Work

Prenatal greenness, air pollution, and birthweight: Assessing sensitive windows of exposure and sub-populations in a multi-exposure setting

Year: 2026

Type: article

Abstract: • Birthweight is positively associated with greenness even after air pollutant co-adjustment. • The greenness-birthweight association is protective across all trimesters of pregnancy. • Addresses with the lowest greenness had the largest negative PM 2.5 -birthweight associations. • Nature-based solutions may attenuate air pollution’s negative impacts. Studies show that prenatal neighborhood greenness is positively associated with birthweight. However, few go beyond a pregnancy-long greenness average or consider air pollution co-exposures. We used time-varying greenness and air pollution estimates to explore sensitive windows and subpopulations. We examined Michigan (U.S.) birth records between 2007 and 2016 (n = 798,071). We derived the Normalized Difference Vegetation Index (NDVI) from Landsat images (30 m 2 resolution) to estimate greenness within 270 m and 1230 m radial buffers around each mother’s address, to represent greenness immediately surrounding addresses and within a short walk, respectively, in the three seasons before birth. We joined estimated weekly 1 km 2 gridded PM 2.5 , NO 2 , and O 3 concentrations, and fit distributed lag models to assess trimester-specific greenness, weekly air pollution, and birthweight, adjusting for temperature, seasonality, maternal factors, and gestational age. We examined whether the NDVI-birthweight association varied by socioeconomic status, and whether the air pollution-birthweight association varied by NDVI tertile. In adjusted models, an IQR (0.2 unit) increase in NDVI within a 270 m buffer was associated with a 12.3 g (95% CI: 9.7 g, 15.0 g) higher birthweight. Positive associations were observed in all trimesters, and across all maternal education and neighborhood median household income levels. PM 2.5 -birthweight associations (IQR = 5 μg/m 3 ) were largest in the lowest NDVI tertile (PM 2.5 : −21.3 g, 95% CI: −31.1 g, −11.5 g). Birthweight is positively associated with residential greenness in all trimesters after co-adjusting for air pollutants. Addresses surrounded by the least greenness had the strongest inverse PM 2.5 -birthweight association. Nature-based solutions may attenuate air pollution’s negative impacts.

Source: Environment International

DOI: 10.1016/j.envint.2026.110079