Thinking of taking a trip to Florida? Then beware the sea air if you discover that there has been a recent 鈥渞ed tide鈥�, a seasonal infestation of toxic algae notorious for killing marine life.
Richard Pierce and his colleagues at the Mote Marine Laboratory in Sarasota, Florida, have found that concentrations of brevetoxin 3, one of three neurotoxins produced by Karenia brevis 鈥� the major cause of red tides in Florida 鈥� can reach concentrations in the air 50 times as high as in the water itself. This might explain reports by beachgoers of dry coughs and streaming eyes during red tides.
Pierce says that toxins leak into the water from ruptured algal cells and are lofted into the air inside bubbles created in the surf. Onshore winds then carry the toxin-containing aerosols onto the beach (Harmful Algae, vol 4, p 965).
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He estimates that up to 85 per cent of the aerosol particles containing the toxins would end up in the upper airway, causing nose and throat irritation. Up to 6 per cent would reach into the lungs, potentially causing wheezing and chest tightness.
In red tide updates issued by the Mote Lab, Pierce advises beachgoers visiting western Florida to wear a mask if they experience any respiratory problems.
