Medical geology: a geologist’s view of environmental exposure and disease Dr Jennifer Le Blond Junior Research Fellow in Earth Sciences and Engineering, Imperial College London Medical geology is a multidisciplinary approach to investigating relationships between the geological environment and its impact on the health of humans, animals and plants. The principle role of a medical geologist is to identify the characteristics of the local geological environment that could cause disease or symptoms of ill health in exposed populations, working in collaboration with epidemiologists and medical doctors describing the form and distribution of the disease. One such example of medical geology is my own research on the occurrence of podoconiosis. Podoconiosis (non-filarial elephantiasis) is a noncommunicable, yet entirely preventable disease endemic in tropical countries such as Ethiopia and Cameroon. While the prevalence of podoconiosis has been correlated with various environmental factors (such as altitude and barefoot exposure to ‘volcanic deposits’), the definitive triggers have not yet been identified. I will discuss our research, characterising soil samples from areas with known podoconiosis prevalence. Thus far, we propose that clay minerals could play an important role in disease initiation, and our preliminary studies have already challenged the few pre-existing hypotheses regarding podoconiosis aetiology. I will elaborate on our plans for future analysis of the finer fractions within the soil samples and targeted cellular toxicity testing, to better understand the processes that could occur once the soil enters into the human body. Our continued study of the geological and environmental characteristics, combined with parallel studies into the genetic susceptibility, will increase both awareness of the disease and the likelihood of prevention.