Bad Tidings

On a recent sunny day, Dr. John van Dongen took his family out for a boat ride near his home in Naples. What should have been a pleasant day on the water turned into something else: Eyes began to water, chests felt congested and shoals of dead fish floated ominously beneath the water's surface. Van Dongen turned the boat around and took his family home. This Southwest Florida horror story has become all too familiar to residents and tourists, as red tide has invaded offshore waters, annoying beachgoers and sending some to doctors with respiratory complaints.

On that particular day, van Dongen says there were no news alerts about the bloom; it was an undocumented one that appeared in his boat's path. Van Dongen, a family practice physician whose office is in Old Naples near the beach, says that lately he has seen more people coming in to his office complaining of the effects of red tide: itchy and watery eyes, congestion, coughing and even difficulty breathing.

"It's becoming worse every year," says van Dongen. "Last year we had it for almost six weeks. This year it was more severe but for a shorter period. One lady with asthmatic problems had to go to the emergency room."

Dr. Barbara Kirkpatrick, a senior scientist at Mote Marine Laboratory in Sarasota and a former respiratory therapist, has been studying the effects of red tide on humans for six years with a team of researchers from several agencies, including the Centers for Disease Control, Florida Department of Health and the University of Miami. Kirkpatrick says that her gut instinct is that red tide is getting worse; indeed, she feels that harmful algal blooms are getting worse worldwide. However, it is difficult to prove that the incidence of red tide has increased.

"With better monitoring, the more we look for it, the more we find it," she says. "With satellite pictures, if there is a bloom 30 miles offshore, we can aim our boat toward it and get a sample. And as we populate the coastline, there are more people getting affected; that's a no-brainer."

Florida red tide is what occurs when there is a bloom, or a larger than usual concentration, of a species of algae, Karenia brevis. Paradoxically, the bloom does not always turn the water red; it can look green, brown, purple or even appear normal. K brevis has always naturally existed in the Gulf of Mexico off Florida's coast. When the algae get into warm water rich in nutrients, they multiply, or bloom. When this happens, they release a toxic vapor into the surrounding water and air. This causes fish and marine mammal deaths (147 manatees died during the 1996 bloom), contaminates shellfish beds and acts as an irritant to the mucosal membranes in humans, irritating allergies and causing congestion, swelling and secretions. At the present time, there is no way of predicting when a bloom will hit an area.

Red tide was documented as far back as 1840. Even further back, the logs of Spanish explorers noted massive fish kills. Red tide was first linked to irritation in humans back in 1948; however, research has been sporadic and not much has concentrated on the effects of the aerosol on humans. That's what interests Kirkpatrick, who is studying two human populations to try to figure out what exactly red tide does to us. One group consists of Sarasota County lifeguards who are occupationally exposed to red tide.

Kirkpatrick and her fellow researchers examined the lifeguards before and after their day at work, and found that irritation was limited to the upper airway-eyes and nose-with no change in breathing patterns. However, in the second population she studied, a group of asthmatics, she found upper respiratory irritations as well as lower chest congestion, wheezing and changes in airflow parameters.

"People are more prone if they have asthma or emphysema," says Dr. Joel Moll, medical director of the emergency department at the Cleveland Clinic Florida in Naples. "Some asthmatics have triggers that are environmental."

Moll says that news reports of blooms usually coincide with increased numbers of people coming into the emergency room complaining of coughing and wheezing. The good news, says Moll, is that the only solution is a fairly easy one, for tourists and residents, anyway: Avoid the beach when a red-tide alert is put out. There is no cure for the response people have to red tide, other than treating the symptoms.

Kirkpatrick's research shows that for asthmatics, normal asthma medication decreases the effects of the toxin. The inhaler that is prescribed as an emergency inhaler also reversed the effects of the toxin in animal studies, she says.

"If you're an asthmatic and there's red tide in town, now is not the time to cheat on your medicine,"

says Kirkpatrick.

Other common-sense measures are to watch for the "red-tide tickle," that persistent cough that many people are irritated by during a bloom. If you hear many people on the beach coughing, says Kirkpatrick, go home. It means that there is probably a bloom offshore.

"Pay close attention to media reports, and if there's a report of a bloom, avoid going to the beach," says van Dongen. "Especially if there's an onshore wind and you experience itching in eyes or coughing, pack up your car and go home."

Although van Dongen mostly sees Naples residents in his practice, many of them tell him stories of relatives deciding against a Florida vacation because of red tide.

"This is an environmental problem with a lot of ramifications, and a lot of agencies need to get involved," says van Dongen.

"As a community, this needs to be high priority, not just economically but environmentally. If we ignore warning signs, in the long term we will regret it. It's become a real problem for Southwest Florida."

Kirkpatrick agrees the problem needs to be addressed, and she hopes studies like hers can begin that process.

"We have a lot of anecdotal information, but we don't have science, and science sets policy," she says. "Until you have science, you can't set the public health message."