HR: 1400h
AN: H33C-04    [Abstracts]
TI: Dioxin Chronology and Fluxes in Sediments of the Houston Ship Channel, Texas: Influences of Non-steady State Sediment Transport and Total Organic Carbon
AU: Yeager, K
EM: kevin.yeager@usm.edu
AF: Univ. Southern Mississippi, 1020 Balch Blvd., Stennis Space Center, MS 39529, United States
AU: Santschi, P
EM: santschi@tamug.edu
AF: Texas A&M Univ., 5007 Ave. U, Galveston, TX 77551, United States
AU: Raifai, H
EM: rifai@uh.edu
AF: Univ. of Houston, N107 Engineering Bld. 1, Houston, TX 77204, United States
AU: Suarez, M
EM: Monica.Suarez@mail.uh.edu
AF: Univ. of Houston, N107 Engineering Bld. 1, Houston, TX 77204, United States
AU: Brinkmeyer, R
EM: brinkmer@tamug.edu
AF: Texas A&M Univ., 5007 Ave. U, Galveston, TX 77551, United States
AU: Hung, C
EM: cchung@mail.ntou.edu.tw
AF: Institute of Marine Environmental Chemistry and Ecology, National Taiwan Ocaen Univ., Keelung, Twn 20224, China
AU: * Schindler, K
EM: kimberly.schindler@usm.edu
AF: Univ. Southern Mississippi, 1020 Balch Blvd., Stennis Space Center, MS 39529, United States
AU: Andres, M
EM: articcatfish@neo.tamu.edu
AF: Texas A&M Univ., 5007 Ave. U, Galveston, TX 77551, United States
AU: Weaver, E
EM: eaw7105@neo.tamu.edu
AF: Texas A&M Univ., 5007 Ave. U, Galveston, TX 77551, United States
AB: Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are persistent contaminants that bio-accumulate and pose serious risks to biota and humans. The primary objective of this study was to determine the history and mechanisms of dioxin accumulation in sediments of the Houston Ship Channel (HSC) using analytical data on natural and anthropogenic radionuclides (7Be, 137Cs and 210Pb) and dioxins. Results showed that present-day sedimentary dioxin accumulation rates are orders of magnitude higher than atmospheric inputs to the HSC, as determined from a wetland sediment core (FW1) and direct measurements. Most stations showed dioxin peaks in the near surface, indicating continuing inputs despite federal regulations. Stations with high dioxin inventories (11270 > 11193 > 16499 > 15979 > 11261) reflect accentuated accumulation in the HSC as one moves west towards Buffalo Bayou (11270, 15979), at the confluence of the HSC and the San Jacinto River (11261) and upstream in the San Jacinto River (11193). While station 11270 had the highest dioxin inventory, and nearby station 11261 had the highest sediment accumulation rates and dioxin fluxes, present-day dioxin fluxes at 11270 are less than average fluxes and inventories for station 11261 are less than average inventories, for all sites. These results support the interpretation that the HSC is influenced by episodic sediment resuspension, erosion and lateral transport processes driven by tides, wind, shipping and dredging, which can cause intermittently high accumulations of dioxins.
DE: 0496 Water quality
DE: 1040 Radiogenic isotope geochemistry
DE: 1834 Human impacts
DE: 4251 Marine pollution (0345, 0478)
SC: Hydrology [H]
MN: 2007 Joint Assembly