2 research outputs found
Development and Practical Application of Petroleum and Dispersant Interspecies Correlation Models for Aquatic Species
Assessing
the acute toxicity of oil has generally relied on existing
toxicological data for a relatively few standard test species, which
has limited the ability to estimate the impacts of spilled oil on
aquatic communities. Interspecies correlation estimation (ICE) models
were developed for petroleum and dispersant products to facilitate
the prediction of toxicity values to a broader range of species and
to better understand taxonomic differences in species sensitivity.
ICE models are log linear regressions that can be used to estimate
toxicity to a diversity of taxa based on the known toxicity value
for a surrogate tested species. ICE models have only previously been
developed for nonpetroleum chemicals. Petroleum and dispersant ICE
models were statistically significant for 93 and 16 unique surrogate-predicted
species pairs, respectively. These models had adjusted coefficient
of determinations (adj-<i>R</i><sup>2</sup>), square errors
(MSE) and positive slope ranging from 0.29 to 0.99, 0.0002 to 0.311,
and 0.187 to 2.665, respectively. Based on model cross-validation,
predicted toxicity values for most ICE models (>90%) were within
5-fold
of the measured values, with no influence of taxonomic relatedness
on prediction accuracy. A comparison between hazard concentrations
(HC) derived from empirical and ICE-based species sensitivity distributions
(SSDs) showed that HC values were within the same order of magnitude
of each other. These results show that ICE-based SSDs provide a statistically
valid approach to estimating toxicity to a range of petroleum and
dispersant products with applicability to oil spill assessment
Framework for Optimizing Selection of Interspecies Correlation Estimation Models to Address Species Diversity and Toxicity Gaps in an Aquatic Database
The
Chemical Aquatic Fate and Effects (CAFE) database is a tool
that facilitates assessments of accidental chemical releases into
aquatic environments. CAFE contains aquatic toxicity data used in
the development of species sensitivity distributions (SSDs) and the
estimation of hazard concentrations (HCs). For many chemicals, gaps
in species diversity and toxicity data limit the development of SSDs,
which may be filled with Interspecies Correlation Estimation (ICE)
models. Optimization of ICE model selection and integration ICE-predicted
values into CAFE required a multistep process that involved the use
of different types of data to assess their influence on SSDs and HC
estimates. Results from multiple analyses showed that SSDs supplemented
with ICE-predicted values generally produced HC5 estimates that were
within a 3-fold difference of estimates from measured SSDs (58%β82%
of comparisons), but that were often more conservative (63%β76%
of comparisons) and had lower uncertainty (90% of comparisons). ICE
SSDs did not substantially underpredict toxicity (<10% of comparisons)
when compared to estimates from measured SSD. The incorporation of
ICE-predicted values into CAFE allowed the development of >800
new
SSDs, increased diversity in SSDs by an average of 34 species, and
augmented data for priority chemicals involved in accidental chemical
releases