Polluted air increases the risk of low birth weight - The Mundo.es

At first glance, it may seem that a baby grows inside the womb is safe from the dangers of pollution. However, the reality is quite different. As the largest European study to date, in which Spain participates through the Center for Research in Environmental Epidemiology-Creal-, exposure to traffic pollutants and industry during pregnancy increases the risk of giving birth to a underweight baby (provided below 2,500 grams after 37 weeks gestation).

These new data show that for every increase of five micrograms per cubic meter in exposure to fine particles (PM2, 5), one of the most dangerous air pollutants, during pregnancy, the odds of low birth weight increase by 18% . The fork is wide, as the average exposure levels of PM2, 5 of the study population (more than 74,000 women from 12 European countries) ranged from less than 10 micrograms per cubic meter to nearly 30 micrograms per cubic meter (differences are determined by traffic density, population, type of street, in the presence of industry, harbor, building level, etc..).

“If levels of PM2, 5 diminish to 10 micrograms per cubic meter (the reference value of the World Health Organization-WHO-annual average air quality) could prevent 22% cases of low birth weight of births over 37 weeks, “exemplifies Jordi Sunyer, codirector of Creal.

Currently, the legal limit is 25 micrograms per cubic meter, as Sunyer says, “both Spanish as European cities approved” in compliance with European standards. However, the data can not be taken as positive. “Our study shows that even below legal levels found health effects. WHO therefore recommends that the threshold is lowered,” and in the same line, “we ask that you review the rules. Though he stresses,” there is a limit below which there is no effect . The relationship is always more quantity, more repercussions. “

Ultimately, “our findings suggest that a significant proportion of cases of low birth weight in Europe could be avoided if urban air pollution, especially fine particles is reduced,” argues Marie Pedersen, lead author of the study and CREAL researcher. “We also look at other pollutants such as nitrogen oxides and particulate matter (PM10). In all cases, we observed effects on birth weight and head circumference [another of the parameters analyzed], but the results were outstanding with PM2, 5 “, exposes Sunyer.

Consequences

When head circumference is below the lower limit of the gestational age of the newborn, points Carmen Muñoz, coordinator in neonatology Puerta del Hierro Hospital in Madrid, it “could have long-term, an evolution abnormal neurological “.

“It is important to be born with a few grams lighter,” says Felix Omeñaca, neonatologist at the Hospital La Paz in Madrid. “But when intrauterine growth is restricted, ie below the programmed-babies do not grow at the rate that should be inside the uterus-, it can have an impact on the health of small “.

scientific literature points to a list of problems related to air pollution, such as cardiac or respiratory (wheezing and asthma). “Several studies claim that in the long term, babies who are small for gestational age may be at increased risk of developing hypertension, diabetes and hyperlipidemia (what has been called metabolic syndrome),” the Muñoz neonatologist. Even a recent analysis of air quality related to autism.

However, the authors underline the new epidemiological work just published the journal The Lancet Respiratory Medicine ‘, “the results of investigations carried out so far are inconclusive.”

On this occasion, we have used data from the European cohort study to the effects of air pollution (ESCAPE). The researchers, coordinated by the Creal and INSERM (Grenoble, France), managed data from 14 studies conducted in 12 European countries (Norway, Sweden, Denmark, Lithuania, England, Netherlands, Germany, France, Hungary, Italy, Greece and Spain), involving more than 74,000 women who had their babies between February 1994 and June 2011. In Spain, 2,623 mother-child intervened integrated in the INMA-Childhood and Environment, whose director is Jordi Sunyer. What differentiates it from other jobs, remarks, “not only is the sample size, but all countries used the same measuring devices”.

After studying in detail all the information collected during pregnancy and to take into account other risk factors such as maternal smoking, age, weight and education, “can say that air pollution is a factor controllable risk regarding low birth weight is concerned. ” It is true that “there are still no studies showing that less pollution have positive impact on birth weight, but other in respiratory effects and mortality decline “.