A review on sources of brominated flame retardants and routes of human exposure with emphasis on polybrominated diphenyl ethers

Abstract

The presence of brominated flame retardants (BFRs) in various environmental matrices, including humans, has been well documented. Increasing levels of these emerging contaminants in various environmental compartments suggest the wide application of these chemicals in products of everyday use. The release of BFRs from treated products is generally believed to be the major source of these contaminants into the environment, particularly in indoor environments. The sources and pathways through which BFRs enter the human system are evaluated in this paper. Human exposure via consumption of contaminated food and water, inhalation and ingestion of dust, as well as dermal absorption, are important pathways for these contaminants. Consumption of fatty foods especially fish, meat, dairy products as well as human milk constitute important routes for human exposure to these contaminants. Although brominated diphenyl ether (BDE) 209 has been found to be less bioaccumulative due to its high molecular weight, its dominance in indoor dust samples could be responsible for its detection in most human tissues investigated. BDE 47 is the most dominant polybrominated diphenyl ether (PBDE) congener found in human tissues. Regional differences in BFR levels in various environmental and biological matrices reflect their consumption patterns with higher levels mostly reported in the North American environments than in other regions of the world.

Polybrominated biphenyl ethers in breast milk and infant formula from Shanghai, China: Temporal trends, daily intake, and risk assessment

“…Based on our previous studies, the concentrations of BDE153 in food collected from markets and in indoor/outdoor house dust in Shanghai were much lower than those of BDE47 (Yu et al, 2011(Yu et al, , 2012b. Food and house dust were generally considered the major sources of PBDEs for humans (Daso et al, 2010;Harrad et al, 2010;Li et al, 2014). Thus, the high concentrations and unique pattern of PBDEs in breast milk, with BDE153 having the higher concentration than BDE47, could possibly be explained by the higher persistence of BDE153 than BDE47 (6.5 vs. 1.8 years estimated from the daily intake and the total body burden under steady state conditions in non-occupationally exposed adult humans) (Geyer et al, 2004).…”

Preliminary screening of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) flame retardants in landfill leachate

“…Due to concerns over their environmental persistence, toxicity, bioaccumulation potential and their propensity to undergo long-range atmospheric transport, the production and use of the penta-, octa-BDEs as well as HBCDD technical formulations have been globally restricted (UNEP 2009). Presently, only TBBPA and deca-BDE technical formulations are still being produced, although there are concerns over the possible microbial mediated or photolytic breakdown of the deca-BDE congener to the more toxic lower brominated congeners (Daso et al 2010). Recent reports from Europe and North America are indicating declining trends in the environmental levels of these BFRs, especially PBDEs (Airaksinen et al 2014, Kong et al 2014.…”

Occurrence of Selected Polybrominated Diphenyl Ethers and 2,2′,4,4′,5,5′-Hexabromobiphenyl (BB-153) in Sewage Sludge and Effluent Samples of a Wastewater-Treatment Plant in Cape Town, South Africa

“…Some of these were highlighted in recently published review articles (Shaw and Kannan 2009;Daso et al 2010). Discharges from wastewater treatment plants (WWTPs), particularly those receiving effluent from the industries as well as homes, are important point sources of PBDEs into the environment (North 2004;Song et al 2006;Peng et al 2009).…”