As part of the One Health Citizen Science (OHCS) project — designed to facilitate data collection and promote health in areas experiencing high environmental pressures — community participation is regarded as a fundamental principle and a practice aimed at deepening knowledge and implementing preventive measures in the fields of the environment and health. This paper presents the Sulcis Iglesiente pilot project (Sardinia), developed jointly by the University of Cagliari, the National Research Council and ANFFAS, an association supporting people with intellectual disabilities. We describe how accessible and interdisciplinary approaches – including easy-to-read language, augmentative and alternative communication tools, and structured mediation by educators – have enabled the informed and meaningful participation of people with intellectual disabilities in identifying local environmental risks and discussing the implications for health. The experience of the pilot project suggests that cognitive accessibility and inclusive engagement can improve the representativeness of data and create opportunities to shape fairer and more effective public policies, in line with the principles of equity and health literacy.