Methods for Deriving Pesticide Aquatic Life Criteria - Reviews of Environmental Contamination and Toxicology - page 93

higher than needed, because the BMF term in the denominator is lacking and, if
present, would reduce the NOEC water .
The Canadian water quality criteria derivation protocol (CCME 1999) does not
add an additional factor for bioaccumulation. However, to derive a full guideline for
a bioaccumulative chemical does require reporting of bioaccumulation data; if such
data are lacking, then only an interim guideline can be derived. Moreover, Canada
has separate tissue residue guidelines (TRGs) for protection of fish-eating wildlife
(CCME 1997). These TRGs are not translated into safe water levels, but are
expressed as safe levels in fish tissue. Many TRGs are based on human health studies,
because data on safe dietary levels of chemicals in wildlife are unavailable.
Similar to the Canadian approach, the USEPA Great Lakes guidance (USEPA
2003a) does not incorporate bioaccumulation into aquatic life criteria. Rather, it
provides for derivation of separate water quality criteria for the protection of wild-
life and human health. The end result is that separate water quality criteria exist for
aquatic life, wildlife, and human health. Presumably, the decision about which
one(s) to apply to a particular water body, depends on beneficial use designations.
The authors of the Australia/New Zealand guidelines (ANZECC and ARMCANZ
2000) chose not to incorporate bioaccumulation into water quality criteria derivation
guidelines for two major reasons. First, the authors determined that the link between
concentrations of bioaccumulative chemicals in water and secondary poisoning is not
strong. Second, they determined that there is insufficient international guidance for
deriving bioaccumulation-based criteria. To address uncertainty surrounding what
constitutes a safe level for bioaccumulative chemicals (chemicals with log K ow values
between 3 and 7), when setting criteria for them, the Australia/New Zealand guide-
lines use the 1st percentile of the species distribution (rather than the 5th). Also, the
guidelines allow for site-specific, case-by-case application of available methods for
translating wildlife dietary levels into water quality criteria.
Because there is a potential for secondary poisoning effects in aquatic and
terrestrial animals, as well as human health concerns (which affect commercially
and recreationally important species), it is important to include a method of incor-
porating bioaccumulation into water quality criteria derivation. If a linkage can be
made between dietary exposure and adverse effects (e.g., from wildlife studies or
FDA action levels) then those effects data should be used, along with BCFs, BAFs,
and BMFs to translate food item concentration limits into water concentrations.

7.3.3 Threatened and Endangered Species

Because of their protected status, it is probable that very little toxicity test data will
exist for TES. However, it is important to ensure that these species are protected by
water quality criteria. Setting national criteria for TES that have limited geographic
range makes little sense, which explains why very few of the national criteria deri-
vation methodologies address TES. However, if the goal of a project is to develop
regional criteria, then protection of TES should be considered.