By Janelle Weaver
Asthmatic children exposed to higher concentrations of particulate matter from traffic are more likely to be bothered by a respiratory condition called rhinoconjunctivitis, new research shows. The NIEHS-funded study, published on March 21 in PLOS ONE, suggests that further efforts to reduce such environmental exposures are critical for protecting this vulnerable population.
“Ambient air pollution, including traffic-related exposures, have increasingly been shown to have adverse health effects upon developing children, including increased respiratory disease,” said senior study author Nadia Hansel, M.D., M.P.H., associate dean for research at Johns Hopkins Medicine. “In this study, we highlight an underappreciated link between particulate air pollution and upper airway symptoms of rhinoconjunctivitis that can have a significant impact on the well-being of these pediatric populations.”
A Growing Problem in the Developing World
Asthma and allergic respiratory diseases are the leading chronic illnesses among children and have become a rising global health burden in the last several decades. Rapid urbanization in the developing world has been implicated in the increased prevalence of respiratory and allergic disease in populations specifically living in urban areas with poor air quality. In particular, low-income countries are disproportionately affected by rhinoconjunctivitis, which is often associated with asthma and includes symptoms such as a runny nose, sneezing, nasal stuffiness, and itchy red eyes.
Recent attention to the growing prevalence of rhinitis symptoms has led to efforts to identify environmental factors contributing to upper respiratory disease among vulnerable children. But until now, no studies had examined the impact of air pollution upon quality of life related to uncontrolled upper respiratory symptoms.
“This issue is relevant to all people exposed to air pollution, but sheds specific light on children in low-income, low-resource areas, particularly those trying to manage asthma,” said Bonnie Joubert, Ph.D., a scientific program director in the Population Health Branch at NIEHS and a program official for several NIEHS-funded projects led by Hansel.
Black Carbon Is the Culprit
In the new study, Hansel and her collaborators administered the Rhinoconjunctivitis Quality of Life Questionnaire at repeated intervals over a one-year period to 484 9- to 19-year-old asthmatic children living in two adjacent residential communities in Lima, Peru. Both of these resource-poor areas have experienced rapid growth over the past several decades, and residents live in open-air homes with varied proximity to highly trafficked main commuter routes. The researchers also used monitoring equipment located on the roofs of 30 houses to measure ambient concentrations of particulate matter less than 2.5 μm (PM2.5) and its black carbon component—an indicator of vehicular traffic-related combustion.
They found that an increase specifically in the black carbon component of PM2.5 was associated with worse rhinoconjunctivitis quality of life. Specifically, the odds of being bothered by rhinoconjunctivitis increased by 83 percent for a 10 μg/m3 increase in airborne PM2.5, and by 80 percent for a 10 percent increase in the proportion of the black carbon component. “To our knowledge, this is the first study to demonstrate a direct quantitative link between exposure to airborne particulate matter and worse burden of rhinoconjunctivitis symptoms,” Hansel said.
Improving Quality of Life
In future studies, Hansel and her team will investigate relationships between air pollution and other markers of upper airway disease and respiratory health in these children. They also plan to examine whether therapeutic strategies to combat rhinoconjunctivitis symptoms in children exposed to this type of pollution improve asthma symptoms or quality of life.
“Exposures to traffic-related air pollution, especially in developing regions of the world, can be challenging to avoid.” Hansel said. “However, recognition of the implications of traffic air pollution on the burden of upper airway disease is important so that we can focus attention on treating rhinoconjunctivitis in children who live in actively industrializing regions of the world, in order to improve their health-related quality of life.”
Citation: Bose S, Romero K, Psoter KJ, Curriero FC, Chen C, Johnson CM, Kaji D, Breysse PN, Williams DL, Ramanathan M, Checkley W, Hansel NN. 2018. Association of traffic air pollution and rhinitis quality of life in Peruvian children with asthma. PLoS One 13(3):e0193910. [Abstract ]