The Occurrence and Toxicity of Dioxins and Dioxin-Like Polychlorinated Biphenyls in Foodstuffs Collected From Different Cities of Iran: A Systematic Review

Dioxins compounds are persistent organic contaminants that adversely affect human health and the environmental system. Although the occurrence and toxicity of dioxins congeners are reported worldwide, their status in Iran is very scarce, and no study has been conducted to understand the evidence for occurrence and toxicity of dioxins compounds in Iran yet. Therefore, This systematic review provided a comprehensive report on the levels, occurrence, and health outcome effects of dioxins and dioxin-like Polychlorinated biphenyls (DL-PCBs) in foodstuffs collected from different cities of Iran. We used The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) to design this review, and six databases (Scopus, Scientific Information Database (SID), PubMed, Web of Knowledge, Scopus, and Google Scholar) were searched from inception until January 2022. A total of 9 articles with data on 396 food samples were considered for the final report. The total toxicity equivalency quantity (TEQ) was ranged from 0.06 ± 0.02 to 15.72 ±16.38 and the mean total dioxin congeners levels in most of the samples were below the standard limits and the measured intake levels of dioxin congeners were in the safe level. Although most of the samples did not exceed the maximum allowable thresholds, 44% of studies reported that the concentration of dioxin compounds in most of their samples was above the thresholds defined by world health organization (WHO) (3 pg TEQ/g fat). Therefore, suitable policy actions and more attention are needed to control and reduce the emission of dioxin congeners and their associated risk factors.