Survivors’ Life After Toxic Gas: Lake Nios

Six months after a mysterious toxic gas came from Lake Nios, Cameroon, to asphyxiate life in the surrounding valley, villages here remain eerily quiet, like ghost towns. An estimated 1,700 people perished; up to 7,000 survivors were evacuated to refugee camps or to adjacent, unaffected villages outside the regional quarantine. The government’s future resettlement plans for these people now depends on a scientific consensus from a mid-March conference in the capital city, Yaounde.

Since the disaster, the government has restricted access to the valley. At the town of Nios, fertile, untrampled fields are shrouded in six-foot elephant grass. White patches speckle the ground beside each mud-brick home in the village. The white powder of quicklime marks the shallow graves of the villagers. A gentle breeze, cooling the midday heat, rustles through unharvested crops of spoiling bananas, plantains, corn and yams. The usual hum of the African village--a medley of children playing, radios blaring and roosters crowing--is missing. Every home, although locked and shuttered, has been broken into and looted.

Human losses are worse. With entire families gone--minus elders and priests--refugees have lost support for regeneration. Many of those who died had significant influence in the villages’ political, social and moral structures. A survivor at one refugee camp said: “Only 17 of us remain . . . from our clan of 60. I do not know where are the rest.”

Forbidden to return to their home compounds--the traditional sites for funerals and other rituals--many survivors were unable, for months, to begin the traditional yearlong process of mourning. Not until late November was a mass funeral called by the a neighboring fon , or chief, and local Catholic clergy, so that families could formally initiate their mourning.

Some survivors have moved in with nearby friends or relatives. The generosity and loyalty of the extended African family is at work; many refugees--suddenly uprooted and evacuated--arrived with nothing more than the clothes they wore. Even without land, crops and livestock, these people are slowly assimilating into their new villages. Yet most are eager to return to their fertile valley, when and if the government permits.

More than 2,000 others remain in refugee camps controlled by Cameroon authorities. With neither resources nor relatives, these camp-dwellers have received the bulk of international aid. From the outset, in order to prevent overlapping efforts and inefficiency, the government insisted on directing all aid distribution and scientific investigation. An early outpouring of international assistance--food, tents, blankets, health workers and medicines--created immediate distribution problems. Government officials and the military had to deal with impassable mud roads and a thinly developed local infrastructure. Fortunately, most survivors were not in critical condition; and, since then, a steady trickle of outside aid has been just adequate for their needs.

Nearly all health problems directly attributable to gas exposure were resolved within seven to 10 days. Survivors recalled the pungent odor of rotten eggs; they suffered symptoms of burning eyes, difficult breathing and confusion, before losing consciousness for up to 48 hours. Upon waking, survivors trekked to nearby villages and were transported by the military to regional medical centers. Survivors with serious burns--even those who required extensive skin grafting--have recovered completely without excessive scarring. To date, health workers have noted no unusual problems among reproductive age women, newborn infants or children. Some subtler effects of gas asphyxiation on fetal development may not be apparent for years.

The largest of several scattered “temporary” refugee camps, Kimbi River Valley, supports nearly 1,500 people. Rows of bright, white canvas tents reflect the sunlight. Cots and blankets are labeled according to donors--Swiss, German, Italian, French, American and more. Children surround the visitor’s car but they are somber, expectant; their clothes are tattered, their skins pocked with scabies. Poor sanitation, bad water, marginal nutrition and overcrowding will create dangerous epidemics here unless conditions improve. A recent vaccination campaign helps, but is only a partial solution.

Fortunately, the new health center was well supplied in December, thanks to a donation from Save the Children Foundation. This group has been the only private voluntary organization to develop effective, continuing collaboration with the government in relief work. Enlisted by Cameroon, Save the Children has registered 2,133 children affected by the disaster, including 1,306 orphans. The government targets these children and their resettlement villages for long-term assistance.

Having physically recovered, survivors await the government’s plans and a time to put their lives in order. One of them, Elias Tufu, told Save the Children’s Kathleen Walsh about his worries for the future:

“After the explosion, the first thing to pain us was here,” tapping his index finger to his temple. “The last thing to pain us is here also.” Again, he touched his head.

The exact cause of the disaster remains disputed, despite several scientific studies. Preliminary results from pathological tissue specimens and toxicologic water analysis reveal no specific toxic agents, but an inordinately high level of carbon dioxide dissolved in lake water samples. The bulk of evidence and scientific consensus implicate carbon dioxide gas as the cause of asphyxiation. A large, dense cloud of it was released from the lake, swept down the valley around Nios, and suffocated those on low ground while sparing people on high ground. Hydrogen sulfide gas created the odor of rotten eggs, but in such small quantities that it did not harm people.

A number of theories with differing long-term implications have been offered. A similar catastrophe in 1984 at nearby, volcanic Lake Monoun was caused by an earthquake-induced landslide and killed 37 people in a sparsely populated area. At Lake Nios, however, no landslide occurred; there is no evidence of disruption in bottom sediment.

One possibility is that a huge burst of volcanic gas erupted into the depths of the lake and into the atmosphere--an extremely unusual event. Or, a slower, intermittent seepage--associated with organic decomposition or magmatic movement deep under the lake--could have created an enormous reservoir of gas. The dark, still, anoxic waters of Lake Nios remain stratified; they rarely mix with surface water. But a disturbance may trigger catastrophic mixing of deep and shallow layers of water, causing rapid release of carbon dioxide usually stored in the depths. Potential triggers include earthquakes, landslides, volcanic eruptions, wind direction changes or surface cooling. Some geologists think that seasonal wind shifts, combined with slight cooling of surface water, may have set off the gas release.

The Ministry of Health monitored renewed disruption at Lake Nios in December. Two visiting scientists reported hearing an explosion and seeing the lake, usually calm and blue, churning and red-orange. The area remains under quarantine; there were no new injuries. But recurrent disruption may prevent future resettlement. The government hopes that the March conference will produce sufficient scientific consensus to guide resettlement policy. For now, the Nios quiet continues.