Toronto, June 22 : Having a portable air cleaner in the home can reduce the negative impacts of air pollution on brain development in children, says a new study. The study, published in the journal Environmental Health Perspectives, found that the children born to mothers who had used the air cleaners had an average full-scale intelligence quotient (FSIQ) that was 2.8-points higher than the group that did not use an air cleaner during pregnancy. "These results, combined with evidence from previous studies, strongly implicate air pollution as a threat to brain development," said researcher Ryan Allen from Simon Fraser University, in Canada. The team recruited 540 pregnant women in Ulaanbaatar, Mongolia to participate in the study. Ulaanbaatar has some of the worst air quality in the world, well-exceeding guidelines set by the World Health Organisation (WHO). The women were less than 18 weeks into their pregnancies and non-smokers who had not previously used air filtering devices in their homes. They were randomly assigned to either the control or intervention group. The intervention group was provided with one or two HEPA filter air cleaners and encouraged to run the air cleaners continuously for the duration of their pregnancies. The air cleaners were removed from the home once the child was born. The researchers later measured the children's FSIQ at four years of age. Children in the intervention group also had significantly greater average verbal comprehension index scores, which is consistent with results from previous observational studies. The research suggests that a child's verbal skills may be particularly sensitive to air pollution exposure. /IANS