Red Tides Worsen Asthma with Breathtaking Seascapes

[Guest guest]

It has been mentioned several times about moving to a beach area to

feel better. This article talks about the effects it has on people

with asthma, I'm sure it can have similar effects on those of us

with other pulmonary problems. Just my opinion.

Sharon

Red Tides Worsen Asthma with Breathtaking Seascapes

http://www.medpagetoday.com/Pulmonary/Asthma/dh/4825

By Neil Osterweil, Senior Associate Editor, MedPage Today

Reviewed by Jasmer, MD; Associate Clinical Professor of

Medicine, University of California, San Francisco

January 08, 2007

MIAMI -- Harmful algal blooms known as red tides release toxins that

can leave people with asthma gasping still harder for air, reported

researchers here.

After spending just 60 minutes on a beach where a Florida red tide

was present, teens and adults with asthma had small but significant

decreases in standard measures of pulmonary function, reported Lora

E.

Fleming, M.D., Ph.D., of the University of Miami Rosenstiel School of

Marine and Atmospheric Science.

" In the normal population, inhaled aerosolized red tide toxins can

lead to eye irritation, rhinorrhea, nonproductive cough, and

wheezing, " Dr. Fleming and colleagues reported in the January issue

of

Chest.

" However, these symptoms usually subside after leaving beach areas, "

Dr. Fleming and colleagues said. " Our study shows that Florida red

tide toxins may have a greater impact on patients with asthma, who

experienced significant respiratory problems and decreased lung

function after just one hour of beach exposure to the toxins. "

Although the investigators only looked at short-term exposure,

previous studies have shown that there are increased rates of

emergency department admission for asthma exacerbation, upper airway

disease, pneumonia, and bronchitis during periods of active red-tide

blooms. Aerosols produced by the blooms can drift inland for at least

a mile, wafting with them highly potent toxins known as brevetoxins.

Brevetoxins are sodium channel blockers and may activate histamine,

and in animal studies have been shown to cause significant

bronchoconstriction.

To get a better grasp of the effects of brevetoxins on lung function,

the investigators asked 97 volunteers with asthma, mean age 38.2 +

18.6 years (range, 12 to 69 years) to spend an hour at the beach on

two separate occasions: during a Florida red tide bloom, and when the

waters were free of algal blooms.

The patients, all of whom had physician-diagnosed asthma, were asked

to fill out questionnaires and were tested with spirometry both

before

and after their beach time.

The authors measured forced expiratory volumes at 1 second (FEV1),

midexpiratory phase of forced expiratory flow, peak expiratory flow,

and forced vital capacity.

While the patients were sunning themselves and strolling along the

strand, the authors conducted environmental monitoring, water, and

air

sampling. The patients were also given personal air monitors to carry

while at the beach.

The investigators found that the participants were significantly more

likely to report respiratory symptoms after being exposed to red tide

aerosols than before exposure. On spirometry testing, the

participants

were found to have small but statistically significant decreases in

FEV1, midexpiratory phase of forced expiratory flow, and peak

expiratory flow after exposure.

Decreases in lung function were particularly pronounced among those

participants who required regular asthma medications. No significant

differences in lung function were detected when the waters were free

of Florida red tide, however.

When they further divided the population in those who lived inland

(66) and coastal dwellers (31), they found that the inlanders were

more likely than the coast dwellers to have more severe asthma, to

report symptoms, and to have decreased respiratory function after

toxin exposure.

However, those who lived inland had higher baseline spirometry scores

compared with coastal residents, suggesting that the beach dwellers

already had compromised lung function from prior exposures to

brevetoxins.

In addition, when the authors broke down the data according to asthma

medication use in the 12 hours prior to the study, they found that

there were no significant differences in spirometry or respiratory

symptoms between recent medication users and non-users after exposure

to the toxins, despite previous animal data suggesting that asthma

medications were protective against the effects of brevetoxin.

" This suggests that without the prior preventive use of these asthma

and brevetoxin-blocking medications, the effects of aerosolized

red-tide brevetoxins among the participants with more severe asthma

might have been even greater, " the authors wrote.

" People with asthma, whether residents or tourists, need to be aware

of the Florida red tides and their potential to exacerbate asthma, as

well as their own personal reaction to Florida red tides, " said

Barbara Kirkpatrick, Ed.D, of the Mote Marine Laboratory in Sarasota,

a co-author.

Action Points:

Inform patients with asthma that red tides, or harmful aglal blooms,

release toxins that can exacerbate asthma symptoms in susceptible

patients.

= -- = -- = --

Chest. 2007;131:187-194.

http://www.chestjournal.org/cgi/content/abstract/131/1/187

Aerosolized Red-Tide Toxins (Brevetoxins) and Asthma*

Lora E. Fleming, MD, PhD, MPH, MSc; Barbara Kirkpatrick, EdD;

Lorraine

C. Backer, PhD, MPH; Judy A. Bean, PhD; Adam Wanner, MD, FCCP;

Reich, MS; Zaias, DVM, PhD; Yung Sung Cheng, PhD;

Pierce, PhD; Jerome Naar, PhD; M. Abraham, PhD and G.

Baden, PhD

* From the National Institute of Environmental Health Sciences Marine

and Freshwater Biomedical Sciences Center (Drs. Fleming, Zaias, and

Abraham), Rosenstiel School of Marine and Atmospheric Sciences, and

School of Medicine (Dr. Wanner), University of Miami, Miami, FL; Mote

Marine Laboratory (Drs. Kirkpatrick and Pierce), Sarasota, FL;

National Center for Environmental Health (Dr. Backer), Centers for

Disease Control and Prevention, Atlanta, GA; Children's Hospital

Medical Center and University of Cincinnati (Dr. Bean), Cincinnati,

OH; Florida Department of Health (Mr. Reich), Tallahassee, FL;

Lovelace Respiratory Research Institute (Dr. Cheng), Albuquerque, NM;

and the Center for Marine Science Research (Drs. Naar and Baden),

University of North Carolina at Wilmington, Wilmington, NC.

Correspondence to: Lora E. Fleming, MD, PhD, MPH, MSc, c/o Department

of Epidemiology & Public Health, University of Miami School of

Medicine, 1801 NW Ninth Ave, Highland Professional Building, Suite

200

(R 669), Miami, FL 33136; e-mail: lfleming@...

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, ia

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 ? 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 FEV1, 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.