Indoor air pollution from gas cooking and infant neurodevelopment.

BACKGROUND: Gas cooking is a main source of indoor air pollutants, including nitrogen dioxide and particles. Because concerns are emerging for neurodevelopmental effects of air pollutants, we examined the relationship between indoor gas cooking during pregnancy and infant neurodevelopment. METHODS: Pregnant mothers were recruited between 2004 and 2008 to a prospective birth cohort study (INfancia y Medio Ambiente) in Spain during the first trimester of pregnancy. Third-trimester questionnaires collected information about the use of gas appliances at home. At age 11 to 22 months, children were assessed for mental development using the Bayley Scales of Infant Development. Linear regression models examined the association of gas cooking and standardized mental development scores (n = 1887 mother-child pairs). RESULTS: Gas cookers were present in 44% of homes. Gas cooking was related to a small decrease in the mental development score compared with use of other cookers (-2.5 points [95% confidence interval = -4.0 to -0.9]) independent of social class, maternal education, and other measured potential confounders. This decrease was strongest in children tested after the age of 14 months (-3.1 points [-5.1 to -1.1]) and when gas cooking was combined with less frequent use of an extractor fan. The negative association with gas cooking was relatively consistent across strata defined by social class, education, and other covariates. CONCLUSIONS: This study suggests a small adverse effect of indoor air pollution from gas cookers on the mental development of young children.

[Air pollutant exposure during pregnancy and fetal and early childhood development. Research protocol of the INMA (Childhood and Environment Project)]. / Exposición a contaminantes atmosféricos durante el embarazo y desarrollo prenatal y neonatal: protocolo de investigación en el proyecto INMA (Infancia y Medio Ambiente).

INTRODUCTION: The INMA (INfancia y Medio Ambiente [Spanish for Environment and Childhood]) project is a cooperative research network. This project aims to study the effects of environment and diet on fetal and early childhood development. This article aims to present the air pollutant exposure protocol during pregnancy and fetal and early childhood development of the INMA project. METHODS: The information to assess air pollutant exposure during pregnancy is based on outdoor measurement of air pollutants (nitrogen dioxide [NO2], volatile organic compounds [VOC], ozone, particulate matter [PM10, PM2,5 ] and of their composition [polycyclic aromatic hydrocarbons]); measurement of indoor and personal exposure (VOC and NO2); urinary measurement of a biological marker of hydrocarbon exposure (1-hydroxypyrene); and data gathered by questionnaires and geographic information systems. These data allow individual air pollutant exposure indexes to be developed, which can then be used to analyze the possible effects of exposure on fetal development and child health. CONCLUSION: This protocol and the type of study allow an approximation to individual air pollutant exposure to be obtained. Finally, the large number of participants (N = 4,000), as well as their geographic and social diversity, increases the study's potential.

Socioeconomic status and exposure to multiple environmental pollutants during pregnancy: evidence for environmental inequity?

BACKGROUND: Inequities in the distribution of environmental exposures may add an extra burden to socially disadvantaged populations, especially when acting during vulnerable periods such as pregnancy and early life, but such inequities may be more complex and uncertain than is generally assumed. We therefore examine whether socioeconomic inequities exist in pregnancy exposures to multiple common environmental contaminants in air, water and food. METHODS: A Spanish population-based birth cohort study enrolled over 2000 pregnant women between 2004 and 2008. Questionnaires assessed parental education, occupation, country of birth, diet and many other factors. Environmental pollutant assessments included nitrogen dioxide as a marker of traffic-related air pollution, trihalomethanes as a marker of tap water disinfection by-products, organochlorine biomarkers measured in maternal serum during pregnancy (polychlorinated biphenyls (PCB), dichlorodiphenyl dichloroethylene (p,p'-DDE), hexachlorobenzene and ß-hexachlorocyclohexane) and mercury concentrations measured in cord blood. RESULTS: Associations between socioeconomic status indicators and nitrogen dioxide and trihalomethanes were generally weak and inconsistent in direction. Concentrations of PCB, hexachlorobenzene and mercury were higher in higher social classes than lower social classes. p,p'-DDE and ß-hexachlorocyclohexane were not related to social class. Social class explained between 1% and 5% of the variability in pollutant concentrations, much less than other variables such as region of residence, country of birth and maternal age. DISCUSSION: This study demonstrates that the general assumption that more disadvantaged populations have higher levels of exposure to environmental pollution does not always hold and requires further elucidation in different international settings.