Environmental distribution of brominated flame retardants in Belgium

Brominated flame retardants (BFRs) are a diverse group of chemicals that are used to increase fire safety. They are incorporated into a wide range of products, such as TVs, computers, household appliances, textiles and upholstery. Some of them, such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), have led to both scientific and public concern since they have been found to accumulate in Man and wildlife. BFRs are linked to adverse physiological effects both in vitro and in vivo (e.g. interference in neurobehavioural development, foetal health and thyroid function). Adequate data on the effects are currently still insufficient to fully understand their toxicology.; This thesis presents analytical method development and measurements of BFRs in a wide range of environmental samples. Since concentrations of BFRs are low and since environmental pollution is not only restricted to these compounds, analysing these chemicals in environmental samples is a challenging task, necessitating severe quality control. Therefore, all methods that were developed and optimised in this work were finally validated through successful participation in inter-laboratory exercises. This thesis provides insight into the environmental distribution of BFRs and into the analytical aspects involved. In the first part of this thesis, the presence of PBDEs was investigated in aquatic environments. Geographical distribution and levels of PBDEs in sediments and biological samples, such as invertebrates and fish, were studied. In the second part of this thesis, the presence of PBDEs was investigated in terrestrial environments. Biological samples of representative wildlife avian and mammalian top predators were investigated for PBDEs. BIDE 209, a compound that is supposedly not bioavailable, was detected in the majority of the samples, which contradicts previously published statements and which suggests that legislative action is recommended for this chemical. In the third part of this thesis, PBDEs were investigated in relation to Man. A method for the determination of PBDEs, including BIDE 209, in (human) serum was developed. Additionally, human dietary exposure was assessed by means of a market-basket study. The fourth and final part of this thesis focuses on HBCD, which was investigated in selected aquatic samples.