Biomagnification of Higher Brominated PBDE Congeners in an Urban Terrestrial Food Web in North China Based on Field Observation of Prey Deliveries

Abstract

As an important group of brominated flame retardants, polybrominated diphenyl ethers (PBDEs) persist in the wildlife food webs. However, the biomagnification of PBDEs has not been adequately studied in the terrestrial food webs. In this study, a terrestrial food web composed of common kestrels, sparrows, rats, grasshoppers, and dragonflies in the urban environment from northern China was obtained. A field prey delivery study, reinforced by δ 13 C and δ 15 N analyses, indicates that sparrows are the primary prey items of common kestrels. Concentrations of PBDEs were in the following order: common kestrel > sparrow > rat > grasshopper and dragonfly with BDE-209 as the dominant congener. Biomagnification factors (BMFs) were calculated as the ratio between the lipid normalized concentrations in the predator and prey. The highest BMF (6.9) was determined for BDE-153 in sparrow/common kestrel food chain. Other higher brominated congeners, such as were also biomagnified in this terrestrial food chain with BMF of 1.3À4.7. BDE-47, -99, and -100 were found to be biodiluted from sparrow to common kestrel (BMFs < 1). Measured BMF values for BDE-153, -47, -99, and -100 were consistent with predicted values from a nonsteady-state model in American kestrels from another study. Retention factors and metabolism of BDE congeners may be confounding factors influencing the measured BMFs in this current study.

Occurrence and biomagnification of organohalogen pollutants in two terrestrial predatory food chains

“…For instance, aquatic birds were usually BDE-47 accumulated, whereas the birds feeding entirely or partially on terrestrial-based food items had elevated abundance of BDE-153 or higher brominated congeners (Chen and Hale, 2010). Our previous study (Yu et al, 2011) also suggested the particular concern over the bioaccumulation and biomagnification of BDE-209 and its degradation products because of their possibly high ecological risks in terrestrial ecosystems. A study conducted in Belgium also showed indisputable biomagnification of PBDEs in two avian food chains (great titÀsparrowhawk and rodentÀbuzzard feeding relationships), whereas no biomagnification was found in the rodent-fox food chain (Voorspoels et al, 2007).…”

Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

“…Then, the extract was further cleaned up using SPE column chromatography, which has been proven to be an effective method for purifying PBDEs in small samples of biota (He et al, 2010;Yu et al, 2011). In consideration of the large sample volumes used in the present study, a separation step using a complex silica gel column was added between the GPC treatment and SPE column chromatography steps.…”

“…One tenth of the extracts of fish carcasses was used to quantify the PBDE congeners using a method described in detail previously (Zeng et al, 2012;Yu et al, 2011). The remaining extracts were used to determine purities and to perform CSIA using the method developed in the present study.…”

Organohalogen contamination in passerine birds from three metropolises in China: Geographical variation and its implication for anthropogenic effects on urban environments

“…Procedures for sample pretreatment have been given in details in our previous study (Yu et al, 2011) with modest modifications. Approximately 1 g muscle tissue was homogenized after lyophilization and Soxhlet extracted with acetone/hexane (1:1, v/v).…”

“…Flash EA 112 series elemental analyzer coupled with a Finnigan MAT ConFlo III isotope ratio mass spectrometer using freeze-dried subsamples. Specific analytical approach and the assessment of isotopic ratios were previously given elsewhere (Yu et al, 2011).…”