Air Quality Guidelines Global Update 2005 - World Health ...

NITROGEN DIOXIDE
Nitrogen dioxide
unit (mean)
10 ppb (range of 3-year
average 7.0–31.3 ppb)
10.3 μg/m 3 (range of
annual averages 12–58
μg/m 3 )
8.5 μg/m 3 (range of
annual averages 19–67
μg/m 3 )
10 μg/m 3 (range of
4-week measurements
6–46.7 μg/m 3 )
1 ppb (range of 4-year
average 4.2–8.0 ppb)
34.6 ppb (range of 8year
average 4–39 ppb)
Nitrogen dioxide
odds ratio (95% CI)
1.76 (1.04–3.23)
wheeze, adjusted
2.10 (1.10–4.75)
asthma, adjusted
1.13 (0.99–1.29)
wheeze, adjusted
1.18 (0.93–1.51)
asthma, adjusted
0.94 (0.79–1.12)
wheeze, adjusted
1.24 (1.02–1.51)
dry cough at night,
adjusted
1.20 (0.90–1.60),
adjusted
1.02 (1.00–1.03)
between community,
adjusted
1.07 (1.02–1.13)
between community,
adjusted
–95 ml (–189 –1 ml)
FVC, adjusted
–101ml (–165–38 ml)
FEV1, adjusted
–211 ml/s (–378–44
ml/s) MMEF, adjusted
Comments
363
Incidence of asthma (range 0–3.6%) and
wheeze (range 0–6.5%) was low; no absolute
numbers are given.
Outdoor levels at the home of subjects were
estimated using a validated model. Reported
associations refer to disease status at
two years. Estimates of similar size obtained
for highly correlated pollutants PM2.5 and
soot. Strongest association seen for ear, nose
and throat infections and air pollutants.
GIS-based modelling of exposure at the
birth address. Comparable effect estimates
obtained for PM2.5 and soot. Stronger effect
estimates obtained at age of 1 year (1.36
(1.07–1.74) dry cough at night, adjusted),
especially in males.
Analyses used estimated winter-time averages
outside the children’s homes; range of
these exposures not presented. Stronger
effects for children who did not fulfil the
criterion for recurrent wheeze until their
second year of life. Interaction between
nitrogen dioxide and exposure to environmental
tobacco smoke.
Associations of similar strength were seen
for PM2.5 and elemental carbon. The effect
of nitrogen dioxide was independent of
adjustments for PM10, PM10–2.5, acids and
elemental carbon. Co-linearity of the effect
was observed for ozone, PM2.5 and elemental
carbon
Effects on FVC and FEV1 were largest for acid
vapours, which were highly correlated with
nitrogen dioxide.
Outdoor population-based studies: long-term effects
Studies of long-term health effects have assessed the association between nitrogen
dioxide and morbidity and mortality in children and adults. These studies
have assessed the health effects associated with both between- and within-area
variability of nitrogen dioxide. Misclassification of exposure is a major concern in