns in the global world. The poultry sector is a substantial threat to heavy metal intoxication for Bangladeshi people due to contaminated drinking water and feed sources, as well as the poultry sector's surrounding environment and soil. This study was carried out to ascertain the residual concentrations of heavy metals (Pb, Cd) and trace elements (Cr, Fe, Cu, and Zn) in various edible chicken body parts (breast, liver, gizzard, heart, kidney, and brain) to observe the quality of the consumed chickens and to assess public health risk. Atomic absorption spectrometry (AAS) was used to check the content of toxic heavy metals and trace elements in 108 samples of 18 broiler chickens collected from six different locations of Dhaka North City Corporation markets in Bangladesh. The measured concentrations (mg/kg fresh weight) ranged from 0.33±0.2 to 4.6±0.4, 0.004±0.0 to 0.125±0.2, 0.006±0.0 to 0.94±0.4, 4.05±4.2 to 92.31±48.8, 0.67±0.006 to 4.15±2.7, and 4.45±0.62 to 23.75±4.3, for Pb, Cd, Cr, Fe, Cu, and Zn respectively. Except for Pb and Cu most of the investigated heavy metals and trace element levels in chickens were lower than the maximum allowable concentration (MAC) set by FAO/WHO and other regulatory agencies., The estimated level of Pb was nearly six times higher in the chicken brain. The estimated daily intake (EDI) values for all the studied metals were below the preliminary tolerated daily intake (PTDI). The target hazard quotient (THQ) values of the broiler chicken meat samples varied for adults and children, and the range was found to be 0.037-0.073 for Pb, 0.007-0.01 for Cd, 0.0-0.08 for Cr, 0.002-0.004 for Fe, for 0.00-0.002 Cu, and 0.004-0.008 for Zn, not exceeding the maximum level of 1 according to USEPA. The calculated THQ and total target hazard quotient (TTHQ) values were measured at less than one, suggesting that the consumption of chicken meat has no carcinogenic danger to its consumers. The Target carcinogenic risks (TCRs) of Pb, Cd, Cr, and Cu were within acceptable limits. The TCR values for children were, to some extent, higher than that of adults, which proposes that regular monitoring of both harmful and essential elements in chicken samples is necessary to determine whether or not any possible health risk to consumers exists. In terms of health, this study demonstrated that consumers are chronically exposed to elemental contamination with carcinogenic and non-carcinogenic effects.

Possible health risk assessment for heavy metal concentrations in water, sediment, and fish species and Turkmen pregnant women's biomonitoring in Miankaleh Peninsula, Iran

This study investigated the human biomonitoring of heavy metals in the water, sediments, and tissues of mostly consumed fish species using Turkmen pregnant women's biomarkers in winter 2019, at the Miankaleh Peninsula, north of Iran. Metal concentrations were measured in various fish organs as well as pregnant women's blood, hair, and nail as biological indicators. For this purpose, a total of 20 water and sediment, 14 fish, and 16 human samples were collected. Inductively coupled plasma mass spectrometry (ICP-MS) was used to evaluate the concentration of Cr, Co, Cu, As, Hg, and Pb. Results showed metals with the highest concentrations as Cu and Cr in water (93.35 and 80.91 µg/l, respectively), Hg and Pb in sediment (7.40 µg/g for both), Cu and Pb in the liver (27.00 and 18.9 µg/g for C. carpio; 1414 and 31.7 µg/g for L. auratus), muscle (10.00 and 18.80 for C. carpio; 37.20 and 8.27 µg/g for L. auratus), and skin (26.40 and 9.90 for C. carpio; 10.80 and 11.74 µg/g for L. auratus). In addition, Cu, in pregnant women samples, had the highest values at 2.53 mg/l, 8.87, 36.46, and 29.04 µg/g for blood, hair, fingernail, and toenail, respectively. However, Co showed the lowest concentration in all studied samples. Fish liver and fingernail of pregnant women did reveal the highest heavy metal accumulation, whereas fish muscle and blood of pregnant women had the lowest accumulated heavy metals. The concentration of Hg in water, sediment, fish muscle, and women's blood and hair exceeded the limits suggested by various organizations. Therefore, this study highlighted that heavy metal concentration, in particular Hg, in water, sediments, and fish is a serious risk to the health of local inhabitants who rely on fisheries products and recommended that necessary information should be provided to warn Turkmen pregnant women in consumption of Hg-contaminated fish in this area.

Content of total aflatoxin, lead, and cadmium in the bovine meat and edible offal: study of their human dietary intake, health risk assessment, and molecular biomarkers

The objectives of the present study were first to determine the residual contents of total aflatoxins (AFTs), lead (Pb), and cadmium (Cd) in the edible tissues of the cattle reared in Al-Ahsa, Saudi Arabia. Al-Ahsa is the largest governorate in the Eastern Province of Saudi Arabia. The two main economic activities of Al-Ahsa are oil production (industrial) and agriculture. Besides, dietary intake and possible health risks for Saudi population were further calculated. In order to establish potential molecular biomarkers for xenobiotic exposure in cattle, the mRNA expression of xenobiotic-metabolizing enzymes (XMEs) including cytochrome P450 (CYP) 1A1, NAD(P)H dehydrogenase [quinone] 1 (NQO1), metallothionein (MT) 1A, and heat shock protein (HSP) 70 was investigated in the different tissues of the cattle. The tested XMEs were selected because of their specific roles in the metabolism and detoxification of AFTs, Pb, and Cd. The obtained results revealed that the liver had significantly the highest AFT content, while all examined muscle samples had no AFT residues. Consumption of the bovine liver and kidneys represents the highest source for the dietary exposure to total AFTs (0.05-0.98 μg/kg/day), Pb (0.06-0.19 mg/kg/day), and Cd (0.08-0.19 mg/kg/day) among the examined tissues. Therefore, excessive intake of such organs might pose a public health concern, particularly among children. Significant upregulation of mRNA expressions of CYP1A1, NQO1, MT1A, and HSP70 was observed in the different tissues of the cattle in comparison with the muscle. This upregulation had significant positive correlation with the accumulated AFTs, Pb, and Cd. This indicates the possible use of CYP1A1, NQO1, MT1A, and HSP70 as potential biomarkers for the exposure of the cattle to AFTs, Pb, and Cd.

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.

Seven potential sources of arsenic pollution in Latin America and their environmental and health impacts

This review presents a holistic overview of the occurrence, mobilization, and pathways of arsenic (As) from predominantly geogenic sources into different near-surface environmental compartments, together with the respective reported or potential impacts on human health in Latin America. The main sources and pathways of As pollution in this region include: (i) volcanism and geothermalism: (a) volcanic rocks, fluids (e.g., gases) and ash, including large-scale transport of the latter through different mechanisms, (b) geothermal fluids and their exploitation; (ii) natural lixiviation and accelerated mobilization from (mostly sulfidic) metal ore deposits by mining and related activities; (iii) coal deposits and their exploitation; (iv) hydrocarbon reservoirs and co-produced water during exploitation; (v) solute and sediment transport through rivers to the sea; (vi) atmospheric As (dust and aerosol); and (vii) As exposure through geophagy and involuntary ingestion. The two most important and well-recognized sources and mechanisms for As release into the Latin American population's environments are: (i) volcanism and geothermalism, and (ii) strongly accelerated As release from geogenic sources by mining and related activities. Several new analyses from As-endemic areas of Latin America emphasize that As-related mortality and morbidity continue to rise even after decadal efforts towards lowering As exposure. Several public health regulatory institutions have classified As and its compounds as carcinogenic chemicals, as As uptake can affect several organ systems, viz. dermal, gastrointestinal, peptic, neurological, respiratory, reproductive, following exposure. Accordingly, ingesting large amounts of As can damage the stomach, kidneys, liver, heart, and nervous system; and, in severe cases, may cause death. Moreover, breathing air with high As levels can cause lung damage, shortness of breath, chest pain, and cough. Further, As compounds, being corrosive, can also cause skin lesions or damage eyes, and long-term exposure to As can lead to cancer development in several organs.

Influences of lead exposure on its accumulation in organs, meat, eggs and bone during laying period of hens

Elevating levels of environmental lead (Pb) results in serious hazards to health of animals and human beings. In this study, daily diet with three different levels of Pb (Pb nitrate at doses of 1, 10, and 100 mg/kg body weight) were fed to ISA Brown layers. It showed that the kidney and liver have the relatively high Pb concentration (2.34 and 0.51 ppm) after culture, while the meat has the Pb concentration as low as 0.07 ppm (lower than the standard of Codex Alimentarius). It was also confirmed that egg laying worked as a potential pathway for hens to excrete Pb as Pb concentrations in eggshell and yolk increased from 0.10 to 3.11 ppm. However, the Pb concentration in egg white remains at a safe level (<0.10 ppm). Furthermore, even the intake of low dose Pb can cause a decline of bone mineral density and bone strength. Raman spot and mapping analysis indicated that carotenoids content in humerus from the hens of high dose group increased significantly, which hence can be applied as an indicator for resist stress. The degradation of bone quality will further damage the health of laying hens. Therefore, Pb exposure not only toxifies organs and reduces physiological features (e.g., body weight and laying rate) instantly, but also hurts poultry via degrading bone quality in long term. Additionally, the probability of excessive Pb in poultry meat is less than those of viscera and eggs, indicating its low risk to food safety.

Health risk assessment of Cd, Cr, Cu, Ni and Pb in the muscle, liver and gizzard of hen's marketed in East of Iran

The present study aimed to determine the average concentration of some metals, including cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni) and lead (Pb) in the chicken, hen's liver, and gizzard in the east of Iran. Estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI) and carcinogenic risk (CR) were calculated. In this cross-sectional study, fifty one samples including chicken, hen's liver and gizzard were obtained from Birjand, Iran. Measurement of Cd, Cr, Cu, Ni, and Pb was carried out by using an Inductively Coupled Plasma-Optic Emission Spectroscopy (ICP-OES). All of the measured metals were detected in 100 % of the samples. The metals had a different distribution pattern. The highest concentration of Cd and Cu was in the liver samples while the Cr and Ni had the highest levels in the chicken. Pb concentration was at the highest level in the gizzard. The least amount of Cr, Ni, and Pb was found in the liver while Cu had the least content in the muscle. EDI had an acceptable level, but the highest daily intake of all studied metals was through muscle. Cr had the highest THQ and it was more than one in the meat. HI in chicken was more than one. Liver and gizzard of hens had a neglectable HI. CR was neglectable in the case of both Cd and Pb, but it was considerable for Cr and Ni. The consumption of chicken in both adults and children may pose a significant health risk for consumers.

Determination of heavy metals and selenium content in chicken liver at Erbil city, Iraq

Heavy metal contamination of poultry meat is a critical issue for human health due to associated risks of cytotoxicity and systemic pathologies after ingestion of such metals. A total of twenty chicken liver samples were collected from markets of Erbil city and analyzed for ten heavy metals contents by Inductively Coupled Plasma Optical Emission Spectrometry. The targeted metals were cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), mercury (Hg), zinc (Zn) and selenium (Se). The average concentrations (mg/kg) of targeted trace elements were 0.06±0.027, 0.06±0.05, 2.05±0.34, 1.85±0.47, 0.15±0.17, and 33.53±5.24 for Co, Cr, Cu, Mn, Ni, and Zn respectively. Copper (Cu) levels significantly exceeded the maximum permissible limit of WHO. Moreover, the average concentrations of toxic heavy metals and selenium were 0.07±0.037, 0.278±0.10, 0.11±0.083, and 2.01±0.454 mg/kg for Cd, Pb, Hg, and Se respectively. Hg and Pb levels exceeded the permissible limits of WHO. Higher levels of Cu and Hg in poultry may pose a serious threat to consumers which demand countermeasures and precautions to be taken. Iraqi Standards Authority and relevant official institutions are strongly recommended to regulate safe disposal of heavy metal waste in the environment to reduce animal exposure to such metals.

Manganese Chloride Exposure Causes Disorder of Energy Metabolism and Induces Oxidative Stress and Autophagy in Chicken Liver

Manganese (Mn) pollution is an important environmental problem because of the potential toxicity to human and animal health. However, the effects of Mn on energy metabolism and autophagy are not clear. Consequently, we examined the effects of excessive and chronic exposure to Mn on liver function, oxidative stress, respiratory chain complex activity, and autophagy in chicken liver. Our results indicated that the accumulation of Mn in the liver and levels of AST and ALT in the serum of the Mn-exposed group were significantly higher (P < 0.05) than those in the control group at 90 days; the activities of GSH-Px, SOD, CAT, Na⁺-K⁺-ATPase, Mg²⁺-ATPase, Ca²⁺-ATPase, and respiratory chain complexes (I, II, III) in the Mn-exposed group were significantly decreased (P < 0.05) compared to the control group. However, the MDA content, NO content, iNOS activity, mRNA and protein levels of iNOS, and autophagy-related genes in the Mn-exposed group were significantly increased (P < 0.05) compared to the control group. In contrast, the mRNA level and protein expression of mTOR were significantly decreased (P < 0.05) compared to the control group. Furthermore, the characteristic autophagic vacuolar organelles were observed in the Mn-exposed group. These results suggested that excess Mn exposure can cause a disorder of energy metabolism by mitochondrial injury and induce oxidative stress and autophagy, which eventually lead to liver damage.

Toxic effects of heavy metals Pb and Cd on mulberry (Morus alba L.) seedling leaves: Photosynthetic function and reactive oxygen species (ROS) metabolism responses

To explore the mechanism of how lead (Pb) and cadmium (Cd) stress affects photosynthesis of mulberry (Morus alba L.), we looked at the effects of different concentrations of Pb and Cd stress (at 100 and 200 μmol L^-1), which are two heavy metal elements, on leaf chlorophyll (Chl), photosynthesis gas exchange, Chl fluorescence, and reactive oxygen species (ROS) metabolism in mulberry leaves. The results showed that higher concentrations of Pb and Cd reduced leaf Chl content, especially in Chl a where content was more sensitive than in Chl b. Under Pb and Cd stress, the photosynthetic carbon assimilation capacity of mulberry leaves was reduced, which was a consequence of combined limitations of stomatal and non-stomatal factors. The main non-stomatal factors were decreased photosystem II (PSII) and photosystem I (PSI) activity and carboxylation efficiency (CE). Damage to the donor side of the PSII reaction center was greater than the acceptor side. After being treated with 100 μmol L^-1 of Pb and Cd, mulberry leaves continued to be able to dissipate excess excitation energy by starting non-photochemical quenching (NPQ), but when Pb and Cd concentrations were increased to 200 μmol L^-1, the protection mechanism that depends on NPQ was impaired. Excessive excitation energy from chloroplasts promoted a great increase of ROS, such as superoxide anion (O₂^•-) and H₂O₂. Moreover, under high Pb and Cd stress, superoxide dismutase (SOD) and ascorbate peroxidase (APX) were also inhibited to some extent, and excessive ROS also resulted in a significantly higher degree of oxidative damage. Compared with Cd, the effect of Pb stress at the same concentration level displayed a significantly lower impact on Chl content, photosynthetic carbon assimilation, and stomatal conductance. Meanwhile, Pb stress mainly damaged activity of the oxygen-evolving complex (OEC) located on PSII donor side, but it reduced the electronic pressure on the PSII acceptor side and PSI. Furthermore, under Pb stress, the NPQ, SOD, and APX activity were all significantly higher than those under Cd stress. Thus under Pb stress, the degree of photoinhibition and oxidative damage of PSII and PSI in mulberry leaves were significantly lower than under Cd stress.

Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria

Nigeria receives copious annual precipitation to nourish its forests and agriculture, it has an extensive river drainage system, and it possesses valuable mineral deposits that stimulate both commercial and artisan mining activities. The combination of these features complicates Nigeria's efforts to produce adequate amounts of healthy foods to support its population. Toxic heavy metals like lead, cadmium, and mercury, and toxic metalloids such as arsenic, are also present in its mineral deposits and they migrate gradually into the soil and water of Nigeria by natural means. However, mining activities can liberate higher levels of toxic metals, which adversely affect Nigerian ecosystems and its food chains. Thus, environmental pollution due to anthropogenic activities is a major public health concern in Nigeria. This review covers the importance of native Nigerian and African wild and cultivated plants along with livestock and wild animals as sentinel species to evaluate heavy metals as environmental stressors and the use of sentinel species for food safety monitoring and for predicting potential risks to human health.

Estimation of cadmium content in Egyptian foodstuffs: health risk assessment, biological responses of human HepG2 cells to food-relevant concentrations of cadmium, and protection trials using rosmarinic and ascorbic acids

Cadmium (Cd) is an environmental pollutant that can get entry into human body via ingestion of contaminated foods causing multiple organ damage. This study aimed at monitoring Cd residues in 20 foodstuffs of animal origin that are commonly consumed in Egypt. Health risk assessment was conducted via calculation of Cd dietary intakes and non-carcinogenic target hazard quotient. An in vitro approach was performed to investigate the constitutive effects of Cd on human hepatoma (HepG2) cells under food-relevant concentrations. Trials to reduce Cd-induced adverse effects on HepG2 cells were done using rosmarinic (RMA) and ascorbic acids (ASA). The achieved results indicated contamination of the tested foodstuffs with Cd at high levels with potential human health hazards. Cd at food-relevant concentrations caused significant cytotoxicity to HepG2 cells. This may be attributed to induction of oxidative stress and inflammation, as indicated by the overexpression of stress and inflammatory markers. At the same time, Cd downregulated xenobiotic transporters and upregulated the proliferation factors. Co-exposure of HepG2 cells to Cd and micronutrients such as RMA and ASA led to recovery of cells from the oxidative damage, and subsequently cell viability was strongly improved. RMA and ASA ameliorated the biological responses of HepG2 cells to Cd exposure.

Coexistence and association between heavy metals, tetracycline and corresponding resistance genes in vermicomposts originating from different substrates

Coexistence of antibiotics/heavy metals and the overexpression of resistance genes in the vermicompost has become an emerging environmental issue. Little is known about the interaction and correlation between chemical pollutants and biological macromolecular compounds. In this study, three typical vermicompost samples were selected from the Yangtze River Delta region in China to investigate the antibiotic, heavy metal and corresponding antibiotic resistance genes (ARGs) and heavy metal resistance genes (HRGs). The results indicated the prevalence of tetracycline (TC), copper (Cu), zinc (Zn), cadmium (Cd), corresponding TC-resistance genes (tetA, tetC, tetW, tetM, tetO, and tetS) and HRGs (copA, pcoA, cusA, czcA, czcB, and czcR) in the three vermicompost samples. In addition, the ARG level was positively associated with the water-soluble TC fraction in the vermicompost, and it was same between the HRG abundance and exchangeable heavy metal content (p < 0.05). Moreover, a positive correlation was found between ARG and HRG abundance in the vermicompost samples, suggesting a close regulation mechanism involving the expression of both genes. The result obtained here could provide new insight into the controlling risk of heavy metals, TC, and relevant resistance genes mixed contamination in the vermicompost.

Antioxidant systems responses and the compatible solutes as contributing factors to lead accumulation and tolerance in Lathyrus sativus inoculated by plant growth promoting rhizobacteria

Short-term lead (Pb) uptake by plants is important to better understand the mechanisms of metal uptake, plant tolerance and detoxification strategy. Thus we examined the response of Lathyrus sativus to 1 mM Pb application in hydroponic sorption kinetics at 24, 48 and 72 h, and we investigated the contribution of two inocula I1 (R. leguminosarum (M5) + B. simplex + Luteibacter sp + Variovorax sp) and I5 (R. leguminosarum (M5) + P. fluorescens (K23) + Luteibacter sp + Variovorax sp) in plant mechanisms responses. Pb application induced its immediate uptake by L. sativus with highest concentrations, which increased gradually mostly for inoculated plants. The control plant shoots accumulated the highest concentration of lead at 24 h. However, at 48 and 72 h this potential uptake was significantly enhanced in plants inoculated with I5. Moreover, inoculation increased significantly root Pb-uptake with the maximum reached at 72 h. We observed a progressive decline in chlorophyll contents after Pb exposure in control plants that was higher than in PGPR-treated plants and the greatest improvement (152%) was recorded in I5 inoculated leaves. The PGPR also promoted significant elevation in the carotenoid content with the highest increases (188%) in plants inoculated with I5 at 72 h. Data illustrated remarkable augmentation in malondialdehyde, ion leakage level and decrease in membrane stability. Whereas, inoculation enhanced significantly cellular membrane integrity through increases in membrane stability index as compared to the control plants. In response to Pb, proline biosynthesis, as well as total soluble sugars concentration, immediately increased and the stimulatory effect was more pronounced in inoculated plants at 72 h. Lead considerably altered the activities of SOD, GPOX, CAT and APX enzymes in leaves and roots in a time- and inoculation- dependent manner. It is concluded that antioxidant enzymes, carotenoids, soluble sugars and proline were involved in the main defense mechanism and tolerance of Lathyrus sativus to Pb oxidative stress, as well lead accumulation, and are likely to operate in combination.

Potential health risk consequences of heavy metal concentrations in surface water, shrimp (Macrobrachium macrobrachion) and fish (Brycinus longipinnis) from Benin River, Nigeria

Health risk consequences of consumption of heavy metal-contaminated water, shrimp (Macrobrachium macrobrachion) and fish (Brycinus longipinnis) from Benin River in Nigeria were evaluated. Three stations around Koko Community (Abialegbe, Ebenco/Optima and Total Facility) with known anthropogenic activities (industrial and petrochemical installations and loading) were studied. Samples of surface water, shrimp and fish were collected and analyzed using Buck scientific atomic absorption spectrophotometer, model 210VGP. Health risk indices were reported as Estimated Daily Intake (EDI), Target Hazard Quotient (THQ) and Total Target Hazard Quotient (TTHQ). Eight heavy metals were analyzed in water, shrimp and fish. Nickel (Ni) was observed to be the most dominant heavy metal in water, while Iron (Fe) was the most dominant in shrimp and fish. Heavy metal levels in water were below recommended limits set by World Health Organization (WHO) and Standard Organization of Nigeria (SON) except for cadmium (Cd), nickel (Ni) and lead (Pb). Assessment of non-carcinogenic health risk by target hazard quotient (THQ) indicated that THQ estimated for heavy metals in water (dermal exposure) and shrimp were below the threshold value of 1. However, THQ for heavy metals in water (oral exposure) and consumption of fish were above threshold value of 1 indicating potential health risk. Total Target Hazard Quotient (TTHQ) estimated for heavy metals in water (oral exposure) and consumption of fish were above 1 indicating potential non-carcinogenic health risk to consumers. The continuous monitoring of heavy metals in Benin River is of necessity in order to ensure the safety of aquatic organisms and humans who rely heavily on aquatic resources.

Metal contamination in quail meat: residues, sources, molecular biomarkers, and human health risk assessment

Quail meat is an emerging source of high-quality animal protein. Quails are exposed to a wide range of xenobiotics such as heavy metals. In this study, residual concentrations of four toxic metals, of significant public health importance, including cadmium (Cd), lead (Pb), arsenic (As), and nickel (Ni), were determined in edible tissues of quails. In addition, metal loads were measured in water, feed, and litter samples collected from same quail farms as possible sources for quail exposure to heavy metals. The possible use of metallothionein (MT) and heat shock protein 70 (Hsp70) as molecular biomarkers of exposure to heavy metals was further investigated. Furthermore, the dietary intake and the potential risk assessment of the examined heavy metals among children and adults were calculated. The edible tissues of quails contained high concentrations of four heavy metals (contents (ppm/ww) ranging from 0.02 to 0.32 in Cd, 0.05 to 1.96 in Pb, 0.002 to 0.32 in As, and 1.17 to 3.94 in Ni), which corresponded to the high contents of these metals in the feeds, water, and litter. MT and Hsp70 mRNA expressions showed positive correlations with the concentrations of heavy metals in tissues indicating the possibility to use these proteins as biomarkers for quail's exposure to toxic metals. Dietary intake of quail meat and risk assessment revealed potential risks especially for children after prolonged exposure to the examined metals. Thus, legislations should be established and continuous screening of metal residues should be adopted in order to reduce the toxic metal concentrations in feeds and drinking water for quails. Reduction of exposure to heavy metals subsequently would lead to minimization of exposure of such toxicants through consumption of quail meat.

Lead and cadmium excretion in feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia

Lead (Pb) and cadmium (Cd) are toxic metals that exist ubiquitously in the environment. Children in polluted areas are particularly vulnerable to metal exposure, where clinical signs and symptoms could be nonspecific. Absorbed metals are excreted primarily in urine and reflect exposure from all sources. We analyzed Pb and Cd concentrations in blood, feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia, to determine concurrent childhood exposure to the metals. Moreover, the study determined the Pb and Cd relationships among urine, feces and blood as well as accessed the potential of urine and fecal analysis for biomonitoring of Pb and Cd exposure in children. Fecal Pb (up to 2252 mg/kg, dry weight) and urine Pb (up to 2914 μg/L) were extremely high. Concentrations of Cd in blood (Cd-B) of up to 7.7 μg/L, fecal (up to 4.49 mg/kg, dry weight) and urine (up to 18.1 μg/L) samples were elevated. metal levels were higher in younger children (0-3 years old) than older children (4-7). Positive correlations were recorded for Pb and Cd among blood, urine and fecal samples whereas negative correlations were recorded with age. These findings indicate children are exposed to both metals at their current home environment. Moreover, urine and feces could be useful for biomonitoring of metals due to their strong relationships with blood levels. There is need to conduct a clinical evaluation of the affected children to fully appreciate the health impact of these metal exposure.