Psychosocial vulnerability of people working in informal gold mines in French Guiana: a multicentric cross-sectional survey in 2024-2025.

Introduction: In French Guiana, workers involved in illegal gold mining-mainly migrants from Brazil's poorest states-constitute a highly vulnerable population. Living and working without legal status in remote Amazonian areas, they face limited access to essential health and social services and unstable conditions (1, 2). This study aimed to describe psychosocial vulnerability in this hard-to-reach population, identify associated factors, and explore vulnerability profiles. Methods: A cross-sectional descriptive survey was conducted among adults engaged in illegal gold mining in French Guiana (3). Participants were enrolled at logistical bases along the borders with Suriname and Brazil. After informed consent, trained field investigators administered a standardized questionnaire covering sociodemographic characteristics, mining activities, mental health, violence exposure, food insecurity, perceived safety, quality of life, and healthcare access. Data were analyzed using descriptive statistics, validated scores, and cluster analysis to identify vulnerability profiles. Results: Between December 2024 and April 2025, 480 participants were enrolled, 95.4% of whom were Brazilian. Over half (55.7%) reported medium or poor health, and 43.9% lived more than a day's travel (by boat or on foot) from the nearest health facility. Social vulnerability was substantial: 16.7% reported no social support, 43.7% felt unsafe, and 29.8% had been exposed to violence. Food insecurity was frequent, with 20.5% experiencing moderate hunger and 0.4% severe hunger. Overall, 21.9% screened at elevated mental-health vulnerability. Food insecurity was independently associated with inclusion in Brazil, financial difficulties, lack of social support, and social isolation. Mental-health vulnerability was associated with female sex, social isolation, and feeling unsafe at mining sites. Conclusion: Brazilian migrants involved in illegal gold mining in French Guiana face substantial multidimensional vulnerabilities. The findings highlight cumulative vulnerabilities and support the need to consider targeted harm-reduction and coordinated cross-border public-health strategies to promote health equity.Trial registration number: NCT05540470.