149238 Asthma, Aerosolized Florida Red Tide Toxins (Brevetoxins), and Off-shore Winds

Wednesday, November 7, 2007: 3:15 PM

Lora E. Fleming, MD, PhD , Department of Epidemiology & Public Health, University of Miami, Miller School of Medicine, Miami, FL
Barbara Kirkpatrick, EdD, RRT , Mote Marine Laboratory, Environmental Health Program, Sarasota, FL
Lorraine C. Backer, PhD, MPH , National Center for Environmental Health, US Centers for Disease Control and Prevention, Chamblee, GA
Andrew Reich, MS, MSPH , Florida Department of Health, Aquatic Toxins Program, Tallahassee, FL
Judy Bean, PhD , Childrens Hospital Medical Center of Cincinnati, Cincinnati, OH
Adam Wanner, MD , Pulmonary Medicine, University of Miami Miller School of Medicine, Miami, FL
Kate Nierenberg, MS , Mote Marine Laboratory, Environmental Health Program, Sarasota, FL
Julie Zaias, DVM PhD , Pathology, University of Miami Miller School of Medicine, Miami, FL
Yung Sung Cheng, PhD , Lovelace Respiratory Institute, Albuquerque, NM
Richard Pierce, PhD , Mote Marine Laboratory, Environmental Health Program, Sarasota, FL
Jerome Naar, PhD , Center for Marine Research, Wilmington, NC
William M. Abraham, PhD , Mt Sinai Hospital, Miami, FL
Yue Zhou, PhD , Lovelace Respiratory Institute, Albuquerque, NM
Michael Henry, MS , Mote Marine Laboratory, Environmental Health Program, Sarasota, FL
Gary Kirkpatrick, PhD , Mote Marine Laboratory, Environmental Health Program, Sarasota, FL
Janet Benson, PhD , Lovelace Respiratory Institute, Albuquerque, NM
Andrea Bourdelais, PhD , Center for Marine Research, Wilmington, NC
Sharon M. Watkins, PhD , Florida Department of Health, Aquatic Toxins Program, Tallahassee, FL
Mark Harrington, MS , Twin Cities Hospital, Niceville, FL
Daniel Baden, PhD , Center for Marine Science, University of North Carolina at Wilmington, Wilmington, NC
Florida red tides occur annually in the Gulf of Mexico as blooms of marine dinoflagellates, Karenia brevis. K. brevis produces highly potent natural polyether toxins, brevetoxins, which cause bronchoconstriction in experimental animals. In prior studies, people with asthma had increased respiratory symptoms and deceased pulmonary function after walking on beaches during Florida red tides. Brevetoxins, measured by LCMS, HPLC and ELISA, were detected in both seawater and aerosol samples collected on the beach.

In a subsequent study, high concentrations of Karenia brevis cells (1-4.6 million cells/L) and brevetoxins (13.4-128.0 um/L) were found in seawater. However, because of strong off-shore winds, concentrations of brevetoxins in aerosols were close to analytic limits of detection (0.01-0.14 ng/m3) in high-volume air samples. Sixty-four persons with physician-diagnosed asthma were evaluated before and after a 1 hour walk on the beach using a questionnaire and spirometry. Compared with results obtained before beach exposure, participants were significantly more likely to report respiratory symptoms and demonstrate significant decreases in pulmonary function afterwards. This is consistent with previous studies with on-shore winds and measurable concentrations of brevetoxins in aerosol samples. There were no differences in respiratory symptoms or pulmonary function during a study without Florida red tide.

This study demonstrated adverse health effects in asthmatics from inhaling aerosolized brevetoxins at concentrations close to current limits of detection. This study has implications for asthmatics in geographic areas that regularly experience Florida red tides: previously it was believed to be “safe” to use beaches as long as the winds were off-shore.

Learning Objectives:
1. Identify the exposures of Florida red tide toxins 2. Identify the effects of aerosolized Florida red tide toxins, particularly in asthmatic populations 3. Explore possible public health and medical responses to this recurrent natural event

Keywords: Toxicants, Asthma