|Budget Amount *help
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1996: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
Information on molecular structure of chlorodioxins is accumulated. X-ray diffraction analysis of 1,3,6,8-TCDD gave the results that the molecular is planer with normal bonding lengthes and angles. 1,3,7,8-TCDD,1,2,3,7,8-TCDD,2-amino-2,3,7,8-TCDD 2 were synthesized and analyzed by X-ray diffraction. Those crystals are very fine needles and diffraction intensity was too small to get a refined results. Molecular orbital calculation of 22 isomers gave the result that all isomers have a planer structre with a bond length (C-Cl) of 1.775-1.777 and bond angle (C-O-C) of 113ﾟ
1,3,6,8-TCDD is known to occur widely in the environment as an impurity of herbicide CNP.
The toxicity test of 1,3,6,8-TCDD using Japanese Medaka and Freshwater Snail (Sakamakigai) showed low toxicity, although high bioaccumulation was observed. Toxicity test of dioxins and related compounds with rat cell showed toxic effect for 1,2,4,7,8-PCDD and 3,4,3', 4'-TCAB suggesting the presence of toxic isomera and congeners other than 2,3,7,8 substitted isomers.