Despite a growing public awareness of and concern for the link between environmental pollution and human health risks, there is a relative dearth of research on teacher perceptions of including environmental health topics in K-12 classrooms. We examined the impact of an environmental health-focused professional development (PD) program on middle school teachers. We used a concurrent nested mixed methods approach to measure teachers' pre-/post-perceptions of environmental health science concepts and their integration into science curriculum and classroom practices. Our analysis revealed three primary themes: teachers (1) found the PD and curriculum on environmental health beneficial; (2) emphasized that the material and curriculum promote multiple scientific connections with students; and (3) had increased confidence in teaching the topic and using environmental monitoring tools. The findings suggest that environmental health is a promising content area for teachers to integrate in the classroom in order to meet state science standards.