Determination of heavy metals in albumen of hen eggs from the Markazi Province (Iran) using ICP-OES technique

Health risk assessment of heavy metal pollutants in Iranian hen eggs: a systematic review and meta-analysis

Eggs are a high-quality, nutrient-dense source of protein that is available at a relatively low price and the contamination of eggs by heavy metals is an important issue in public health. This review aimed to assess the risk of heavy metal pollutants in Iranian hen eggs. Original full-text available studies in Iran, detecting levels of Pb, Cd, As, and Hg in whole or part of the egg, and published between January 2000 and March 2023 were selected based on the inclusion criteria. The random-effect model was used to estimate the pooled concentrations of Pb, Cd, As, and Hg in Iranian eggs in meta-analysis. The incremental lifetime cancer risk (ILCR) and the target hazard quotient (THQ) were estimated by both calculation and Monte Carlo simulations to determine the carcinogenic and non-carcinogenic risk of egg consumption, respectively. The pooled concentrations of heavy metals in Iranian hen eggs from nine articles (11 datasets: 10 studies on Pb, 7 on Cd, and 5 on As and Hg concentrations) were Pb 0.29 (95% CI 0.20-0.39) mg kg-1, Cd 0.04 (95% CI 0.03-0.06) mg kg-1, As 0.05 (95% CI 0.03-0.07) mg kg-1, and Hg 0.03 (95% CI 0.02-0.04) mg kg-1. THQ did not show the non-carcinogenic risk; however, the ILCR for Pb concentration showed the threshold carcinogenic risk (mean ILCR = 8.94e - 4 and 9.0E - 4 by calculation and Monte Carlo simulations, respectively), with the greater risk for Cd (mean ILCR = 2.02e - 2). The carcinogenic risk of Pb and Cd concentration in Iranian hen eggs shows the urgent need for programs and policies to lower the risk for consumers by providing healthier feeding.

Heavy metal contamination in duck eggs from a mercury mining area, southwestern China

Objective

Mercury (Hg) contamination in the environment around mercury mines is often accompanied by heavy metal contamination.

Methods

Here, we determined concentrations of chromium (Cr), zinc (Zn), strontium (Sr), barium (Ba), and lead (Pb) in duck eggs from a Hg mining area in Southwest China to assess the contamination and health risk.

Results

Duck eggs obtained from the mining area exhibit higher concentrations of Cr, Zn, Sr, Ba, and Pb compared to those from the background area, with egg yolks containing higher metal levels than egg whites. Specifically, the mean Cr, Zn, Sr, Ba, and Pb concentrations of duck eggs from the Hg mining area are 0.38, 63.06, 4.86, 10.08, and 0.05 μg/g, respectively, while those from the background area are only 0.21, 24.65, 1.43, 1.05, and 0.01 μg/g. Based on the single-factor contamination index and health risk assessment, heavy metal contamination in duck eggs poses an ecological risk and health risk.

Conclusion

This study provides important insight into heavy metal contamination in duck eggs from Hg mining areas.

The detoxification of cadmium in Japanese quail by pomegranate peel powder

Environmental pollution and exposure to toxic metals such as cadmium (Cd) can cause severe and chronic diseases and have significant side effects on vital organs. The present study aimed to evaluate the effect of pomegranate peel on biochemical factors and lipid peroxidation in intoxication by Cd in Japanese quail. Two hundred seventy quails in different groups were fed diets containing Cd and pomegranate peel from 6 to 35 days old. Then, serum biochemical parameters were assessed, including liver enzymes, urea, and thiobarbituric acid. In the quails, Cd significantly increased MDA, urea, and AST (P < 0.05). Adding pomegranate peel at 1.5 and 2% levels decreased these parameters significantly (P < 0.05). In conclusion, dietary enrichment using pomegranate peel reduced the adverse effects of Cd by improving lipid peroxidation, aspartate aminotransferase (AST), and urea in Japanese quail.

Consumer health risk assessment of Arsenic and Mercury in hen eggs through Monte Carlo simulations

BACKGROUND

This study was conducted to assess the concentration of heavy metals (arsenic and mercury) and estimate the probability that consumption of hen egg products collected in Iran has carcinogenic or non-carcinogenic consequences.

METHODS

A total of eighty-four hen eggs from 21 major brands were randomly selected from among thirty local supermarkets in two seasons (winter (January) and summer (August) 2022). Arsenic (As) and Mercury (Hg) was determined by using ICP-MS. The human health risk assessment refers to the formulation of the USEPA standard focused on Estimated Daily Intake (EDI), International Lifetime Cancer Risk (ILCR), Target Hazard Quotient (THQ), and Monte Carlo simulation (MCS) as a probabilistic method. Data analysis was carried out using the statistical software SPSS. Differences in mean concentrations of As and Hg in two seasons were tested by paired t-test.

RESULTS

Over two seasons, the average As and Hg concentrations in hen eggs were 0.79 and 0.18 µg.kg^-1, respectively. Seasonal difference in As concentration (p = 0.451) was not significant, whereas that of Hg concentration (p < 0.001) was significant. The calculated value of EDI was 0.29 µg As/day and 0.06 µg Hg/day. The EWI in the maximum scenario of as level in hen eggs was estimated to be 8.71 µg As and 1.89 µg Hg/month for Iranian adults. THQ's mean for As and Hg in adults was determined to be 0.00385 and 0.00066, respectively. In addition, ILCRs by MCS for As were 4.35E-4.

CONCLUSION

In total, the result indicates that there was not a significant risk of developing cancer; the calculation of THQ was still below the accepted level of 1, indicating that there was no risk while, according to most regulatory programs (ILCR > 10^- 4) shows a threshold carcinogenic risk of arsenic through consuming in hen eggs. Therefore, policymakers need to be aware that it is prohibited to establish chicken farms in heavily polluted urban areas. It is essential to regularly conduct examinations to measure the presence of heavy metals in both ground waters used for agriculture and the feed provided to chickens. Additionally, it is advisable to focus on raising public awareness about the importance of maintaining a healthy diet.

Risk assessment of lead and cadmium concentrations in hen's eggs using Monte Carlo simulations

The hen egg is one of the main sources of cheap, great quality, and nutritious food. This study aimed at determining the level of lead (Pb) and cadmium (Cd) in hen eggs and at assessing the carcinogenic and non-carcinogenic risks caused by the consumption of hen eggs collected in Iran. A total of 42 hen eggs from 17 major brands were randomly sampled from supermarkets. Lead and cadmium concentrations were determined by using inductively coupled plasma mass spectrometry (ICP-MS). Additionally, using the Monte Carlo simulation (MCS) method to calculate dietary exposure, target hazard quotient (THQ), and incremental lifetime cancer risk (ILCR), the related human health risk associated with ingesting these hazardous metals for adults was evaluated. The average Pb and Cd concentrations in whole eggs were 7.16 ± 0.248, and 2.83 ± 0.151 μg kg^-1, respectively, which were less than the maximum permitted levels, established by FAO/WHO and the Institute of Standards and Industrial Research of Iran (ISIRI). Pb and Cd concentrations were significantly correlated at the 0.05 level (r = 0.350). Regarding the levels of Pb and Cd in eggs, overall, the estimated weekly intake (EWI) of these metals for adults by egg consumption was determined 0.014 and 0.007 mg/week, respectively, which were lower than the risk values suggested. The carcinogenic and non-carcinogenic indexes of Cd and Pb indicated that the adult population in Iran was safe (THQ Pb and Cd <1, ILCR <10^-6 Pb). It should be emphasized that this research primarily focuses on egg consumption, which may account for a relatively small portion of Iranian consumers' overall exposure to Pb and Cd. Therefore, a comprehensive study on the risk assessment of these metals through whole-diet foods is recommended. The findings showed that lead and cadmium levels in all evaluated eggs were suitable for human consumption. Adults' Pb and Cd exposure from eating eggs was significantly lower than the risk levels established by Joint FAO/WHO Expert Committee on Food Additives (JECFA), per the exposure assessment. According to the THQ values of these dangerous metals, which were below one value, egg eating by Iranian consumers does not present a non-carcinogenic risk. In addition, this finding provides accurate and reliable information for policymakers to improve food safety status to reduce public health hazards.

The Occurrence of Lead in Animal Source Foods in Iran in the 2010s Decade: A Systematic Review

Lead is a toxic, non-biodegradable, and accumulative heavy metal released into the environment by natural and anthropogenic activities. Despite health concerns due to the consumption of lead-contaminated foods, no systematic and comprehensive review studies have been published about the lead occurrence in animal source foods in Iran. The present study aimed to review the papers investigating the Pb contamination in animal-based food groups (including meat, fish, milk and dairy products, egg and honey) in Iran. A comprehensive search was performed with selected keywords in databases of Scopus, Web of science, and Magiran to find articles that had been published from January 2010 to December 2019. Of 371 identified articles on Pb contaminations in foods, 60 articles were selected using PRISMA. The lead concentrations were higher than the maximum recommended limits in 3 of 9 studies on meat and meat products, 12 of 26 studies on fish and canned fish, and 5 of 18 studies on milk and dairy products. However, the Pb contamination observed in studies on honey and egg was not comparable due to the lack of national and international standards. These results represent the importance of environmental monitoring and assessment for reducing exposure of animals to Pb, resulting in an improvement of food safety.

Lead exposure through eggs in Iran: health risk assessment

Introduction. Contamination of food, including animal protein sources, with heavy metals is a major threat to humans. The aim of this research was to determine lead concentrations in eggs from different Iranian regions and assess risks to human health. Study objects and methods. In this study, lead concentrations in eggs produced at laying hen farms in Qom, Isfahan (Kashan city), and Khorasan Razavi (Mashhad city) provinces were measured by an atomic absorption device. Health risk was estimated using the Human Health Risk Assessment (HHRA) model. Results and discussion. The levels of lead in eggs were significantly different (P ≤ 0.05) among the three regions. They were lower than the permissible limit (0.1 mg/kg) for Kashan (0.0756 mg/kg) and Mashhad (0.0633 mg/kg), but eggs from Qom contained 0.1163 mg/kg of lead. In all the three regions, the estimated daily intake (EDI) of lead was lower than the maximum tolerable daily intake (MTDI), indicating no health risk for lead through egg consumption among Iranian consumers. Also, no risks were detected for adults in terms of non-cancer risk, or target hazard quotients (THQ), and carcinogenic risk (CR) of lead (THQ < 1 and CR < 10–6). Conclusion. The results of this study indicated that lead health risk through egg consumption is within safe limits. However, the nutritional importance and high consumption of eggs among households necessitate a more careful monitoring of lead concentrations to meet public health requirements.

Biomonitoring of toxic metals in feathers of predatory birds from eastern regions of Hungary

The aim of our study was to investigate the concentrations of toxic metals in the feathers of predatory birds in the Hortobágyi Madárpark (Bird Hospital Foundation). Samples were collected from different predatory birds originated from the eastern and north-eastern region of Hungary. Inductively coupled plasma optical emission spectrometry was used to determine the concentration of toxic metals. The mean values varied between bird species groups, their concentrations were between 0.29 ± 0.24 and 0.40 ± 0.30 mg/kg for arsenic (As), 0.09 ± 0.03 and 0.20 ± 0.18 mg/kg for cadmium (Cd), 1.15 ± 1.40 to 2.30 ± 1.52 mg/kg for lead (Pb) and 0.58 ± 0.31 to 2.19 ± 1.25 mg/kg for mercury (Hg), respectively. The measured values are not over the considered threshold values for these toxic metals and in accordance with similar concentrations of them recorded in similar species within Europe. No significant differences were found in their concentration between genders or age in the species. According to the detected concentrations of these metals, their levels accumulated in the feather of the investigated birds do not indicate the possibility of poisoning.

Health Risk Assessment for Human Exposure to Trace Metals and Arsenic via Consumption of Hen Egg Collected from Largest Poultry Industry in Iran

The relative contribution of foodstuffs to intake of heavy metal is still equivocal, and thus, available data are rare. Here, the concentration of ten heavy metals and arsenic were measured in the content of hen egg from five strains of commercial laying hens to evaluate contamination level and potential health risk among local and international consumers in Iran. The estimated daily intake (EDI) of all heavy metals was significantly lower than the provisional tolerable daily intake (PTDI) and respective tolerable daily intake (TDI). The non-carcinogenic and carcinogenic risk values for eating eggs were in the safe range for all consumers, indicating that the no health risk for consumers due to the daily intake of either arsenic or heavy metals. Therefore, intake of heavy metal exposure through the consumption of commercial egg product in Iran is completely safe for both national and international consumers.

Dietary supplementation of Yucca schidigera extract enhances productive and reproductive performances, blood profile, immune function, and antioxidant status in laying Japanese quails exposed to lead in the diet

The present study investigated the toxic impacts of lead (LD) on the productive and reproductive performances of Japanese quails and the role of Yucca schidigera extract (YSE) in reducing these impacts. A total of 360 mature Japanese quails (at 2 months of age) were used and the experiment was lasted for 8 wk. The birds were divided into 6 equal groups as follows: control (basal diet), basal diet + 100 mg LD/kg diet, basal diet + YSE (100 mg/kg diet), basal diet + YSE (200 mg/kg diet), basal diet + LD (100 mg/kg diet) + YSE (100 mg/kg diet), and basal diet + LD (100 mg/kg diet) + YSE (200 mg/kg diet). LD resulted in a significant decrease in feed intake (FI), feed conversion ratio (FCR), and egg production of birds compared with the control group. Supplementation of YSE (100 or 200) to LD containing diet could significantly improve the quail performance parameters to be comparable with the control values. Fertility and hatchability % were decreased by LD, whereas YSE at both levels (100 or 200) separately or in combination with LD showed fertility and hatchability percentages comparable to that of control. Triglycerides, cholesterol, and LDL contents in LD plus YSE100 or LD plus YSE200 groups were significantly decreased than LD alone group. LD significantly decreased superoxide dismutase and catalase activities in the serum with no effect on reduced glutathione content. Co-exposure to YSE100 or YSE200 with LD significantly increased the catalase activity and numerically increased the superoxide dismutase activity than LD alone. YSE100 or YSE200 decreased malondialdehyde contents than LD alone group. LD plus YSE100 or YSE200 groups exhibited significant improvements in the level of immunoglobulins. Co-exposure to YSE with LD significantly decreased the LD residues in egg than the LD group. The obtained results showed that YSE exhibited a potential modulatory role against the LD-induced inhibitory effects on the productive and reproductive performances of Japanese quails and YSE at 200 mg/kg diet was more effective than 100 mg/kg diet in reversing the LD-induced alterations.

What do we know about exposure of Iranians to cadmium? Findings from a systematic review

Cadmium is an important environmental contaminant. High consumption of chemical fertilizers and industrial activities in recent decades has caused people to be worried about exposure to cadmium. There is no policy for environmental and biological monitoring of exposure to cadmium in the general population in Iran. This study was aimed to review cadmium content in consuming foods and biological samples in Iran, systematically. We developed a comprehensive search strategy and used it to search on Web of Science, Scopus, Science Direct, and Scientific Information Database until 28 December 2016. The totals of 285 articles were identified and finally 31 original papers were selected. Cadmium contamination was found in Iranian food groups such as rice, cereal and legumes, canned tuna fish, vegetables, fruit juice, and egg. This study showed that cadmium amount in 75% of the consumed rice samples (domestic and imported) was higher than the maximum limits approved by institute of standards and industrial research of Iran. Lettuce samples in Yazd were recorded the highest concentration of cadmium compared to other studies. In addition, high amount of cadmium was observed in the blood of the general population. Regarding the cadmium contamination in food and blood samples in Iran, policies must be adopted to reduce exposure to cadmium through different matrices as much as possible.

Dietary exposure to toxic and essential trace elements by consumption of wild and farmed carp (Cyprinus carpio) and Caspian kutum (Rutilus frisii kutum) in Iran

This study was conducted to determine and compare the concentrations of mercury (Hg), cadmium (Cd), arsenic (As), lead (Pb), nickel (Ni), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), cobalt (Co), and selenium (Se) in the muscle of wild and farmed carp (Cyprinus carpio) and wild and farmed Caspian kutum (Rutilus frisii kutum) collected from south-western Caspian Sea areas of Iran between December 2014 and March 2015. In addition, risk assessment of consumers to exposure to metals through fish consumption was estimated. In all the samples, the arsenic concentration was lower than the detection limit. The Pb, Cd, Hg and Mn concentrations were significantly higher in the wild fish samples compared to the farmed fish samples. There was no significant difference in the Fe, Zn, Cu, Co, Ni and Se concentrations of the wild and farmed carp and the wild and farmed Caspian kutum. Iron displayed the highest concentration of all the analysed metals in both the wild and farmed fish, followed by Zn and Cu. The highest Hg, Cd, Pb, Ni, Fe, Zn, Cu, Mn, Co and Se concentrations were 0.056, 0.011, 0.065, 0.120, 4.151, 3.792, 2.948, 2.690, 0.037 and 0.162 μg g^-1, respectively. The estimated daily intake of all metals was acceptable, and the hazard quotient values showed that consumption of the analysed fish posed no health risk to consumers.