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Effects of Triclosan on Marine Benthic and Epibenthic Organisms (Journal Article)
Citation:
PERRON, M., K. T. HO, M. G. CANTWELL, R. M. BURGESS, AND M. C. PELLETIER. Effects of Triclosan on Marine Benthic and Epibenthic Organisms (Journal Article). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 31(8):1861-1866, (2012).
Impact/Purpose:
In this study, the acute toxicity effects of triclosan on the epibenthic mysid shrimp, Americamysis bahia, and the sediment dwelling amphipod, Ampelisca abdita were investigated. Median lethal concentrations (LC50s) were determined for these organisms in water-only and whole sediment exposures. The LC50 values obtained were well within the range of literature values found for estuarine/marine organisms and suggest these marine species are among the most sensitive based on a lethality endpoint. Additionally, a bioaccumulation study was performed with the marine polychaete Nereis virens using triclosan-spiked sediments to investigate the bioaccumulative behavior of triclosan. Accumulation of triclosan in polychaete tissue was observed. Despite some loss over time, these levels persisted above control concentrations after depuration indicating a need to investigate the chronic effects of triclosan on estuarine/marine aquatic organisms. Use of the standard equilibrium partitioning model with measured sediment concentrations indicated the need for more studies to understand the effects of other forms of carbon (e.g., black carbon), triclosan ionization, and organism metabolism of triclosan on the chemical’s behavior and toxicity in the environment.
Description:
Triclosan (TCS) is an antimicrobial compound that has been widely used in consumer products, such as toothpaste, deodorant, and shampoo. Due to its widespread use, TCS has been detected in various environmental media including wastewater, sewage sludge, surface waters, and sediments. Triclosan is acutely toxic to numerous aquatic organisms, but very few studies have been performed on estuarine/marine benthic organisms. For whole sediment toxicity tests, the sediment dwelling estuarine amphipod, Ampelisca abdita, and the epibenthic mysid shrimp, Americamysis bahia, are commonly used organisms. In the present study, median lethal concentration values (LC50) were obtained for both of these organisms using water-only and whole sediment exposures. Acute 96 hr water-only toxicity tests resulted in LC50 values of 73.4 and 74.3 µg/L for the amphipod and mysid, respectively. For the seven day whole sediment toxicity test, LC50 values were 303 and 257 mg/kg (dry weight) for the amphipod and mysid, respectively. Using equilibrium partitioning theory, these whole sediment values are equivalent to interstitial water LC50 values of 230 and 190 µg/L for the amphipod and mysid, respectively, which are within a three-fold difference of the observed 96 hr LC50 water-only values. Triclosan was found to accumulate in polychaete tissue in a 28 d bioaccumulation study with a biota-sediment accumulation factor (BSAF) of 0.23 kg organic carbon/kg lipid. These data provide some of the first toxicity data for TCS with marine benthic and epibenthic species while also indicating a need to better understand the effects of other forms of sediment carbon, TCS ionization, and organism metabolism of TCS on the chemical’s behavior and toxicity in the aquatic environment.