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Abstract: In vivo studies indicate that prenatal or neonatal exposure of rodents to polybrominated diphenyl ethers (PBDEs) disrupts thyroid hormone balance, but few studies have reported an association of PBDEs and insulin-like growth factor 1 (IGF-1). The goal was to examine whether PBDEs exposure affects the levels of thyroid hormones and IGF-1 in cord blood. Study participants were healthy pregnant women recruited from the general population in central Taiwan between 2000 and 2001 and in southern Taiwan from 2007 to 2009. One-hundred-forty-nine breast milk samples (n =149), which were collected within one month after delivery, were analyzed using a high resolution gas chromatograph equipped with a high resolution mass spectrometer. The average and median levels of breast milk Σ14PBDEs were 5.34 and 3.38ng/g lipid in 2000–2001 and 5.22 and 3.13ng/g lipid in 2007–2009, respectively. In general, levels of PBDE congeners were very low in this study population and not significantly different between the years 2000–2001 and 2007–2009. Breast milk Σ14PBDEs were not significantly correlated with thyroid hormones and IGF-1 in cord blood. After examining multiple stepwise linear regression models with adjustment for maternal age, pre-pregnancy body mass index (BMI), parity, gestational age, and region (namely, central and southern Taiwan), we found that log of T4 in cord blood was significantly but slightly correlated with higher BDE-154 (B =0.113, p =0.017) in breast milk. The log of FT4 concentration was significantly related to a decrease in the log of BDE-99 level (B =−0.137, p =0.043) and an increase in the log of BDE-154 level (B =0.158, p =0.008). Meanwhile, the log of IGF-1 level was also significantly linked to an increase in the log of BDE-196 level (B =0.532, p =0.028) and decrease in the log of BDE-85 level (B =−0.235, p =0.018). Few epidemiological studies report an association between PBDEs exposure and IGF-1. Based on our findings, further in vivo and epidemiological studies are encouraged and needed to explore associations between PBDEs exposure and levels of thyroid hormones and IGF-1. [Copyright &y& Elsevier]

Elementary school classroom dust is an important source of exposure to polybrominated dibenzo- p -dioxins/furans and diphenyl ethers (PBDD/DF/DEs) for school-age children. Our goal is thus to investigate concentrations of PBDD/DF/DEs in elementary school classroom dust to further assess the impact on school-age children via ingestion. The dust from classrooms, including both normal (NR) and computer classrooms (CR), was collected from six urban and four rural schools. Fourteen PBDEs and twelve PBDD/Fs were measured using high-resolution gas-chromatography/high-resolution mass-spectrometry. The mean levels of Σ 14 PBDEs in NR and CR dust from the urban classrooms were 370 and 2510 ng/g and those whose dust from the rural classrooms were 464 and 1780 ng/g. The means of ΣPBDD/Fs were 0.0401 ng-WHO 2005 -TEQ/g (concentration: 4.72 ng/g) in urban NR dust, 0.0636 ng-WHO 2005 -TEQ/g (7.51 ng/g) in urban CR dust, 0.0281 ng-WHO 2005 TEQ/g (3.60 ng/g) in rural NR dust, and 0.0474 ng-WHO 2005 TEQ/g (6.28 ng/g) in rural CR dust. The PBDEs pattern in NR dust was quite different from that in CR dust, but the PBDD/Fs patterns in NR and CR dust were similar. A linearly significant correlation coefficient ( n = 20, r = 0.862, p < 0.001) was found between ΣPBDEs and ΣPBDD/Fs in NR and CR dust, indicating that the PBDEs and PBDD/Fs in the dust may be from the same sources in the elementary school classrooms. This study assessed the risks (daily intake and cancer and non-cancer risks) of PBDEs and PBDD/Fs for the children from the classroom dust, and the calculated risk values did not exceed the related thresholds. With regard to the exposure scenarios for school-age children in an indoor environment, the results suggest that they might ingest more dust PBDD/DF/DEs in their homes than in the schools. In conclusion, the exposure of Taiwanese elementary school children to PBDD/DF/DEs via indoor dust was with a safe range based on our findings. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present study is to determine whether levels of polybrominated diphenyl ethers in breast milk in the general population are associated with demographic parameters, socioeconomic status, lifestyle factors, and occupational exposure. Forty-six participants are randomly selected from healthy women recruited between April 2007 and April 2008 from local hospitals in southern Taiwan. Thirty PBDE isomers in breast milk are analyzed using a gas chromatograph with a high resolution mass spectrometer. The mean±standard deviation of ∑PBDEs in breast milk is 3.59±1.07ng/g lipid. Our current value of ∑PBDEs in breast milk is 0.7-fold lower compared to the past value in our previous study between 2000 and 2001. Higher levels of ∑PBDEs might be significantly associated with older maternal age and maternal age of the present study is between 22 and 42 years old. Levels of ∑PBDEs and certain PBDEs in breast milk are not correlated with maternal pre-pregnant BMI (Body mass index), parity, and lipid contents of breast milk. The ∑PBDEs level in breast milk is lower in more educated women after controlling for age and pre-pregnancy BMI in our subjects. The main factors associated with ∑PBDEs in breast milk are age and education level among the binary variables of demographic, socioeconomic, and lifestyle characteristics in this report. The exploratory relationships are found between PBDEs in breast milk and age, education level, or occupational exposure due to small sampling size. [Copyright &y& Elsevier]