Public health risk of trace metals in fresh chicken meat products on the food markets of a major production region in southern China

Assessment of potentially toxic element contents in chickens and poultry feeds from Bangladesh markets: Implications for human health risk

Chicken (Gallus domesticus) is a significant source of animal protein for the people of Bangladesh. However, anthropogenic activity may contaminate chicken meat with potentially toxic elements (PTEs) despite the nutritional benefits. Current work aims to determine the accumulated content of PTEs (Pb, Cd, Cr, As, and Hg) in chickens and poultry feeds commercially sold in Bangladesh markets and compare with WHO, FAO, EU, EC, FSANZ standards. Three different chicken varieties, native (local variety, freehand raised), poultry (raised for meat only), and layer chicken (commercially raised for eggs and later used for meat), were investigated, and commercial poultry feeds were used to raise the latter two varieties. The Pb, Cd, Cr, As, and Hg contents (mg kg-1 fresh weight (f.w.) were 0.481-1.067, 0.025-0.118, 0.069-0.319, 0.007-0.071, 0.002-0.019, respectively. In addition, associated health risks due to the PTEs in different varieties of chicken organs, e.g., meat, liver, and kidney, were evaluated. The study suggests that the poultry feeds should be carefully monitored regarding PTEs content to avoid potential human health risks due to chicken consumption in Bangladesh.

Concentrations, Sources, and Health Risk of Heavy Metals in Edible Parts of Broilers from Northeast of Algeria

Heavy metals contamination of poultry products is a major concern for public health. This study aimed to determine the concentration of mercury (Hg), lead (Pb), and iron (Fe) in the edible parts of broilers, as well as in feed, drinking water, and litter as sources of contamination and to assess their possible human health risk in the province of Jijel (Northeast Algeria). The range of Hg, Pb, and Fe in edible parts were 0.004-0.007, 0.185-0.480, and 28.536-88.306 mg/kg, respectively, and the difference in content was only significant (p < 0.05) for lead. Breast and thigh samples had Pb concentrations above the maximum limit. Spearman coefficient analysis revealed that most correlations were positive between metals detected in feed, water, and litter and those in the edible parts of broilers. But most of them were insignificant (p > 0.05). The estimated daily intake (EDI) values of examined metal exceeded the tolerable daily intake (PTDI). The target hazard quotients (THQ) and hazard index (HI) of all metals were lower than 1, suggesting no significant carcinogenic risks. The calculated incremental lifetime cancer risk (ILCR) of Pb was higher than 10-4 for men, women, and children, indicating the presence of carcinogenic risk. Considering the wide consumption of broiler meat, regular national monitoring of heavy metals in the broiler production chain is recommended to protect population health.

Oxidative stress response in avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) leads to significant economic losses in the poultry industry worldwide and restricts the development of the poultry industry. Oxidative stress, through the production of reactive oxygen species (ROS), damage iron‑sulfur (FeS) clusters, cysteine and methionine protein residues, and DNA, and then result in bacterial cells death. APEC has evolved a series of regulation systems to sense and quickly and appropriately respond to oxidative stress. Quorum sensing (QS), second messenger (SM), transcription factors (TFs), small regulatory RNAs (sRNAs), and two-component system (TCS) are important regulation systems ubiquitous in bacteria. It is of great significance to control APEC infection through investigating the molecular regulation mechanism on APEC adapting to oxidative stress. However, how the cross-talk among these regulation systems co-regulates transcription of oxidative stress-response genes in APEC has not been reported. This review suggests exploring connector proteins that co-regulate these regulation systems that co-activate transcription of oxidative stress-response genes to disrupt bacterial antioxidative defense mechanism in APEC, and then using these connector proteins as drug targets to control APEC infection. This review might contribute to illustrating the functional mechanism of APEC adapting to oxidative stress and exploring potential drug targets for the prevention and treatment of APEC infection.

Risk assessment and origin of metals in chicken meat and its organs from a commercial poultry farm in Akwa Ibom state, Nigeria

Contamination of chicken with metals is on the increase, despite its known attendant health risks to human consumers. The study aimed to evaluate the concentration of some metals in various organs of chicken, their sources, and the health risks they pose to human consumers. Samples of liver, meat, gizzard, borehole water, soil, diets, and droppings were investigated for the presence of some metals (Cr, Co, Mn, Zn, Al, As, Cd, Ni, and Hg), and their sources using principal component analysis (PCA). In addition, health risk assessment was manually computed using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and carcinogenic risk (CR) parameters. Cr, Mn, Co, and Zn accumulated more in the liver, while Cd and Ni were only observed in the gizzard. The starter diet recorded higher levels of all the metals compared to the grower and finisher diets except for As. All the metals were detected in the poultry surrounding soil and the drinking water of the birds except for Hg. Furthermore, PCA implicated the soil, water, and diets of the birds as the sources of these metals. The THQ, HI, and CR due to the dietary intake of the gizzard indicate a risk of cancer in children and adults. There is a need to ensure that the identified sources of these metals (soil, water, and diets) are routinely monitored to ensure compliance with safety guidelines.

Quantification of toxic metals in chicken egg and chicken feed via SOM-artificial neural network

Poultry products such as meat and eggs are rich sources of proteins, vitamins, and minerals. It is a good indicator of healthy food. Keeping in view, the present study is designed to evaluate the prevalence of toxic heavy metals (lead, nickel, cadmium, and chromium) in chicken eggs and feed. For this purpose, five samples of egg and feed were collected from five different commercial markets in Skardu City. Each sample was prepared using the wet digestion method and analyzed using a flame atomic absorption spectrophotometer. The results showed that lead, nickel, and chromium were present in varying amounts in the feed and egg, with nickel being the most concentrated metal, followed by lead and chromium in egg samples, while the feed samples showed the highest concentration of chromium followed by lead and nickel. However, concentrations of selected heavy metals except cadmium were all above the permissible limit of the World Health Organization. The self-organizing map-artificial neural network is employed for the identification of patterns of heavy metals in chicken feed and egg samples. The lower left neurons of the maps showed higher heavy metal concentrations found in samples taken from Bazar, whereas the rest of the samples showed varied concentrations. A comparison of feed and egg concentrations showed that nickel concentration was lower in feed samples than in egg samples. The lead concentration decreased in eggs except in the Krasmathang feed sample. Chromium concentration presented a negative correlation due to the extremely high concentration found in the Bazar feed sample.

Elemental Profile in Chicken Egg Components and Associated Human Health Risk Assessment

Egg is a food product of high nutritional quality, extensively consumed worldwide. The objectives of this study were the determination of the elemental profile in eggs (egg white, yolk, and eggshell), the estimation of the non-carcinogenic health risk associated with the presence of heavy metals in investigated egg samples, and the development of statistical models to identify the best predictors for the differentiation of egg components. The assessments were carried out in a total set of 210 samples, comprising home-produced and commercial eggs, using inductively coupled plasma mass spectrometry. The results suggested measurable differences amongst hen eggs coming from different husbandry systems. The statistical models employed in this study identified several elemental markers that can be used for discriminating between market and local producer samples. The non-carcinogenic risk related to the consumption of the analyzed egg samples was generally in the safe range for the consumers, below the maximum permitted levels set by Romanian and European legislation. Food contamination is a public health problem worldwide, and the risk associated with exposure to trace metals from food products has aroused widespread concern in human health, so assessing the heavy metal content in food products is mandatory to evaluate the health risk.

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.

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.

Comparison of composting factors, heavy metal immobilization, and microbial activity after biochar or lime application in straw-manure composting

Composting is an efficient way of disposing agricultural solid wastes as well as passivating heavy metals (HMs). Herein, equivalent (3%) biochar (BC) or lime (LM) were applied in rice straw and swine manure composting, with no additives applied as control group (CK). The results indicated that both the additives increased NO₃^--N content, organic matter degradation, humus formation, and HM immobilization in composting, and the overall improvement of lime was more significant. In addition, the additives optimized the bacterial community of compost, especially for thermophilic and mature phase. Lime stimulated the growth of Bacillus, Peptostreptococcus, Clostridium, Turicibacter, Clostridiaceae and Pseudomonas, which functioned well in HM passivation via biosorption, bioleaching, or promoting HM-humus formation by secreting hydrolases. Lime (3%) as additive is recommended in swine manure composting to promote composting maturity and reduce HM risk. The study present theoretical guidance in improving composting products quality for civil and industrial composting.

Highly regenerative, fast colorimetric response for organo-toxin and oxo-anions in an aqueous medium using a discrete luminescent Cd(II) complex in a heterogeneous manner with theoretical revelation

The highly luminescent complex [CdQ₂(H₂O)₂] (1) shows ultra-selectivity and high sensitivity to the explosive organo-toxin trinitrophenol (TNP). This detection is extremely fast with a high quenching constant (5.3 × 10⁴ M^-1) and a very low limit of detection (LOD) of 137 nM/59 ppb. This motivated us to detect the lethal carcinogenic arsenical drug roxarsone (ROX), which is reported here for the first time. The quenching constant and LOD for ROX using 1 were found to be 4.9 × 10⁴ M^-1 and 86 nM (or 37 ppb), respectively. Moreover, the probe also recognizes three lethal toxic oxo-anions (MnO₄^-, Cr₂O₇^2- and CrO₄^2-) with outstanding quenching constant (2.2 × 10⁴ M^-1, 1.4 × 10⁴ M^-1 and 1.1 × 10⁴ M^-1) and very low LODs (141 nM/61 ppb, 178 nM/78 ppb and 219 nM/95 ppb). Compared to the previously reported homogeneous sensing nature of the discrete complexes, our complex showed the detection of toxic pollutants in a heterogeneous manner, which results in high recyclability and hence multi-cycle sensing capability. Interestingly, 1 shows the possibility for real-time monitoring through naked eye detection by visible colorimetric changes in solid, solution and strip paper methods, i.e., triphasic detection ability. In addition, the sensor also exhibited the cross-sensing ability for these pollutants. The experimental sensing mechanism is strongly supported by the exhaustive theoretical investigation. Based on the fluorescence signal shown by each analyte, an integrated AND-OR logic gate is constructed. Furthermore, the sensing ability of 1 remains intact towards the detection of versatile real field samples including lethal carcinogenic arsenical drug roxarsone in the real food sample.

Distribution and safety assessment of heavy metals in fresh meat from Zhejiang, China

There are increasing concerns on heavy metals in animal derived foods. We analyzed the levels of As, Cd, Cr, Cu, Hg, Ni, and Pb in 1066 fresh meat samples including pork, beef, mutton, chicken and duck from Zhejiang province, southeast China. The average levels of As, Cd, Cr, Cu, Hg, Ni, and Pb were 0.018, 0.002, 0.061, 0.801, 0.0038, 0.055, and 0.029 mg/kg wet weight respectively. There are significant positive correlations among Cd, Hg and Pb (P < 0.05) and negative correlations for Cu–Pb or Cu–Cd (P < 0.05). The exposure assessment showed that the health risk to humans by consuming these meat products was relatively low. However, regular monitoring of heavy metals in meat products is still recommended considering their intensive industrial activities.

Bioaccumulation and transfer of zinc in soil plant and animal system: a health risk assessment for the grazing animals

Heavy metals pollution has thorough worldwide apprehensions due to the instantaneous growth of industries. Farming regions are irrigated mainly with wastewater which contains both municipal and industrial emancipations. Keeping in view the above scenario, a study was designed in which three sites irrigated with ground, canal, and municipal wastewater in the District Jhang were selected to determine the zinc accumulation and its transfer in the soil, plant, and animal food chain. Zinc concentration was ranged as 18.85-35.59mg/kg in the soil, 26.42-42.67 mg/kg in the forage, and 0.982-2.85mg/kg in the animal samples. Investigated zinc concentration in soil and forages was found to be within the recommended WHO/FAO limits, but blood samples exceed the standards of NRC (2007). The maximum level of pollution load index (0.427-0.805mg/kg) and enrichment factor (0.373-0.894 mg/kg) for zinc was noticed upon wastewater irrigation. Daily intake (0.039 to 0.082 mg/kg/day) and health risk index (0.130 to 0.275 mg/kg/day) of zinc metal was higher in the buffaloes that feed on wastewater-irrigated forages. Bio-concentration factor (0.840 to 2.01mg/kg) for soil-forage was >1 which represents that these plants accumulated the zinc concentration into their tissues and raised health issues in grazing animals on consumption of wastewater-contaminated forages. As animal-derived products are part of human food, then zinc toxicity prevailed in livestock tissues ultimately affects the human food chain. Overall, findings of this study concluded that animal herds should be monitored periodically to devise preventive measures regarding the toxic level of heavy metals availability to livestock.

Arsenic and toxic metals in meat and fish consumed in Niger delta, Nigeria: Employing the margin of exposure approach in human health risk assessment

This study provides information on the health risk of As, Cd, Hg, Pb and V exposure from Nigerian foods consumption (fish, cow, goat and chicken meat) in different age-groups (children, adolescent, adult, senior) and six areas of Niger Delta, Nigeria (Choba, Khana, Eleme, TransAmadi, Uyo, and Yenogoa). The health risk assessment was performed by estimating the weekly or monthly intake of metals from foods and Margin of Exposure (MOE) approach by using established benchmark dose levels (BMDLs). Regarding As, cow and chicken meat products contributed to As exposure intake especially in children resulting in values higher than BMDL_0.1 for cancer risk in TransAmadi and Uyo areas. Cadmium exposure was due to cow, chicken and goat meat ingestion mostly in adolescent above the tolerable monthly intake limit in TransAmadi and Uyo areas. Concerning Hg and V, the exposure from Nigerian food did not constitute a potential health hazard. Lead exposure in children were above or close to BMDL_0.1 for developmental neurotoxicity by ingestion of cow and goat meat in all the Nigerian areas. In adult and senior the Pb dietary exposure were above the BMDL₁₀ providing a low to negligible risk for kidney effects. The potential concern for health effects in Niger Delta population needs further efforts to decrease As, Cd and Pb dietary exposure especially for children and adolescent, who are more vulnerable to adverse life events.

Impact of Dietary Humic Substances Supplementation on Selected Minerals in Muscles of Broiler Chickens

In this study, we assessed the effect of humic substances on the changes of some mineral (Ca, Mg, Cu and Zn) content in the thigh and breast muscle of broilers. Group 1 (G1) was supplemented with 0.7 % Humac Natur Mycosorb (HNMy), and G2 with 0.3 % HNMy. The control group (GC) received a basal diet without any supplements. In the breast muscle of broilers from the group G1 we found a statistically significantly higher (P < 0.05) Ca content and significantly reduced (P < 0.05) in the thigh muscle Ca content from the group G2 compared to the control group (GC). A statistically significant increase in Mg content (P < 0.05) was analyzed in breast muscles in the group G1 and also significant reduction (P ≤ 0.01) in Cu in the breast and thigh muscles was found in the group G1 and in the breast muscle from the group G2 compared to the GC. Significantly lower content of Zn (P ≤ 0.05) was found in the breast and thigh muscles of broilers in the group G2 and strong positive correlation (r = 0.9093) were observed between Ca in breast muscle from the group G2 and Ca in thigh muscle from the control group. A negative correlation (r = –0.7656) was shown for Mg between thigh muscle from the group G2 and Ca in thigh muscle from the GC. A strong negative correlation was confirmed (r = –0.9221) for Zn content in breast muscles between groups G2 and G1. The high positive correlation for Zn was occurred between breast muscle from the control group and thigh muscle from the group G1 (r = 0.9786).

Probabilistic health risk assessment of toxic metals in chickens from the largest production areas of Dhaka, Bangladesh

Chicken is one of the major protein sources and more affordable for the population of Bangladesh. Its quality monitoring is of high priority for food safety and public health risk assessment. This study determined metals (Fe, Cu, Zn, As, Ni, Cr, Sr, Hg, and Pb) in chickens from different farms of a high production area of Dhaka, Bangladesh, using an energy-dispersive X-ray fluorescence spectrometer to calculate the health risk through chickens consumption. In most cases, the toxic metals (As, Ni, Cr, Hg, and Pb) showed very high concentrations in different parts of chickens, especially livers that contained several times higher concentrations than the maximum allowable concentration (MAC). Analytical results showed some feed and water contain high concentrations of As and Cr that might be bioaccumulated in chicken. The estimated daily intake (EDI) for all metals was below the provisional tolerable daily intake (PTDI) values except As and Fe in few farms. Target hazard quotients (THQs) for most metals were less than 1 but THQs of As and Cr of few farms were higher than 1, indicating that the consumer would possess As- and Cr-based health hazards. Total target hazard quotient (TTHQ) of 42% for composite and 36% for body parts samples were > 1, suggesting potential health risk. The probabilistic risk and individual samples cancer risk (TR) were exceeded the acceptable level (10^-4) for As and 75% of composite and 58% of body parts of chicken showed acceptable limit (10^-6 to 10^-4) for Pb, indicating that the peoples might be exposed to lifetime cancer risk in the long run.

Health Risk Assessment of Heavy Metal Accumulation in Broiler Chickens and Heavy Metal Removal in Drinking Water using Moringa Oleifera Seeds in Lomé, Togo

BACKGROUND

Heavy metals are persistent in the environment and can cause bioaccumulation in the food chain. Drinking water contamination by heavy metals can pose a risk to poultry and to human health. The need for affordable, reliable and effective methods of water treatment has led to the use of plants materials, including coagulants such as Moringa oleifera seeds, to ensure poultry products are safe for consumers.

OBJECTIVES

The aim of the present study was to investigate the effects of drinking water treatment by Moringa oleifera seed on the concentration and distribution of metals such as arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) in different parts of broilers chickens and theirs effects on consumer health.

METHODS

A total number of 264 one-day old chickens (Cobb-500) were assigned to three treatments, with 22 birds in each treatment and replicated four times: untreated well water (UW), well water treated with Moringa oleifera seeds and filtered (MOF) and well water treated with Moringa oleifera seeds but unfiltered (MOU). Thirty birds were randomly chosen from different treatments and slaughtered at day 45 of the experiment and samples of livers, kidneys, gizzards and breasts were obtained and analyzed for toxic metals concentrations using atomic absorption spectrophotometry.

RESULTS

The results indicated that the bioaccumulation of heavy metals was lower in MOF than those in UW and MOU. The target hazard quotient (THQ) for individual metals was below acceptable limits except for As and Pb in UW and MOU. The carcinogenic risk (TR) was estimated for each metal due to consumption of different types of chicken.

CONCLUSIONS

Moringa oleifera seeds are an environmentally friendly natural coagulant and able to treat water containing undesirable heavy metal concentrations and ensure that poultry meat is safe for consumers.

COMPETING INTERESTS

The authors declare no competing financial interests.

ETHICS APPROVAL

This study was approved by the ethics Committee of the University of Lomé-Togo.

Measurement of green total factor productivity on Chinese laying hens: From the perspective of regional differences

Eggs contain the essential cholesterol and protein for the human body, which plays an irreplaceable role in human survival, production and life. There are significant differences in the development of laying hens feeding in different regions. It is of great significance to improve egg production and reduce pollution emission for China’s laying hens industry. Based on the SBM model, this paper constructs MML index, considering unexpected output under common frontier, to comprehensively evaluate the green total factor productivity on Chinese laying hens (GTCL). The results show that: (1) GTCL shows a large spatial and temporal differentiation under both the common frontier and the regional frontier. Compared with the eastern region and central region, the western region has obvious advantages in GTCL. (2) GTCL overall shows a downward trend, however, it emerges an upward trend in recent years. (3) Compared with small-scale and large-scale, middle-scale GTCL has advantages. According to the above empirical results, combined with the China’s actual national situation, this paper finally puts forward some policy recommendations to improve GTCL.

Investigation into clinicopathological and pathological findings, prognosis, and aetiology of lorikeet paralysis syndrome in rainbow lorikeets (Trichoglossus haematodus)

Objective

To report the temporal and spatial distribution of rainbow lorikeets presenting with lorikeet paralysis syndrome (LPS) and their clinicopathologic and pathologic findings, exposure to toxins, and response to treatment.

Methods

Records of lorikeets admitted in 2017 and 2018 to facilities in south‐east Queensland (QLD) were reviewed and LPS and non‐LPS cases were mapped and their distribution compared. Plasma biochemistries and complete blood counts were done on 20 representative lorikeets from south‐east QLD and Grafton, New South Wales (NSW). Tissues from 28 lorikeets were examined histologically. Samples were tested for pesticides (n = 19), toxic elements (n = 23), botulism (n = 15) and alcohol (n = 5).

Results

LPS occurred in warmer months. Affected lorikeets were found across south‐east QLD. Hotspots were identified in Brisbane and the Sunshine Coast. Lorikeets had a heterophilic leucocytosis, elevated muscle enzymes, uric acid and sodium and chloride. Specific lesions were not found. Exposure to cadmium was common in LPS and non‐LPS lorikeets. Treated lorikeets had a 60–93% See Table 2 depending on severity of signs.

Clinical significance

The primary differential diagnosis for lorikeets presenting with lower motor neuron signs during spring, summer and autumn in northern NSW and south‐east Queensland should be LPS. With supportive care, prognosis is fair to good.

A review of chemical and microbial contamination in food: What are the threats to a circular food system?

A circular food system is one in which food waste is processed to recover plant nutrients and returned to the soil to enable the production of more food, rather than being diverted to landfill or incineration. The approach may be used to reduce energy and water use in food production and contribute to the sustainability of the system. Anaerobic digestion and composting are common food waste treatment technologies used to stabilize waste and produce residual materials that can replenish the soil, thus contributing to a circular food system. This approach can only be deemed safe and feasible, however, if food waste is uncontaminated or any contaminants are destroyed during treatment. This review brings together information on several contaminant classes at different stages of the food supply chain, their possible sources, and their fates during composting and digestion. The main aim is to identify factors that could impede the transition towards a safe, reliable and efficient circular food system. We investigated heavy metals, halogenated organic compounds, foodborne pathogens and antibiotic resistance genes (ARGs) in the food system and their fates during digestion and composting. Production and processing stages were identified as major entry points for these classes of contaminants. Heavy metals and foodborne pathogens pose less risk in a circular system than halogenated organics or antibiotic resistance. Given the diversity of properties among halogenated organic compounds, there is conflicting evidence about their fate during treatment. There are relatively few studies on the fate of ARGs during treatment, and these have produced variable results, indicating a need for more research to clarify their fate in the final products. Repeated land application of contaminated food waste residuals can increase the risk of accumulation and jeopardize the safety of a circular food system. Thus, careful management of the system and research into the fate of the contaminants during treatment is needed.

Snack foods and lead ingestion risks for school aged children: A comparative evaluation of potentially toxic metals and children's exposure response of blood lead, copper and zinc levels

Snack foods are common and highly advertised to children and serve their natural predispositions for sweet and salty tastes. However, the risk issues of low-cost snacks eaten by 0-6 aged children are lack of more concern. To better understand the issue of low-cost snacks this study considered potentially toxic metals (PTMs) impact on children's health risk, measured PTMs in a collection of 570 collected low-cost snacks contributed by 1342 voluntary participants children aged 0-6 years involved in Xi'an city are conducted. Nine priority PTMs and amounts ranked as Mn > Zn > Cu > Cr > Sb > Pb > Ni > Cd > Co. The Estimated Weekly Intake of PTMs in snacks for children accounted for a proportion of the Provisional Tolerance Weekly Intake. Children's daily snack ingestion of Cr, Cd and Pb were especially concerning. It was noted that all PTMs in flour products contribute to the total Target Hazard Quotient (THQ>1) were observed having a non-carcinogenic risk compared to the single metals Cr, Co and Cd with carcinogenic risk. The correlations between Cu, Pb, Zn in low-cost snacks and children's bloods reflected PTMs especially for Pb that transfers into children's bodies mostly through low-cost foodstuffs ingestion. Also, the elevated blood lead levels (BLLs) depended on readily available, low-quality snacks accessible for children. Therefore, multi-initiatives aimed at improving the quality, increasing awareness, and a PTM monitoring program for low-cost snack food market to young children should be undertaken.

Manganese in the Diet: Bioaccessibility, Adequate Intake, and Neurotoxicological Effects

Manganese (Mn) is an essential element that participates in several biological processes. Mn serves as a cofactor for several enzymes, such as glutamine synthetase and oxidoreductases, that have an important role in the defense of the organisms against oxidative stress. The diet is the main source of Mn intake for humans, and adequate daily intake levels for this metal change with age. Moreover, in higher amounts, Mn may be toxic, mainly to the brain. Here, we provide an overview of Mn occurrence in food, addressing its bioaccessibility and discussing the dietary standard and recommended intake of Mn consumption. In addition, we review some mechanisms underlying Mn-induced neurotoxicity.

Multiple metal(loid)s bioaccessibility from cooked seafood and health risk assessment

Seafood has been generally considered to be the main diet exposure source of metal(loid)s. We evaluated health risk of mercury (Hg), arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), copper (Cu), and zinc (Zn) through consumption of cooked seafood based on bioaccessibility, which was obtained by physiologically based extraction test method. Results showed that cooking practices could decrease metal(loid)s concentration from seafood (by 6.0-45.7%). Metal(loid)s release from seafood in this study followed the descending order of Hg > Zn > Ni > Cd > Pb > As > Cu > Cr. On average, cooking lowered the bioaccessibility of As, Hg, Cd, Pb, Ni, Cr, Cu, and Zn by 15.2, 26.1, 30.9, 30.7, 25.7, 31.2, 17.6, and 22.4%, respectively. Health risk calculation results showed that Cr, Ni, and Zn in seafood species in this study were within the human health benefits range. Hg, Cd, Pb, and Cu exposure from cooked seafood was within the safe dose. However, we found that there is a potential of having cancer (especially bladder and lung cancer) for people exposure to iAs from seafood based on bioaccessible contents the first time.

As3+ or/and Cu2+ exposure triggers oxidative stress imbalance, induces inflammatory response and apoptosis in chicken brain

Arsenic (As) and copper (Cu) are common environmental pollutants in nature. When they are excessively present in living organisms, they can cause heavy metal poisoning. There were relatively few studies of the toxicological concentrations of As and Cu in the brain using chicken as a model. Therefore, in this study, arsenic trioxide or/and copper sulfate were added to chicken diets for a 12-week toxicity test. The test results showed that excessive intake of As or/and Cu led to a significant reduction in the total antioxidant capacity (T-AOC), catalase (CAT) and hydroxyl radicals. And significant increase in nitric oxide synthase (NOS) indicates an imbalanced oxidation reaction. In addition, the increase in heat shock protein (HSPs), the increase of NF-κB pathway-related pro-inflammatory mediators, the change of apoptosis factors on the death receptor and mitochondrial apoptosis pathway show that, As or/and Cu exposure induced chicken brain has heat shock response (HSP), tissue inflammation and apoptosis. This damage is inseparable from the oxidative imbalance. It is worth noting that these injury changes are time-dependent, and the combined effect of these two metals is more severe than that of a single group of injuries. Our findings can inform the regulation of animal feed additives and avoid agricultural economic losses or biological health damage.

Comparisons of pollution characteristics, emission situations, and mass loads for heavy metals in the manures of different livestock and poultry in China

The application of livestock and poultry manures was the predominant source of heavy metals in agricultural soils, particularly in China. It is important to systematically compare the pollution characteristics, emission situations and mass loads for heavy metals in the manures of different livestock and poultry in China. According to analysis and estimation based on the reported concentration levels of eight heavy metals (Zn, Cu, Pb, Cd, Cr, Hg, As, and Ni) and the feed quantities of livestock (pig, cattle, and sheep) and poultry in 2017, the concentrations of Zn and Cu and the over-standard frequencies of Zn, Cu, Cd, and As were much higher than those of other heavy metals, especially in pig manure. In 2017, the total emission of livestock and poultry manure in China was 1.64 × 10⁹ t (FW), which was mainly excreted from cattle (45.77%); while the total emission of heavy metals sourced from manures was 2.86 × 10⁵ t (DW), with the predominant contribution originating from pig manure (71.52%). The highest mass loads of manures and heavy metals were observed in Shandong, Tianjin, Henan, and Shanghai, where heavy metal contamination may be occurring (especially for Zn and Cu). The heavy metal concentrations in livestock and poultry manures of China were similar to other countries; however, more heavy metals were discharged into agricultural land through manure (especially for Zn and Cu). For many countries, abundant Zn and Cu exist in agricultural soils, principally contributed by livestock and poultry manures. These heavy metals originate from their addition to livestock and poultry feeds. Therefore, reducing the addition of Zn and Cu in feeds is an effective measure to lower their input into agricultural soils.

Public health risk of toxic metal(loid) pollution to the population living near an abandoned small-scale polymetallic mine

Small-scale mining activities in many developing countries have caused severe environmental issues to the surrounding areas, which ultimately threatened the health of local populations. Based on detailed characterization of the local drinking water and surface soil, as well as foodstuffs, this study comprehensively assessed the public health risk of toxic metal(loid)s to the population living in three villages surrounding an abandoned small-scale polymetallic mine in southern China. The agricultural soils contained elevated levels of Cu, Zn, As, Cd, and Pb, which originated from the mining district, and as expected, the locally cultivated rice and vegetables were contaminated by As, Cd, and Pb to varying extents. Arsenic occurred in both inorganic and organic forms in the rice and vegetables, with inorganic As (i-As) accounting for 82.2% (45.4-100%) and 94.7% (65.2-100%) of the total As contents in rice and vegetables, respectively. Results of health risk assessment indicate that the residents in the impacted villages had serious non-carcinogenic and carcinogenic risk. Dietary exposure to i-As and Cd through rice and vegetable consumption was the primary cause of non-carcinogenic risk, while i-As intake was the dominant contributor of carcinogenic risk. These findings suggest that significant environmental pollution by toxic metal(loid)s could result from small-scale metal mines, even after being abandoned, and the accumulation of the toxic metal(loid)s in food crops could pose significant health risk to the local residents. Immediate actions should be taken to discourage them from consuming the locally produced food crops, while long-term control measures for containment of toxic metal(loid) pollution are being developed, and high priority should be given to the remediation of Cd and As in the contaminated soils.

Evaluation of Heavy Metal Content in Feed, Litter, Meat, Meat Products, Liver, and Table Eggs of Chickens

We assessed the concentrations of Fe, Cu, Zn, Mn, Se, Co, Cr, Pb, Cd, and Ni in chicken meat and meat products, feed, and litter, as well as laying hens' eggs, feed and litter to monitor the quality of products on the market and their safety for human consumption as judged by recommended daily allowance (RDA) and tolerable upper levels. Samples were chosen as the most popular poultry products in Saudi Arabia. A total of 45 broiler samples of frozen or fresh meat, liver, burger, or frankfurter were chosen from the same brand. Additionally, 60 table eggs from four commercial brands were collected, and the edible parts of these were used to determine levels of minerals and toxic elements. Furthermore, 30 feed and litter samples were collected from the starter, grower, and layer diets of broilers and laying hens. The results indicated that there were significant levels of most of the trace elements and heavy metals in the different meat sources. Furthermore, the liver contained the highest levels of elements, except for Cr, Co, and Ni. The highest Cr level was detected in the fresh meat, followed by frozen meat. Trace elements (Mn and Co) and heavy metals (Ni and Pb) were not detected in either the frozen or the fresh meat. The chicken burger and the frankfurter exhibited similar trace-element and heavy-metal contents, except for Zn and Mn, as the frankfurter showed higher concentrations than the burger. Differences in most of the trace and toxic elements among the different sources of eggs were not found to be significant, except for Zn. Differences between the broiler meat and table eggs were only substantial for Fe and Zn. Fe was significantly higher in meat than in eggs, and the opposite trend was found for Zn. The liver contained higher heavy metals than the eggs, except for Cr. In addition, the burger had higher concentrations of essential (Cu and Co) and heavy metals (Pb and Ni) than the eggs but had lower levels of Zn and Cr. The frankfurter exhibited significantly higher levels of Fe, Cu, Mn, Co, Pb, and Ni than the eggs but lower levels of Zn and Cr. To summarize, Cd, Pb, As, and Se were not detected in the broiler meat or eggs, indicating no risks from these toxic elements. Conversely, the liver exhibited the highest content of heavy metals, except for Cr, indicating that the intake of Pb and Cd was above the recommended daily allowance (RDA) for adults. The meat products exhibited higher Pb, Cd, and Ni levels than the broiler meat and the table eggs, suggesting that they posed a health threat to humans, and the intake of Pb in the meat products was higher than the RDA. Thus, chicken meat and table eggs, which are primary protein sources, are safe sources of human nutrition, while liver and meat products may present potential health hazards through the food chain.

Arsenic (III) or/and copper (II) exposure induce immunotoxicity through trigger oxidative stress, inflammation and immune imbalance in the bursa of chicken

The environmental hazards of arsenic (As) and copper (Cu) contamination have swept through quite a few districts worldwide. Whereas, molecular mechanisms involved in As- and Cu-induced immunotoxicity in Gallus gallus bursa of Fabricius (BF) are complex and elusive. Male Hy-line chickens were exposed to arsenic trioxide (As₂O₃; 30 mg/kg) and copper sulfate (CuSO₄; 300 mg/kg) alone or in combination, respectively, to examine the potential ecotoxicity of them. The ions homeostasis and BF index of chicken had distinct changes after As or/and Cu exposure. Moreover, As or/and Cu treatment significantly increased the MDA content and NOS activity, and simultaneously resulted in reductions in CAT and AHR activities. Subsequently, it was further exhibited up-regulations of nuclear factor-κB (NF-κB), inflammatory mediators and pro-inflammation cytokines accompanied by depletion of anti-inflammatory cytokines and severe pathological conditions. Moreover, decreased ratio of IFN-γ/IL-4 and increased level of IL-17 illustrated an imbalance of the immune response. Meanwhile, incremental mRNA transcription and protein levels of heat shock proteins (HSPs) alleviated toxicity caused by As or/and Cu. Importantly, exposure to both contaminants significantly soared the BF injury in comparison with exposure to As or Cu alone. All these results illustrated that exposure to As₂O₃ or/and CuSO₄ elicited BF tissue damage and ions changes, and its severity was associated with prolonged persistence of oxidative damage, accompanied by a dysregulated immune response which played a vital role in inflammatory injury. Additionally, combined management of As₂O₃ and CuSO₄ could exacerbate BF injury.

China's Ban on Phenylarsonic Feed Additives, A Major Step toward Reducing the Human and Ecosystem Health Risk from Arsenic

Phenylarsonic feed additives were once widely used in poultry and swine production around the world, which brought significant and unnecessary health risk to consumers due to elevated residues of arsenic species in animal tissues. They also increased the risk to ecosystems via releases of inorganic arsenic through their environmental transformation. Out of concern for the negative impacts on human and ecosystem health, China, one of the world's largest poultry and swine producing countries, recently banned the use of phenylarsonic feed additives in food animal production. This ban, if fully enforced, will result in reduction of approximately 1160 cancer cases per year from the consumption of chicken meat alone, and avoid an annual economic loss of nearly 0.6 billion CNY according to our risk analysis. Furthermore, the inventory of anthropogenic arsenic emissions in China will be cut by approximately one-third with the phase-out of phenylarsonic feed additives. This ban is also expected to lead to significant reduction in the accumulation of arsenic in the soils of farmlands fertilized by poultry and swine wastes and, consequently, lower the accumulation of arsenic in food crops grown on them, which could have even greater public health benefits. But effective enforcement of the ban is crucial, and it will require detailed supervision of veterinary drug production and distribution, and enhanced surveillance of animal feeds and food products. Furthermore, control of other major anthropogenic sources of arsenic is also necessary to better protect human health and the environment.

Raw poultry meatballs with soya flour: Shelf life and nutritional value

Poultry meat is a valuable source of protein for human consumption. It plays an important role in countries with poor ungulate meat production, including the Republic of Kazakhstan. The intake of fibre by the Kazakh population also remains low, while the intake of saturated fatty acids is excessive. Therefore, it is recommended to combine meat with plant products, e.g. soya flour. In the present research, we developed and evaluated a new meatball product containing different amounts of soya flour. The meatballs proved to be a semi-finished high-protein product. They also demonstrated a good fatty acid and mineral profile. The product with 30% of soya flour showed the best results: 27% of protein, low content of saturated fatty acid, and shelf life of 48 h. To extend the shelf life of the meatballs under refrigerator conditions, new disinfection methods should be developed.

The disturbance of autophagy and apoptosis in the gizzard caused by copper and/or arsenic are related to mitochondrial kinetics

As toxic elements when excessive, arsenic (As) and copper (Cu) are two naturally occurring elements that may be ingested by the organism at the same time. However, the precise damaged mechanism and the pathways that are activated by As and/or Cu is rarely researched in gizzard, a unique organ of birds. In this study, ultrastructural observations, TdT-mediated dUTP Nick-End Labeling, real-time quantitative PCR and Western blotting were performed to evaluate the toxic effects of chronic exposure to Cu²⁺ and/or arsenite on chicken gizzard. The results revealed that increased apoptosis and autophagy levels induced by Cu²⁺ and arsenite appeared to be independent of oxidative stress, which didn't have significant changes in different treatment groups at the same time point. Nevertheless, the redox balance gradually deviated with the extension of time. And increased mitochondrial division and decreased fusion were also caused by Cu²⁺ and arsenite. In conclusion, apoptosis and autophagy in gizzard induced by Cu²⁺ and/or arsenite, at least, strongly linked with the disruption of mitochondrial homeostasis. Our study showed that the combination of Cu²⁺ and arsenite produces stronger toxicity. The results of this study can serve as a reference for agicultural feeding and environmental protection, that is, to avoid the combined exposure of Cu²⁺ and arsenite to prevent greater economic losses and health risks.

Public health risk of heavy metal residues in meat and edible organs of broiler in an intensive production system of a region in Pakistan

The aim of this study was to find the concentration of lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn), and zinc (Zn) in feed, drinking water, and their residues in meat and internal organs in broilers at three different locations in Charsadda. For this purpose, a total of 48 representative water and feed samples and 240 meat and internal organs of broilers were collected. Significantly (P < 0.05) higher concentrations of Zn and Mn were found in feed samples. In water samples assessed for heavy metals, a significantly (P < 0.05) higher concentration of Pb was observed at Umerabad and Kula Dher as compared with Nisatta whereas a significantly (P < 0.05) higher concentration of Ni was recorded at Umerabad as compared with Nisatta and Kula Dher. Similarly, a significantly (P < 0.05) higher concentration of Mn in water was recorded at Kula Dher as compared with Nisatta and Umerabad. The concentration of Pb in water at all locations and the concentration of Ni at Umerabad were above the maximum permissible limits. A significantly (P < 0.05) higher concentration of Pb in the liver, breast, and thigh muscles and a significantly (P < 0.05) higher concentration of Mn in the liver, gizzard, breast, and thigh muscles of broilers were recorded at Kula Dher. A significantly (P < 0.05) higher mean concentration of Pb, Cd, Ni, Mn, and Zn was recorded in the liver as compared with the gizzard, breast, and thigh muscles. It was concluded from the present study that broiler farms near the roadside/canal and waste disposal site/wastewater drains cause accomulaiton of high concentrations of some heavy metals in meat and internal organs of broiler birds.

Risk of exposure to total and inorganic arsenic by meat intake among different age groups from Brazil: a probabilistic assessment

Beef and poultry as well as cattle and chicken livers are staple food items for Brazilian population, and previous studies had detected arsenic levels in these foods. This study aims to evaluate the risk of exposure to total and inorganic arsenic by meat intake in three age groups from Brazil (11-16, 16-21, and > 21 years). Our hypotheses are (i) that there is differences in the risk of exposure between age groups and (ii) the older individuals (> 21 years) are under higher risk. To test these hypotheses, we calculated the probabilistic estimated daily intake of total As (TAs^EDI) from poultry, beef, cattle liver, and chicken liver, and the probabilistic estimated incremental lifetime skin, bladder, and lung cancer risk (ILCR) associated with inorganic As ingestion from poultry only. TAs^EDI and ILCR from poultry differed among groups which confirm the first hypothesis. However, TAs^EDI and ILCR results cannot support the second hypothesis. Even though the age groups are under a low risk of exposure to As by meat intake, the results indicate that bladder/lung cancer risk (from poultry intake) slightly exceeds the safe limits in the older population.

Assessment of Trace Metals in Consumer Chickens in Bangladesh

BACKGROUND

Bangladesh is a densely populated country with a high demand for non-vegetable protein. Poultry meat is an important source of protein due to its affordability. Trace metals are persistent in the environment and are subject to bioaccumulation in the food chain. Contaminated poultry feed can pose a risk to human health as it biomagnifies and bioconcentrates toxic metals up the food chain, which can enter the human body and cause adverse and toxic health effects.

OBJECTIVES

The aim of the current study was to assess the concentration and distribution of metals such as arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu) and nickel (Ni) in different types and parts of poultry in markets in Dhaka, Bangladesh.

METHODS

A total of 15 chickens were collected from five commercial markets of Dhaka city. Three types of poultry were selected, broiler, layer and cock. Altogether, 45 chicken samples were analyzed for toxic metals concentrations using inductively coupled plasma optical emission spectroscopy.

RESULTS

The concentrations of As, Cd, Co, Cr, Cu and Ni obtained in the broiler, layer and cock chickens were 0.728, 0.232, 0.392; 0.595, 0.245, 0.271; 0.058, 0.016, 0.096; 5.275, 1.562, 22.180; 3.571, 2.269, 4.241, and 0.332, 0.211, 0.433 mg/kg (wet weight), respectively. The results indicate that the concentrations of As, Cr, and Cu in the analyzed samples exceeded the maximum permissible levels, whereas the concentrations of Cd and Ni were within acceptable limits. Metal concentrations decreased in the order of Cr > Cu > As > Cd > Ni > Co. The target hazard quotient and cancer risk values were estimated for each metal due to consumption of the different types of chicken.

CONCLUSIONS

The estimated metal concentrations of As, Cr and Cu were higher than the permissible levels of international standards, indicating a health risk. Groundwater in many parts of the country is contaminated with As and is a probable source of As contamination in poultry. High concentrations of Cr and Cu in chicken may be caused by contaminated poultry feed. In the present study, layer chickens were comparatively less contaminated with metals than other types of chicken. The estimated target hazard quotient and cancer risk values of the analyzed chicken samples were lower than acceptable limits for all individual trace metals in the three types of chicken, indicating no non-carcinogenic and cancer health risk from ingestion of a single trace metal through consumption of these chickens.

ETHICAL APPROVAL

This study was approved by the Academic Committee of the Institute of Leather Engineering and Technology, University of Dhaka, Bangladesh.

COMPETING INTERESTS

The authors declare no competing financial interests.

Transcriptome profile analysis of leg muscle tissues between slow- and fast-growing chickens

Chicken is widely favored by consumers because of some unique features. The leg muscles occupy an important position in the market. However, the specific mechanism for regulating muscle growth speed is not clear. In this experiment, we used Jinghai yellow chickens with different body weights at 300 days as research subjects. The chickens were divided into fast- and slow-growing groups, and we collected leg muscles after slaughtering for use in RNA-seq. After comparing the two groups, 87 differentially expressed genes (DEGs) were identified (fold change ≥ 2 and FDR < 0.05). The fast-growing group had 42 up-regulated genes and 45 down-regulated genes among these DEGs compared to the slow-growing group. Six items were significantly enriched in the biological process: embryo development ending in birth or egg hatching, chordate embryonic development, embryonic skeletal system development, and embryo development as well as responses to ketones and the sulfur compound biosynthetic process. Two significantly enriched pathways were found in the KEGG pathway analysis (P-value < 0.05): the insulin signaling pathway and the adipocytokine signaling pathway. This study provides a theoretical basis for the molecular mechanism of chicken growth and for improving the production of Jinghai yellow chicken.

Roxarsone exposure jeopardizes nitrogen removal and regulates bacterial community in biological sequential batch reactors

Roxarsone is widely present in wastewaters of many animal farms in China. However, little is known about how long-term roxarsone exposure influences the nitrogen removal of biological wastewater treatment in agricultural settings. Here we investigated the nitrogen removal performance of a biological sequential batch reactor (SBR) and the changes of bacterial community, upon long-term roxarsone exposure. The long-term roxarsone dosing decreased the SBR nitrogen removal by 52.4%, with an immediate inhibition on denitrification and a delayed inhibition on nitrification. The analyses of bacterial enzymatic activities and 16 S rRNA sequencing revealed that bacterial activities generally decreased, and the nitrogen-cycling bacterial community was changed, particularly by the decrease (Acinetobacter and Methylophilaceae), persistence (Flavobacterium and Methylotenera), and emergence (Aeromonas) of certain bacterial genera. Overall, chronic roxarsone exposure could suppress nitrification and denitrification, which may even have broad implications on the use efficiency and cycling of nitrogen in agroecosystems.

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.