Spatial and Temporal Trends of Dissolved Polybrominated Diphenyl Ethers and Non-BDE Flame Retardants in the Aquatic Environment across Countries

Measuring dissolved concentrations of polybrominated
diphenyl ethers
(PBDEs) and non-BDE flame retardants on a global scale provides critical
insights into the effectiveness of the Stockholm Convention. In the
present study, we deployed passive sampling devices at 43 seawater
and freshwater sites covering 21 countries from 2016 to 2020. The
detection frequencies were 20–94% for BDE congeners and 33–42%
for dechlorane plus, higher than those (0–20%) for other target
compounds. The median concentrations of dissolved Σ9PBDE (sum of BDE-28, -47, -66, -85, -99, -100, -153, -154, and -183)
were 0.28 and 0.64 pg L–1 in seawater and freshwater,
respectively. The concentrations of dissolved Σ9PBDE,
along with published data, slightly increased before 2016 and remained
steady from 2016 to 2018, indicating delayed effects of the global
phaseout of technical Penta- and Octa-BDEs. The log-transformed concentrations
of individual BDE congeners were better correlated with regional gross
domestic product than with population density. The potential ecological
risk of BDE-47 was low, and there was a lack of key risk indicators
for other compounds. The present study documented the delayed response
of the aquatic environment to the regulatory actions on reducing PBDE
emissions.

在全球范围内监测多溴二苯醚（polybrominated diphenyl ethers, PBDEs）与非BDE类阻燃剂的溶解态浓度，可为《斯德哥尔摩公约》的实施成效提供关键科学参考。本研究于2016至2020年间，在覆盖21个国家的43个海水与淡水采样点位部署了被动采样装置。目标物中，BDE同系物的检出率为20%~94%，德克隆（dechlorane plus）的检出率为33%~42%，均显著高于其余目标化合物（0~20%）。溶解态Σ9PBDE（即BDE-28、-47、-66、-85、-99、-100、-153、-154与-183的总和）的中位浓度在海水与淡水中分别为0.28 pg·L⁻¹和0.64 pg·L⁻¹。结合已发表数据，溶解态Σ9PBDE的浓度在2016年前呈小幅上升趋势，2016至2018年间则保持稳定，这反映出商用五溴二苯醚与八溴二苯醚的全球淘汰政策存在滞后效应。经对数转换后的单种BDE同系物浓度，与区域国内生产总值（gross domestic product, GDP）的相关性优于其与人口密度的相关性。BDE-47的潜在生态风险较低，其余目标化合物则缺乏关键风险评估指标。本研究证实了水生环境对削减多溴二苯醚排放的管控措施存在滞后响应。