During active K brevis bloom exposure periods, significant differences were found for all participants between pre- and post- beach report of symptoms and pre- and post- spirometry. During exposure periods, participants reported a significant increase in symptoms, predominantly chest tightness, and differences were measured objectively on lung function testing. In contrast, no significant differences were observed between pre- and post- beach symptoms or spirometry during nonexposure periods.
Researchers further evaluated subpopulations based on area of residence and the use of asthma medication within 12 hours prior to the study. Inland residents were more likely than coastal residents to be severe asthmatics and had more reported symptoms and decreased respiratory function after toxin exposure. However, inland residents had higher baseline spirometry scores, compared with coastal residents, suggesting that coastal residents were already affected by the toxins through their environmental residential exposure even prior to study exposure, and, therefore, reacted less to the one-hour beach exposure. Furthermore, participants who reported using asthma medication within 12 hours prior to the study had similar post-exposure differences in spirometry and respiratory symptoms compared with those who did not use medication even though a sheep model asthma study indicated that these medications have been shown to block the effects of the Florida red tide toxins.
"It is possible that coastal residents, who had less of a reaction to the toxins, have learned not to get exposed or may use more asthma medications to deal with red tides," said study coauthor Barbara Kirkpatrick, EdD, Mote Marine Laboratory, Sarasota, FL. "People with asthma, whether residents or tourists, need to be aware of the Florida red tides and their potential to exacerbate asthma, a
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Contact: Jennifer Stawarz
jstawarz@chestnet.org
847-498-8306
American College of Chest Physicians
8-Jan-2007