People who live close to a busy road are no more likely than those living further away from heavy traffic to experience declines in lung function over time, new research from the UK shows.
Dr. Andrea Venn of the University of Nottingham and her colleagues also found no evidence that living near traffic increased the likelihood of asthma; chronic obstructive pulmonary disease (COPD), such as emphysema or chronic bronchitis; or allergic disease.
Still, they caution that more research is needed to confirm or disprove their findings.
"Because of relatively high levels of background pollution in our study area and possible misclassification of exposure, we cannot completely rule out an adverse effect, and further study is needed that incorporates life-time exposure to pollution in populations with wide variation in exposure," they write in the journal BMC Pulmonary Medicine.
Most research on traffic pollution and lung health has focused on children, Venn and her team write, and the studies that have looked at adults have had conflicting results. She and her colleagues looked at 1,329 adults participating in a study of diet and chronic lung disease who had reported on their residence and health in 1991, and were followed up in 2000. All lived in a relatively urban section of Nottingham.
The researchers used specific coordinates for a person's home, rather than their postal code, to assess how close he or she lived to major roads. For another measurement of nearby air pollution, they estimated nitrogen dioxide concentration in the air near a person's home.
Measurements of lung function and allergic illness were no different in people who lived within 150 meters of a busy road compared to those who lived further away, Venn and her colleagues found. They also compared study participants' lung function in 1991 and 2000, and found no relationship between decline in lung function and proximity to traffic. There was also no association between any of these factors and nitrogen dioxide concentration.
They conclude: "We found no evidence to suggest that home proximity to major roads is a major determinant of the risk of asthma, COPD or allergic disease, or progression of obstructive lung disease in adults."