Biomass cooking carbon monoxide levels in commercial canteens in Kigali, Rwanda.

Carbon monoxide (CO) is harmful to human health, yet there is limited evidence concerning emissions associated with biomass fuel cooking in occupational settings. Real-time 48-hour monitoring of CO concentrations at breathing height, was undertaken in staff and student kitchen and serving areas of two commercial canteens. We characterized two diurnal CO peaks coinciding with cooking activities. Peak CO concentrations of 255.5 ppm and 1-hour average of 76.3 ppm (IQR: 57.8-109.0 ppm) were observed in the student kitchen; the staff kitchen levels were 208.5 ppm, and 76.3 ppm (IQR: 52.5-114.0 ppm), respectively. High magnitude CO concentrations (8-hour average: 40.7 ppm SD: 40.0 ppm) which exceed World Health Organisation (WHO) Indoor Air Quality standards were observed. Further investigation of personal exposure and health impacts among kitchen staff is required, to inform interventions in this setting.