Associations of residential greenness, traffic noise, and air pollution with birth outcomes across Alpine areas

Aim This explorative study aimed to investigate the association of residential greenness, traffic noise, and air pollution with birth outcomes in several Alpine areas with unique topography.We used data from two cross-sectional studies (UIT, n = 573 and BBT, n = 518) in the Tyrol Region (Austria/Italy). Only mothers who had lived in their current residence during the whole pregnancy were included. They completed a questionnaire, and medical records were used to draw data on birth weight, low birth weight (LBW), preterm birth, and small for gestational age (SGA). Normalized Difference Vegetation Index (NDVI) in the year of birth was assigned at the residential address as a measure of greenness. Road/railway traffic noise (Ldn) and air pollution (NO2) were calculated about 10 years after birth and used as surrogates for exposure levels during pregnancy.In the UIT survey, higher NDVI500-m was consistently associated with lower odds for LBW and SGA, while an increase of Ldn was associated with higher odds for LBW. Other effect estimates were in the expected direction albeit non-significant. In the BBT survey, most findings were inconclusive (for NDVI) or present only in subgroups (for Ldn and NO2).This study provides inconclusive evidence that the surrounding environment might be associated with birth outcomes in mountainous areas. Given the disparate associations across the study areas, further research in larger representative samples is warranted.