HBCD MONITORING PROJECT - Europe-wide Monitoring of the Brominated Flame Retardant HBCD in Fish, Bird Eggs and SPM
Background & Aim
Hexabromocyclododecane (HBCD) is a flame retardant mainly used in building insulation composed of extruded or expanded polystyrene foam. Even if recent studies confirm that HBCD is completely degradable in the environment, studies on HBCD in European freshwaters report varying levels in sediments and biota (e.g. fish), whereas the levels are higher close to areas with known point sources. HBCD is lipophilic, so it can easily accumulate in tissues of organisms. Therefore, besides SPM, two bioindicators (Abramis brama, Corvus frugilegus) are used representing potential HBCD sinks in aquatic and terrestrial ecosystems. The results of the long-term study could give reliable information about persistence, bioaccumulation and toxic potential of HBCD in the environment.The most important objective of the project is to provide data that allow to follow the temporal trend of HBCD concentrations in the European environment over a period of up to ten years and to reveal the impact and relevance of emission control programs implemented by manufacturers and users.
The ‘HBCD monitoring project’ is sponsored by the ‘Industry Working Group for HBCD’, a sector group of the European Chemical Industry Council (CEFIC). Project duration is 2007-2016.
Sampling sites
Six fresh water sampling sites in five countries were selected representing four regions of interest in Europe. The Western Scheldt (NL) and river Tees (UK) were selected because these regions were already known as point sources. Scandinavian studies detected HBCD even in comparatively remote areas. For this reason the estuary of Göta älv, one of the biggest rivers in SW Sweden, was also included. Therivers Mersey (UK) and Rhône (F) are not especially contaminated with HBCD, but both are representatives of large freshwater systems loaded with domestic and industrial waste water. This collection of sampling sites guarantees an overview of distribution of HBCD in the European environment. The Lake Belau (GER), which is located in a rural area of Northern Germany, was chosen as reference site.
Specimens
The monitoring strategy focuses on compartments expected to be sinks for HBCD. For the aquatic environment fish is assumed to be the most appropriate organism for monitoring of bioaccumulating compounds. Following the criteria for an appropriate bioindicator, bream (Abramis brama), which is widely used for monitoring purposes (e.g. for the German Environmental Specimen Bank, ESB), has been selected as most suitable. It is quite common in European rivers, non-migrating and as a bottom feeder, bream is in contact with sediment which is assumed to be an HBCD sink. A representative number of adult breams (n=15) is caught once a year after the spawning season. Catchment is done by gill net or angle. Muscle tissue is dissected under clean air conditions and immediately frozen in liquid nitrogen. Sample processing is done according to the standard operating procedures (SOPs) of the German ESB. Because of the saltwater conditions in Western Scheldt (NL) soles (Solea solea) were taken additionally at this site.
The rook (Corvus frugilegus) is chosen as further specimen because it is sedentary and completely terrestrial feeding (e.g. worms, seeds), thus being directly related to the soil as another possible HBCD sink. The lipid-rich eggs are suitable for monitoring lipophilic compounds representing the load of the female bird. 15 eggs, preferably the first egg of each clutch, are taken out of the nests at the earliest possible date after laying. Sample processing is also done according to the standard operating procedures (SOPs) of the German ESB. Eggs are cooled and transported to the lab, where they are opened under clean air conditions. Egg contents are immediately frozen in liquid nitrogen. Fresh weight and shell characters (length, width, dry weight, shell thickness) are measured for biometric characterisation of samples. Sampling is run in a four-year period at two sampling sites near river Tees (UK) and Lake Belau (GER).
Suspended particular matter (SPM) is collected every three months by the colleagues of Free University Berlin. All HBCD analyses are performed at the Fraunhofer IME.
Results
First results will be presented soon.
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