Abstract: Disclosed herein are methods of assessing a population's health using wastewater samples. For example, the methods assess exposure to pathogens, plasticizers, volatile organic compounds, surfactant, hazardous chemical, nicotine, and/or other environmental toxins. In some aspects, the methods determine the concentration of disease biomarkers, chemical biomarker, certain human hormones, certain genes, pharmaceuticals, illicit drugs, personal care product, pathogens, and/or endogenous mental health markers. In some aspects, the methods assess population health at a neighborhood level. The methods may also be used to assess population health at a larger regional level, for example at a state level or a national level.