Association of ultrafine particle exposure with lung function in elementary school children in the Berlin-Brandenburg Air Study (BEAR)

<bold>Objective:</bold> Health impacts of ultrafine particles (UFP), particularly those from aviation sources (AC-UFP), are not fully investigated. The BEAR-study is a natural experiment investigating acute, medium, and long-term health effects of UFP on children attending elementary schools close the operating Berlin-Brandenburg Airport (BER), the former operating Airport Tegel (TXL) and in control areas (CA) in Berlin, Germany. <bold>Material and Methods:</bold> Parallel to school-based health examinations, spirometry assessments were conducted on school-children at least twice between January 2020 and June 2023. Total particle number concentration (PNC) was continuously monitored. To analyze the association between PNC exposure and lung function, a nested linear mixed-effect model with random intercepts for school and participant was employed. <bold>Results:</bold> 1,094 children with a mean age of 8.6 years (48,7% male) from 16 schools underwent repeated health examinations. Preliminary analysis of 1,150 observations indicated that base-line lung function data did not differ between areas (BER: 1.96±0.4 (FEV1); TLX: 2.03± 0.5 (FEV1); CA: 1.95± 0.4 (FEV1). A continuous increase in both FEV1 and FVC was observed from the first to the third assessment, in line with an age-related lung growth of the children. We identified a negative association between PNC on the day of examination and FEV1 (−0.14 liters per 4,390 particles/cm3, 95% CI [−0.16; -0.11]). After adjusting for area, the estimates remained unchanged. <bold>Conclusions:</bold> The observed adverse associations between PNC, measured in proximity to Berlin airports, and lung-function in children raise concerns about the potential health impact