Lead exposure through eggs in Iran: health risk assessment

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.

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.

Melamine in Iranian foodstuffs: A systematic review, meta-analysis, and health risk assessment of infant formula

The presence of melamine in food is one of the most significant threats to consumer health and food safety now confronting the communities. The goal of this systematic review and meta-analysis was to determine the melamine content of different food products available on the Iranian market. The pooled melamine concentration (95% confidence interval) on 484 samples of animal-based foodstuffs was as follows: 0.22 (0.08, 0.36 mg kg^-1) for milk, 0.39 (0.25, 0.53 mg kg^-1) for coffee mate, 1.45 (1.36, 1.54 mg kg^-1) for dairy cream, 0.90 (0.50, 1.29 mg kg^-1) for yoghurt, 1.25 (1.20, 1.29 mg kg^-1) for cheese, 0.81 (-0.16, 1.78 mg kg^-1) for hen eggs, 1.28 (1.25, 1.31 mg kg^-1) for poultry meat, 0.58 (0.35, 0.80 mg kg^-1) for chocolates, and 0.98 (0.18, 1.78 mg kg^-1) for infant formula. Based on the results of health risk assessment study on toddlers under 2 years old who ingested infant formula (as a melamine-sensitive group), all groups of toddlers are at an acceptable level of non-carcinogenic risk (THQ ≤ 1). Toddlers were classified according to their ILCR (carcinogenic risk) levels due to infant formula consumption as follows: under 6 months (0.0000056), 6-12 months (0.0000077), 12-18 months (0.0000102), and 18-24 months (0.0000117). The melamine carcinogenicity in infant formula for children had an ILCR value of 0.000001-0.0001 in the investigation, which was considerable risk. According to the findings, Iranian food products (notably infant formula) should be analyzed for melamine contamination on a regular basis.