Bigger City, Bigger Breathing Problem

Asthma risk higher in children who have respiratory illness from urban living

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) It's a chain reaction: pollutants in the air of big cities can lead to illnesses in babies and worse case scenario, make it harder to breathe.

A recently published study found that kids living in low-income urban areas might be more prone to developing asthma from infections they had earlier in life.

"Stay indoors if smog is heavy outside."

Children living within cities are naturally exposed to different things in the air than what kids breathe in the suburbs.

Researchers, led by James Gern, MD, professor in the Department of Pediatrics at the University of Wisconsin, thought this could lead to different viral infections based on what was in each environment.

Their focus was to see what possible role respiratory illnesses play in urban children developing asthma versus kiddos in the suburbs.

They looked specifically at illnesses caused by viruses. Respiratory synctyial virus (RSV) and human rhinovirus (HRV) have been linked to starting asthma in children.

They gathered samples from 500 infants who from Boston, Baltimore, New York City and St. Louis, as well as from 285 infants from Madison, Wisc.

The babies were both ill and healthy when the samples were taken.

Overall, researchers found that inner-city babies had significantly lower rates of viral detection.

The authors say this may be due to other causes of respiratory illness, including bacteria and allergic reactions to toxins or pollutants.

The number of times kids got sick was not linked to exposure to tobacco smoke, chemicals in the air, allergens from animals or family history.

Among the urban babies, 4.8 percent of the nasal washes had the adenovirus and 0.7 percent of the suburban babies tested positive.

Compared to suburban babies, sick urban babies had lower rates of two viruses, HRV and RSV, and higher rates of infections caused by the adenovirus.

"Adenovirus infections, either as a single pathogen or when detected in concert with other viruses, were significantly more common in the urban population, and this held true for each of the four urban locations where our study was conducted," the authors wrote in their report.

The big cities had between 10 and 21 percent of the babies test positive (with New York City at the highest) for the adenovirus compared to 6 percent in Madison.

The authors note a few limitations with their study. They didn't consider what reasons specifically led to the different respiratory illnesses and pathogens.

The researchers had also collected the urban and suburban samples seven years apart.

The study was published online September 26 in The Journal of Infectious Diseases.

Reviewed by: 
Review Date: 
September 28, 2012
Last Updated:
October 1, 2012