Emissions and exposure to NOx, CO, CO2 and PM2.5 from a gas stove using reference and low-cost sensors

Gas stoves and cooking are significant sources of indoor pollution. Using a combination of regulatory and calibrated low-cost sensors (LCS) we measured NO, NO2, CO and CO2 emission rates (g hr(-1)) and emission factors (g J(-1)) from a natural-gas stove and oven. The emission rates for gaseous pollutants were significantly higher, by factors of 2.6-29, from the oven compared to the stove for every pollutant measured. To evaluate the indoor air concentrations, we used a calibrated low-cost sensor (TSI Inc, AirAssure) to examine indoor concentration of CO, CO2, NO2 and PM2.5 for one month in one U.S. home with a gas stove during normal activities, including cooking. Indoor concentrations of one or more pollutants exceeded the U.S. EPA's Air Quality Index (AQI) level of 100 (for CO, NO2, and PM2.5) or 2000 ppm (for CO2) for an average of 99 min per day. The AirAssure, with only the manufacturer's calibration, was an excellent indicator of times when indoor concentrations of CO, CO2, and NO2 exceeded these reference levels. Without in-situ calibration, the AirAssure underestimated in-home PM2.5 concentrations. After in-situ calibration, the AirAssure correctly identified 1-min periods when the AQI was >100 85% of the time (up from 46% of the time without calibration).