Human-environmental interactions are a millennia-long affair, but bioarchaeological studies investigating the relationship between environment and health declines in past populations are still limited. This chapter discusses the possible effects of environmental hazards to the health of Roman populations (1st–3rd century AD) in the civitas capital of Aventicum (Switzerland). The location of Aventicum near marshy and often flooded areas, as well as paleoenvironmental data on climatic conditions, natural hazards, and human impacts during the Roman era, all point to a significant role for the environment to shape the health of the human community. This chapter investigates the evidence for that hypothesis in the Aventicum skeletal population. Natural changes, such as warm temperatures and heavy precipitation, are known to favor the growth and size of vectors responsible for infectious conditions, such as malaria. Similarly, high flood activity during the Roman era could have resulted in resource scarcity, primarily affecting pregnant or lactating women, which could be demonstrated by neonatal scurvy.