Asthma rates for inner-city kids higher than those in rural areas

By Gwyn Wright via SWNS

Asthma rates for inner-city kids can be up to three times higher than those who live in the country, according to new research.

And two outdoor air pollutants, ozone and fine particulate matter are linked to the attacks, the study reveals.

The U.S. team found 30 percent of asthma attacks among inner-city children were not caused by viruses, which are the usual cause of asthma attacks among children.

This figure is two to three times as high as that for children living outside cities.

Associations between exposure to the two air pollutants and molecular changes in children’s airways during asthma attacks were also uncovered by the researchers.

Changes to the way genes that play a role in airway inflammation express themselves were found to be linked to higher levels of the two pollutants.

They say unique biological pathways- or actions that cause a cell to change- may be involved in non-viral asthma attacks.

Acting Director of the U.S. National Institute of Allergy and Infectious Diseases, Dr. Hugh Auchincloss, said: “The strong association this study demonstrates between specific air pollutants among children in impoverished urban communities and non-viral asthma attacks further augments the evidence that reducing air pollution would improve human health.”

Asthma is caused by chronic inflammation of the airways.

During an attack, it causes the airway lining to swell, muscles around the airways to contract and the airways to produce extra mucus, which reduces the scope for air to move in and out of the lungs.

Attacks caused by viruses have been studied extensively but those that can occur independently have not.

For the study, the team from the University of Washington in Seattle, Wash. and the University of Wisconsin-Madison looked at the relationship between air pollutant levels and asthma attacks which were not caused by a respiratory virus among 208 children.

The youngsters, who were all aged six to 17, all had attack-prone asthma and lived in low-income neighborhoods in one of nine US cities.

Later they carried out a follow-up study on 189 children aged six to 20 who had persistent asthma and lived in poor neighborhoods of one of four U.S. cities.

The children were followed for six months or until they caught two respiratory illnesses- whichever came first.

Each illness was classified as viral or non-viral and as involving an asthma attack or not.

The researchers matched each illness with air quality index values and levels of individual air pollutants recorded by the US Environmental Protection Agency in the relevant city on the dates surrounding the illness.

Their findings were adjusted for city and season to ensure these variables did not skew the results.

They uncovered the changes to the way genes that play a role in asthma attacks express themselves by analyzing nasal cell samples from children when they caught respiratory illnesses.

The team now wants to help develop and test strategies to prevent or reduce the impact of these pollution-linked asthma attacks among children.

These could include new treatments and devices that can monitor air pollution so sufferers can better manage their condition.

The findings were published in the journal The Lancet Planetary Health.