U.S. Geological Survey (USGS) scientist Virginia Garrisonor Ginger, as she's known to folks in the USGS Florida Integrated Science Center office in St. Petersburg, Fla.suspects that there is something in the air. She suspects that there is something in the dust that is in the air. Garrison has been working within the USGS Earth Surface Dynamics and Ecosystems Programs to study the relations between dust and the health of humans and ecosystems. In particular, she's looking at the atmospheric transport of dust and the many assorted constituents that travel with it.
A poster titled "African and Asian Dust, Coral Reefs, and Human Health" summarizes the work of the team of scientists studying dust from African and Asian deserts and its effects on human and ecosystem health. Two of the major global atmospheric systems were studied: one originating in the Sahara and Sahel regions of Africa and the other in the Gobi and Taklimakan Deserts in Asia. Garrison and her numerous collaborators from around the world are looking at how human-related changes in the desert source regions affect the quantity and quality of particulate matter in downwind regions as the dusty winds move about the globe.
Although these global atmospheric systems have been in place for hundreds of thousands of years, the quantity of dust is known to have increased, and the composition of the dust is believed to have changed because of human activity. Modern human activities, such as the burning of biomass and waste, pharmaceutical and pesticide use, and increased industrialization, introduce new compounds into the dust mix, which can be transported across continents and oceans.
In a quote from an article in the March 12, 2006, issue of West Hawaii Today, Garrison describes her sampling methods and the strange sampling set up she's using to collect air samples. "It kind of looks like R2D2," she says. "It's basically an aluminum tripod equipped with a filter holder, filters, and a blower. It allows us to sample the air." But in many parts of the world, sampling the air isn't easy. Some of the remote regions where sampling needs to be done have no power to operate the equipment, and if you bring in a generator, you produce air pollution that may contaminate your samples.
Garrison has set up sampling stations and trained people in remote areas to operate and service the equipment. She has created private and public partnerships in Cape Verde, Mali, Trinidad, the U.S. Virgin Islands, and Hawai'i to sample the air (or water) and discover what's carried with the dust that may affect residents and ecosystems.
In Trinidad, scientists with the University of the West Indies (UWI) are investigating the possible cause-and-effect relation between African dust in the air and emergency admissions of children with acute asthma. The UWI scientists and graduate students run a station at the top of a lighthouse on the northeast tip of Trinidad, where they can sample air coming from Africa before it moves over the island and picks up particles or contaminants from Trinidad. Part of their work involves studying how pollen can be used as an air-mass tracerto confirm, for example, that a particular air mass came from Africa. The USGS supplied the equipment and training for running the station, which provides information on the concentrations of airborne dust, metals, persistent organic pollutants, and microorganisms coming across the Atlantic. These data provide background information for comparison with air-quality data from the industrialized areas of Trinidad. Garrison and her collaborators in Trinidad hope to separate the effect of particulates, persistent organic pollutants (POPs), metals, and microbes from Africa from the effect of locally generated pollutants on emergency admissions for asthma. These data will be compared with similar data from Cape Verde, a group of islands off Africa's west coast.
The difficulty of locating places to conduct air sampling and identifying trained personnel to maintain sampling stations has led to numerous collaborators. Garrison began working 8 years ago to establish a network for studying African dust that is finally in place for sampling dust, chemical constituents, and microorganisms at four sites: Mali (in the source region in Africa), Cape Verde (off the west coast of Africa), Trinidad (in the very southeastern Caribbean), and the U.S. Virgin Islands (in the northeastern Caribbean). She has also established a station in Hawai'i (for studying dust from Asia).
Although setting up collaborations takes a great deal of time, there always has been significant interest at each location. For one thing, many local citizens and departments of health are concerned about air quality and its effects on human health. Many locals recognize the relation between dust storms and observed increases in human health problems. They want to see whether something in the air triggers asthma and other illnesses. Similarly, Garrison is interested in how dust-carrying air masses may affect coral-reef organisms in dust-impacted locations.
Collaborators want to share this work with others. UWI invited Garrison to be the featured speaker in their annual Research Days, held April 5-7, 2006, during which the university highlighted ongoing research and facilities. The theme of this year's event was "Your Wealth, Your Health, Your Safety, Your Future."
in this issue:
Researcher Studies Effects of African Dust on Human and Coral Health