Tr. Barber et al., TOXICITY OF HEXACHLOROBENZENE TO HYALELLA-AZTECA AND CHIRONOMUS-TENTANS IN SPIKED SEDIMENT BIOASSAYS, Environmental toxicology and chemistry, 16(8), 1997, pp. 1716-1720
Fourteen-day, whole-sediment toxicity tests using the amphipod Hyalell
a azteca and the midge Chironomus tentans were conducted on spiked sed
iment samples representing a range of hexachlorobenzene (HCB) concentr
ations. High rates of survival and growth relative to controls were ob
served in both test species. No observed effects concentrations (NOECs
) were equal to the highest HCB concentration tested (42 mg/kg, normal
ized to 1% total organic carbon). Available literature on the aquatic
toxicity of this hydrophobic chemical shows an absence of lethal and s
ublethal effects from exposure to HCB at or below water solubility con
centrations, and toxicity from exposure to dissolved HCB in sediment p
orewater therefore would not be expected. Because whole-sediment toxic
ity tests integrate exposure to HCB dissolved in porewater and adsorbe
d to particles, it was considered possible that exposure via sediment
ingestion could cause toxicity; however, no such effect was observed i
n this study.