The Berlin-Brandenburg Air Study – a natural experiment investigating health effects from changes in airport-related exposures

BACKGROUND AND AIM: The effects of ambient, air-borne ultrafine particles (UFP), particularly those originating from air traffic, on human health remain poorly understood. Using the simultaneous closing and opening of two airports in Berlin as a unique, natural experiment, we aim to investigate the effect of changing UFP exposure on health in schoolchildren, with a particular focus on aircraft-related UFPs. METHODS: The Berlin-Brandenburg Air Study (BEAR) involves 800 elementary school children (ages 8-12) attending altogether 12-16 schools near the closing Tegel (TXL) airport, near the opening Berlin-Brandenburg (BER) airport, and in control areas (CTL) away from both airports and associated air corridors. Each child undergoes repeated school-based health examinations for lung function, cognitive function (attention and working memory), blood pressure, and quality of life. School-specific particle number concentrations and meteorology are measured daily. Along with other air pollutants and meteorology, size-fractioned UFP measurements are collected at two local monitoring stations. Daily source-specific UFP concentrations will be modeled on a fine spatial scale using a chemistry transport model for periods before and after the airport’s relocation. We will analyze short-term effects of UFP as well as long-term effects on lung growth and cognitive development comparing growth trajectories across the three school areas. RESULTS:Since early 2020, over 300 children in 7 schools (4 near TXL, 2 near BER, 1 in CTL) have completed their first examination. Due to the ongoing COVID-19 pandemic, the pattern of air traffic has changed and field work at the schools has been delayed. We have expanded the time frame and recruitment near BER airport, where we expect insightful comparisons between lockdown conditions and gradually increasing air traffic. CONCLUSIONS:The BEAR study aims to increase understanding on health effects of aircraft-related UFPs, particularly for children’s health and development. We present the study's methodological design and epidemiological background for this natural experiment. KEYWORDS: air pollution, children’s environmental health, exposure assessment, methodological study design, particulate matter