Very high levels of lead, arsenic, and cadmium have been measured in the soil at former mining sites in the Gard department. To understand the sources and modes of exposure for nearby residents, a biomonitoring study was conducted among the general population, collecting data through biological samples (blood for lead and urine for arsenic and cadmium), a questionnaire on dietary habits and lifestyles, as well as environmental samples from garden soils and household dust in participants’ homes. Inclusion was voluntary, and risk factors related to lead, arsenic, and cadmium exposure were quantified using a generalized linear model. An external advisory committee comprising experts in environmental health, biostatistics, nutrition, epidemiology, anthropology, and toxicology translated the study’s findings into appropriate operational measures. The committee engaged the community by consulting various stakeholders to adapt the proposals to the local context.