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Traffic-related pollution linked to risk of asthma in children
Although physicians have long understood that the prevalence of smog and pollution can lead to asthma attacks, uncertainty has remained regarding the impact of long-term pollutant exposure on the development of the disease among children. Recent research, however, has shed light into this.
A study, published in the Journal of Allergy and Clinical Immunology, reveals that children who experience long-term exposure to traffic-related pollution, especially throughout early childhood, may have a significantly increased risk of developing pediatric asthma.
"Our previous research demonstrated that living close to a major roadway and lifetime exposure to air pollutants were associated with lower lung function in seven- to ten-year-old children," said corresponding author Mary B. Rice, MD, MPH. "We suspected that these exposures would also be associated with pediatric asthma."
Researchers analyzed data from more than 1,500 children who were born between 1999 and 2002, lived in the Boston-area and had mothers who were enrolled in a long-term study known as Project Viva. Researchers developed the study to examine the impact of behavioral and environmental factors, including exposure to pollution, on children's health.
During Project Viva, mothers provided medical, socio-economic and demographic information, which was later leveraged by Rice and her colleagues to determine the distance between each child's home address and the closest major roadway. Children's home addresses were also linked to both census and satellite-derived atmospheric data to determine each child's approximate daily exposure to fine particulate matter (PM). The children's daily exposure to soot was also examined. Upon analysis of the geographic data and Project Viva questionnaires, researchers discovered that living close to a major road was linked to childhood asthma.
"Children living less than 100 meters from a major road had nearly three times the odds of current asthma -- children who either experience asthma symptoms or use asthma medications daily -- by ages seven to 10, compared with children living more than 400 meters away from a major road," said Rice. "Even in the Boston area, where pollution levels are relatively low and within Environmental Protection Agency standards, traffic-related pollutants appear to increase the risk of asthma in childhood."
"Younger children spend a larger proportion of their time at home than school-aged children, and their airways are smaller and may be more likely to wheeze in response to pollution," said Rice. "This may explain why pollution exposure was most consistently linked to asthma in young children."
