Associação entre poluição ambiental e transtorno do déficit de atenção com hiperatividade : revisão sistemática

Abstract

The deleterious effects of pollution have already been evidenced in several outcomes related to child health. But there is a scarcity of scientific information on the implications of pollution on the central nervous system of children, which can be exposed even before birth. This study objective to evaluate the possible associations between exposure to environmental pollutants attention deficit disorder and hyperactivity in children. A research was conducted in the literature through the databases MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, Latin American Caribbean Health Sciences Literature, Cumulative Index to Nursing and Allied Health Literature, PsycINFO,Web of Science, and gray literature, with no date or language limit, to analyze the possible associations between exposure to environmental pollutants and attention deficit hyperactivity disorder in children. A total of 13 cohorts were included in the systematic review, containing 123.790 participants were included in the systematic review and 50 associations. Of the selected studies, five authors analyzed the effects of pollutants alone and in eight others the combinations of two or more products (multipollution model). Of the thirteen studies, in eight the authors addressed air pollution, six was about particulate matter (PM). In eight studies, the authors concluded that there are positive associations between pollutants and ADHD and related outcomes, in another five there are inferences or no association. Of the eight studies with a positive association, four are with isolated pollutants, one with BPA; one with lead, one with NO2, and one with MP 2.5. The other four studies are with multi-pollutants; one with organophosphates and pyrethroids; one with carbon derivatives Elemental Carbon (EC) e Black Carbon (BC), and NO2; finally, two with nitrogen derivatives and particulate matter (PM). No association or weak association was found in four studies, only one with isolated pollutant, in the case of HCB, and three were studies with multipollutants, one that analyzed heavy metals; another with MP and NO2; one with nitrogen derivatives and particulate matter (PM). Nine studies (69%) were classified as of good quality. According to the conclusions of the authors of the selected studies, it was possible to evidence a positive association between pollutants with ADHD and related outcomes. The most relevant associations are with BPA; lead; pesticides (organophosphates and pyrethroids); nitrogen derivatives and particulate matter. However, future studies with adequate design are needed to clarify these relationships and to answer if there are differences between the age groups, between genders and different levels of exposure.