title: Survey of dioxins in Tokyo Bay bottom sediment.
abstract: This paper examines dioxin profiles in bottom sediments from Tokyo Bay, Japan using sedimentation dating based on 210Pb measurements and dioxin measurements based on particle size distributions. Dioxin concentrations in surface sediment ranged from 3.2 to 52 pg-TEQ g(-1), with the concentrations in the bay back and central region being higher than those at the front of the bay. The vertical dioxin concentration in sediment core samples showed peak levels from years 1962 to 1980, with the maximum being 110 pg-TEQ g(-1). Principal component analysis indicates that the main source of dioxins in bottom sediment from the back of bay are herbicides such as CNP, while in the front of bay atmospheric deposition due to incineration activities are responsible. Dioxins in bottom sediment were mainly found in the particles <75 microm in size.
authors.affiliation: Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakamaachi, Koganei-shi, 184-8588, Tokyo, Japan. hosomi@cc.tuat.ac.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hosomi
authors.forename: Tomonori
authors.initials: T
authors.lastname: Matsuo
authors.forename: Sirou
authors.initials: S
authors.lastname: Dobashi
authors.forename: Sinji
authors.initials: S
authors.lastname: Katou
authors.forename: Hirohide
authors.initials: H
authors.lastname: Abe
mesh_terms: D004147:Dioxins / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D017745:Incineration; D010316:Particle Size; D012037:Refuse Disposal; D014041:Tokyo; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D004147:Dioxins; D014874:Water Pollutants, Chemical