Characterization of emissions from portable household combustion devices: particle size distributions, emission rates and factors, and potential exposures

A series of source tests were conducted to characterize emissions of particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and total hydrocarbon (THC ) from five types of portable combustion devices. Tested combustion devices included a kerosene lamp, an oil lamp, a kerosene space heater, a portable gas range, and four unscented candles. All tests were conducted either in a well-mixed chamber or a well-mixed room, which enables us to determine emission rates and emission factors using a single-compartment mass balance model. Particle mass concentrations and number concentrations were measured using a nephelometric particle monitor and an eight-channel optical particle counter, respectively. Real-time CO concentrations were measured with an electrochemical sensor CO monitor. CO2, CH4, and THC were measured using a GC-FID technique. The results indicate that all particles emitted during steady burning in each of the tested devices were smaller than 1.0 μm in diameter with the vast majority in the range between 0.1 and 0.3 μm. The PM mass emission rates and emission factors for the tested devices ranged from 5.6±0.1 to 142.3±40.8 mg h−1 and from 0.35±0.06 to 9.04±4.0 mg g−1, respectively. The CO emission rates and emission factors ranged from 4.7±3.0 to 226.7±100 mg h−1 and from 0.25±0.12 to 1.56±0.7 mg g−1, respectively. The CO2 emission rates and emission factors ranged from 5500±700 to 210,000±90,000 mg h−1 and from 387±45 to 1689±640 mg g−1, respectively. The contributions of CH4 and THC to emission inventories are expected to be insignificant due both to the small emission factors and to the relatively small quantity of fuel consumed by these portable devices. An exposure scenario analysis indicates that every-day use of the kerosene lamp in a village house can generate fine PM exposures easily exceeding the US promulgated NAAQS for PM2.5.