Carbon Dioxide Poisoning

Lake Nyos

In 1986, about 2,000 people and countless animals in the remote area of Lake Nyos in Cameroon mysteriously and very suddenly died (indepth story here). There were some survivors - people who had been indoors in closed rooms. Also, all the oil lamps in the entire region had gone out.

After investigation, scientists discovered that the lake (rumored to be home to bad spirits) was bubbling. They found an incredible amount of carbon dioxide (CO2) under pressure. It's normal for CO2 to be found in lakes, but parts of the lake were five parts CO2 to 1 part water. Usually disturbances on the surface of the water relieves enough pressure for the gas to escape slowly out of a lake, but Lake Nyos is sheltered and has very still waters; the gas just built up more and more. The carbon dioxide had exploded and settled in low lying areas (it's heavier than air) where it poisoned people and animals and extinguished all the flames in the area. The eruption was 4 times larger than the 1980 Mt. St. Helens eruption, but CO2 is colorless and odorless.

Scientists and engineers have installed a deep pipe (see image) that brings some of the gas to the surface to release some of the pressure, but they are also trying to find a more reliable long-term solution to prevent another large scale disaster.