A comprehensive image of environmental toxic heavy metals in red meat: A global systematic review and meta-analysis...

Heavy metals are defined by their long biological half-life and non-biodegradability in the environment and the human body. Thus, they can accumulate in considerable amounts within soil-plant-food chains, presenting a potential health risk to humans. This systematic review and meta-analysis aimed to investigate the prevalence and mean levels of heavy metals (As, Cd, Hg, and Pb) in red meat globally. Studies describing the heavy metal contamination of meat were retrieved by searching international general and specific databases between 2000 and 2021. According to the findings, there is a low level of contamination of meat with arsenic (As) and mercury (Hg). In contrast, the lead (Pb) and cadmium (Cd) levels exceed the Codex permissible levels. There was also a highly severe heterogeneity in the results, and no subgroup analysis revealed the cause of this heterogeneity. However, different continent subgroups, types of meat, and fat content of meat are universally defined as the primary sources of high toxic heavy metal (THM) concentrations. Also, the results of the subgroup analysis showed the Asia continent 1020.15 μg/kg (95 % CI = 605.13-1435.18), followed by Africa 965.73 μg/kg (95 % CI = 840.64-1094.42), have the highest level of Pb contamination. Similarly, Asia 232.12 μg/kg (95 % CI = 206.45-257.79) and Africa 84.68 μg/kg (95 % CI = 74.69-94.66) have reported high levels of Cd that exceeded the limit of the standards. The risk assessment results also revealed that red meat consumption carries health risks due to excessive heavy metals content particularily for heavy consumers. As a result, it is necessary to implement strict control measures to prevent heavy metal contamination in these critical food products for all consumers worldwide, particularly in Asia and Africa.