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“Our findings
provide strong evidence for the adverse effects of traffic-related air
pollutants on atopic diseases as well as on allergic sensitization,” wrote Dr.
Heinrich. The results appeared in the second issue for June of the American
Thoracic Society’s American Journal of Respiratory and Critical Care
Medicine.
The study
examined nearly 2,900 children at age four and more than 3,000 at age six to
determine their rates of doctor-diagnosed asthma and/or allergy with relation to
long-term exposure to traffic-related pollution.
Both the
four-year-old and six-year-old groups of children came from prospective cohort
studies and were enrolled at birth in the metropolitan
Munich area. Their exposure to
traffic pollutants was calculated as a function of the distance of their homes
from major roads at birth and at two, three and six years of age. Parents were
given questionnaires about their child’s respiratory diagnoses and symptoms, and
their children were assessed for asthma, wheezing, sneezing and eczema. At six
years of age, the children were tested for food allergies. Air was tested for
particulate matter (e.g., soot) and nitrogen dioxide (NO2) at each of
forty identified points near high-traffic areas once each season between March
1999 and July 2000.
After
controlling for such individual characteristics as parental allergies, pet
ownership, and number of siblings, researchers found significant positive
associations between distance to the nearest road and asthmatic bronchitis, hay
fever, eczema and allergic sensitizations. They also found a distant-dependent
relationship between proximity to the road and risk of allergic sensitization,
with those living closest to major roads having a nearly 50 percent greater risk
of allergic sensitization.
Previous studies
have found that pollutants and allergic sensitization are linked, but using
distance from major roads as a proxy for pollutant exposure has been confused by
the socioeconomic factors that are often closely linked to such locales.
However, in
Munich, as with other older European
cities, the roads and buildings are structured so that economic advantages are
not necessarily correlated with living further from the main thoroughfares. In
this study, it was possible to determine that economic factors were not a
confounding variable in the analysis, but there was a clear difference in the
children’s allergic development with relation to their proximity to a road.
“We consistently
found strong associations between the distance to the nearest main road and the
allergic disease outcomes,” wrote Dr. Heinrich. “Children living closer than 50
meters to a busy street had the highest probability of getting allergic
symptoms, compared to children living further away.”
These news briefs are based
on articles published in the American Thoracic Society's peer-reviewed journal,
the American Journal of Respiratory and Critical Care Medicine.
In reporting on these findings, contact information is for your use only, not
for publication. Journalists may obtain the full text of these articles, request
a complimentary subscription to the journal, or identify an expert not related
to the research to comment on the article by contacting Keely Savoie at
(212) 315-8620 or
Brian Kell, Director of
Communications, at (212) 315-6442.
Founded in 1905,
the American Thoracic Society is the world’s leading medical association
dedicated to advancing pulmonary, critical care and sleep medicine. The Society
has more than 15,000 members who prevent and fight respiratory disease around
the globe, through research, education, patient care and advocacy.
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