Characterisation of Carbon Monoxide concentrations associated with biomass fuel cooking in two university canteen settings, Kigali Rwanda

Abstract

TPS 722: Low and middle income countries: indoor air pollutants, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Biomass burning for cooking in occupational settings is widespread in Low and Middle Income Countries (LMICs), but remains a neglected research area. Adverse health consequences are associated with acute and chronic exposure to elevated Carbon Monoxide levels (CO) from biomass burning. The World Health Organisation (WHO) has an Indoor Air Quality Guideline (IAQ) for mean 8-hour CO concentrations of 10 mg/m3 (8.7 ppm) (WHO, 2010). In this study, CO levels were recorded at 1-minute intervals over a 48-hour period using Electrochemical Lascar EL-USB-CO monitors, at respirable height (150 cm), within two biomass fuel (charcoal, wood) canteen settings (staff, student) at the Nyarugenge Campus, University of Rwanda. Measurements in both canteens were obtained from the kitchens and adjoining serving areas. Hourly average CO concentrations were calculated using the hourly median (IQR), along with 8-hour average concentrations, to represent potential staff shift exposure. Two diurnal peaks, coinciding with cooking activities were observed, with peak 1-minute concentrations of 255.5 ppm (student kitchen) and 208.5 ppm (staff kitchen). Peak average 1-hour concentrations of 76.3 ppm (IQR: 57.8 – 109 ppm) and 76.3 ppm (IQR: 52.5 – 114 ppm), occurred within the morning cooking session, in the student and staff kitchens respectively. Calculated 8-hour average concentrations were highest during the morning staff shift in both the student kitchen (40.7 ppm, SD: 40.0 ppm) and the staff kitchen (34.7 ppm, SD: 35.8). Below WHO IAQ limit values were observed within the two serving areas, with two diurnal peaks coinciding with cooking activity. The CO levels observed from charcoal and wood cooking in this occupational setting are hazardous to human health and in exceedance of WHO IAQ guidelines. Further research into occupational personal exposure levels and health impacts of CO exposure among kitchen and serving staff is needed, alongside development of a clean fuel switching initiative.