A growing concern: investigating sustainable water quality and urban food production in Freetown, Sierra Leone

Clean water and food security are central to sustainable urban living. Yet, in rapidly expanding African cities, they remain unobtainable for many and a barrier to the health and wellbeing of millions of people. In Freetown, Sierra Leone, a city that has experienced rapid in-migration in recent decades, urban food security has become a major concern. One critical response has been the proliferation of urban and peri-urban agriculture (UPA) to support food security and income generation for the poor. However, UPA sites are often exposed to a range of pollutants. This paper examines the environmental health status of three different UPA sites in Freetown. Qualitative and quantitative data show heavy metal concentrations that significantly exceed regulatory limits in crop (sweet potato) leaves and arable soil. Soaring readings of faecal coliform bacteria were observed in water used for irrigation, corroborating health-related findings which demonstrate a direct relationship between water supply, handwashing and diarrhoea. Elevated nutrient concentrations were also observed in surface water during the rainy season. Ultimately, crops were revealed to be hyperaccumulators for environmental contaminants, highlighting both the challenges and potential for nature-based solutions to strengthen food security and public health at UPA sites in Freetown and other growing cities.

• This study explores the intertwined health and environmental impacts of urban and peri-urban agriculture (UPA) on local communities in Freetown, Sierra Leone.

• The data reveal heavy metal concentrations in crop leaves and soil at UPA study sites that exceed regulatory limits.

• Our findings highlight the challenges and potential for nature-based solutions to strengthen food security and public health at UPA sites in Freetown.