Li Qingqing
Email Address
obgliqq@nus.edu.sg
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Publication Determination and occurrence of polybrominated diphenyl ethers in maternal adipose tissue from inhabitants of Singapore(2005) Li, Q.Q.; Loganath, A.; Chong, Y.S.; Obbard, J.P.; CHEMICAL & BIOMOLECULAR ENGINEERING; OBSTETRICS & GYNAECOLOGYPolybrominated diphenyl ethers (PBDEs), as a specific group of brominated flame retardants (BFR), are used in a variety of consumer products including electronics and household furnishings. In recent years, a marked increase in the levels of PBDEs in human biological tissues and fluids, especially breast milk, has been reported in several countries. However, few data are available from countries in the Asia-pacific region, including Singapore. This study presents a validated method procedure and the first available data of the concentrations of PBDE congeners: PBDE-47 (2,2,4,4-Tetrabromodiphenyl ether), PBDE-99 (2,2′,4,4′,5-Pentabromodiphenyl ether), PBDE-100 (2,2′,4,4′,6-Pentabromodiphenyl ether), PBDE-153 (2,2′,4,4′,5,5′-Hexabromodiphenyl ether), PBDE-154 (2,2′,4,4′,5,6′-Hexabromodiphenyl ether) in maternal adipose tissue collected from inhabitants of Singapore. Microwave-assisted extraction (MAE) of PBDEs spiked adipose tissues coupled with GC-MS analysis achieved comparable recoveries to a conventional Soxhlet Extraction (SE) procedure of between 70 and 130%. MAE also yielded comparable precision data (variance less than 13%) relative to the SE procedure. Spiked Carbon-13 PBDE congeners were also used as surrogates for MAE quality assurance and confirmed the efficiency of the procedure. PBDE congeners were detected in all of 16 maternal adipose tissues collected in Singapore, where levels were comparable to available data from Belgium. © 2005 Elsevier B.V. All rights reserved.Publication Persistent organic pollutants and adverse health effects in humans(2006) Li, Q.Q.; Loganath, A.; Chong, Y.S.; Tan, J.; Obbard, J.P.; DIVISION OF ENVIRONMENTAL SCIENCE & ENGG; OBSTETRICS & GYNAECOLOGYPublication Levels of persistent organic pollutant residues in human adipose and muscle tissues in Singapore(2006) Li, Q.Q.; Loganath, A.; Chong, Y.S.; Tan, J.; Obbard, J.P.; DIVISION OF ENVIRONMENTAL SCIENCE & ENGG; OBSTETRICS & GYNAECOLOGYPublication Multivariate data analyses of persistent organic pollutants in maternal adipose tissue in Singapore(2008-04-01) Tan, J.; Qing, Q.L.; Loganath, A.; Yap, S.C.; Xiao, M.; Obbard, J.P.; DIVISION OF ENVIRONMENTAL SCIENCE & ENGG; TROPICAL MARINE SCIENCE INSTITUTE; OBSTETRICS & GYNAECOLOGYPersistent organic pollutants (POPs) were detected in 88 maternal adipose tissue samples collected during year 2004 to 2006, in Singapore. Organochlorine pesticides (OCPs) were the most dominant followed by polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Multivariate data analyses (MVA) including principal component analysis (PCA), partial least-squares regression (PLSR), and partial least-squares discriminant analysis (PLS-DA) were applied to elucidate the relationship between concentrations of POPs in adipose tissues and donors' characteristics. Food consumption played the most significant role in accounting for levels of POPs in adipose tissue. Fish and poultry consumption was the route of PCBs and PBDEs in mothers in Singapore, while β-HCH came mainly from vegetables. An age-dependent accumulation of POPs was found for β-HCH and PCB congeners, and lactation and gestation functioned as a decontamination processes for PCBs in adipose tissue. Gestational diabetes mellitus (GDM) may change the profile of POPs in adipose tissue, probably due to an alteration in lipid metabolism. POPs investigated here may not be the cause of antenatal complication in pregnant women, and baby gender was not related to the pattern of contaminants in maternal adipose tissue. © 2008 American Chemical Society.