Methods for Deriving Pesticide Aquatic Life Criteria - Reviews of Environmental Contamination and Toxicology - page 94

Among the few methodologies that do address TES, procedures are given for
adjustment of criteria on a site-specific basis, provided data are available to assure
that one or more TES may not be protected by the criterion. For example, the Great
Lakes guidance (USEPA 2003a) provides two methods for altering criteria that may
protect TES (listed or proposed for listing): (1) if the SMAV for the TES, or a
surrogate species is lower than the FAV, then that SMAV may be used as the FAV;
or (2) site-specific criteria may be derived using the criteria recalculation proce-
dure, described in the USEPA Water Quality Standards Handbook (USEPA 1994).
The Australia/New Zealand guidelines suggest that TES may be protected through
selection of surrogate species (appropriate to a particular site) for inclusion in the
data set used to derive TVs (ANZECC and ARMCANZ 2000).
The ICE and QSAR approaches provide for quantitatively estimating toxicity for
TES, based on toxicity to surrogate species. While QSARs are limited to a few
specifically acting substances, ICE models can be applied to any substance. In
contrast, the ICE model has only been developed for acute toxicity, whereas
QSARs exist for prediction of both acute and chronic toxicity. These two estimation
techniques would probably best be used as a means to assess potential harm to TES
by comparing estimated toxicity values to derived criteria.

7.3.4 Harmonization/Coherence Across Media

The concept of harmonization is aptly described as follows (RIVM 2001): “The
objective of the harmonization procedure is to compare the concentrations at steady
state in the receiving compartments … with the MPCs that have been derived for
these compartments from the (eco)toxicological data. If this comparison indicates
that maintaining the concentration in the primary compartment (the compartment
of emission) at MPC level results in exceeding the MPC in any of the secondary
compartments, the set of MPCs must be considered incoherent and has to be
adjusted.” Briefly, according to the Dutch methodology (RIVM 2001) the scheme
for harmonizing aquatic life water/sediment/soil ERLs is as follows: (1) if sufficient
direct toxicity data are unavailable for soil or sediment, then the ERL is derived
from water data by the equilibrium partitioning (EqP) method, and this becomes the
final, harmonized soil/sediment ERL; (2) if there is sufficient data to allow statistical
extrapolation (by a refined effects assessment) of soil/sediment data, then the ERL
is derived directly and no further harmonization is required; (3) if the soil/sediment
ERL is determined by a preliminary effects assessment (by application of AFs to
limited data sets), then this value is compared to the value determined by the EqP
approach and the lower of the two values is accepted as the harmonized ERL. This
procedure is used with the caveat that there are uncertainties in both the ERLs and
in the partition coefficients.
To harmonize ERLs with human health risk limits, the Netherlands methodology
(RIVM 2001) uses a multimedia box model to estimate equilibrium concentrations
in secondary (receiving) compartments, providing an ERL has been derived for a
primary (emission) compartment. Utilizing Van De Meent's (1993) SimpleBox