“Respiratory Effects of pre and postnatal Exposure to Air Pollution”
Development of our airways begins during the second trimester of pregnancy and ends about three years of age. During this period, vulnerability to environmental harmful substances and radiations is higher than in other periods. However, although there is wide knowledge about adverse effects of air pollutants on lung function in school-age, the effects of prenatal and early postnatal exposure to air pollution is still largely unknown.
Preschool children represent one of the major challenges in lung function assessment; however, evaluating lung function in this age group is important for clinical reasons and also due to the considerable growth and development of the respiratory system that occurs during this period of life.
To answer these questions, we conducted a study including data from 1295 pregnant women and 1175 newborns from two Spanish geographic areas (Guipuzcoa and Sabadell). Residential exposure to two environmental pollutants, nitrogen dioxide (NO2) and benzene (C6H6) was estimated using geostatistical models, from pregnancy to 4.5 years old.
At the age of 4.5 years children were invited to perform a respiratory function test. In this test, children exposed to higher concentrations of benzene and nitrogen dioxide during pregnancy obtained worse indicators of respiratory function, especially if the exposure occurred during the second trimester of pregnancy. Specifically, exposed children had higher airway obstruction in spirometry tests, and an increased risk of low lung function. This association was even higher in children with atopy and from mothers from the lowest social class and education level. However, mechanisms underlying these associations are still unknown.
As these results are similar to those obtained in other studies, it seems necessary to extend a claim to public representatives for developing health policies to reduce exposure to these environmental pollutants.
Reference: Morales E, Garcia-Esteban R, Asensio de la Cruz O, Basterrechea M, Lertxundi A, Martinez López de Dicastillo MD, Zabaleta C, Sunyer J. Intrauterine and early postnatal exposure to outdoor air pollution and lung function at preschool age. Thorax. 2015 Jan;70(1):64-73.