環境中のヘキサブロモシクロドデカンの分析法および調査

Abstract

1,2,5,6,9,10-hexabromocyclododecane diastereomers (HBCDs) are used as flame retardants in thermal insulation building materials, upholstery textiles, and electronics. Due to the widespread use and the physical and chemical properties, HBCDs are now ubiquitous contaminants in the environment. The environmental distribution and behavior are to be revealed. In Nagoya city, HBCDs have been detected with a high frequency in the environment in various compartments.In the present paper, we report a measurement method and concentrations of HBCDs in various environmental compartments (water, sediment, and biological samples) in Nagoya city, and discuss on environmental distribution, time trends in concentrations and possibility of biodegradation. HBCDs were detected in various water samples, of which concentrations of the total isomers ranged from <0.76 to 79 ng/L. γ-HBCD dominated over the other isomers in water samples. Similarly, sediment samples were dominated by γ-HBCD, which was detected in all samples, ranged from <1.9 to 58 ng/g-dry. In the most of fish and shellfish samples, α-HBCD was the predominant isomer of HBCDs and was found in all the samples in levels from 25 to 6300 ng/g-lipid. On the other hand, γ-HBCD was predominant similar to those in industrial products in some samples which supposed to be collected near the discharge point. In breast milk, α-HBCD was also predominant and was found in all samples in concentrations from <3.7 to 13 ng/g-lipid. In the degradation experiments of HBCDs with sediments, potential for biodegradation was implied under anaerobic condition.