Using Time-Resolved Monitor Wearing Data to Study the Effect of Clean Cooking Interventions on Personal Air Pollution Exposures

Background Personal monitoring can estimate individuals’ exposures to environmental pollutants; however, accuracy depends on consistent monitor wearing, which is under evaluated. Objective To study the association between device wearing and personal air pollution exposure. Methods Using personal device accelerometry data collected in the context of a randomized cooking intervention in Ghana with three study arms (control, improved biomass, and liquified petroleum gas (LPG) arms; N = 1414), we account for device wearing to infer parameters of PM 2.5 and CO exposure. Results Device wearing was positively associated with exposure in the control and improved biomass arms, but weakly in the LPG arm. Inferred community-level air pollution was similar across study arms (~45 μg/m 3 ). The estimated direct contribution of individuals’ cooking to PM 2.5 exposure was 64 μg/m 3 for the control arm, 74 μg/m 3 for improved biomass, and 6 μg/m 3 for LPG. Arm-specific average PM 2.5 exposure at near-maximum wearing was significantly lower in the LPG arm as compared to the improved biomass and control arms. Analysis of personal CO exposure mirrored PM 2.5 results. Conclusions Personal monitor wearing was positively associated with average air pollution exposure, emphasizing the importance of high device wearing during monitoring periods and directly assessing device wearing for each deployment. Significance We demonstrate that personal monitor wearing data can be used to refine exposure estimates and infer unobserved parameters related to the timing and source of environmental exposures. Impact statements In a cookstove trial among pregnant women, time-resolved personal air pollution device wearing data were used to refine exposure estimates and infer unobserved exposure parameters, including community-level air pollution, the direct contribution of cooking to personal exposure, and the effect of clean cooking interventions on personal exposure. For example, in the control arm, while average 48 h personal PM 2.5 exposure was 77 μg/m 3 , average predicted exposure at near-maximum daytime device wearing was 108 μg/m 3 and 48 μg/m 3 at zero daytime device wearing. Wearing-corrected average 48 h personal PM 2.5 exposures were 50% lower in the LPG arm than the control and improved biomass and inferred direct cooking contributions to personal PM 2.5 from LPG were 90% lower than the other arms. Our recommendation is that studies assessing personal exposures should examine the direct association between device wearing and estimated mean personal exposure.