Optimizing air purification strategies to reduce household PM2.5 exposure in Uganda

PROJECT SUMMARY While control of emissions is the most effective method of reducing air pollution exposure, people living in low and middle-income countries (LMICs) are often exposed to many sources of air pollution simultaneously, making a single intervention to reduce emissions difficult. High-efficiency particulate air (HEPA) filter-based

portable air cleaners (PACs) have been demonstrated to effectively reduce particulate matter (PM) exposure regardless of the source, but several barriers have limited their use in LMIC settings. Our overall objective in this research is to demonstrate that an optimized PAC platform can reduce PM exposure in an LMIC

household. Our central hypothesis is that PACs can reduce PM, can remain continuously powered, and can be used consistently within an LMIC home. We propose to test this hypothesis among 20 households within an established cohort in Uganda in a study with the following Specific Aims: 1) Identify and optimize

environmental factors that maximize PM reduction associated with PAC use in a real-world LMIC setting; 2) Design and test the optimal power supply for a PAC in a setting with unreliable electricity; and 3) Determine the feasibility, acceptability, and adherence to a PAC intervention in families of children with a history of

pneumonia. In Aim 1, we will perform a series of controlled experiments in simulation settings and real-world experiments in rural and urban households to measure the effect of PAC filtration rate and location, building characteristics, sources and concentration of air pollution, and seasonality on the efficacy of PM reduction. In

Aim 2, we will assess the characteristics of both the power supply and demand of the PAC system, determine the optimal components of a solar and battery backup system for powering the PAC, and create analytic models for various scenarios of power demand and availability. In Aim 3, we will administer structured surveys,

obtain time-activity diaries, and conduct focus group discussions among adults and children in the households participating in real-world testing of PACs. We will perform a mixed methods evaluation focused on perceptions of benefits vs. burdens of PAC use and identify predictors of efficacy and adherence. The output of this

research will provide the scientific justification for an R01-funded intervention trial of PACs in an LMIC setting. Current options to reduce PM exposure for people living in LMICs are limited, but following this study and a subsequent PAC intervention trial, clinicians and policymakers will have evidence to inform recommendations

for the use of PACs.