The Coastal Resource Coordinator's Bioassessment Manual

HAZMAT 93-1–Toxicity Tests
complex wastewater effluents, similar approaches have been taken with sediment pore
water or sediment elutriate. At the present time, there are no TIE procedures available to
directly test bulk sediment (Ankley et al., 1992). When the cause of toxicity in bulk sediment
is to be determined, TIE procedures can be conducted on sediment elutriates or pore water
samples. However, toxicity of elutriate or pore water must first be confirmed. TIEs are
currently only in the research and development stage.
Figure 3-1. TIE strategy to evaluate contributions of contaminant groups (Ankley et
al., 1991).
For sediment elutriates and pore water, a phased approach to eliminate possible groups of
chemicals causing toxicity can be useful (Ankley et al., 1992; Giesy and Hoke, 1990).
Ammonia can be eliminated as the cause of toxicity if toxicity does not occur in samples
after pH has been increased, or if measured concentrations of ammonia are known to be
below toxic levels. Similarly, hydrogen sulfide is more toxic at low pH values and toxic
levels of hydrogen sulfide have been identified for many species. Cationic metals can be
implicated as a cause of toxicity by testing the toxicity of a chelated sample. If toxicity
decreases after chelation of the sample, cationic metals are implicated and further chemical
analyses of the sample may indicate which metals are responsible. Nonpolar organic
compounds such as PAHs, pesticides, and PCBs are implicated as a cause if toxicity is
3-15 August 1997