Ambient Air Pollution and Respiratory Health in Sub-Saharan African Children: A Cross-Sectional Analysis

Abstract

Ambient air pollution is projected to become a major environmental risk in sub-Saharan Africa (SSA). Research into its health impacts is hindered by limited data. We aimed to investigate the cross-sectional relationship between particulate matter with a diameter ≤ 2.5 μm (PM2.5) and prevalence of cough or acute lower respiratory infection (ALRI) among children under five in SSA. Data were collected from 31 Demographic and Health Surveys (DHS) in 21 SSA countries between 2005–2018. Prior-month average PM2.5 preceding the survey date was assessed based on satellite measurements and a chemical transport model. Cough and ALRI in the past two weeks were derived from questionnaires. Associations were analysed using conditional logistic regression within each survey cluster, adjusting for child’s age, sex, birth size, household wealth, maternal education, maternal age and month of the interview. Survey-specific odds ratios (ORs) were pooled using random-effect meta-analysis. Included were 368,366 and 109,664 children for the analysis of cough and ALRI, respectively. On average, 20.5% children had reported a cough, 6.4% reported ALRI, and 32% of children lived in urban areas. Prior-month average PM2.5 ranged from 8.9 to 64.6 μg/m3. Pooling all surveys, no associations were observed with either outcome in the overall populations. Among countries with medium-to-high Human Development Index, positive associations were observed with both cough (pooled OR: 1.022, 95%CI: 0.982–1.064) and ALRI (pooled OR: 1.018, 95%CI: 0.975–1.064) for 1 μg/m3 higher of PM2.5. This explorative study found no associations between short-term ambient PM2.5 and respiratory health among young SSA children, necessitating future analyses using better-defined exposure and health metrics to study this important link.

The impact of environmental conditions on non-communicable diseases in sub-Saharan Africa: A scoping review of epidemiologic evidence

“…Two studies conducted in Mozambique found temperature declines (2.4°C to 3.0°C or 36.32°F to 37.4°F) were associated with incidence of stroke hospitalisations [ 61 , 62 ]. In another study conducted in 21 countries of SSA, Cai et al (2021) [ 63 ] found prior month average air pollution (PM 2.5 ) exposure was not associated with cough and acute lower respiratory infections among children under five years of age. This null association may be due to several reasons.…”

“…The highest range for PM 2.5 (120-973 μg/m 3 ) was reported in one study conducted in Ethiopia [ 46 ]. PM 2.5 is a common pollutant and is linked with respiratory symptoms, cancer, and cardiovascular diseases [ 9 , 63 , 65 , 66 ]. Air pollution is reported as a major cause of NCD mortality in SSA and was responsible for 1.1 million deaths across the region in 2019 [ 21 ].…”

Long-Term PM2.5 Exposure Is Associated with Symptoms of Acute Respiratory Infections among Children under Five Years of Age in Kenya, 2014

“…The duration of exposure necessary for the development for ARI phenotypes may explain our findings that significant associations between PM levels and ARI symptoms are only present after a minimum of 4 months of exposure, possibly indicative that a cumulative threshold of exposure is necessary for symptoms to manifest. In a recent analysis of the association between ambient air pollution and respiratory health using satellite data and DHS surveys from 31 countries, no association between short-term PM exposure and respiratory health was found [ 92 ]. The authors used prior-month averages and evaluated two outcomes: the presence of a cough, and acute lower respiratory infection (ALRI), defined as the presence of both a cough and wheezing [ 92 ].…”

“…In a recent analysis of the association between ambient air pollution and respiratory health using satellite data and DHS surveys from 31 countries, no association between short-term PM exposure and respiratory health was found [ 92 ]. The authors used prior-month averages and evaluated two outcomes: the presence of a cough, and acute lower respiratory infection (ALRI), defined as the presence of both a cough and wheezing [ 92 ]. The lack of short-term associations, similar to our findings, reinforces the need for both more accurate ambient pollution measures as an exposure and better pathophysiological characterization of the outcome variables.…”

The relationship of the use of mask with the event of acute respiratory tract infection (ARI) in Rice Miller workers in Peukan Bada District, Aceh Besar

“…Acute respiratory infections were once a major health problem in Indonesia 7 . This disease can usually occur as a result of viruses, bacteria, or particles that can enter the lungs causing serious infections 8 . ARI that occurs in children, if not treated with proper treatment can cause death 9 .…”