Air pollution, a recognised global health emergency, that disproportionately affects low-income and middle-income countries (LMICs)1 and has increasingly been implicated in a range of respiratory illnesses and other adverse health outcomes.2 In sub-Saharan Africa, this has been compounded by the challenging socioeconomic and environmental conditions that many communities live in due to rapid urbanisation and burgeoning informal settlements.3

Despite the high burden of infectious diseases in Africa, asthma is the most common non-communicable disease with an increasing prevalence in children and adolescents.4 Understanding the drivers of asthma development and exacerbations, in this context, is key in developing strategies that may help mitigate these risks.

The Thorax study by Meme et al, ‘Asthma symptoms, spirometry and air pollution exposure in schoolchildren in an informal settlement and an affluent area of Nairobi, Kenya’, is an important African study that attempts to unpack some of these issues.5 The contrasting setting for this study; two communities, one informal and the other more affluent in close geographical location, is typical of many sub-Saharan African cities and highlights the epidemiological challenges of understanding health outcomes when environmental risks may differ significantly, even in communities living in close proximity.

This study called Tupumue (Swahili for ‘let us …