Identification and initial characterization of prominent air pollution sources and respiratory health at secondary schools in Ibadan, Nigeria

Objective. Research on air quality in and around schools, and the associated vulnerability of school-age children, is limited in less developed countries (LDCs), particularly Africa. The main objective of this study was to conduct an initial assessment of sources of air pollution in and around schools as a surrogate for air quality and report adverse health effects among students at selected secondary schools in urban Ibadan, Nigeria. Methods. The study was a descriptive cross-sectional survey involving eight secondary schools selected purposively, defined with eight acronyms (listed alphabetically): ABHS, AGS, BOHS, CDSS, IGS, LC, MGS, and OAHS. We used pre-tested, self-administered questionnaires, observational checklists to assess certain environmental health indicators, and interviews. The questionnaire was divided into five sections including environmental and health conditions. A total of 400 students from senior secondary classes, 50 from each school, were selected through stratified random sampling. Results. The school's location, especially if close to high traffic roadways, contributed to reported perceived poor air quality of school environments. The majority of students believed air pollution sources in the school environment were mainly refuse burning and car emissions from nearby roadways. Cough and asthma were the most frequently reported adverse health outcomes. The highest prevalence of reported recent asthma episodes (symptoms) were recorded at BOHS (84%) and at CDSS (62%); furthermore, at ABHS it was nearly 1-in-2 students and at OAHS about 1-in-5 students. BOHS and OAHS each reported over 10% for prevalence of bronchitis. Conclusions. Proximity of study schools to certain sources and activities such as refuse burning and major roadways seemed to present substantial risk factors for reported respiratory morbidity among secondary students in urban Ibadan, Nigeria. Future research should quantify source emissions and exposure and further characterize frequency and severity of respiratory symptoms, among other parameters, at schools in Nigeria and other sprawling urban areas of Africa.