Brominated flame retardants in wild bird eggs from the industrialised heartland of South Africa

Abstract

Brominated flame-retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), were analysed in 77 eggs of 13 wild bird species from Gauteng and northern Free State (the industrial heartland of South Africa). BFRs were in all eggs, but not all BFRs  were quantifiable. Concentrations ranged between 2.9 and 46 ng g⁻¹ wm (wet mass) and the predominant congeners were BDE-47, -153, -154, -183 and -209. The BFR compositional patterns of the congeners in eggs differed between species, feeding guilds, and habitats. Differences in associations of birds with humans seemed to have as much an influence as the trophic levels occupied by the maternal animals. The congener pattern of BFRs differed between terrestrial and aquatic species. The congener concentrations and patterns also differed from eggs from other  countries, suggesting differences in sources. BFR concentrations in eggs from the current study area were below a reported no observed effect level (NOEL; 1 000 ng g⁻¹ wm). Although this suggests that the BFRs do not pose a risk, the NOEL was mostly based on information from birds from moderate and colder climates. This NOEL might not apply to birds from warmer climates with different life histories, as in the current study, because there are currently only draft regulations on importing BFRs or BFR-containing products in South Africa. The BFR-containing products otherwise  destined for countries with BFR restrictions in place may now find their way to South Africa. The additional waste these poorly regulated products generate will eventually find their way to landfills ensuring that release to the environment and consequent exposures to biota will continue without effective interventions and waste management. Our findings indicate the need for on-going environmental monitoring to assess trends, identify hot spots, investigate effects, strengthen waste management, and the need to urgently implement the commitments under the Stockholm Convention.

Keywords: feeding guild, HBCD, hexabromocyclododecane, PBDEs, polybrominated diphenyl ethers, risk assessment, Stockholm
Convention, trophic level, waste