“Gas cookers at home and mental development of young children”


The presence of gas cookers or gas stoves inside the home is common in developed countries (50{3effe4377b6f02be2524d084f7d03914ac32a2b62c0a056ca3444e58c1f10d0b} to 70{3effe4377b6f02be2524d084f7d03914ac32a2b62c0a056ca3444e58c1f10d0b}) and it has long been recognized as a main source of indoor air pollution. Gas cooking produces a complex mixture of compounds. One of them is nitrogen dioxide (NO2) that is the most extensively studied indoor air pollutant. Gas cooking is a main predictor of indoor NO2 concentrations in homes in developed countries, together with cigarette smoking and outdoor traffic-related NO2. Homes with gas appliances can have NO2 concentrations twice as high as other homes and concentrations may exceed the WHO guideline for average annual outdoor NO2. Women and young children are especially exposed because they spend a larger part of their day at home and in the kitchen

Air pollution may impair neurodevelopment. Because maturation of the brain is intensive in the first few years of life, this period of development may be particularly vulnerable to environmental pollutants. Recent studies have observed adverse cognitive and behavioral effects of perinatal outdoor air pollution, and these studies have raised concerns about similar effects from indoor air pollution.

This study examined the relationship between exposure to gas cookers during pregnancy and mental development of children aged 1 to 2 years in a large Spanish birth cohort study.

A total of 1887 mother– child pairs from 4 Spanish regions of the population-based birth cohort study INMA (Asturias; Gipuzkoa, Basque-Country; Sabadell, Catalonia; and Valencia) participated between 2004 and 2008.

The results showed that forty-four percent of mothers have a gas cooker at home in the third trimester of pregnancy, most of them were connected to natural gas. The presence of a gas cooker at home during pregnancy was associated with a slower mental development of young children, particularly those tested after the age of 14 months. This decrease was strongest when gas cooking was combined with less frequent use of an extractor fan. The negative effect of gas cooking did not clearly differ according to socioeconomic factors, diet and life-style habits, and exposure to environmental pollutants.

Given the consistency of exposure over time within families, it is not possible to determine how timing of exposure (prenatal versus postnatal) might affect the association. These findings support those of a recent study in a small birth-cohort study in Menorca, Spain, even if the exact mechanisms by which damage is caused are under discussion.

The potential public health implications of these findings, are substantial because of the frequent use of gas cookers and because neurodevelopmental disorders and disabilities impose a social and economic burden.

Reference: Vrijheid M, Martinez D, Aguilera I, Bustamante M, Ballester F, Estarlich M, Fernandez-Somoano A, Guxens M, Lertxundi N, Martinez MD, Tardon A, Sunyer J; on behalf of the INMA Project. Indoor Air Pollution From Gas Cooking and Infant Neurodevelopment. Epidemiology. 2012 Jan;23(1):23-32.