Time-Dependent Toxicity of Fluoranthene to Freshwater Invertebrates and the Role of Biotransformation on Lethal Body Residues
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- 作者：Lance J. Schuler ; Peter F. Landrum ; and Michael J. Lydy
- 刊名：Environmental Science & Technology
- 出版年：2004
- 出版时间：December 1, 2004
- 年：2004
- 卷：38
- 期：23
- 页码：6247 - 6255
- 全文大小：188K
- 年卷期：v.38,no.23(December 1, 2004)
- ISSN：1520-5851
文摘
The time-dependent toxicity of fluoranthene was examinedfor Hyalella azteca, Chironomus tentans, and Diporeiaspp. C. tentans appeared to be the most sensitive species,and Diporeia was the least sensitive. Incipient LC50values, the concentration at which the LC50 reaches anasymptote and does not change with increasing durationof exposure, for H. azteca and C. tentans were approximately60 and 40 
s/entities/mgr.gif">g·L-1, respectively. Incipient levels were notreached for Diporeia; however, the 28-d LC50 concentrationwas 95.5 s/entities/mgr.gif">g·L-1. There was a temporal relationship withrespect to lethal body residues for each of the test species.For H. azteca, the LR50, the median lethal residue at anidentified exposure time required to cause 50% mortality,based on total fluoranthene equivalents (parent + metabolitecompounds) decreased from 3.19 s/entities/mgr.gif">mol·g-1 at 5 d to 0.80s/entities/mgr.gif">mol·g-1 at 28 d. For C. tentans, the LR50 decreased from 0.43to 0.17 s/entities/mgr.gif">mol·g-1 from 2 to 10 d. The 10-d LR50 for Diporeiawas 9.97 s/entities/mgr.gif">mol·g-1, and the 28-d value was 3.67 s/entities/mgr.gif">mol·g-1.The toxicokinetics are not sufficient to address the temporalchanges in LR50 values. Thus, the data were fit to aDamage Assessment Model that also accounts fortoxicodynamic processes. This analysis provides estimatesof the incipient lethal residues for H. azteca, C. tentans,and Diporeia: 0.84, 0.21, and 3.00 s/entities/mgr.gif">mol·g-1, respectively.When comparing the relative sensitivity among species usinglethal body residues, special attention should be givento ensure that comparisons are made at a common pointin relation to exposure duration (i.e., time to steadystate, Tss). When the LR50(lipid) values among the threespecies were compared at steady state, C. tentans is moresensitive than H. azteca and Diporeia spp.; however,there are no significant differences between the amphipodspecies. The greater sensitivity of C. tentans to fluorantheneas compared to the amphipods may be due, in part, toa potential toxic metabolite.