Temporal trends and developmental patterns of plasma polybrominated diphenyl ether concentrations over a 15-year period between 1998 and 2013

Abstract

Polybrominated diphenyl ethers (PBDEs) were used extensively as flame retardants in furniture containing polyurethane foam until they were phased out of use, beginning in 2004. We examined temporal changes in plasma PBDE concentrations from 1998 to 2013 and characterized patterns of exposure over the early lifecourse among 334 children (903 samples) between birth and 9 years. We examined time trends by regressing PBDE concentration on year of sample collection in age-adjusted models and characterized developmental trajectories using latent class growth analysis (LCGA). Controlling for age, BDE-47 concentrations decreased 5% (95% confidence interval (CI): -9, -2) per year between 1998 and 2013. When considering only postnatal samples, this reduction strengthened to 13% (95% CI: -19, -9). Findings for BDE-99, 100 and 153 were similar, except that BDE-153 decreased to a lesser extent when both prenatal and postnatal samples were considered (-2%, 95% CI: -7, 0). These findings suggest that, on average, pentaBDE body burdens have decreased since the 2004 phase-out of these chemicals. When examining developmental period, PBDE concentrations peaked during toddler years for the majority of children, however, our observation of several unique trajectories suggests that a single measure may not accurately reflect exposure to PBDEs throughout early life.

Keywords: Childhood; Exposure; Flame retardant; PBDE; Prenatal.

Figure 1.

Changes in age-adjusted plasma PBDE concentrations (ng/g lipid) between 1998 and 2013 (n=903 samples from 334 children). Prenatal concentrations were measured in cord plasma.

Figure 2.

Trajectories of plasma PBDE concentrations (ng/g lipid) from birth through 9 years (n=334) estimated using latent class growth analysis; bands represent 95% confidence intervals. The ‘persistent low’ trajectory serves as the reference category.

Figure 3.

Odds ratios (ORs) from multivariable multinomial models examining determinants of PBDE trajectories over early life. The ‘persistent low’ trajectory serves as the reference category. OR from models examining breastfeeding as a predictor of the prenatal high trajectory are not plotted due to the small number of breastfed children that were assigned to this trajectory and resulting wide confidence intervals.