Mercury Level in Worldwide Poultry Food Products: a Systematic Review

Mercury is a metal known for its toxic effects on environmental, animal and human health. The presence of Hg in poultry and its potential impact on food safety still need to be explored, especially considering that poultry is the most consumed source of protein in the global population. This study aimed to systematically review mercury and methylmercury levels in poultry meat and eggs worldwide. The searches were conducted in the Web of Science, PubMed, and Scopus databases, resulting in 123 studies, of which only 30 were deemed suitable. Studies were found across sixteen countries: India, Thailand, Malaysia, China, Poland, Egypt, Ghana, Nigeria, Bangladesh, Iran, USA, Italy, Colombia, Romania, Tanzania, Algeria, and Saudi Arabia. Five poultry species were reported, with chicken being the most recorded species in 16 countries. Among biological samples, eggs and liver were the most used for measuring mercury and methylmercury levels. Levels above those permitted by regulatory organizations such as the United States Department of Agriculture (USDA), China's National Health Commission (NHC), and Thailand's Ministry of Public Health - set at 0.05, 0.05, and 0.02 mg.kg^-1 respectively - were observed in 12 of the 17 countries, with the highest concentrations detected in chicken eggs from Colombia. Therefore, poultry production is not Hg-free and contamination by this metal must be monitored.