Can polychlorinated biphenyl (PCB) signatures and enantiomer fractions be used for source identification and to age date occupational exposure?
Detailed polychlorinated biphenyl (PCB) signatures and chiral Enantiomer Fractions (EFs) of CB-95, CB-136 and CB-149 were measured for 30 workers at a transformer dismantling plant. This was undertaken to identify sources of exposure and investigate changes to the PCB signature and EFs over different exposure periods. Approximately 1.5 g of serum was extracted and PCB signatures were created through analysis by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) and EFs calculated following analysis by gas chromatography with high resolution mass spectrometry (GC-HRMS). A total of 84 PCBs were identified in the serum samples with concentrations of the 7 indicator PCBs ranging from 11-350 ng g(-1) of serum (1.2-39 μg g(-1) lipid). The PCB signatures were interpreted using principal component analysis (PCA) which was able to distinguish workers with background or recent minimal exposure from those with prolonged occupational exposure. Occupationally exposed individuals had a similar PCB profile to Aroclor A1260. However, individuals with prolonged exposure had depleted proportions of several PCB congeners that are susceptible to metabolism (CB-95, CB-101 and CB-151) and elevated proportions of PCBs that are resistant to metabolism (CB-74, CB-153, CB-138 and CB-180). The results also identified a third group of workers with elevated proportions of CB-28, CB-60, CB-66, CB-74, CB-105 and CB-118 who appeared to have been exposed to an additional source of PCBs. The results show near complete removal of the CB-95 E2 enantiomer in some samples, indicating that bioselective metabolism or preferential excretion of one enantiomer occurs in humans. By considering PCB concentrations along with detailed congener specific signatures it was possible to identify different exposure sources, and gain an insight into both the magnitude and duration of exposure.
Biogeochemistry Research Centre, SoGEES, Plymouth University, Plymouth, Devon PL4 8AA, UK. Electronic address: dpmegson@hotmail.co.uk.
David
D
Megson
Department of Chemistry, University of Liège, Allèe de la Chimie, Liège, Belgium.
Jean-Françios
JF
Focant
Exponent Inc., One Capital City Plaza, Suite 1620, 3350 Peachtree Road, Atlanta, GA 30326, USA.
Donald G
DG
Patterson
Department of Chemistry, Brock University, 500 Glenridge Ave, St. Catharines, ON L2S 3A1, Canada; Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, Ontario M9P 3V6, Canada.
Matthew
M
Robson
Biogeochemistry Research Centre, SoGEES, Plymouth University, Plymouth, Devon PL4 8AA, UK.
Maeve C
MC
Lohan
Biogeochemistry Research Centre, SoGEES, Plymouth University, Plymouth, Devon PL4 8AA, UK.
Paul J
PJ
Worsfold
Biogeochemistry Research Centre, SoGEES, Plymouth University, Plymouth, Devon PL4 8AA, UK.
Sean
S
Comber
Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XQ, UK.
Robert
R
Kalin
Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, Ontario M9P 3V6, Canada.
Eric
E
Reiner
Department of Environmental Science, Mount Royal University, 4825 Mount Royal Gate SW, Calgary, Alberta T3E 6K6, Canada.
Gwen
G
O'Sullivan
D004785:Environmental Pollutants / Q000097:blood* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000097:blood* / Q000737:chemistry; D025341:Principal Component Analysis; D013237:Stereoisomerism
D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
Chemical fingerprinting; Chiral; Enantiomer fractions; GC×GC–TOFMS; Human exposure; PCB atropisomers; Polychlorinated biphenyls (PCBs)