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.

Economic Sanctions Affecting Household Food and Nutrition Security and Policies to Cope With Them: A Systematic Review

BACKGROUND

This review was conducted to identify the impact of economic sanctions on household food and nutrition security and policies to cope with them in countries exposed to sanctions.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines 2020 were used to identify, select, appraise, and synthesize studies. Electronic databases in addition to Persian ones have been systematically searched for all related documents published until March 2022. Exclusion criteria were: lack of data related to food insecurity in countries subject to sanction and very low quality of the article. The quality of included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal checklists. The results were presented as qualitative and quantitative syntheses.

RESULTS

Of 1428 identified studies, 36 publications remained in the review, which belong to Iran (n=8), Cuba (n=8), Russia (n=7), Iraq (n=7), and Haiti (n=6), respectively. Declining gross domestic product (GDP), devaluation of the national currency, and the quality of food, increase in inflation, unemployment, and consumer prices, infant and under 5 years mortality, energy, and protein deficiency, and the poverty rate were reported as sanction consequences. The most important strategies to improve food security were the humanitarian assistance provided by the international community (Haiti), equity and priority for vulnerable groups mainly by expanding the healthcare system (Cuba), adopting a food ration system in the oil-for-food program, and fixing the price of food baskets (Iraq), import substitution and self-sufficiency (Russia), support domestic production, direct and indirect support and compensation packages for vulnerable households (the approach of resistance economy in Iran).

CONCLUSION

Due to the heterogeneity of studies, meta-analysis was not possible. Since inadequate physical and economic food access caused by sanctions affects especially disadvantaged and vulnerable groups, planning to improve food security and providing support packages for these groups seems necessary.

COVID-19 pandemic and food security in different contexts: A systematic review protocol

Background

Given the unprecedented nature of the COVID-19 crisis and the importance of early implementation of prevention programs, it is essential to understand better its potential impacts on various food security dimensions and indicators.

Methods

Research databases, including Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Public Health Register, PubMed/MEDLINE, SCOPUS, EMBASE, CINAHL, Web of science, and Google Scholar, will be searched using a search strategy and keywords developed in collaboration with librarians. The review will include all field and community trials and observational studies in all population groups. Searching electronic databases, study selection, and data extraction will be conducted by two researchers independently. Four critical appraisal tools will be used to assess the quality of included studies according to the study design: The Joanna Briggs Institute (JBI) Prevalence Critical Appraisal tool, the JBI critical appraisal checklist for randomized control/pseudo-randomized trial, descriptive/case series, and comparable cohort/case-control. These tools were initially designed for use in systematic reviews. A narrative synthesis will be implemented to summarize findings if meta-analyses are not appropriate.

Discussion

The current systematic review results can be used to predict the effect of COVID-19 on the individuals’ and households’ food security, especially in vulnerable populations, and develop effective interventions. This review can provide information for policymakers to better understand the factors influencing the implementation of these interventions and inform decision-making to improve food security.

Systematic review registration

The present study registration number in the international prospective register of systematic reviews (PROSPERO) is CRD42020185843.