Into the Wild: My Ongoing Journey to Track Lead in Southern Africa's Ecosystems

The adventure has already begun.

With my PhD in ecotoxicology at Wits University, I’ve launched a new chapter in a journey that’s as scientific as it is deeply personal. My fieldwork will take me across Namibia and South Africa, working with brown hyenas, jackals, cheetahs, and leopards — not just to learn more about them, but to use them as sentinels of environmental health.

This builds on my earlier, pioneering work, where I discovered widespread lead exposure in apex predators, even in protected and sanctuary environments. Alarmingly, I found even higher levels of lead in captive cheetahs, largely due to the meat they were being fed — meat that had been hunted with lead-based ammunition.

Now, this research is going bigger. Much bigger.

Dr Marie Lemerle and Dr Catherine Hauw GPS collaring Borwn Hyenas, and taking blood samples to test lead in those animals. Baker's Bay, Namibia.

Why Carnivores? Why Lead?

Carnivores like hyenas, jackals, cheetahs, and leopards sit at the top of the food chain. That makes them excellent indicators of environmental contamination — particularly from lead, which can accumulate and persist in tissues over time.

By analyzing blood and bone samples from these species in various regions — from hunting farms to national parks — we can create a map of lead hotspots across Southern Africa. These hotspots are not just a threat to wildlife. They’re a serious and urgent public health issue, too.

The Human Cost: Lead and Game Meat

In many rural Namibian and South African communities, families rely heavily on game meat for protein — meat that is often shot with lead ammunition. When lead fragments remain in the carcass, they are unknowingly consumed by people, including children.

This is a massive concern.

Lead is a neurotoxin. It damages the brain and nervous system, causes cardiovascular issues, harms kidney and liver function, and can impair fertility. Children are particularly vulnerable: even low levels of lead can result in developmental delays, learning difficulties, and permanent neurological damage.

This project is not just about wildlife anymore — it’s about One Health: the interconnected well-being of animals, ecosystems, and people.

Dr Catherine Hauw doing a health Check of a cheetah in South Africa

A Global Movement, A Local Challenge

Across the world, momentum is growing. In February 2023, the European Union passed regulations to begin phasing out lead ammunition in wetlands. Countries like Denmark and California have already implemented full bans on lead-based hunting ammunition. The science is clear, the direction is set — and yet, in many parts of Southern Africa, lead remains the norm.

It’s time for change.

My hope is that this research can inform and inspire real policy shifts. I’m working to bring ministries of health and environment into the conversation, offering hard data to support a transition to non-lead alternatives. It's about making the invisible visible — showing where lead contamination exists, who it impacts, and what we can do about it.

Looking Ahead

This isn’t just a PhD. It’s a mission. And the journey is far from over.

With the support of scientists, conservationists, communities, and hopefully institutions, I’ll continue collecting data, sharing stories, and advocating for a future where lead is no longer a silent poison in our ecosystems.

Drawing by Jagoba Malumbres-Olarte, during Catherine's talk at the Berlin Wildlife and Research Conference, where she presented her work on lead in cheetahs and leopards.

The future of conservation — and public health — depends on it.

Stay with me on this journey.

— Catherine Hauw