Passing Gas : Making Cameroon's lakes safer.(Lake Monoun and Lake Nyos)

The world often seems inured to suffering in obscure places. But in 1986 a freakish act of nature deep in Cameroon put the impoverished West African nation on the front pages, and into the record books. For unknown reasons, Lake Nyos, a volcanic lake, suddenly released a huge amount of carbon dioxide gas. Nearly 2,000 people and uncounted animals quickly fell unconscious and died of asphyxiation. Government officials were at a loss to counsel the survivors, except to ban many of them from their livelihoods--farming on the lakeshore. Equally alarming, the problem seemed to be on the increase--37 people had died the same way two years earlier, at Lake Monoun, 200 miles away.

Nobody can say exactly what triggered these deadly disasters, but scientists may have learned enough to keep them from happening again. Last month experts from Cameroon, Japan, France and the United States watched as the supreme local authority, Sultan Njoya, poured libations on the water of Lake Monoun to placate the spirits. "The gods of the land, we are here to appease you with oil and wine from your children you left in my hands," he chanted. Then it was the scientists' turn. The villagers in their flowing robes stood ready to take to their heels, dead silent, as a pumping jet began to pull CO2-rich water from the lake bed. Before long, a 25-foot geyser of water and gas was spurting from a pipe sticking out of the lake. The experts were accomplishing their goal: to gradually burp Lake Monoun.

That geyser may signal the end of a unique scientific journey. At first, researchers believed that gas within the two lakes was released during a volcanic eruption. Surveys of other volcanic lakes in Cameroon and as far away as Lake Kivu in eastern Congo helped eliminate this theory--Nyos and Monoun were alone in having such high CO2 concentrations. That left a second theory: that the gas eruptions had something to do with the nature of water that enters the lake from ...