title: Toxicity of cigarette butts, and their chemical components, to marine and freshwater fish.
abstract: BACKGROUND
  Cigarette butts are the most common form of litter, as an estimated 4.5 trillion cigarette butts are thrown away every year worldwide. Many chemical products are used during the course of growing tobacco and manufacturing cigarettes, the residues of which may be found in cigarettes prepared for consumption. Additionally, over 4000 chemicals may also be introduced to the environment via cigarette particulate matter (tar) and mainstream smoke.
  
  
  METHODS
  Using US Environmental Protection Agency standard acute fish bioassays, cigarette butt-derived leachate was analysed for aquatic toxicity. Survival was the single endpoint and data were analysed using Comprehensive Environmental Toxicity Information System to identify the LC50 of cigarette butt leachate to fish.
  
  
  RESULTS
  The LC50 for leachate from smoked cigarette butts (smoked filter + tobacco) was approximately one cigarette butt/l for both the marine topsmelt (Atherinops affinis) and the freshwater fathead minnow (Pimephales promelas). Leachate from smoked cigarette filters (no tobacco), was less toxic, with LC50 values of 1.8 and 4.3 cigarette butts/l, respectively for both fish species. Unsmoked cigarette filters (no tobacco) were also found to be toxic, with LC50 values of 5.1 and 13.5 cigarette butts/l, respectively, for both fish species.
  
  
  CONCLUSIONS
  Toxicity of cigarette butt leachate was found to increase from unsmoked cigarette filters (no tobacco) to smoked cigarette filters (no tobacco) to smoked cigarette butts (smoked filter + tobacco). This study represents the first in the literature to investigate and affirm the toxicity of cigarette butts to fish, and will assist in assessing the potential ecological risks of cigarette butts to the aquatic environment.
authors.affiliation: San Diego State University, 500 W Harbor Drive #134, San Diego, CA 92101, USA. ellislaughter@hotmail.com
authors.forename: Elli
authors.initials: E
authors.lastname: Slaughter
authors.forename: Richard M
authors.initials: RM
authors.lastname: Gersberg
authors.forename: Kayo
authors.initials: K
authors.lastname: Watanabe
authors.forename: John
authors.initials: J
authors.lastname: Rudolph
authors.forename: Chris
authors.initials: C
authors.lastname: Stransky
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Novotny
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D005374:Filtration; D005399:Fishes; D005618:Fresh Water; D015386:Hazardous Substances / Q000633:toxicity*; D006256:Hazardous Waste / Q000009:adverse effects*; D012906:Smoke / Q000032:analysis; D012907:Smoking; D013638:Tars / Q000032:analysis; D014481:United States; D014484:United States Environmental Protection Agency; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D062789:Tobacco Products
chemical_list: D015386:Hazardous Substances; D006256:Hazardous Waste; D012906:Smoke; D013638:Tars; D014874:Water Pollutants, Chemical