Pollutant concentrations and emission rates from natural gas cooking burners without and with range hood exhaust in nine California homes

Combustion pollutant concentrations were measured during the scripted operation of natural gas cooking burners in nine homes. Boiling and simmering activities were conducted on the stovetop and in the oven with and without range hood exhaust ventilation or air mixing via a forced air system. Time-resolved concentrations of carbon dioxide (CO₂), nitric oxide (NO), nitrogen oxides (NO_x), nitrogen dioxide (NO₂), particles with diameters of 6 nm or larger (PN), carbon monoxide (CO), and fine particulate matter (PM_2.5) were measured in the kitchen and bedroom area of each home. Four of the nine homes had kitchen 1 h NO₂ exceed the national ambient air quality standard (100 ppb). In all homes, the highest 1 h integrated PN exceeded 2 × 10⁵ cm⁻³-h, and the highest 4 h PN exceeded 3 × 10⁵ cm⁻³-hr in the kitchen. Range hood performance varied widely, but one with a large capture volume and a measured flow of 108 L/s reduced concentrations 80–95%. Increased awareness of the need to ventilate when cooking, along with building standards for minimum range hood flow rates and volume, could substantially reduce exposures to NO₂ and ultrafine particles in homes.