INMA:”Influence of the Urban Exposome on Birth Weight”

23/09/2019

The exposome is defined as the totality of environmental exposures from conception onwards. This definition aims to provide a holistic view of environmental exposures and their effects on human health by evaluating multiple exposures simultaneously during critical time periods of life. Over recent years, there has been considerable discussion on the topic, but little actual work has been conducted to put the exposome concept into practice. Previous studies showing negative associations between birth weight and environmental exposures such as air pollution, noise, temperature, lack of green space, or disadvantaged neighborhoods. Generally these studies evaluated individual exposure or single exposure families, thus not accounting for possible confounding effects of coexposures.

The Human Early Life Exposome (HELIX) is one of the first large exposome projects, and includes three INMA cohorts, namely Gipuzkoa, Sabadell, and Valencia. It aims to characterize early life exposure to multiple environmental factors and associate these with child health outcomes. As part of the HELIX project, a study investigated the association of the urban exposome, which includes the built environment, air pollution, road traffic noise, meteorology, natural space, and road traffic indicators (60 exposures covering 24 environmental indicators) with birth weight and term low birth weight, in more than 31,000 newborns.

The most consistent statistically significant associations were observed between increasing green space exposure estimated as Normalized Difference Vegetation Index (NDVI), and increased birth weight and decreased term low birth weight risk. Furthermore, statistically significant associations among presence of a number of built-environment exposures, i.e. number of public bus line, land use estimated as Shannon’s Evenness Index (SEI), and traffic density and birth weight were observed.

This was the first large urban exposome study of birth weight. It confirmed previously reported associations for green spaces (NDVI) and generated new hypotheses for a number of built-environment exposures.

Reference: Nieuwenhuijsen MJ, Agier L, Basagaña X, Urquiza J, Tamayo-Uria I, Giorgis-Allemand L, Robinson O, Siroux V, Maitre L, de Castro M, Valentin A, Donaire D, Dadvand P, Aasvang GM, Krog NH, Schwarze PE, Chatzi L, Grazuleviciene R, Andrusaityte S, Dedele A, McEachan R, Wright J, West J, Ibarluzea J, Ballester F, Vrijheid M, Slama R. Influence of the Urban Exposome on Birth Weight. Environ Health Perspect. 2019 Apr;127(4):47007.

Link: https://ehp.niehs.nih.gov/doi/full/10.1289/EHP3971?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed