Yes... This is a disaster related to CO2 of volcanic origin. Two years before this, in 1984, there was another instance nearby, Lake Monoun - 37 villagers died of CO2 poisoning. Any concentration between 20%-30% of CO2 exposure can cause convulsions and coma within 1 minute.
To minimise the possibility of this happening again, a set of pipes have been installed on the bed of Lake Nyos, to control drain off the buildup of CO2. This project ran into financial difficulty because the Cameroon government could not afford it, sadly many international Aid Agencies were not interested in it and eventually the US Government funded it. (OFDA)
OTOH
Carbon Monoxide can be lethal even in low concentrations.... Haemoglobin binds carbon monoxide (CO) 200 to 300 times more than with oxygen, resulting in the formation of carboxyhaemoglobin and preventing the binding of oxygen to haemoglobin because they use the same binding sites.
Thus the blood oxygen transport mechanism fails.
Always take care when you burn anything from wood to BBQ briquettes, gas lamps etc - all these produce CO - and in enclosed spaces it's an invitaion to disaster.
