• Choose a category
• All
• Classic-Fiction

By Root 404 0

ecologist to visit Bamako and Timbuktu on the Niger River in Mali in an effort to understand the organisms that were making their way across the sea. Similarly, another U.S. Geological Survey report in 2001 said that what the researchers called opportunistic pathogens were hitching rides from Africa on the wind—the sand is heavy enough that the dust clouds block the solar radiation that would otherwise damage the bacteria on their journey to the New World. Large dust arrivals from Africa have now been found over 30 percent of the continental United States; although no one has yet estimated its mass, it would be a small fraction of the amount that leaves the Sahara. About half the volume that reaches the United States settles on Florida. On any given day, a third to a half of the dust drifting through Miami comes not from local beaches but from Africa. "It may," the study suggested, "pose a significant public health threat."

This might seem something of an exaggeration, but in the summer of 2001 a NASA-funded study tracked a cloud of Saharan dust to the Gulf of Mexico, where it settled, with unnerving consequences— causing a huge bloom of toxic red tide. The Saharan dust reached the West Florida shelf around July 1, increasing iron concentrations in the surface waters by 300 percent. Through a complex process involving enzymes and plantlike bacteria called Trichodesmium, the iron enriched the nitrogen content of the ocean, and in October an 8,100-square-mile bloom of red algae had formed between Tampa Bay and Fort Myers, Florida. Red tides give off toxins that can cause respiratory disorders in humans, and also poison local shellfish. Anyone eating the contaminated shellfish would suffer paralysis and severe memory problems. This particular red tide also killed millions of fish and hundreds of manatees.

A study at Harvard in 2004 found an increase in dangerous epidemic diseases created by the decrease in global forests and by increasing numbers of devastating storms like hurricanes.8 And it is known that these dust events bring chlordane and DDT traces back across the Atlantic, chemicals invented in, but now banned in, North America.9 There's a nice irony: America is being bombarded with DDT from Africa and chlordane and lindane from Asia, very toxic chickens flying home to roost.

Pollution goes where the winds take it. Researchers from the University of California at Davis were monitoring the air quality on Mauna Loa, a 13,680-foot mountain in Hawaii, and to their dismay found clear traces of industrial pollution from China, including arsenic, copper, and zinc, kicked into the atmosphere five days earlier. "It seems that Hawaii is like a suburb of Beijing," one of them said. On the other hand, for Europeans, it is the United States who are the aggressors, and dirty air from the United States regularly fouls northern European forests. Beltway commuters in Washington, intent only on the politics of the moment, are actually damaging the lungs of hikers in Britain's Lake District. Aerosols including toxic metals, nutrients, viruses, and fungi have been tracked from the Gobi Desert to Beijing, from West Africa to the Caribbean, from Ontario to New England, and from Germany to Sweden.10

Science magazine in April 2000 published a study that attributed a sudden increase of carbon dioxide concentrations in the American Southwest to Canadian forest fires. Episodic spikes in emissions on the central Atlantic Coast of America were caused by forest fires burning thousands of miles away, in the sub-Arctic Northwest Territories. A single fire in this remote region emitted two and a half tons of C02 per hectare (about two acres) of forest burned, and dumped it on the United States—and total emissions from forest fires exceeded all other sources by a factor of two. This is unfair— Kentucky makes enough of its own pollutants without inadvertently importing others from Canada, but turnabout is fair play, I guess, for it is not for nothing that Nova Scotia is sometimes referred to as the tailpipe of North America, since sulfur dioxide and