Exposure to ambient air pollution and noise in relation to adverse health effect in children

Adverse health impacts of ambient air pollution and noise have been
reported previously. However, many published studies were in adults
or aged population, little attention has been paid to children and
in particular to noise and the potential combined effect with air
pollution. In addition, we considered health parameters, which are
underinvestigated so far. In our study, we explored associations
between ambient air pollution and noise with blood pressure (BP),
and exhaled nitric oxide (eNO) in school-aged children, using data
from two German birth cohorts. Noise levels within a 50m buffer
around each participant’s home address were assessed using
geographic information system. Exposure estimates of annual average
concentrations of air pollution for each participant’s residence
were calculated using a land use regression model. Short-term
concentrations of air pollution were collected from background
monitoring sites. Information on BP and eNO was collected during a
physical examination at the 10-year follow-up of the cohorts. We
studied the health impacts of ambient air pollution and noise in
children from three different aspects. The association between
traffic noise and BP was explored in 605 children, and the results
showed that higher minimum levels of weighted day-evening-night
noise and nighttime noise around the home residence may increase a
child’s BP. Based on this finding, we conducted a second analysis
to figure out the combined associations between air pollution and
noise with BP, and found that ambient air pollution was not
consistently associated with BP with adjustment for noise.
Furthermore, the effects of ambient air pollution on eNO were
explored within 1985 children, and we observed a significant
positive association between short-term, but not long-term, air
pollution with childhood eNO. In conclusion, our study provided
more epidemiological evidence on the adverse health impacts of
ambient air pollution and noise in school-aged children, and
highlighted the confounding association between ambient air
pollution and noise. More studies are needed to better assess the
combined health effects of ambient air pollution and noise in
children.