The finding that early life exposure to air pollutants affects the
so-called peripheral airways, “has not been reported before,” said
lead author Dr. Erica S. Schultz of the Karolinska Institutet
Institute of Environmental Medicine in Stockholm, Sweden.
“The lungs and airways are exposed to different air pollutants
throughout life, but as the lungs are not fully developed at birth,
young children are considered to be particularly vulnerable to
adverse effects,” she said.
Because the effects are small, they may have little impact on
healthy people living in areas with little pollution, Schultz and
her coauthors write.
But the findings may be relevant in areas with high pollution levels
and for people with respiratory conditions.
The researchers studied roughly 2,400 children recruited between
1994 and 1996 in Sweden for whom they had data on air pollution
exposure as infants and lung function as teens. In particular, they
studied the “resistance” in the teen’s peripheral airways, or how
hard it is to get air through those passages.
The researchers focused on nitrogen oxides in vehicle exhaust and
particulate matter from road erosion. They used records of road
traffic, meteorological conditions and topography to model pollution
levels at residential and school addresses for the kids in the first
year of life and for the year prior to their 16th birthdays.
As infant exposure to nitrogen oxides increased by 10 micrograms per
cubic meter, teen airway resistance also increased. The association
was strongest for boys and for those with asthma at age 16.
Pollution exposure at ages 15 and 16 was not related to lung
The authors reported in the Journal of Allergy and Clinical
Immunology that particulate matter did not have a significant
relationship with airway resistance.
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“An increasing amount of studies demonstrate the importance of
airway periphery for lung health,” Schultz told Reuters Health by
email. “What´s concerning is that the effect from first year of life
seem to be long-lasting although we yet don’t know the full clinical
implication of this effect.”
Most teens would not feel any symptoms of their reduced lung
function as the effect was small, she said.
Stockholm has relatively low air pollution levels, she said. For
more polluted cities, the effects may be greater and cause
conditions like asthma, heart attacks, strokes and early death.
“From this study, we cannot say that children with asthma or any
other respiratory conditions will become worse from current
exposure, even though that has been reported from several other
studies,” Schultz said.
But policymakers should take traffic air pollution levels into
considerations when planning for housing, schools and daycare
centers, she said.
SOURCE: http://bit.ly/20wLuxb Journal of Allergy and Clinical
Immunology, online May 7, 2016.
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