title: Aerosolized red-tide toxins (brevetoxins) and asthma.
abstract: BACKGROUND
  With the increasing incidence of asthma, there is increasing concern over environmental exposures that may trigger asthma exacerbations. Blooms of the marine microalgae, Karenia brevis, cause red tides (or harmful algal blooms) annually throughout the Gulf of Mexico. K brevis produces highly potent natural polyether toxins, called brevetoxins, which are sodium channel blockers, and possibly histamine activators. In experimental animals, brevetoxins cause significant bronchoconstriction. In humans, a significant increase in self-reported respiratory symptoms has been described after recreational and occupational exposures to Florida red-tide aerosols, particularly among individuals with asthma.
  
  
  METHODS
  Before and after 1 h spent on beaches with and without an active K brevis red-tide exposure, 97 persons >or= 12 years of age with physician-diagnosed asthma were evaluated by questionnaire and spirometry. Concomitant environmental monitoring, water and air sampling, and personal monitoring for brevetoxins were performed.
  
  
  RESULTS
  Participants were significantly more likely to report respiratory symptoms after K brevis red-tide aerosol exposure than before exposure. Participants demonstrated small, but statistically significant, decreases in FEV(1), midexpiratory phase of forced expiratory flow, and peak expiratory flow after exposure, particularly among those participants regularly using asthma medications. No significant differences were detected when there was no Florida red tide (ie, during nonexposure periods).
  
  
  CONCLUSIONS
  This study demonstrated objectively measurable adverse changes in lung function from exposure to aerosolized Florida red-tide toxins in asthmatic subjects, particularly among those requiring regular therapy with asthma medications. Future studies will assess these susceptible subpopulations in more depth, as well as the possible long-term effects of these toxins.
authors.affiliation: National Institute of Environmental Health Sciences Marine and Freshwater Biomedical Sciences Center, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL, USA. lfleming@med.miami.edu
authors.forename: Lora E
authors.initials: LE
authors.lastname: Fleming
authors.forename: Barbara
authors.initials: B
authors.lastname: Kirkpatrick
authors.forename: Lorraine C
authors.initials: LC
authors.lastname: Backer
authors.forename: Judy A
authors.initials: JA
authors.lastname: Bean
authors.forename: Adam
authors.initials: A
authors.lastname: Wanner
authors.forename: Andrew
authors.initials: A
authors.lastname: Reich
authors.forename: Julia
authors.initials: J
authors.lastname: Zaias
authors.forename: Yung Sung
authors.initials: YS
authors.lastname: Cheng
authors.forename: Richard
authors.initials: R
authors.lastname: Pierce
authors.forename: Jerome
authors.initials: J
authors.lastname: Naar
authors.forename: William M
authors.initials: WM
authors.lastname: Abraham
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Baden
mesh_terms: D000293:Adolescent; D000328:Adult; D000336:Aerosols; D000368:Aged; D000818:Animals; D001249:Asthma / Q000209:etiology*; D002648:Child; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000472:pathogenicity*; D004784:Environmental Monitoring; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005431:Florida; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D008387:Marine Toxins / Q000633:toxicity*; D013058:Mass Spectrometry; D008875:Middle Aged; D035964:Oxocins / Q000633:toxicity*; D012129:Respiratory Function Tests; D011795:Surveys and Questionnaires; D000095702:Polyether Toxins
chemical_list: D000336:Aerosols; D008387:Marine Toxins; D035964:Oxocins; C053342:brevetoxin; D000095702:Polyether Toxins