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Polybrominated diphenyl ether (PBDE) congeners are constituents of flame retardants, and there is growing concern regarding their persistence, bioaccumulation, and toxicity. We collected breast milk samples between late 2001 and early 2003 from 54 U.K.-resident mothers. Of these, 27 originated from southeast England (London), and the other 27 originated from northwest England (Lancaster). Analysis of milk-fat extracts by gas chromatography-mass spectrometry was performed to determine the levels of 15 PBDE congeners, 15 polychlodnated biphenyl (PCB) congeners, and other selected chlorinated compounds. PCB and organochlorine (OC) levels in southeast samples were consistently higher, and significant differences (p < 0.05) were observed. ∑PBDE levels ranged from 0.3 to 69 ng/g lipid (geometric mean, 6.6 ng/g), and PBDE47 was the most abundant congener. ∑PCB levels ranged from 26 to 530 ng/g lipid (geometric mean, 150 ng/g) and were composed mainly of PCB-153 (26%), PCB-138 (20%), and PCB-180 (13%). OC levels for 1,1,1-trichloro-2,2bis(p-chlorophenyt)ethane (p,p'-DDT) and its metabolites (∑DDX) ranged from 24 to 2,300 ng/g lipid (geometric mean, 160 ng/g); hexachlorobenzene ranged from nondetectable levels to 180 ng/g lipid (geometric mean, 17 ng/g); and ∑hexachlorocydohexane levels ranged from 1.2 to 1,500 ng/g lipid (geometric mean, 16 ng/g). Using nuclear magnetic resonance-based metabonomics, samples (n = 7) containing the highest contaminant levels were compared with samples (n = 7) containing the lowest levels. Excellent separation along the first principal component implied that the chemical constituents of the two groups were significantly different. Although reasons for such differences remain obscure, lifestyle factors associated with a more heterogeneous London cohort could be responsible. Identifying primary routes of contaminant exposures and their biologic effects is of great importance. . . [ABSTRACT FROM AUTHOR]

Earthworms were taken across an environmental gradient of metal contamination for ecotoxicology assessment. Both indigenous (Lumbricus rubellus and L. terrestris) and introduced earthworms (Eisenia andrei, exposed in mesh bags) were studied. Changes in the levels of small molecule metabolites in earthworm tissue extracts were analysed by 1H NMR spectroscopy as a means of identifying combination biomarker compounds. Principal components analysis of the NMR spectral data revealed that biochemical changes were induced across the metal contamination gradient. Native worms (L. rubellus) from the most polluted sites were associated with an increase in the relative concentration of maltose; a decrease was also seen in the concentration of an as yet unidentified biomarker compound. Introduced worms (E. andrei) did not show differences to the same extent. Direct integration of the resonances from histidine and 1-methylhistidine showed that relative histidine concentrations were elevated slightly for L. rubellus, confirming the results of earlier mesocosm studies. Conversely, the relative concentrations of both histidine and 1-methylhistidine were greatly reduced by metal contamination in L. terrestris. This study demonstrates the utility of NMR spectroscopy in detecting previously unknown potential biomarkers for ecotoxicity testing and identified maltose as a potential biomarker compound deserving of further study.