Study shows air pollution lowers children's mental ability
New research suggests that a child's cognitive ability can be affected by a mother's exposure to air pollution. The study, by the Columbia Center for Children's Environmental Health (CCCEH) in New York, US, was carried out in Cracow, Poland, and confirms previous findings from a similar study in New York City last year. The findings, published in the journal Environmental Health Perspective, provide further evidence about the effects of urban air pollutants on human health. The study looked at whether children exposed to high levels of polycyclic aromatic hydrocarbons (PAHs) demonstrated lower levels of thinking and reasoning skills. PAHs are released into the atmosphere by the burning of fossil fuels for transport and heating, as well as for energy production. The research was carried out on 214 children who were born between 2001 and 2006 in Cracow, the second largest city in Poland. The children all had healthy, non-smoking mothers who wore personal air monitors in backpacks while they were pregnant to measure pollution levels. As part of the study, the mothers also provided blood samples and completed questionnaires. An air pollution level of 17.96 nanograms (1 nanogram is 1 billionth of a gram) per cubic metre was used as the median. Exposure levels higher than this were rated as high exposure and those below as low exposure. After birth the children were monitored up to the age of five when they were given a test called the 'Raven Coloured Progressive Matrices (CPM) Test' which measures thinking ability and is designed for children aged five and upwards. Other possible factors for possible low cognitive ability were also taken into consideration including lead levels, exposure to cigarette smoke and the educational attainment of the mother. The researchers found that children exposed to high levels of PAHs had a significantly lower ability in reasoning and thinking tests than children who had had minimal exposure. 'The effect on intelligence was comparable to that seen in New York City children exposed prenatally to the same air pollutants,' explained co-author Professor Frederica Perera, Director of the CCCEH at the Mailman School of Public Health at Columbia University. 'This finding is of concern because IQ (intelligence quotient) is an important predictor of future academic performance, and PAHs are widespread in urban environments and throughout the world.' Commenting on the study's findings, lead author Dr Susan Edwards said: 'These results contribute to the cumulative body of published evidence linking ambient air pollution levels and adverse health effects in children and are clearly relevant to public health policy.' The CCCEH found similar conclusions in a test carried out in 2009 using a group of non-smoking African American and Dominican American women. 'Air pollution knows no boundaries,' said Linda Birnbaum, Director of the National Institute of Environmental Health Sciences, which funded the latest study. 'Researchers around the globe are finding that air pollution is harmful to children's development.'
Countries
Poland, United States