Aquatic toxicity of triclosan.
The aquatic toxicity of triclosan (TCS), a chlorinated biphenyl ether used as an antimicrobial in consumer products, was studied with activated-sludge microorganisms, algae, invertebrates, and fish. Triclosan, a compound used for inhibiting microbial growth, was not toxic to wastewater microorganisms at concentrations less than aqueous solubility. The 48-h Daphnia magna median effective concentration (EC50) was 390 microg/L and the 96-h median lethal concentration values for Pimephales promelas and Lepomis macrochirus were 260 and 370 microg/L, respectively. A no-observed-effect concentration (NOEC) and lowest-observed-effect concentration of 34.1 microg/L and 71.3 microg/L, respectively, were determined with an early life-stage toxicity test with Oncorhynchus mykiss. During a 96-h Scenedesmus study, the 96-h biomass EC50 was 1.4 microg/L and the 96-h NOEC was 0.69 microg/L. Other algae and Lemna also were investigated. Bioconcentration was assessed with Danio rerio. The average TCS accumulation factor over the five-week test period was 4,157 at 3 microg/L and 2,532 at 30 microg/L. Algae were determined to be the most susceptible organisms. Toxicity of a TCS-containing wastewater secondary effluent to P. promelas and Ceriodaphnia was evaluated and no observed differences in toxicity between control and TCS-treated laboratory units were detected. The neutral form of TCS was determined to be associated with toxic effects. Ionization and sorption will mitigate those effects in the aquatic compartment.
Orvos
David R
DR
Sweet Briar College, Department of Environmental Studies, Virginia 24595, USA. dorvos@sbc.edu
Versteeg
Donald J
DJ
Inauen
Josef
J
Capdevielle
Marie
M
Rothenstein
Arthur
A
Cunningham
Virginia
V
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000633:toxicity*; D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D056890:Eukaryota / Q000187:drug effects / Q000254:growth & development*; D005399:Fishes / Q000254:growth & development* / Q000378:metabolism; D007448:Invertebrates / Q000187:drug effects / Q000254:growth & development*; D008018:Life Cycle Stages / Q000187:drug effects; D019055:No-Observed-Adverse-Effect Level; D012098:Reproduction / Q000187:drug effects; D012722:Sewage / Q000382:microbiology; D023382:Toxicity Tests, Acute; D014260:Triclosan / Q000737:chemistry / Q000633:toxicity*; D014337:Trout / Q000254:growth & development; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000254:growth & development / Q000378:metabolism
D000891:Anti-Infective Agents, Local; D002250:Carbon Radioisotopes; D012722:Sewage; D014874:Water Pollutants, Chemical; D014260:Triclosan