The brominated flame retardants, PBDEs and HBCD, in Canadian human milk samples collected from 1992 to 2005; concentrations and trends

• Published in: Environment international 2014-09, Vol.70, p.1-8
• Main Authors: Ryan, John Jake, Rawn, Dorothea F.K.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biomonitoring; Brominated flame retardants (BFRs); Canada; Environment. Living conditions; Environmental Exposure; Environmental pollutants toxicology; Female; Flame Retardants - analysis; Gas Chromatography-Mass Spectrometry; Halogenated Diphenyl Ethers - analysis; Hexabromocyclododecane (HBCD); Human milk; Humans; Hydrocarbons, Brominated - analysis; Medical sciences; Milk, Human - chemistry; Polybrominated diphenyl ethers (PBDEs); Public health. Hygiene; Public health. Hygiene-occupational medicine; Toxicology
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2014.04.020

Human milk samples were collected from individuals residing in various regions across Canada mostly in the years 1992 to 2005. These included five large cities in southern Canada as well as samples from Nunavik in northern Quebec. Comparative samples were also collected from residents of Austin, Texas, USA in 2002 and 2004. More than 300 milk samples were analysed for the brominated flame retardants (BFRs), PBDEs and HBCD, by extraction, purification and quantification using either isotope dilution gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-MS. The Canadian total PBDE values in the years 2002–2005 show median levels of about 20μg/kg on a lipid basis; a value significantly higher than in the 1980s and 1990s. Milk samples from Inuit donors in the northern region of Nunavik were slightly lower in PBDE concentrations than those from populated regions in the south of Quebec. Milk samples from Ontario contained slightly lower amounts of PBDEs in two time periods than those from Texas. HBCD levels in most milk samples were usually less than 1ppb milk lipid and dominated by the α-isomer. This large data set of BFRs in Canadian human milk demonstrates an increase in the last few decades in human exposure to BFRs which now appears to have stabilized. PBDE Congeners in human tissues as percent of total PBDEs [Display omitted] •PBDEs and HBCD were measured in more than 300 Canadian human milk collected from 1992 to 2005.•During this period, concentrations of PBDEs on a lipid basis increased over time to a median value of about 20μgkg-1.•Milks samples from Inuit donors in northern Quebec in two time periods showed slightly lower concentrations than those from southern Quebec.•Variation in levels of PBDEs spatially within Canada was small and Canadian milk levels were a little lower than those from the USA but much higher than Europe or Asia.