Toyib Olaniyan1, Mohamed Jeebhay2, Martin Röösli3, Rajen N Naidoo4, Nino Künzli5, Kees de Hoogh6, Apolline Saucy7, Mahnaz Badpa8, Roslynn Baatjies9, Bhawoodien Parker10, Joy Leaner11, Mohamed Aqiel Dalvie12. 1. Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa. Electronic address: toyib.olaniyan@canada.ca. 2. Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa; Division of Occupational Medicine, University of Cape Town, Cape Town, South Africa. Electronic address: Mohamed.jeebhay@uct.ac.za. 3. Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, 4002, Basel, Switzerland; University of Basel, Petersplatz 1, 4003, Basel, Switzerland. Electronic address: martin.roosli@swisstph.ch. 4. University of Kwazulu-Natal, Durban, South Africa. Electronic address: naidoon@ukzn.ac.za. 5. Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, 4002, Basel, Switzerland; University of Basel, Petersplatz 1, 4003, Basel, Switzerland. Electronic address: nino.kuenzli@swisstph.ch. 6. Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, 4002, Basel, Switzerland; University of Basel, Petersplatz 1, 4003, Basel, Switzerland. Electronic address: c.dehoogh@swisstph.ch. 7. Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, 4002, Basel, Switzerland; University of Basel, Petersplatz 1, 4003, Basel, Switzerland. Electronic address: apolline.saucy@swisstph.ch. 8. Swiss Tropical and Public Health Institute, Socinstrasse 57, P.O. Box, 4002, Basel, Switzerland; University of Basel, Petersplatz 1, 4003, Basel, Switzerland. Electronic address: mahnaz.badpa@stud.unibas.ch. 9. Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa; Department of Environmental and Occupational Studies, Faculty of Applied Sciences, Cape Peninsula University of Technology, Cape Town, 7700, South Africa. Electronic address: baatjiesr@cput.ac.za. 10. Department of Environmental Affairs and Developmental Planning, Western Cape Government, Cape Town, South Africa. Electronic address: bhawoodien.parker@westerncape.gov.za. 11. Department of Environmental Affairs and Developmental Planning, Western Cape Government, Cape Town, South Africa. Electronic address: joy.leaner@westerncape.gov.za. 12. Centre for Environmental and Occupational Health Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa. Electronic address: aqiel.dalvie@uct.ac.za.
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.
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.
Authors: Yutong Samuel Cai; Harry Gibson; Rema Ramakrishnan; Mohammad Mamouei; Kazem Rahimi Journal: Int J Environ Res Public Health Date: 2021-09-15 Impact factor: 3.390
Authors: Khairul Nizam Mohd Isa; Juliana Jalaludin; Saliza Mohd Elias; Norlen Mohamed; Jamal Hisham Hashim; Zailina Hashim Journal: Int J Environ Res Public Health Date: 2022-04-11 Impact factor: 4.614
Authors: Oluwaseyi Olalekan Arowosegbe; Martin Röösli; Nino Künzli; Apolline Saucy; Temitope Christina Adebayo-Ojo; Mohamed F Jeebhay; Mohammed Aqiel Dalvie; Kees de Hoogh Journal: Int J Environ Res Public Health Date: 2021-03-24 Impact factor: 3.390