Comparative distribution, sourcing, and chemical behavior of PCDD/Fs and PCBs in an estuary environment.

PCDD/F and PCB field data (1041 samples) in five media (dissolved, suspended sediment, bed sediment, catfish, and blue crab) were studied to explore dual contaminant patterns in the Houston Ship Channel, Texas, USA. PCDD/Fs showed greater concentration than PCBs in suspended sediments while PCBs were higher in apparent dissolved (truly dissolved+DOC-associated), fish, and crab. PCDD/Fs at nearly all locations contributed more strongly to dioxin-like toxicity.

PCB dry and wet weather concentration and load comparisons in Houston-area urban channels.

All 209 PCB congeners are quantified in water in both dry and wet weather urban flows in Houston, Texas, USA. Total water PCBs ranged from 0.82 to 9.

Spatial and temporal variation of polychlorinated biphenyls in the Houston Ship Channel.

An on-going study in the Houston Ship Channel (HSC) characterized polychlorinated biphenyl (PCB) levels in sediment, water, and tissue in 2002-2003 and 2008. The observed PCB concentration ranges in all media were higher than those measured in other PCB-impacted water bodies in the world, with the highest concentrations occurring within the industrialized segments. Contrary to polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/PCDF) observations, the PCB concentrations in the dissolved phase were greater than the suspended phase.

Bioaccumulation of polychlorinated dibenzodioxins and dibenzofurans in catfish and crabs along an estuarine salinity and contamination gradient.

Elevated but variable levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/Fs) were observed in hardhead sea catfish (HH) and blue crabs (BCs), as well as in water and sediment, of the Houston Ship Channel system, Texas, USA. It is hypothesized that the variation was caused by the spatial variability of PCDD/F contamination, together with the natural mobility of organisms in satisfying prey, temperature, salinity, and reproductive requirements. Structural equation modeling was applied to explore the congener-specific relationships between PCDD/F levels in HH and BC tissues and independent predictors such as PCDD/F contamination levels, environmental factors such as salinity and temperature, temporal-spatial factors such as site depth and season, and biological factors such as length, weight, and lipid content.

Concentrations of polychlorinated biphenyls (PCBs) in water, sediment, and aquatic biota in the Houston Ship Channel, Texas.

Polychlorinated biphenyls (PCBs) were quantified in water, sediment, and catfish and crab tissue collected from the Houston Ship Channel (HSC) in Texas. The total concentrations of the 209 PCB congeners ranged from 0.49 to 12.

Depositional flux of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in an urban setting.

Dry and wet deposition fluxes of the PCDD/F substituted congeners were measured at two different sites (Clinton Drive and Lang Road) in Houston, TX between December 2003 and April 2004. Average total dry deposition fluxes of 351 and 125pgm(-2)d(-1) were found at Clinton Drive and Lang Road, respectively. A wet deposition flux of 2.

Distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans in suspended sediments, dissolved phase and bottom sediment in the Houston Ship Channel.

Spatial distributions of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in the water column and bottom sediments of the Houston Ship Channel in Texas were measured three times over a 1-year period. Total TEQ concentrations in water ranged from 0.01 to 0.

Statistical investigation of polychlorinated dibenzo-p-dioxins and dibenzofurans in the ambient air of Houston, Texas.

Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (dioxins and furans) are persistent, bioaccumulative and highly toxic chemical constituents that appear in the environment at very low and difficult to measure levels. Although dioxins and furans are widely recognized as toxic contaminants needing regulation, their temporal and spatial concentration profiles and the factors impacting their partitioning and congener distribution are only moderately understood. This paper presents the results from one of the most extensive ambient air dioxin and furan sampling efforts conducted in a geographic area to date.