Climate change is expected to increase exposure to PM2.5 infiltrating indoors in the greater Boston area. Researchers at the Harvard School of Public Health, used data from indoor and outdoor sulfur PM concentrations in 340 homes, and modeled the relationship between indoor concentration and temperature, projecting results between 2046 and 2065. Particle infiltration was predicted to increase by 7% for naturally-ventilated homes, and by 2% for all homes, with largest increases in the summer. Importantly, these results include the reaction of occupants to changes, through window opening or air conditioning use.