Poor urban air quality is a major development issue globally, placing a huge burden on public health and in turn the economy, with 3.2 million premature deaths each year attributed to outdoor fine particulate matter air pollution, according to the Global Burden of Disease 2010 project.
In Kenya, half the population will be living in cities by 2050. The population of its capital city Nairobi is approaching 4.5 million and the number of vehicles is growing exponentially, generating emissions that are dangerous for the public - especially for vulnerable groups working alongside the roadways. Air quality is deteriorating due to the increasing traffic and inadequate air pollution policy and regulation. The emissions caused by burning industrial waste, rubbish and urban biomass, as well as natural mineral dust, all contribute to this situation. Yet air quality data is often unavailable, and the sparse data that does exist often omits gaseous air pollution.
Dr Joshua Vande Hey, Lecturer in Environment and Health in the University’s School of Physics and Astronomy and a member of the Centre for Environmental Health and Sustainability, has strengthened the capacity within Nairobi to monitor and improve air pollution. His research background is in optics and atmospheric sensor engineering, but his research has broadened to understanding indoor and outdoor air pollution, evaluating its effects on human health, and assessing the effectiveness of exposure mitigation strategies.
Identifying the sources of Nairobi’s air pollution
In Nairobi, 40% of journeys are made using public transport and 49% are made by foot - primarily among the low-income population. Additionally, low-income residents often work at informal businesses alongside major roads, leaving them particularly vulnerable to the negative health impacts of air pollution which include asthma, infant mortality and premature death through heart and lung disease, making exposure reduction a pressing need. Although Nairobi’s public transport fleet is relatively new, buses lack particle filters and are considered a major source of certain pollutants. Dr Vande Hey, with collaborators led by Professor Madara Ogot at the University of Nairobi, is assessing the potential to reduce emissions through retrofitting the existing Nairobi public transport bus fleet with Diesel Particulate Filters (DPFs). In order for the Government to demand or incentivise retrofits for the many private sector companies involved, clear scientific assessment of the impact of the intervention was needed. Such an assessment requires understanding of local transport policy and experience with air pollution monitoring and mitigation. This British Council Newton Utafiti-funded project - the first such endeavour in Kenya - built a strong relationship between the Universities of Leicester and Nairobi and is moving towards enabling the Kenyan Government to develop policy to improve the health and welfare of its low-income urban populations.