Assessing population-level stress through glucocorticoid hormone monitoring in wastewater
Erin M. Driver, Adam J. Gushgari, Joshua C. Steele, Devin A. Bowes, Rolf U. Halden
Abstract
Stress is oftentimes overlooked in societies, despite its life-threatening impact. Here, we assessed the feasibility of measuring endogenous stress hormones to estimate population-level stress by wastewater-based epidemiology (WBE). Two primary glucocorticoids, cortisol and cortisone, were monitored in wastewater by liquid chromatography tandem mass spectrometry (LC-MS/MS), to assess changes in these physiological markers of stress in a student population (n = 26,000 ± 7100) on a university campus in the southwestern U.S. Daily composite samples were collected for seven consecutive days each month during the Fall (Autumn) 2017 and Spring 2018 academic semesters (n = 134). Reproducible weekly patterns were seen in stress hormone excretion, with the highest levels occurring on Mondays (124 ± 44 μg d−1 per person) and Tuesdays (127 ± 54 μg d−1 per person) and the lowest on Sundays (87 ± 32 μg d−1 per person). Stress levels on weekdays (defined by class schedules Monday-Thursday) were significantly higher than on weekends (p < 0.05). During both Fall and Spring semesters, per person stress levels of these hormones were significantly higher (p < 0.05) during the first two months of each semester, 162 ± 28 μg d−1 per person (August), 104 ± 29 μg d−1 per person (September), 180 ± 14 μg d−1 per person (January), and 114 ± 54 μg d−1 per person (February) than in the remaining measured weeks in the semester, including finals week captured in both semesters. Overall Spring semester stress levels (113 ± 45 μg d−1 per person) were significantly higher than the Fall (94 ± 42 μg d−1 per person), p < 0.01. This study is the first to demonstrate the utility of endogenous biomarkers, specifically glucocorticoid hormones, to monitor population health status (in this instance community stress) in near real-time by wastewater assessments.