B56-06 Association of Short-Term Pollen Exposure and Lung Function in COPD Patients of the Space Study

Rationale Chronic obstructive pulmonary disease (COPD) continues to be a major global health burden, affecting hundreds of millions of adults and ranking among the leading causes of death. While the effects of air pollution on COPD outcomes are well established, much less is known about how natural aeroallergens—particularly pollen—might influence respiratory function in this population. Because pollen is known to provoke inflammation and airway reactivity in asthma, and because climate change is extending pollen seasons and concentrations, we explored whether short-term increases in ambient pollen could alter lung function among individuals with stable COPD. Methods Thirty former smokers with moderate COPD took part in the Study of Air Pollution and COPD Exacerbation (SPACE) in Boston, Massachusetts. Participants (average age 71 years) completed daily morning spirometry before taking any medications, using standardized portable devices, during four separate 30-day observation periods covering different seasons between 2017 and 2019. Regional pollen data—representing tree, grass, weed, and other types—were obtained from a monitoring site in Salem, Massachusetts. Using distributed lag linear models, we estimated the association between pollen exposure and daily FEV1 and FVC while accounting for temperature, major air pollutants (PM2.5, NO2, O3), and seasonal variation. Results Higher short-term pollen exposure was consistently linked with lower FEV1. Specifically, a 3-day lag in total pollen corresponded to a decrease of 5.45 mL in FEV1 (95% CI: -9.58, -1.30), and a 3-day cumulative exposure showed a similar reduction (-4.87 mL; 95% CI: -9.56, -0.16). No meaningful association was observed for FVC. When results were stratified by nitrogen dioxide levels, the reduction in FEV1 appeared more pronounced on days with higher NO2 (-8.29 mL; 95% CI: -16.05, -0.52), although confidence intervals overlapped. The direction and size of the effect remained stable across multiple sensitivity analyses that included humidity and co-pollutants. CONCLUSIONS Among patients with COPD, short-term rises in airborne pollen were linked with small but statistically significant declines in FEV1, suggesting transient impairment in expiratory airflow. The pattern of stronger effects in higher-pollution conditions hints at a possible interaction between allergens and traffic-related pollutants. These findings support the idea that natural aeroallergens may contribute to daily fluctuations in lung function among people with COPD. As pollen seasons intensify with climate change, clinicians and patients may need to consider pollen exposure in routine COPD management and preventive planning. This abstract is funded by: NIH