The Interlinkages Between Ambient Temperature and Air Pollution in Exacerbating Childhood Asthma: A Time Series Study in Cape Town, South Africa

<b>Background:</b> Given the rapid global increase in asthma cases, understanding the impact of climate change on respiratory health is necessary for evidence-based policymaking, particularly in low- and middle-income countries (LMICs). Objectives: To estimate the short-term associations between temperature (mean and diurnal range), particulate matter (PM_2.5 and PM₁₀), nitrogen dioxide (NO₂), ozone (O₃), and childhood asthma exacerbations in Cape Town, South Africa. <b>Methods:</b> We analysed daily hospital records (<i>n</i> = 7753; 2009, 2014, 2019) alongside citywide air quality and meteorological data using negative binomial mixed-effects models and distributed lag non-linear models to capture delayed effects. <b>Results:</b> NO₂ and PM₁₀ were consistently associated with a higher exacerbation risk, with additional delayed effects observed for PM_2.5, PM₁₀, and NO₂. Mean temperature and diurnal temperature range were also linked to an increased risk at short (lag 0-1) and medium (lag 4-5) delays. <b>Conclusions:</b> Temperature variability and traffic-related air pollution contribute to childhood asthma exacerbations in urban LMIC settings. The findings support child-centred early warning systems and stricter air quality controls aligned with WHO guidance.