title: Occurrence and toxicity of antimicrobial triclosan and by-products in the environment.
abstract: OBJECTIVE
  A review was undertaken on the occurrence, toxicity, and degradation of triclosan (TCS; 5-chloro-2,4-dichlorophenoxy)phenol) in the environment. TCS is a synthetic, broad-spectrum antibacterial agent incorporated in a wide variety of household and personal care products such as hand soap, toothpaste, and deodorants but also in textile fibers used in a range of other consumer products (e.g., toys, undergarments and cutting boards among other things).
  Because of its partial elimination in sewage treatment plants, most reports describe TCS as one of the most commonly encountered substances in solid and water environmental compartments. It has been detected in a microgram per liter or microgram per kilogram level in sewage treatment plants (influents, effluents, and sludges), natural waters (rivers, lakes, and estuarine waters), and sediments as well as in drinking water.
  
  
  RESULTS
  Moreover, due to its high hydrophobicity, TCS can accumulate in fatty tissues and has been found in fish and human samples (urine, breast milk, and serum). TCS is known to be biodegradable, photo-unstable, and reactive towards chlorine and ozone.
  
  
  CONCLUSIONS
  As a consequence, it can be transformed into potentially more toxic and persistent compounds, such as chlorinated phenols and biphenyl ethers after chlorination, methyl triclosan after biological methylation, and chlorinated dibenzodioxins after photooxidation. The toxicity of TCS toward aquatic organisms like fish, crustaceans, and algae has been demonstrated with EC50 values near TCS environmental concentrations. It has even been shown to produce cytotoxic, genotoxic, and endocrine disruptor effects.
  
  
  CONCLUSIONS
  Furthermore, the excessive use of TCS is suspected to increase the risk of emergence of TCS-resistant bacteria and the selection of resistant strains.
authors: Université Européenne de Bretagne, Université de Bretagne Sud, Vannes Cedex, France. gilles.bedoux@univ-ubs.fr
authors: Gilles
authors: G
authors: Bedoux
authors: Benoit
authors: B
authors: Roig
authors: Olivier
authors: O
authors: Thomas
authors: Virginie
authors: V
authors: Dupont
authors: Barbara
authors: B
authors: Le Bot
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000032:analysis / Q000378:metabolism / Q000633:toxicity; D059001:Aquatic Organisms / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D006801:Humans; D007448:Invertebrates / Q000187:drug effects; D010944:Plants / Q000187:drug effects; D018570:Risk Assessment; D014260:Triclosan / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity*; D014714:Vertebrates / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity*
chemical_list: D000891:Anti-Infective Agents, Local; D014874:Water Pollutants, Chemical; D014260:Triclosan