The Toxicologist - Society of Toxicology

modating a reliable data evaluation given the high false positives potential at part
per trillion levels. None of the analytes were detected in soil-leachate and groundwater
samples. Fluoxetine was detected in the leachate of biosolids and the implications
were evaluated. While this study was based on agreed upon protocol, challenge
is to prove “safe” conditions. Public continually request additional analysis as
new analytical methods evolve. Therefore, instead of individual chemical analysis
and risk estimations, biomarker assays that measure response to chemical groups
could serve as alternative analytical tools at biosolids facilities. This project also addressed
effective public communication challenges and the perceptions of exposures
to large mixture of microconstituents.
1265 SITE EVALUATION OF BIOACCESSIBILITY OF
DIOXINS/FURANS FROM SOIL.
Y. W. Lowney 1 , G. Brorby 2 and R. Kalmes 2 . 1 Exponent, Boulder, CO and
2 Exponent, Oakland, CA.
A bioaccessibility extraction test for dioxins/furans in soil was implemented for soils
from a former magnesium plant in Nevada. Fingerprint analyses indicated that the
majority of the congeners were furans, particularly octafurans, whereas most of the
published studies on bioaccessibility were conducted on 2,3,7,8-tetrachlorodibenzo-p-dioxin
(2,3,7,8-TCDD). Therefore, the objective of the study was
to provide site-specific information to understand the relative oral bioavailability of
dioxins/furans from site soils (on a toxicity equivalent [TEQ] basis). Ten surface
soil samples were collected from areas of the site where data indicated that
dioxin/furan TEQ concentrations generally ranged between 1000 and 3000 ppt
and that included a representative range of organic carbon content, the latter having
been shown to affect bioaccessibility. The soil samples were allowed to air dry,
sieved to the