Sheila was a child in Cameroon when she first got hooked on kaolin.

“I was in primary school,” she says. “My aunt would eat it, and it was often me who had to go and buy it for her.” Sheila is currently studying at university in France. Many people back home, she says, continue to consume this substance every day. Some even become dependent on it.

Kaolin isn’t exactly hard to come by – you can purchase it from most Cameroonian markets – but it’s not something that appears on any lists of banned substances. Kaolin isn’t a new street drug. It’s dirt.

Eating dirt, or geophagy, has a long history in Cameroon. Colonial era texts concerning the region describe the behaviour in detail. “I am told that all of [the children] eat it,” writes one perplexed author in Notes on the People of Batanga. “Even those belonging to the mission, who are […] strangers to the sensation of hunger.”