► New concept proposed for gauging the overall health of small-area human populations. ► BioSCIM uses Sewage Chemical-Information Mining to measure biomarkers in sewage. ► Real-time, low-cost assessment of community-wide heath is possible. ► Isoprostanes (biomarkers of oxidative stress) are identified as targets for BioSCIM. ► Panel of orthogonal biomarkers with complementary properties may broaden [...]