Air Pollution Linked to Infant Bronchiolitis

Air pollution exposure can put infants at a higher risk of developing the condition bronchiolitis, a new study published in the current (November 2009) edition of the American Journal of Respiratory and Critical Care Medicine has asserted.  The research element of this study was carried out over a three-year period and took place in British Columbia, Canada.  Here, close to 12,000 infants with diagnosed bronchiolitis were assessed in parallel with their relative exposure to air pollutants including NO (Nitric Oxide), NO2 (Nitrogen Dioxide), CO (Carbon Monoxide), SO2 (Sulphur Dioxide) and general particulate matter. 

Readings from monitoring sites located 10 kilometres or less from the houses in which these children lived were taken into account here, along with ambient pollution measurements involving contributors like traffic. 

Bronchiolitis and Air Pollutants

Once factors like the infant’s sex, whether it had been breastfed and whether its mother had smoked during pregnancy had been taken into account, the scientists involved discovered significant links between bronchiolitis and air pollutants, expressed in specific risk-percentage terms below:

• Sulphur Dioxide – a four per cent higher risk of bronchiolitis observed.
• Nitric Oxide – an eight per cent higher risk of bronchiolitis
• Nitrogen Dioxide – a 12 per cent higher risk of bronchiolitis
• Carbon Monoxide – a 13 per cent higher risk of bronchiolitis

These risks increased by an additional six per cent if the child resided within 50 metres of a major road.

“In general, we found that traffic-derived air pollutants were associated with infant bronchiolitis as well as wood smoke and industrial emissions”, head scientist involved, the University of Washington’s Doctor Catherine Karr, explained.  “The magnitude of the effect is modest, but is comparable to most air pollution studies in North America.  The importance of these small magnitude effects become significant when you consider that they affect a great number of children because these exposures are so ubiquitous.”

Infant Bronchiolitis

Bronchiolitis is a respiratory infection that can develop in babies and infants.  It affects the bronchioles (the lungs’ smallest airways), suppressing the ability to breathe normally.  Infant bronchiolitis is untreatable with drugs, although it can be made more manageable and, in many instances, it disappears of its own accord.

“This study adds to a growing body of research showing a link between neighbourhood air pollution hotspots and paediatric respiratory disease”, the University of British Columbia’s Professor Michael Brauer – a primary figure involved in the study – commented.  Describing bronchiolitis as an ‘important and costly childhood illness’, he added: “Reducing exposure to air pollution may be one approach to decrease bronchiolitis occurrence.”

Respiratory Conditions: Air Pollution

While this new study solidifies the link between childhood respiratory conditions and air pollution, additional research is required to make it fully concrete.  One project that offers a potential way of achieving this is the National Children’s Study - in which organisations including the US EPA (Environmental Protection Agency) are participating – since, amongst other topics, this will study childhood exposure to air pollution against the backdrop of other factors like genetics.

For the moment, said Doctor Karr: “I think we have a role in educating parents about concerns regarding air pollution and promoting precautionary approaches where feasible.”

See also:

Air Pollution Health Effects: New Findings

International Air Pollutants Pose Increased Health Risk