Controlling environmental factors could reduce suffering from children's lung disease

provided by American Lung Society

uch of the suffering from lung disease in children is due to largely preventable causes air pollution, secondhand smoke and cockroach allergen suggest studies presented at the American Lung Association/American Thoracic Society International Conference last month. One study suggests a link between air pollution and increased risk of infant death. A second study found that secondhand smoke exposure in childhood is associated with diminished lung function in young adulthood, while a third study suggests that cockroach allergen may be associated with an increased risk of developing asthma in childhood.

"Lung disease is the most common chronic disease of children, and the prevalence and incidence of lung disease in children is rising worldwide," said Michelle Cloutier, M.D. of the University of Connecticut, who moderated a conference press panel about children and lung disease. "If we can decrease children's exposure to environmental factors that contribute to lung disease, then we will be able to reduce pediatric lung disease, as well as lung disease in adults in the future."

Some infant deaths in Mexico City may be associated with air pollution, suggests one study presented at the conference. Researchers reviewed death certificates in one area of the city, and compared them with levels of the air pollutants ozone, nitrogen dioxide, sulfur dioxide and particulate matter.

"In our study we found evidence that air pollution is associated with acute increases in infant mortality," said lead researcher Margarita Castillejos, M.D. of Universidad Autonoma Metropolitana-Xochimilco. "The pollution-related excess mortality we observed among infants is greater, in terms of percent of change, than what we observed among the elderly in Mexico City."


Sweating the smallest stuff


On the average day there were three deaths of infants less than one year old. The researchers found a correlation between increased levels of the smallest particulate matter, known as PM2.5, three to four days previously and increases in infant mortality. Excess infant mortality was also associated with levels of ozone, sulfur dioxide and nitrogen dioxide three to five days previously, but not with exposure of the current day.

PM2.5 particles have a diameter of 2.5 microns or less, small enough to penetrate deep into the lungs. Sources include industrial emissions and automobile exhausts.

Another study presented at the conference adds to evidence that secondhand smoke is harmful to children's lungs. This study of almost 1,500 Yale University students who never smoked included both students whose mothers had smoked at home while they were growing up and students whose mothers were nonsmokers. The lung function of those whose mothers had smoked was diminished by 6 percent compared with students whose mothers had not smoked. The effects were more pronounced in females The researchers from Columbia University School of Public Health say their study suggests that exposure to maternal smoking in the home while growing up during the first 18 years of life may adversely affect respiratory health.

"Previous studies have looked at the childhood effects of secondhand smoke. What's new about this study is that we found these effects persist into young adulthood, when the students move away from home," said lead researcher Patrick Kinney, Sc.D.


A bug connection


High levels of cockroach allergen in children's homes increase the risk of developing asthma, suggests a third study presented at the conference. Harvard researcher Augusto A. Litonjua, M.D., noted that although exposure to cockroach allergen has been associated with greater asthma-related illness in those already allergic to the allergen, this study suggests that it may actually play a role in the development of asthma in young children.

The researchers investigated the relationship between home allergen levels and the prevalence and incidence of asthma 14 months later in 235 children, whose average age was 4.

Dust samples were collected from the children's homes and analyzed for the presence of cockroach allergen. The researchers found 11 new doctor-diagnosed asthma cases. Exposure to high levels of cockroach allergen was associated with a fourfold increased risk of developing asthma, the investigators found.

Of the estimated 14.6 million Americans with asthma, almost one third 4.8 million are under the age of 18. Between 1982 and 1994, the overall prevalence of asthma rose 61 percent, while the prevalence of pediatric asthma rose 72 percent.

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