The association between ambient NO2 and PM2.5 with the respiratory health of school children residing in informal settlements: A prospective cohort study.
Environ Res
; 186: 109606, 2020 07.
Article
en En
| MEDLINE
| ID: mdl-32371276
ABSTRACT
BACKGROUND:
No previous epidemiological study has investigated the combined association of long-term ambient nitrogen dioxide (NO2) and particulate matter of diameter size-2.5 (PM2.5) exposure with asthma outcomes among schoolchildren in Africa.OBJECTIVES:
This study investigated the independent and co-pollutant association of long-term exposures to ambient air pollutants on asthma-associated outcomes in a cohort of schoolchildren in the Western Cape Province of South Africa.METHODS:
A total of 590 grade-4 schoolchildren residing in four informal settlements were studied. Spirometry and fractional exhaled nitric-oxide (FeNO) measurements were conducted, including a standardized questionnaire administered to caregivers at baseline and 12-months follow-up. Annual NO2 and PM2.5 levels were estimated for each child's home using land-use regression modelling. Single- and two-pollutant models were constructed to assess the independent and co-pollutant association of both air pollutants (NO2 and PM2.5) on new cases of asthma-associated outcomes adjusting-for host characteristics, indoor exposures and study area.RESULTS:
The annual average concentration of PM2.5 and NO2 were 10.01µg/m3 and 16.62µg/m3 respectively, across the four study areas, and were below the local Standards of 20µg/m3 and 40µg/m3, for both pollutants, respectively. In the two-pollutant-adjusted models, an interquartile range (IQR) increase of 14.2µg/m3 in NO2 was associated with an increased risk of new onset of ocular-nasal symptoms (adjusted odds ratio-aOR 1.63, 95% CI 1.01-2.60), wheezing (aOR 3.57, 95% CI 1.18-10.92), more than two or more asthma symptom score (aOR 1.71, 95% CI 1.02-2.86), and airway inflammation defined as FeNO > 35 ppb (aOR 3.10, 95% CI 1.10-8.71), independent of PM2.5 exposures.CONCLUSION:
This study provided evidence that ambient NO2 levels below local standards and international guidelines, independent of PM2.5 exposure, increases new cases of asthma-associated outcomes after 12-months.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Contaminantes Atmosféricos
/
Contaminación del Aire
Tipo de estudio:
Etiology_studies
/
Observational_studies
/
Prognostic_studies
/
Qualitative_research
/
Risk_factors_studies
Límite:
Child
/
Humans
País/Región como asunto:
Africa
Idioma:
En
Revista:
Environ Res
Año:
2020
Tipo del documento:
Article