Beware Saharan dust

A report yesterday by the Associated Press (AP) said, "An enormous hazy cloud of dust from the Sahara Desert is blowing toward the southern United States, but meteorologists do not expect much effect beyond colourful sunsets."

The leading edge of the cloud which is nearly the size of continental USA should move across Florida between Monday and Wednesday.

A spokesman for the national weather service in Miami said the dust cloud could create spectacular sunrises and sunsets, noting, "This is not going to be a tremendous event but it will be kind of interesting." The AP article said dust clouds are normal at this time of year. They start when weather patterns called tropical waves pick up dust from the desert in North Africa, carry it a couple of miles into the atmosphere and drift westwards.

But one US environmental protection expert, Ken Larson, said that if the dust is concentrated enough it could cause difficulties for people with respiratory problems. The expert advised AP, "If somebody is subject to a respiratory condition, if they see hazy skies they might want to take a little more precaution, not participate in strenuous activity, and stay indoors."

A spokesman at the Piarco Meteorological Services told Sunday Newsday that he did not yet have information on the dust cloud and whether or not it would affect us. He said Trinidad and Tobago usually experiences smaller dust plumes at this time of year. "One is over us right now, and two more are further east of us. It’s a normal occurrence this season."

A report yesterday in the South Florida Sun-Sentinel said that while South Florida should see the western edge of the dust cloud, "they’ll notice it more in the Caribbean, like in San Juan (Puerto Rico)." Caribbean reefs could be harmed by pathogens like fungi and bacteria which are carried in the dust cloud, said a source at Nova Southeastern University.

The Sun-Sentinel said, "So far there is no evidence the pathogens harm humans, although on the Caribbean island of Trinidad an abnormal number of infants have asthma problems." The story ended with an ironic twist, "It is difficult for tropical storm development to occur in these dust outbreaks."