title: Assessing the toxicity of dodecylbenzene sulfonate to the midge Chironomus riparius using body residues as the dose metric.
abstract: Dodecylbenzene sulfonate (DBS) is a component of linear alkylbenzene sulfonate (LAS), an anionic surfactant, mainly used in household detergents. Due to the large quantity of DBS in use, there is concern over adverse environmental effects. This work examined the toxicokinetics and toxicity of the 2-phenyl isomer of dodecylbenzene sulfonate in 4-d, 10-d, and partial life-cycle tests on the midge, Chironomus riparius, exposed to aqueous solutions. Toxicokinetics were determined in 10-d uptake and 5-d elimination tests. The toxicokinetics were based on parent compound concentration in water and yielded an uptake coefficient (ku) of 17.5 (14.87-20.20) ml/g/h, an elimination rate constant (ke) of 0.073 (0.062-0.085) per h, a bioconcentration factor (BCF) of 56 to 240, and a half-life (t 1/2) of 9.5 (8.0-11.0) h. Biotransformation measurements did not reveal evidence for DBS metabolism. Thus, body residues, determined in the toxicity study, represent parent compound. In toxicity tests, 4- and 10-d LR50s (the body residue required to cause 50% mortality) in live midges were 0.72 (0.65-0.79) and 0.18 (0.08-0.42) mmol/kg, respectively. Thirty-day LR50s were 0.18 (0.09-1.64) and 0.21 (0.15-0.39) mmol/kg in duplicate studies. Of the sublethal endpoints, only developmental time increase was significant, with the lowest-observed-effect residues of 0.085 (0.067-0.105) and 0.100 (0.087-0.114) mmol/kg for male and female midges, respectively. Deformities in surviving larvae were also observed as chronic responses for body residues exceeding the 30-d LR50. The body residues required for mortality suggest that DBS acts like a polar narcotic in the midge.
authors.affiliation: Environmental Science Graduate Program and Department of Entomology, Ohio State University, 1735 Neil Avenue, Columbus, Ohio 43210, USA.
authors.forename: Haejo
authors.initials: H
authors.lastname: Hwang
authors.forename: Susan W
authors.initials: SW
authors.lastname: Fisher
authors.forename: Kyeok
authors.initials: K
authors.lastname: Kim
authors.forename: Peter F
authors.initials: PF
authors.lastname: Landrum
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Larson
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Versteeg
mesh_terms: D000818:Animals; D001557:Benzenesulfonates / Q000493:pharmacokinetics / Q000633:toxicity*; D001822:Body Burden; D001835:Body Weight / Q000187:drug effects; D002683:Chironomidae / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D005298:Fertility / Q000187:drug effects; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D007928:Lethal Dose 50; D008297:Male; D013501:Surface-Active Agents / Q000493:pharmacokinetics / Q000633:toxicity*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D001557:Benzenesulfonates; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; C001114:dodecylbenzenesulfonic acid