Assessing the potential impact of global warming on infiltration of outdoor air pollutants into residential indoor environments

摘要

Aim. Rising temperatures due to climate change are expected to impact human adaptive response, including changes to home cooling and ventilation patterns. These change may affect potential air pollution exposures via alteration in residential air exchange rates, which impact contributions from indoor and outdoor particle sources to indoor air. We conducted a field study examining associations between particle infiltration and temperature to inform future studies of air pollution health effects. Methods. We measured indoor and outdoor fine particulate matter (PM_(2.5)) in Atlanta in 60 homes totaling 840 sampling-days. Indoor-outdoor sulfur ratios were used to estimate particle infiltration. Linear mixed-effects models were used to examine sulfur ratio-temperature relationships. Projected meteorological values were incorporated in the models to predict sulfur ratios in a 20 year future scenario (2046-2065) and past scenario (1981-2000). Results. The average sulfur ratio in Atlanta was 0.70 ± 0.30, with a 0.21 lower sulfur ratio in summer compared to transition seasons. Sulfur ratios were also 0.19 lower in houses using air conditioning (AC) compared to those without AC usage. We observed a negative linear relationship between temperature and sulfur ratio; a 1 degree Celsius increase in temperature was associated with a decrease in the sulfur ratio of 0.008. Future temperature was projected to increase by 2.1 degrees Celsius compared to the past, which would result in a corresponding 0.023 increase in sulfur ratio during cooler months and a 0.037 decrease during warmer months. Conclusion. We observed substantial variability in sulfur ratios in Atlanta by temperature, season, and AC usage, and projected changes to sulfur ratios in the future under a warming climate. Ongoing analyses will compare these relationships to a similar study in Boston. These analyses can help to provide a better understanding of the potential influence of climate change on PM_(2.5) health effects.