[Correlations between HBCD and thyroid hormone concentrations in human serum from production source area].

The levels of hexabromocyclododecane (HBCD) in human serum from the HBCD production source region were detected by UPLC-ESI-MS/MS. The concentrations (lipid weight) of ∑ HBCD in 80 serum samples ranged from not detectable to 2702.5 ng · g(-1). The mean and median values were 104.9 ng · g(-1) and 5.9 ng · g(-1), respectively. The most abundant HBCD isomer in 42 samples was γ-HBCD, while α-HBCD was the most abundant isomer in the other 26 serum samples. There was no significant difference in ∑ HBCD concentration among different age and gender. In this study, the thyroid hormone abnormality rate in the 80 residents was up to 33%. The thyroid hormone abnormality rate of the residents whose serum HBCD was detected was significantly higher than those without HBCD in serum. Since the local residents were highly exposed to HBCD, the probability of thyroid abnormality might be significantly increased.

[Correlations between PBDEs and thyroid hormone concentrations in adults from production source area].

Polybrominated diphenyl ethers (PBDEs) concentrations in 36 resident serum samples from PBDEs production source area were analyzed by gas chromatography/negative chemical ionization/mass spectrometry(GC-NCI-MS) method, and the concentrations of thyroid hormones were determined as well. The sigma5PBDEs (BDE-28, -47, -153, -183, -209) concentrations(lipid weight) in serum ranged from 130.3 to 4 478.4 ng x g(-1), with an average value of 529.9 ng x g(-1). BDE-209 was a dominant PBDE congener, on average accounting for 69.8% of the total PBDEs concentrations. Spearman rank correlation coefficient was calculated between PBDEs and thyroid hormone, it showed that there were high significant negative correlation between BDE-28, -47, -153, -183 and thyroid-stimulating hormone (TSH), and significant negative correlation was also found between BDE-183 and free thyroxine (fT4). Additionally, there were significant positive correlation between BDE-28, -47 and triiodothyronine (T3), as well as between BDE-28, -153, -183 and free triiodothyronine(fT3). In summary, the concentrations of PBDEs in serum in this study were at a high level, and BDE-209 was the predominant congener. The exposure to the PBDEs may affect thyroid hormone levels, and the further research should focus on the relationship between PBDEs and thyroid hormone concentrations.