Polybrominated Diphenyl Ether Concentrations in Human Breast Milk Specimens Worldwide

Background: Polybrominated diphenyl ethers (PBDEs) are a class of flame retardants of ubiquitous presence in numerous consumer products. PBDEs may impair neurodevelopment in infants. There is a lack of meta-analysis on PBDE concentrations in human breast milk worldwide. We aimed to summarize global research data on PBDE concentrations in human breast milk specimens in recent years. Methods: We conducted a systematic review through PubMed search of original studies on PBDE concentrations in human individual breast milk specimens collected in the general population over the recent 15-year period (2000–2015) worldwide. Results: A total of 49 eligible studies (total number of study subjects = 7,502) were identified. The pooled means (95% CI) of total PBDE concentration in breast milk (ng/g lipid) were 66.8 (44.7, 88.9) in North America, 2.6 (2.2, 3.1) in Europe, and 2.8 (2.4, 3.3) in Asia, respectively. The pooled means (95% CI) of median total PBDEs concentration in breast milk (ng/g lipid) were 40.0 (30.8–49.1) in North America, 1.9 (1.4–2.4) in Europe, and 2.2 (1.3–3.2) in Asia. The high concentrations of total PBDEs in breast milk in North America were mainly due to high concentrations of brominated diphenyl ether-47 (BDE-47), BDE-99, BDE-100, and BDE-153. There were too few studies from other continents (Africa, South America, and Oceania) for meaningful meta-analysis. Conclusion: Total PBDE concentrations in breast milk in the recent 15-year period were over 20 times higher in North America versus Asia or Europe, and comparable in Europe versus Asia. There is a need for more research data from other continents.