Doctoral student Sarah Lebu studies how climate change and natural disasters affect sanitation in informal communities in Africa.
The impact of climate change may evoke images of extreme weather, wildfires and floods, but for those without stable housing or sanitation infrastructure, even small increases in average rainfall and temperature can have disastrous consequences.
In many growing cities in Africa, housing has not kept pace with rapid city expansion. This has left many families to live in informal communities — low-income areas where homes are not durable and lack protection from flooding or high temperatures. The strain of climate change makes it difficult for utilities to provide adequate sanitation and ventilation to these areas, putting residents at risk of flood damage, water-borne diseases and overheating.
Sarah Lebu, a doctoral student in environmental sciences and engineering, focuses her research at the intersection of climate change and city planning to understand how these affect sanitation. Born in Kenya, her work is centralized in Eastern Africa, including Nairobi, where approximately 60–70% of people live in informal communities with few toilets and minimal infrastructure for drainage or clean water.
“Many of these services are sold,” Lebu said. “Imagine having to buy every ounce of water you drink or pay to use the toilet each time you go. It’s very expensive.”
Plans for city development don’t always take residents into consideration: whether homes are susceptible to flooding, whether toilets are available, or whether unique health needs of women, children, people with disabilities and other groups are met. In many ways, her work is one of environmental justice, collaborating with communities to map structural inequities and alert city leaders.
“When governments operate like a community doesn’t exist, we need to get them to understand the conditions there,” she explained. “The best people to articulate that are the residents themselves.”
As an undergraduate, Lebu studied wildlife health in Uganda during the 2010 anthrax outbreak. It led her to study public health and city planning in Berkley, California, before coming to UNC-Chapel Hill. She believes her public health training helped her synthesize the technical and people skills needed to understand resident needs, identify trusted community leaders and support them with data to make a compelling case to policymakers.
“In this work, cultural humility is critical. I am just a facilitator — contributing and learning from the community. I’m not the expert there.”
Lebu explored this approach during a project in Mathare, an informal settlement in Nairobi, where only one in seven households had a toilet. After going door to door, she found that most people acknowledged the need for better sanitation, but they couldn’t make decisions about their homes because they were tenants of landowners who lived miles away.
“We learned to build a chain of communication, where we talked to women who were home while their husbands were at work. And then we would meet husbands who would help us meet the landowners.”
This approach has driven policy breakthroughs, as she saw in her work to help the informal community of Mukuru in Nairobi attain a Special Planning Area designation that would halt potentially harmful development activities. Lebu’s team worked with non-governmental representatives to identify natural leaders in Mukuru, collaborate on a map of community health risks and bring that information to city hall.
“That was a powerful blueprint to guide other informal settlements in the area. And after that, we started creating a master plan where we consider not just health but how we can prevent health impacts to communities affected by industry or pollution.”
She currently works with the UNC Water Institute, alongside Jennifer and Don Holzworth Distinguished Professor Aaron Salzberg, PhD, Associate Professor Joe Brown, PhD, PE, and Assistant Professor Musa Manga, PhD. Her work models how extreme rainfall and flooding will affect sanitation and uses participatory methods to understand what that impact will look like in communities. She stresses the need for decolonization in global health through research practices that reflect cultural humility and explore issues often overlooked.
“People talk about diarrhea or cholera,” she explained, “but women also report high rates of sexual violence, because they encounter predators while walking long distances to toilets on unlit streets. Women and children also adjust their diets because they can’t go to the bathroom at night, which results in urinary tract infections. I want to ensure that these are not forgotten in the sanitation sector.”
For Lebu — who grew up in a rural town near Lake Victoria and experienced sanitation challenges in the water there — it has been powerful to see the circle of inclusion broadening. Being able to attend professional conferences and co-author studies alongside local community members brings her optimism for the future.
“Getting people to speak up and be part of the solution is important. I think public health is moving more in that direction, and I really appreciate that.”
