This site is part of a research project that examines the relationship between cause and justice through an ethnographic study of an occupational and environmental health epidemic. In northwest Nicaragua, a new form of renal failure is killing sugar plantation workers. Since 2000, roughly one-third of all deaths among men in the area have been attributed to "chronic kidney disease of non-traditional causes" (CKDnt). In 2005, alleging that CKDnt was linked to pesticide exposure, a group of Nicaraguan workers mobilized alongside transnational labor lawyers to convince the World Bank to fund a study of the problem. Tracing the emergence of a popular movement that turned CKDnt from a local crisis into into a global health concern, this project will show how three distinct ideas of cause circulate through the domains of law and science as well as through collective social movements. Within global health, cause is most familiar as a synonym for disease etiology. In law, cause references reasonable grounds for a claim. In social movements, cause connotes a common goal or moral end. A more refined understanding of how these three ideas intersect can enhance anthropological understandings of how the meaning and operations of social justice develop. As a disease for which there is no clear medical fix, CKDnt has created space for the poor to help shape global health agendas, and for global health scientists to rethink the social justice value of their research. Beyond global health, then, this project addresses a broader question: To what extent is a unified definition of cause necessary for doing justice? By illustrating how global health and social movements are shaping each other amid Nicaragua's CKDnt epidemic, this project will pose an answer to this question while contributing to a broader debate in anthropology, science studies, and politics about how causal models and ideas of justice shape each other.