Hazard evaluation of ten organophosphorous insecticides against the midge, Chironomus riparius via QSAR

SAR and QSAR in Environmental Research
By: , and 



Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25°C) and pH (6, 7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log Kow was able to explain about 40–60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40–70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, 1χv and 3κ were best able to describe the variation in response among all compounds at each pH (70–90%). In the presence of sediment, even molecular connectivity could not describe the variability until the partitioning potential to sediment was accounted for by assuming equilibrium partitioning. After correcting for partitioning, the same molecular connectivity terms as in the aqueous exposures described most of the variability, 61–87%, except for the 11°C data where correlations were not significant. Molecular connectivity was a better tool than LSER or the unidimensional variables to explain the steric fitness of OP insecticides which was crucial to the toxicity.
Publication type Article
Publication Subtype Journal Article
Title Hazard evaluation of ten organophosphorous insecticides against the midge, Chironomus riparius via QSAR
Series title SAR and QSAR in Environmental Research
DOI 10.1080/10629369908039110
Volume 10
Issue 5
Year Published 1999
Language English
Publisher Wiley
Publisher location Hoboken, NJ
Contributing office(s) Great Lakes Science Center
Description 28 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title SAR and QSAR in Environmental Research
First page 423
Last page 450
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