Dust in the Wind SAVE THE LAGOON Safer Indian River Indian River Lagoon Aquatic Preserves Indian Riverkeeper Indian River Lagoon News and Events Indian River Habitat for Humanity Action St. Lucie River St. Johns Riverkeeper US DISTRICT ATTORNEY, US ATTORNEY, FORT PIERCE, FBI FORT PIERCE FLORIDA UNited States Department of Justice, United States Attorney General, United States Secretary of ThE iNTERIOR Dust in the Wind Researchers have since found a variety of live bacteria and fungus in dust hitting the Caribbean, defying conventional wisdom among microbiologists that microbes could not survive a five-day trip three miles up in the atmosphere. Swarms of live locusts made it all the way across alive in 1988 and landed in the Windward Islands, Shinn says. If one-inch grasshoppers can make it, I imagine almost anything can make it. A 2001 study by USGS researchers found that the number of viable fungus and bacteria in Caribbean air is two to three times higher during dust events than during normal weather conditions. Although the vast majority of diseases afflicting coral have not been identified (beyond descriptions of the symptoms they cause), scientists have linked dust to at least one specific coral-killing microbe. Garriet Smith and colleagues at the University of South Carolina have identified the pathogen behind the mass die-offs of sea fans, the graceful soft corals of the Caribbean, as Aspergillus sydowii-a soil fungus that does not reproduce in salt water. In the very first sample of airborne dust from the Virgin Islands that Ginger Garrison sent to Smith, he found live Aspergillus sydowii in its pathogenic form, among many other microorganisms. The fungal disease may also enter the sea in local runoff from deforested areas, but dust studies have established African dust storms as its most plausible source on isolated reefs and near small islands with no forests and little runoff. In addition to carrying living hitchhikers, clouds of African dust bring intense pulses of nutrients like iron and nitrates that may be stimulating harmful algal blooms and the rapid growth of both coral-smothering algae and microbes that cause coral diseases. Microbiologist Hans Paerl of the University of North Carolina calls the dust-composed of aluminum, silicon, iron, phosphates, nitrates, and sulfates-Geritol for bugs. There may be other unhealthy substances adhering to the particles as well: some studies suggest the dust carries high concentrations of beryllium-7, a radioactive isotope that appears to adhere to dust particles as they travel through the atmosphere. While seeking medical care for her respiratory tract infection in Malis capital of Bamako, Ginger Garrison asked around and found that lung problems are terribly common in Mali during the dust season. After the seasonal floods of the Niger River recede and its banks dry, mud-mixed with raw sewage, human and animal waste, and miscellaneous garbage left behind-turns to dust. Microbes, synthetic organics, pharmaceuticals, antibiotics, you name it, Garrison explains. Then the winds come, and its a perfect avenue to take those substances aloft, often north toward Europe or west toward the United States. She also observed the ubiquitous garbage burning and wonders what carcinogens, endocrine disrupters, or heavy metals from garbage burning might also find their way into the atmosphere with dust. She hopes to set up a second monitoring station near Bamako to look for heavy metals and synthetic chemicals like DDT, in addition to the station she set up in late 2000 for monitoring microbe levels in dust. Africa is not the only source of dust that affects faraway places. Nutrients from the deserts of northwestern China sustain Hawaiian rainforests growing on weathered soils. Chinese haze has long afflicted residents of Japan and Korea, where the yellow dust, laden with pollutants picked up from Chinese cities it passes over, is called the gate-crasher of Spring. South Korean officials suspect that the dust may have been the source of a recent outbreak of foot-and-mouth disease among cattle along Koreas west coast. Last Spring, Korea suffered through 20 days of unhealthy haze from abroad, the longest yellow dust spell there in 40 years. Chinese dust even caused hazy sunsets around the western United States for several days in April 2000. The Chinese, Japanese, and South Korean governments have launched a program to revegetate dust-generating lands in China, and researchers from around the Pacific Rim have begun intensive studies of Chinese dust and its impacts. To date, the dust blowing from Africa-unlike Chinese dust-has attracted little attention as a public health issue. The desertification (severe degradation of arid and semi-arid lands) that exacerbates dust formation also has serious economic and human consequences close to home: one in six people in Mali have become environmental refugees, forced to leave their land as it turns to dust. Despite the massive amount of land claimed by expanding desertification each year, the phenomenon receives only infrequent attention, perhaps because the effects seldom seem to transcend international borders. These new studies of well-traveled dust may turn that impression on its head. Given all the locally generated pollution in the Caribbean, its understandable that African dust is on few peoples radar screens. But reversing the decline of the regions once flourishing underwater ecosystems may be impossible without investing more effort in stabilizing the wind-whipped lands of northern Africa. Its just another example of how small the Earth is, and how so many things are interconnected: global processes mixed up with how people live their lives, says Garrison. The mounting evidence of damaging fallout thousands of miles from sources of dust may help convince the rest of the world to pay more attention again to the forgotten, dusty corners of planet Earth. Maybe were not quite as isolated as we thought from areas with major health problems, says Garrison. And maybe we should be more concerned about the welfare of people and the land in these far away places.
Posted on: Wed, 04 Dec 2013 18:10:13 +0000
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