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Thursday, June 9th, 2009

New INMA press release. "Contamination in homes can affect children’s cognitive development and behaviour"

Barcelona, 8 June 2009 – There is increasingly more proof that air pollution increases the risk of suffering from cerebrovascular and neurodegenerative diseases. And even more recently, different studies have revealed possible harmful effects of contamination on infant development. Besides other significant sources of breathable air pollution in homes, an additional source of contamination to take into account is that which comes from burning gas for heating and for cooking foods. These domestic tasks, so common in developed countries, produce nitrogen dioxide, one of the most toxic nitrogen oxides for cells. To prevent the oxidative stress caused by this type of toxic substance, our bodies have a mechanism in which the gene GSTP1 (glutathione S-transferase S1) takes part. Its function is to encode an antioxidant protein for synthesis that, as seen in several other studies, is extremely active during the first year of life in newborns’ brains.

Between 1997 and 1999, with the objective of studying the effects of environmental contaminants on children that are present in homes, researchers at the Environmental Epidemiology Research Centre (CREAL) of the Municipal Institute on Medical Research (IMIM) and the Balearic Health Institute monitored a cohort made up of 482 Majorcan male and female babies over their first three months of life and then again at four years of age. In the first stage during the first three months of life, the quality of air breathed in their homes of residence and the concentration of nitrogen oxide present in the ambience were analysed. In the second stage of the study, at four years of age, all children were evaluated with respect to their principal cognitive functions using the McCarthy test and also with regard to their normal capacity for attention and activity. Blood and saliva samples were obtained for DNA analysis and the determination of the variant of the GSTP1 gene in each child.

The analysis of the study results obtained made it clear that, independently of other sociocultural factors, environmental contamination in households are related to children's cognitive development, that the concentrations of nitrogen dioxide intervene in the appearance of behavioural disorders and that these undesirable effects are seen when the child is a carrier of a specific variant of the GSTP1 gene and is incapable of eliminating oxidants. It is important to stress that the use of an extractor reduces these effects, as well as ventilating the inside of the home while cooking with gas.

In conclusion, data indicate that during the earliest years of life, exposure to pollution coming principally from burning gas for domestic uses can affect cognitive functions and can increase the symptoms of impulsivity. Nonetheless, the study must be continued to determine if these effects disappear with age.

Reference article:
‘Association of Early-life Exposure to Household Gas Appliances and Indoor Nitrogen Dioxide with Cognition and Attention Behaviour in Preschoolers’. American Journal of Epidemiology, DOI: 10.1093/aje/kwp067