10 research outputs found
Levels and Concentration Ratios of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers in Serum and Breast Milk in Japanese Mothers
Blood and/or breast milk have been used to assess human exposure to various environmental contaminants. Few studies have been available to compare the concentrations in one matrix with those in another. The goals of this study were to determine the current levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in Japanese women, with analysis of the effects of lifestyle and dietary habits on these levels, and to develop a quantitative structure–activity relationship (QSAR) with which to predict the ratio of serum concentration to breast milk concentration. We measured PBDEs and PCBs in 89 paired samples of serum and breast milk collected in four regions of Japan in 2005. The geometric means of the total concentrations of PBDE (13 congeners) in milk and serum were 1.56 and 2.89 ng/g lipid, respectively, whereas those of total PCBs (15 congeners) were 63.9 and 37.5 ng/g lipid, respectively. The major determinant of total PBDE concentration in serum and milk was the geographic area within Japan, whereas nursing duration was the major determinant of PCB concentration. BDE-209 was the most predominant PBDE congener in serum but not in milk. The excretion of BDE 209 in milk was lower than that of BDE 47 and BDE 153. QSAR analysis revealed that two parameters, calculated octanol/water partition and number of hydrogen-bond acceptors, were significant descriptors. During the first weeks of lactation, the predicted partitioning of PBDE and PCB congeners from serum to milk agreed with the observed values. However, the prediction became weaker after 10 weeks of nursing
Concentrations and Profiles of Urinary Polycyclic Aromatic Hydrocarbon Metabolites (OH-PAHs) in Several Asian Countries
Concentrations
of 12 hydroxylated polycyclic aromatic hydrocarbons
(OH-PAHs) were determined in 306 urine samples collected from seven
Asian countries (China, India, Japan, Korea, Kuwait, Malaysia, and
Vietnam) by high-performance liquid chromatography-tandem mass spectrometry
(HPLC-MS/MS). The total concentrations of OH-PAHs found in the seven
Asian countries were in the following increasing order: Malaysia (median:
2260 pg/mL) < Japan (4030 pg/mL) < China (5770 pg/mL) < India
(6750 pg/mL) < Vietnam (8560 pg/mL) < Korea (9340 pg/mL) <
Kuwait (10 170 pg/mL). The measured urinary concentrations
of 1-hydroxypyrene (1-PYR) in samples from Malaysia, Korea, and Japan
(∼ 100 pg/mL) were similar to those reported for North America
and Western Europe. The concentrations of 1-PYR in urine samples from
China, India, and Vietnam were 4–10 times higher than those
reported for other countries, thus far. Among the 12 OH-PAH compounds
analyzed, hydroxynaphthalene (NAP: sum of 1-hydroxynaphthalene and
2-hydroxynaphthalene) was the dominant compound (accounting for 60–90%
of total OH-PAHs), followed by hydroxyphenanthrene (PHEN: sum of 2-hydroxyphenanthrene,
3-hydroxyphenanthrene, 4-hydroxyphenanthrene, and 9-hydroxyphenanthrene
[3–16%]), 2-hydroxyfluorene (3–20%), and 1-PYR (2–8%).
The total daily intakes (DIs) of PAHs were estimated based on the
urinary concentrations of their metabolites. The DIs of naphthalene
were found to be higher for populations in Korea, Kuwait, and Vietnam
(> 10 μg/day) than those of the other countries studied (∼
5 μg/day). The DIs of phenanthrene and pyrene (> 10 μg/day)
in the populations of China, India, and Vietnam were higher than those
estimated for the populations in the other countries studied (∼
5 μg/day)