Time-dependent lethal body residues for the toxicity of pentachlorobenzene to Hyalella azteca.
The study examined the temporal response of Hyalella azteca to pentachlorobenzene (PCBZ) in water-only exposures. Toxicity was evaluated by calculating the body residue of PCBZ associated with survival. The concentration of PCBZ in the tissues of H. azteca associated with 50% mortality decreased from 3 to 0.5 micromol/g over the temporal range of 1 to 28 d, respectively. No significant difference was observed in the body residue calculated for 50% mortality when the value was determined using live or dead organisms. Metabolism of PCBZ was not responsible for the temporal response because no detectable PCBZ biotransformation occurred over an exposure period of 10 d. A damage assessment model was used to evaluate the impact and repair of damage by PCBZ on H. azteca. The toxicokinetics were determined so that the temporal toxicity data could be fit to a damage assessment model. The half-life calculated for the elimination of PCBZ averaged approximately 49 h, while the value determined for the half-life of damage repair from the damage assessment model was 33 h.
Landrum
Peter F
PF
Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Administration, Ann Arbor, Michigan 48105, USA. peter.landrum@noaa.gov
Steevens
Jeffery A
JA
Gossiaux
Duane C
DC
McElroy
Michael
M
Robinson
Sander
S
Begnoche
Linda
L
Chernyak
Sergei
S
Hickey
James
J
D033304:Amphipoda / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001711:Biotransformation; D002722:Chlorobenzenes / Q000378:metabolism / Q000633:toxicity*; D006207:Half-Life; D007928:Lethal Dose 50; D008962:Models, Theoretical; D009026:Mortality; D018570:Risk Assessment; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D002722:Chlorobenzenes; D014874:Water Pollutants, Chemical; C003060:pentachlorobenzene