The Modifying Role of Socioeconomic Position and Greenness on the Short-Term Effect of Heat and Air Pollution on Preterm Births in Rome, 2001–2013

• Main Authors: Federica Asta, Paola Michelozzi, Giulia Cesaroni, Manuela De Sario, Chiara Badaloni, Marina Davoli, Patrizia Schifano
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: International Journal of Environmental Research and Public Health
• Subjects: Socioeconomic factors; Urban environment; Green spaces; Preterm birth; Maternal exposure; Temperature; Air pollution
• Online Access: https://www.mdpi.com/1660-4601/16/14/2497

Urban green spaces have been associated with health benefits, but few studies have evaluated the role of greenness on pregnancy outcomes. We examined how the association between short-term exposure to heat and air pollution on the probability of preterm delivery is affected by the spatial variation of socioeconomic position (SEP) and greenness. We analyzed a cohort of newborns in Rome, from April to October of 2001−2013, defining preterm as births between the 22nd and the 36th week of gestation. We used a time series approach, with maximum apparent temperature (MAT), PM₁₀, NO₂, and O₃ as exposure variables. As greenness indicators, we considered maternal residential proximity to green spaces and the Normalized Difference Vegetation Index (NDVI) within a 100 m buffer around each woman’s residential address. We enrolled 56,576 newborns (5.1% preterm). The effect of a 1 °C increase in temperature on the daily number of preterm births was higher in women with low SEP (+2.49% (90% CI: 1.29−3.71)) and among those living within 100 m from green spaces (+3.33% (90% CI: 1.82−4.87)). No effect modification was observed for NDVI or PM₁₀. SEP was an important effect modifier of the heat-preterm birth relationship. The role of greenness in modifying this association between heat and preterm delivery should be further investigated.