San Diego

US researchers are planning an extensive study programme following reports that atmospheric dust may be transmitting microorganisms between continents.

Results collated at a workshop held on 14–15 August in Florida will be used as the basis for a grant application to the National Science Foundation early next year, participants say. They hope that the foundation will support the investigation as part of its biocomplexity programme.

Organized by the US Geological Survey (USGS), the workshop brought together 50 scientists from 18 institutions and government agencies.

Participants say recent studies suggest that clay dust from the Sahara desert — particularly from Mali — might be transporting fungi, viruses and chemical contaminants to the Caribbean, the Gulf of Mexico and the southern United States.

For instance, Aspergillus sydowii, which causes disease in Caribbean sea fans, is a possible culprit in the retreat of coral reef in the Caribbean. The fungus has been found in aerosols collected in the Virgin Islands, which are hit by dust storms swept across the Atlantic Ocean from June to October.

Researchers are also studying dust as a cause of the rising number of asthma cases in Barbados and Puerto Rico. Eugene Shinn, a USGS geologist, has even suggested that long-range dust storms could transport the virus that causes foot-and-mouth disease in livestock. He admits there are no data to support this hypothesis, but says that satellite photos from February show a storm sending plumes of African dust over Britain shortly before the outbreak of the disease there.

Ginger Garrison, a marine ecologist at the USGS Center for Coastal Geology in St Petersburg, Florida, says research is planned to analyse dust samples in the mid-Atlantic during storm episodes to compare them with samples from Mali and the Virgin Islands. "We have found quite a load of microorganisms hitchhiking on dust particles across the Atlantic," she says.

The researchers also hope to coordinate with the Asian Pacific Regional Aerosol Characterization Experiment, which has studied dust movements from the Gobi Desert to the western United States.