Dr. Wilson Y. Fantong, Director of Research at Institute of Geological and Mining Research in Cameroon, delivered the plenary lecture on Wednesday, where he spoke about how local sustainable solutions such as biochar filtration brought the smile back into the people in the Sahel region of northern Cameroon.

Having trained as a geologist in Cameroon, Fantong initially went into gold exploration. While in the field, Fantong saw children drinking contaminated water from artisanal gold pits. This forever changed Fantong’s perception towards water, and motivated him to change his focus to hydrogeology. Although fluoride was not the focus of his doctoral research at Toyama University in Japan, Fantong was alarmed by the elevated fluoride concentrations in the water of his field site in northern Sahel region of Cameroon. The upper limit of safe fluoride levels (1.5 mg/L), as recommended by the World Health Organization, was also not applicable to the region. Adapting this calculation to the region, Fantong found that the safe fluoride level was around 0.75 mg/L, which was regularly exceeded.

Moreover, the elevated fluoride concentrations in the water created a societal issue. A silent but pervasive condition of dental fluorosis* was recognized by the communities within the Sahel region, but its cause was not well understood. Until 2007, the lack of understanding of the cause of fluorosis led to stigmatization of those afflicted.

Fantong was not only inspired to identify the problem but also find a solution.

Firstly, he mapped the fluoride concentrations in the region to give a “bird’s eye view” of the problem. The resulting map eventually led to the revision of the global map of fluoride levels for Cameroon in the International Groundwater Resources Assessment Centre (IGRAC). Despite Cameroon being densely drained by several basins, Fantong found the groundwaters of lake Chad and Benue basins have high fluoride concentrations due to the water-rock interaction with fluorapatite, which is a secondary mineral in the granites.

With the support of the community, Fantong explored different solutions that led to the development of biochar filtration, a low-cost method using a byproduct of local cow rearing. The biochar proved to be effective in defluoridation of the water, and also removed other potentially harmful elements such as arsenic and uranium. In combination with education and outreach, fluorosis was eventually successfully destigmatized in the communities.

Dr. Fantong demonstrated that “medical geology can be used to identify some of these health problems [that] are geogenic”, further noting that local sustainable solutions like biochar filtration can help communities solve societal problems and adapt to climate change.

*Dental Fluorosis is a condition that is caused by prolonged exposure to high fluoride levels during the development of teeth that disrupts normal production of enamel by the cells making it. Mild fluorosis appears as small, white patches on the teeth, but more severe cases show staining, pitting, and mottled teeth (Source: European Commission on Public Health).