A new study shows that obese children exposed to high levels of air pollution could be three times more likely to develop asthma in comparison to their peers who are not obese and exposed to less air pollutants. This conclusion was drawn up by researchers at Columbia University Medical Center (CUMC), who analysed 311 children in predominantly Dominican and African-American areas of New York City. The air within each child's home was monitored for a period of two weeks at age 5 or 6, in order to assess that child’s exposure to a type of air pollutants known as polycyclic aromatic hydrocarbons (PAH). In addition, the child's height and weight were tracked and respiratory questionnaires were asked. It was found that 20% of the children were suffering from asthma and going off body mass index, 20% could be classified as obese. It was determined that high exposure to PAH exposure was only linked to asthma for the obese children. The link was due to alkylated forms of PAH; released by a variety of things such as candles, cooking, cigarette smoke, incense, and more. A two-to-three-fold rise in asthma risk was witnessed amongst obese children that were exposed to significant levels of PAH chemicals 1-methylphenanthrene and 9-methylphenanthrene, but just PAH or obesity on their own could not foresee asthma risk. Lead author Kyung Hwa Jung, PhD, associate research scientist in the Department of Medicine at Columbia University College of Physicians and Surgeons, said: “Our results suggest that obesity may magnify the effects of these air pollutants, putting children at greater risk for having asthma.” The study is useful as it could result in the development of better targeted treatment. “These findings suggest that we may be able to bring down childhood asthma rates by curbing indoor, as well as outdoor, air pollution and by implementing age-appropriate diet and exercise programs,” commented senior author Rachel Miller, MD, Professor of Medicine (in Pediatrics) and Environmental Health Sciences, chief of Pediatric Allergy and Immunology at CUMC, and co-deputy director of the Columbia Center for Children's Environmental Health at Columbia's Mailman School of Public Health. Asthma and obesity are two conditions that have been on the increase in recent decades, both in the US and in the UK. Obviously this study was conducted in the US, where the percentage of American children who are obese has risen from 7% in 1980 to 20% in 2008, while childhood asthma has gone up from 4% in 1980 to 10% in 2009. In the UK, there are 5.4 million people currently receiving treatment for asthma, of which 1.1 million are children (1 in 11) and 4.3 million are adults (1 in 12). Last year a 11-year-old boy from Manchester hit the headlines after weighing in at a staggering 24 stone.