Assessing the potential impact of climate change on particle infiltration in two US cities: Boston, MA and Atlanta, GA

Rising temperatures associated with climate change are expected to impact human adaptive responses, including changes to home cooling and ventilation patterns. In this study, we assembled a large database on indoor/outdoor sulfur ratio (Sr) as a surrogate to link concentrations of indoor particles of outdoor origin to ambient temperature in two US cities with distinct climates and housing characteristics: Boston and Atlanta. We subsequently predicted Sr in the 20-year future (2046-2065) and past (1981-2000) scenarios. We found differential effects of temperature on ambient PM2.5 infiltration by air conditioning (AC) usage and between the two cities. Climate change was projected to enhance seasonal differences in PM2.5 infiltration. Findings from this study will not only help minimize PM2.5-related exposure misclassification in epidemiologic studies but also provide a better understanding of the effect modification of PM2.5-related mortality in the future.