The effects of air pollution on human health are well documented in a range of epidemiological studies; exposure increases the risk of lung cancer, heart disease, bronchitis and other cardiorespiratory conditions. The economic cost of this health loss is also significant. The World Bank estimates that globally in 2013 air pollution led to $5.11 trillion in welfare losses, and $225 billion in lost labour income.

Whilst these headline figures are alarming, they tend to gloss over the disproportionate impact of poor air quality on certain populations, locations and occupations.

Knowledge sharing around air pollution

In May 2023 a range of stakeholders convened by ODI under the Africa-Europe Mayors’ Dialogue platform with the University of Birmingham, came together to contextualise the Gambia’s air pollution challenges and explore how interdisciplinary research can fill existing gaps in knowledge in the country.

The event enabled a knowledge exchange across continents with researchers and practitioners from the University of Birmingham, ODI (United Kingdom), the South East European University (North Macedonia), Health Effects Institute (United States / Kenya) and Air Qo (Uganda) sharing their experiences with the Kanifing Municipal Council (the Gambia) team and learning from the KMC team about the countries specific challenges.

Air pollution in the Gambia

The impact of air pollution on health is complex and multifaceted, with a number of factors exacerbating or minimising the extent to which poor air quality leads to morbidity or mortality. In the case of the Gambia, the Institute for Health Metrics and Evaluation (IHME) ranked air pollution as the second highest risk factor driving most death and disability combined in 2019.

Cooking fuel is a major source of air pollution in the country, with only around 3% of the Gambian population using primarily clean fuels and technologies for cooking. That means 97% of the population are reliant on fuels that will lead to elevated levels of air pollution that pose a risk to health.

Other contributors to poor air quality in the Gambia include the agricultural industry, vehicle emissions, waste burning, and fine Sahara dust. Seasonal variations are also significant with high levels of air pollution occurring during the dry season (May to September). However, with limited monitoring it is difficult to ascertain how pollution varies spatially and temporally.

The importance of monitoring air quality

Long term air quality monitoring data is currently limited in the Gambia. There are no regulatory monitoring devices in the country, and whilst there has been some work done with low-cost sensors, this too is sporadic and fragmented in terms of its coverage.

As air pollution is both temporally and spatially specific, understanding how best to tackle poor air quality in a specific location requires an understanding of the relevance of different sources. Exposure to air pollution is largely determined by the concentration of air pollutants in the environments where people spend time and the duration spent within them.

Understanding who may be more vulnerable and why is an important element of air quality management. To understand exposure of vulnerable populations to air pollution it is therefore important to identify the microenvironments in which they spend significant amounts of time.

Learning lessons from efforts to expand air quality monitoring

In North Macedonia, the South East European University have pioneered the deployment of low cost sensors in the city of Tetova to augment limited existing monitoring. The data they have gathered is invaluable in improving understanding of how air pollution varies across city locations and between indoor and outdoor areas.

The University of Birmingham led A Systems Approach to Air Pollution project has experimented with dynamic air pollution monitoring to ascertain air pollution levels experienced by different populations, occupations and locations with a focus on road-based hotspots. This has included monitoring onboard buses and motorcycle taxis.

Lessons can be drawn from locally led and managed air quality monitoring in Uganda where AirQo have pioneered the roll out at scale of low-cost air quality monitors designed to suit African infrastructure.

Learning from air pollution researchers and practitioners

Stakeholder discussions culminated in a series of conclusions:

• The scale of the challenge related to air pollution in the Gambia and its relationship to social, economic and political factors is clear.
• There is a need to assess what the main sources of air pollution are and from where they originate, which will help KMC prioritise initiatives.
• The deployment of low-cost sensors can support this objective, but decision makers must consider capacity and capabilities needed and whether alternative forms of data are sufficient to meet need.
• Effort to improve air quality and minimise its health impacts must be based on the collection of evidence. Evidence of the levels of air pollution, evidence of its variation spatially and temporally and evidence of who is impacted most and how.
• The importance of interdisciplinary teams that work with and across stakeholder groups at various levels and leverage learning from a range of disciplines is needed. Understanding who has the power to affect change and what motivates or impedes their ability to act is paramount.
• KMC has bio-char initiatives to move away from charcoal, but more analysis is required to ascertain impact on air quality.
• There have been many initiatives led by KMC that anecdotally have reduced air pollution (e.g., solid waste management), however there is no base-line data to evidence these claims.
• It may be valuable to combine real time monitoring with optical algorithms that allow historic records to extrapolate back in time to assess the impact of initiatives over the last five years.

Finally, it is important to examine the co benefits of wider urban initiatives and how they can support air quality management. For example, efforts to improve solid waste collection and its management (a key focus of KMC) have greatly increased waste collection and improved conditions in the city’s main dumpsite. Increased waste collection has reduced fly-tipping and burning of waste in private compounds and at fly-tip locations. Improved conditions in the city’s main dumpsite such as firebreaks (in the form of new concrete roads), hydrants, a fire-truck stationed on site and security and management of the site have culminated this year in the first dry season without fire.

Other planned initiatives include improving the road network to reduce congestion, with KMC piloting an urban bus service and creating taxi interchange points. These are viewed as a tool to reduce traffic pollution and improve city transport. The city’s bio-char initiatives and efforts to stimulate the circular economy could also create a local market price for waste materials reducing the amount that enters the waste stream. Interventions around air pollution can build on these improvements and would offer significant, additional public health benefits.