The US National Academy of Sciences has published a systematic review of epidemiology (human data) and animal studies of the brominated flame retardant family PBDEs (polybrominated diphenyl ethers), stating that “sufficient evidence shows PBDEs are a presumed hazard to humans with respect to intelligence”.
The report specifically assessed BDE-47 (a tetra PBDE), based on six rodent studies and on a review of human data by Lam et al. 2017, considered as “fulfilling the requirements of a systematic review”. This review assesses 15 studies relating human developmental exposure to any PBDE(s) to intelligence or attention-related behaviour. The Academy found a “moderate” level of evidence that exposure to BDE-47 is associated with decreases in learning in rodents and in IQ in humans, noting that a hazard can be “presumed” but that current methods might not be able to predict exposure levels at which humans are affected.
“Application of Systematic Review Methods in an Overall Strategy for Evaluating Low-Dose Toxicity from Endocrine Active Chemicals”, US National Academy of Sciences, 2017, 180 pages https://www.nap.edu/catalog/24758/application-of-systematic-review-methods-in-an-overall-strategy-for-evaluating-low-dose-toxicity-from-endocrine-active-chemicals
“Developmental PBDE Exposure and IQ/ADHD in Childhood: A Systematic Review and Meta-analysis”, J. Lam et al., Environmental Health Perspectives 2017 http://dx.doi.org/10.1289/EHP1632