Pharmaceuticals and other urban contaminants threaten Amazonian freshwater ecosystems

Urban areas in the Brazilian Amazon have grown at an unprecedented rate during last years. About 90% of wastewater produced by these urban are discharged untreated into Amazonian freshwater ecosystems, constituting a potential environmental pathway for pharmaceuticals and other chemicals consumed modern societies (e.g. psychostimulants, personal-care products, hormones). The distribution River their risks biodiversity not been evaluated so far. Here, we show results largest chemical monitoring campaign conducted region. We assessed exposure patterns 43 contaminants 40 sampling sites distributed along River, three major tributaries (Negro, Tapajós Tocantins Rivers), four large cities (Manaus, Santarém, Macapá, Belém). using species sensitivity distributions mixture toxicity approaches. found that constitute important hot-spots contamination, with mixtures containing up to different compounds concentrations reaching world’s maxima some them. pollution can result long-term effects 50–80% aquatic next areas. Moreover, identified several ubiquitous which be used as tracers anthropogenic pressure basin. conclude burden created urbanization significantly contributes loss region should further controlled.