Assessing personal PM_2.5 exposure using a novel neck-mounted monitoring device in rural Rwanda

There is growing global concern regarding the detrimental health impacts of PM_2.5 emissions from traditional stoves that utilize polluting fuels. Conventional methods for estimating daily personal PM_2.5 exposure involve personal air samplers and measuring devices placed in a waist pouch, but these instruments are cumbersome and inconvenient. To address this issue, we developed a novel neck-mounted PM_2.5 monitoring device (Pocket PM_2.5 Logger) that is compact, lightweight, and can operate continuously for 1 week without recharging. Twelve participants who utilized charcoal, firewood, or propane gas for cooking in rural regions of Rwanda wore the Pocket PM_2.5 Logger continuously for 1 week, and time-series variations in personal PM_2.5 exposure were recorded at 5-min intervals. Individual daily exposure concentrations during cooking differed significantly among users of the different fuel types, and PM_2.5 exposure was at least 2.6 and 3.4 times higher for charcoal and firewood users, respectively, than for propane gas users. Therefore, switching from biomass fuels to propane gas would reduce daily individual exposure by at least one-third. An analysis of cooking times showed that the median cooking time per meal was 30 min; however, half the participants cooked for 1.5 h per meal, and one-third cooked for over 4.5 h per meal. Reducing these extremely long cooking times would reduce exposure with all fuel types. The Pocket PM_2.5 Logger facilitates the comprehensive assessment of personal PM_2.5 exposure dynamics and is beneficial for the development of intervention strategies targeting household air pollution.