Contamination trends and factors affecting the transfer of hexabromocyclododecane diastereomers, tetrabromobisphenol A, and 2,4,6-tribromophenol to breast milk in Japan

Environ Pollut. 2018 Jun;237:936-943. doi: 10.1016/j.envpol.2018.03.015. Epub 2018 Mar 20.


This study investigated contamination trends and factors affecting the levels of brominated flame retardants (BFRs), including hexabromocyclododecane (HBCD) diastereomers, tetrabromobisphenol A (TBBP-A), and 2,4,6-tribromophenol (2,4,6-TBP), in breast milk in Japan. Breast milk samples (n = 64) were collected from mothers living in six prefectures in Japan. The mean concentrations were 2.2, 0.19, 0.29, 3.0, and 0.59 ng/g lipid weight for α-HBCD, β-HBCD, γ-HBCD, TBBP-A, and 2,4,6-TBP, respectively. Based on the previous studies, the levels of ΣHBCD in Japanese women's milk appear to be increasing, and the levels of TBBP-A are higher than those in other Asian countries. Although ΣHBCD were not correlated to phenolic BFRs, the concentration of β-HBCD was significantly correlated to the concentrations of TBBP-A (r = 0.440, p < 0.01) and 2,4,6-TBP (r = 0.320, p < 0.01). The concentration of γ-HBCD increased significantly with maternal age (r = 0.378, p < 0.01), but the concentrations of the other analytes were not dependent on age. The concentration of α-HBCD was higher in primiparae than in multiparae (p < 0.05), while TBBP-A was higher in multiparae. No significant correlation was found between the phenolic BFR levels in milk and mothers' age, working place, and drinking/smoking habits. These results suggest that exposure to α- and γ-HBCD diastereomers could be affected by maternal age and parity, respectively, because of their different kinetics and sources. Therefore, these factors should be considered when conducting infant risk assessments.

Keywords: 2,4,6-Tribromophenol; Breast milk; Brominated flame retardant; Exposure; Hexabromocyclododecane; Tetrabromobisphenol A.

MeSH terms

  • Asia
  • Environmental Pollutants / analysis*
  • Female
  • Flame Retardants / analysis
  • Humans
  • Hydrocarbons, Brominated / analysis*
  • Infant
  • Japan
  • Maternal Exposure / statistics & numerical data*
  • Milk, Human / chemistry*
  • Mothers
  • Phenols / analysis*
  • Polybrominated Biphenyls / analysis*


  • Environmental Pollutants
  • Flame Retardants
  • Hydrocarbons, Brominated
  • Phenols
  • Polybrominated Biphenyls
  • hexabromocyclododecane
  • tetrabromobisphenol A
  • 2,4,6-tribromophenol