Cumulative impacts of urban runoff and municipal wastewater effluents on wild freshwater mussels (Lasmigona costata)

► Wild freshwater mussels were collected from an urbanized river. ► Mussels living downstream of cites had reduced condition factor and mean age. ► Metal concentrations in mussel gills increased with multiple urban inputs. ► Ammonia and chloride at the downstream sites reach levels toxic to mussels. ► Chronic exposure to a complex contaminant mixture negatively impacted mussels.