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Background:
Epidemiological
studies have shown
positive
associations between
particulate matter
(PM) air pollution
and short-term
mortality and
morbidity for
asthma. The
hypothesis that lung
inflammation is
responsible for
these effects has
been tested in panel
and controlled
exposure studies in
asthmatic adults,
with inconsistent
results.
Objectives:
We investigated
whether personal
exposure to PM10 and
PM2.5 were related
to changes in the
clinical course of
asthma and to lung
inflammatory
responses in adult
asthmatics.
Methods: A
cohort of 32
asthmatic patients
was followed for 2
years. Asthma
control test (ACT)
and St Georges
Respiratory
Questionnaire (SGRQ)
scores, forced
expired volume in
the first second
(FEV1), exhaled
nitric oxide (FeNO),
and pH of exhaled
breath condensate (EBC)
were determined on 6
occasions during
different seasons.
Personal exposure to
PM was measured for
24 hours prior to
clinical
assessments.
Results: A 10
μg/m3 increase in
PM10 personal
exposure was
associated with an
increase in SGRQ
scores (regression
coefficient ß=0.22;
95% confidence
interval [CI],
0.005 to 4.451;
P=.055) and with a
decrease in ACT
scores (ß=-0.022;
95% CI, 0.045 to
0.001; P=.060),
whereas no
associations were
found between PM10
and FEV1, FeNO, or
EBC pH. A positive
association was
detected between
FeNO and outdoor O3
(P=.042) and SO2
(P=.042)
concentrations in
the subgroup of
nonsmoking
asthmatics.
Conclusions:
We concluded that
increments in
personal exposure to
PM10 are associated
with a decrease in
asthma control and
healthrelated
quality of life.
However, this study
does not provide
evidence that
24-hour exposures to
PM are associated
with short-term
changes in lung
function or
inflammatory
responses of the
lung.
Key words:
Pollution.
Inflammation. Lung.
Questionnaire.
Exhaled nitric
oxide. Breath
condensate.
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