A Field Study of Soil and Biological Specimens from a Herbicide Storage and Aerial-Test Staging Site Following Long-Term Contamination with TCDD
A study was made of the residual levels of 2,3,7,8-tetrachloro- dibenzo-p-dioxin (TCDD) in soil and biological samples collected from an area on Eglin AFB, Florida, that was used for storing and loading herbicides from 1962–1970. The study deals only with the immediate vicinity of the storage and loading area and its associated drainage system. Soil and sediment samples were collected and analyzed to determine residual TCDD levels. Various tissues from specimens representing 12 species of the native fauna were also analyzed for TCDD content.
Soil concentrations above 1 parts-per-billion (ppb) TCDD were largely confined to a small area immediately surrounding the concrete loading pad. Nevertheless this area where storage and loading operations had occurred, soil concentrations of TCDD as high as 275 ppb were found with concentrations of one-third that amount present to a depth of one meter at two of the nine sampling sites.
TCDD was present in many of the organisms collected from the upper portions of the drainage system of the contaminated area, but no organisms collected from Tom’s Bayou, 3000 meters downstream, contained detectable levels of TCDD. Visual observations revealed no gross abnormalities on any of the specimens. Histopathological studies of tissues from five contaminated specimens, representing five species, showed no microscopic anomolies.
Isomeric analyses of soil, sediment, biological samples, and Herbicide Orange held in storage for at least 10 years verified that the predominant isomer was 2,3,7,8-TCDD.
KeywordsSoil Concentration Phenoxyacetic Acid Fill Dirt Predominant Isomer Metal Spatula
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