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 PM2.5 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/m3). The estimated direct contribution of individuals' cooking to PM2.5 exposure was 64 µg/m3 for the control arm, 74 µg/m3 for improved biomass, and 6 µg/m3 for LPG. Arm-specific average PM2.5 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 PM2.5 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 PM2.5 exposure was 77 µg/m3, average predicted exposure at near-maximum daytime device wearing was 108 µg/m3 and 48 µg/m3 at zero daytime device wearing. Wearing-corrected average 48 h personal PM2.5 exposures were 50% lower in the LPG arm than the control and improved biomass and inferred direct cooking contributions to personal PM2.5 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.

Experiences with the Mass Distribution of LPG Stoves in Rural Communities of Ghana.

Household air pollution (HAP) is a leading cause of morbidity and mortality worldwide. To limit HAP exposure and environmental degradation from biomass fuel use, the Government of Ghana promotes liquefied petroleum gas (LPG) use in rural Ghana via the Rural LPG program (RLP). We assessed the experiences of the RLP in 2015, 2 years after its launch. A mixed methods approach was used involving Focus Group Discussions (19) and in-depth interviews (25). In addition, a survey questionnaire was administered to elicit socio-demographic characteristics, household cooking practices and stove use patterns of 200 randomly selected respondents. At about 9 months after LPG acquisition, < 5% of LPG beneficiaries used their stoves. Some of the reasons ascribed to the low usage of the LPG cookstoves were financial constraints, distance to LPG filling point and fear of burns. Community members appreciate the convenience of using LPG. Our results underscore a need for innovative funding mechanisms contextualized within an overall economic empowerment of rural folks to encourage sustained LPG use. It emphasizes the need for innovative accessibility interventions. This could include establishing new LPG filling stations in RLP beneficiary districts to overcome the barriers to sustained LPG use.