Traffic-related air pollution and birth weight: the roles of noise, placental function, green space, physical activity, and socioeconomic status (FRONTIER)
Payam Dadvand1 & Jordi Sunyer1, Maria Dolores Gómez-Roig2, Elisa Llurba3, Maria Foraster1, Mar Alvarez1, Gustavo Arévalo4, Mariona Bustamante1, Xavier Basagaña1, Mireia Gascon1, Michael Jerrett5, Jose Lao4, Edurne Mazarico Gallego2, Teresa Moreno6,Tim Nawrot7, Mark J Nieuwenhuijsen1, Xavier Querol6, Joel Schwartz7, Cathryn Tonne1
1ISGlobal, Spain; 2BCNatal, University of Barcelona, Spain; 3Sant Pau University Hospital, UAB, Spain, 4Barcelona Regional, Spain; 5Fielding School of Public Health, University of California, Los Angeles, USA; 6IDAEA-CSIC, Spain; 6Hasselt University, Belgium; 7Harvard School of Public Health, USA
Background. FRONTIER aims to provide a robust and comprehensive evaluation of the impact of maternal exposure to traffic-related air pollution on fetal growth. Towards this aim, it will (i) disentangle the effects of noise; (ii) identify the relevant window(s) of exposure; (iii) evaluate its modification by socioeconomic status, stress, and physical activity; (iv) elucidate the role of placental function as an underlying mechanism; and (v) explore the potential of green spaces to mitigate it.
Methods. FRONTIER is establishing a new pregnancy cohort in Barcelona (BiSC), Spain. Fetal growth is being characterized by anthropometric measures at birth together with ultrasound-based trajectories of fetal development. Placental function is being evaluated using Doppler ultrasound indicators. Time-activity patterns are being objectively characterized using a combination of smartphones and personal physical activity monitors. We will develop and validate an innovative exposure assessment framework integrating data on time-activity patterns with a hybrid modeling framework combining dispersion and land use regression models and campaigns of personal and home-outdoor air pollution monitoring to estimate maternal exposure level as well as inhaled dose of NO2, PM2.5, PM2.5 light absorption, and PM2.5 Cu, Fe, and Zn contents (markers of non-tailpipe emissions) at the main microenvironments for pregnant women (home, workplace, and commuting routes). We will assess maternal exposure to noise by integrating measurements at participants’ home-outdoor using noise monitors together with modeled microenvironmental levels of noise and data on noise sensitivity, annoyance, and protections against noise. We will apply detailed information on different characteristics of each tree canopy in our study region together with a high-resolution remote-sensing map of greenness to separately characterize the canopy and greenness surrounding maternal residential address. We will develop single- and multi-pollutant models to evaluate the impact of air pollution exposure and inhaled dose on fetal growth and the mediatory role of placental function.
Results & Conclusions. FRONTIER accomplished its recruitment phase on March 30, 2021, by enrolling 1,086 pregnant women who had an average age of 34.8 years with 30.8% having high school education and less and 74% having European origin. For the pre-pandemic period, the mean (SD) of the third trimester measured personal, home-indoor, and home-outdoor NO2 levels were 28.1 (11.7), 24.1 (10.9), and 39.2 (13.9) μg/m3, respectively. The last births in this cohort are expected to occur by Sep-Oct 2021, after which the descriptive statistics of the full cohort are expected to be ready.