RESPIRATORY SYMPTOMS AND PEAK EXPIRATORY FLOW IN SURVIVORS OF THE NYOS DISASTER

In August 1986, gases from the Nyos volcanic lake killed 1,746 persons in northwestern Cameroun, but 1,500 others living in the affected are a survived. Gas emanations contained carbon dioxide, sulfur dioxide, a nd hydrogen sulfide, The objective of this study was to evaluate the d elayed respiratory consequences of the inhalation of such volcanic gas es, Two groups of subjects living in the same area, exposed (Nyos grou p; n=381) or not exposed (control group; n=128) to Nyos gases, were ev aluated with a short questionnaire and by measurement of peak expirato ry flow (PEF, percent predicted) in March 1991, Eleven percent of the subjects smoked, more often men than women (23% vs 4%; p<0.001), In th e whole population (exposed and unexposed), smoking was associated wit h a 3.6-fold increase in the frequency of cough (p<0.001) and with a 6 -fold increase in the frequency of sputum production (p<0.005), but no t with a decrease in PEF, There was no difference in the frequency of dyspnea, cough, sputum production, and PEF between Nyos and control gr oups. We conclude that 55 months after the emanation of gases from Nyo s volcanic lake, there was no difference in respiratory symptoms and P EF between survivors who inhaled volcanic gases and control subjects, whereas smoking was associated with cough and sputum production.