a yearlong epidemiologic study on unintentional acute carbon monoxide poisoning in fars province, southwest iran

background: knowing the pattern of carbon monoxide (co) poisoning in each region is vital for enhanced health planning. this study was designed to evaluate the epidemiologic pattern of unintentional acute co poisoning in major cities of fars province, southwest of iran.  methods: this one-year cross-sectional study was carried out on unintentional co poisoning incidents in fars province, iran, during the year 2011. the target population was people living in 7 major cities under supervision of shiraz university of medical sciences including shiraz, eghlid, neyriz, khorambid, marvdasht, darab and bavanat. results: during 2011, 111 co poisoning events occurred in the catchment area. these events involved 420 individuals (50.2% men) who were present during the poisoning event, of which 281 individuals with mean age of 27.8 ± 14.8 years were poisoned (46.5% men). the majority of co poisoning events (77.3%) occurred in colder months of the year. most events happened in urban areas (61.3%). the most common source of co was water heater (27.5%) closely followed by gas stove (24.8%). the majority of poisoned patients were asleep during the event (150/281: 53.3%). the main causes of co generation were inbound gas return (62.2%) and inappropriate ventilation (28.8%). the fatality rate of co poisoning was significantly higher in men compared to women both in involved individuals and poisoned patients (p = 0.035, < 0.001; respectively). moreover, poisoned victims who were asleep during the accident were more likely to die than those who were awake (14.3 vs. 3.7%, p < 0.001). conclusion: generally, the incidence and fatality rate of co poisoning in the current study were comparable to those of the world statistics, but higher than in developed counties. attention and emphasis on the safety of gas heaters, stoves, and other gas-powered appliances in residential places should be enforced.