Expansion of wastewater-based disease surveillance to improve health equity in California's Central Valley: sequential shifts in case-to-wastewater and hospitalization-to-wastewater ratios.

Introduction: Over a third of the communities (39%) in the Central Valley of California, a richly diverse and important agricultural region, are classified as disadvantaged-with inadequate access to healthcare, lower socio-economic status, and higher exposure to air and water pollution. The majority of racial and ethnic minorities are also at higher risk of COVID-19 infection, hospitalization, and death according to the Centers for Disease Control and Prevention. Healthy Central Valley Together established a wastewater-based disease surveillance (WDS) program that aims to achieve greater health equity in the region through partnership with Central Valley communities and the Sewer Coronavirus Alert Network. WDS offers a cost-effective strategy to monitor trends in SARS-CoV-2 community infection rates. Methods: In this study, we evaluated correlations between public health and wastewater data (represented as SARS-CoV-2 target gene copies normalized by pepper mild mottle virus target gene copies) collected for three Central Valley communities over two periods of COVID-19 infection waves between October 2021 and September 2022. Public health data included clinical case counts at county and sewershed scales as well as COVID-19 hospitalization and intensive care unit admissions. Lag-adjusted hospitalization:wastewater ratios were also evaluated as a retrospective metric of disease severity and corollary to hospitalization:case ratios. Results: Consistent with other studies, strong correlations were found between wastewater and public health data. However, a significant reduction in case:wastewater ratios was observed for all three communities from the first to the second wave of infections, decreasing from an average of 4.7 ± 1.4 over the first infection wave to 0.8 ± 0.4 over the second. Discussion: The decline in case:wastewater ratios was likely due to reduced clinical testing availability and test seeking behavior, highlighting how WDS can fill data gaps associated with under-reporting of cases. Overall, the hospitalization:wastewater ratios remained more stable through the two waves of infections, averaging 0.5 ± 0.3 and 0.3 ± 0.4 over the first and second waves, respectively.

Assessing population-level stress through glucocorticoid hormone monitoring in wastewater.

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.

Alcohol, nicotine, and caffeine consumption on a public U.S. university campus determined by wastewater-based epidemiology.

Alcohol, nicotine, and caffeine use in at-risk populations is a public health concern that claims over 550,000 lives annually. Self-reported surveys from college students often reveal overconsumption of these substances. Unfortunately, the costs of these surveys are high, and consequently, the results from few studies are often extrapolated across the entire target population. Here we employed wastewater-based epidemiology (WBE) to directly measure the levels of these three psychotropic substances and their metabolites in sewage from a large public Southwestern U.S. university campus during the 2017-2018 academic year. Results showed per person alcohol consumption was 11.3 ± 7.5 g d-1 person-1 or 0.8 ± 0.5 drinks d-1 person-1, similar to averages of nationwide estimates from self-reporting of this subpopulation aged 18-25 years (10.1 ± 0.8 g d-1 person-1 or 0.7 ± 0.06 drinks d-1 person-1). Caffeine and nicotine consumption determined by WBE were significantly lower (p < 0.05) than nationwide estimates from self-reporting (caffeine: 114 ± 49 vs. 178 ± 19 mg d-1 person-1; nicotine: 627 ± 219 vs. 927 ± 243 µg d-1 person-1). Strong positive correlations were found for consumption of alcohol and nicotine (Spearman rs: 0.71; p < 0.01), and nicotine and caffeine (0.59, p < 0.01), but not alcohol and caffeine (0.17). Alcohol and nicotine consumption were significantly higher on weekends compared to weekdays (p < 0.01), while caffeine consumption was higher during the week (p < 0.05). This first U.S. WBE study on alcohol, nicotine, and caffeine use among U.S. college students demonstrated the feasibility and practicality of longitudinally tracking the behavior of an entire campus population of 60,000 students directly, repeatedly, and more inexpensively (US$0.58/person) compared to conventional questionnaires (US$127/person).

Long-term tracking of opioid consumption in two United States cities using wastewater-based epidemiology approach.

Access to near-real time opioid use data is essential to the effective management of the U.S. opioid crisis. Current narcotic data collection methods are limited by time delay and would be complimented by a rapid data acquisition technique. Use of wastewater-based epidemiology (WBE) analysis may offer access to near real-time data on opioid consumption but application in the United States has been limited. From 2015 to 2017, monthly 24-h time-weighted composite samples of municipal raw wastewater from two Midwestern U.S. cities were routinely analyzed using liquid chromatography-tandem mass spectrometry for morphine, codeine, oxycodone, heroin, fentanyl, and select opioid metabolites. Concentrations of opioids (ng/L) in raw wastewater from City 1 and 2, respectively, were: morphine (713 ±â€¯38; 306 ±â€¯29; detection frequency (DF): 100%), oxycodone (17.8 ±â€¯1.1; 78 ±â€¯6; DF: 100%), codeine (332 ±â€¯37; 100 ±â€¯27; DF: 93%), heroin (41 ±â€¯16; 9 ±â€¯11; DF: 81%), and fentanyl (1.7 ±â€¯0.2; 1.0 ±â€¯0.5; DF: 62%). Average opioid consumption rates estimated using WBE ranged between 9 and 2590 mg/day/1000 persons. Anticipated overdoses and overdose-deaths calculated from analyte concentrations in wastewater forecasted 200 opioid-related overdoses/year and 39 opioid related overdose-deaths/year across the two cities during the year 2016, which aligned well with observed coroner-reported opioid deaths. This long-term U.S. screening study of opioids in wastewater was the first to utilize wastewater epidemiological data to estimate the number of expected overdose and overdose-deaths, and to identify detectable levels of the powerful synthetic opioid fentanyl in community wastewater consistently over the course of one whole year.

Critical review of major sources of human exposure to N-nitrosamines.

More than 24 N-nitrosamine compounds contribute to the total N-nitrosamine (TNA) burden monitored routinely to assess human exposure to this important group of known and suspected human carcinogens. A literature review (n = 122) identified multiple sources of human exposure to TNAs, including waters (40 ±â€¯10.5 ng/L; average ± standard deviation), food and beverages (6.7 ±â€¯0.8 ng/g), tobacco (16,100 ±â€¯3650 ng/g) and personal care products (1500 ±â€¯750 ng/g). Due to source control interventions, levels of TNAs in beer have dropped by about 96% between 1980 and 1990, whereas N-nitrosamine levels in other known sources have shown little to no change. Maximum daily TNA exposure in the U.S. in units of ng/d is estimated at 25,000 ±â€¯4,950, driven by consumption of tobacco products (22,000 ±â€¯4350), food (1900 ±â€¯380), alcohol (1000 ±â€¯200), and drinking water (120 ±â€¯24). Behavioral choices of individuals in non-occupational settings were calculated to result in a spectrum of exposure values ranging from a lower bound of 1900 ±â€¯380 ng/d to a higher bound of 25,000 ±â€¯4950 ng/d, indicating opportunities for a possible 12-fold reduction in TNA exposure to 8% of the above maximum through deliberate choices in diet and lifestyle.

Tracking narcotics consumption at a Southwestern U.S. university campus by wastewater-based epidemiology.

Wastewater-based epidemiology (WBE) was applied to estimate the consumption of twelve narcotics within a Southwestern U.S. university campus. Seven consecutive 24-hour composite raw wastewater samples (n = 80) were obtained once per month from sampling locations capturing >95% of campus-generated wastewater. Samples were analyzed for indicators of consumption of morphine, codeine, oxycodone, heroin, fentanyl, methadone, buprenorphine, amphetamine, methylphenidate, alprazolam, cocaine, and MDMA using LC-MS/MS. Eleven indicator compounds (oxycodone, codeine, norcodeine, 6-acetylmorphine, EDDP, amphetamine, alprazolam, alpha-hydroxyalprazolam, cocaine, benzoylecgonine, and MDMA) occurred at 100% detection frequency across the study, followed by morphine-3-glucuronide (98%), noroxycodone (95%), methylphenidate (90%), heroin (7%), norfentanyl (7%), and fentanyl (5%). Estimates of average narcotics consumption ranked as follows in units of mg/day/1000 persons: heroin (474 ± 32), cocaine (551 ± 49), amphetamine (256 ± 12), methylphenidate (236 ± 28), methadone (72 ± 8), oxycodone (80 ± 6), alprazolam (60 ± 2), MDMA (88 ± 35), codeine (50 ± 4), and morphine (18 ± 3). This campus-based WBE study yielded baseline data on 12 narcotics for a U.S. campus and demonstrated for the first time the feasibility of detecting the fentanyl metabolite norfentanyl in this setting.

Occurrence of N-nitrosamines in U.S. freshwater sediments near wastewater treatment plants.

In the present study, 40 freshwater sediments collected near 14 wastewater treatment plants (WWTPs) across the United States were analyzed for eight N-nitrosamines by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Three N-nitrosamines were detected for the first time in freshwater sediments in units of ng/g dry weight at the specified detection frequency: N-nitrosodibutylamine (NDBA; 0.2-3.3; 58%), N-nitrosodiphenylamine (NDPhA; 0.2-4.7; 50%), and N-nitrosopyrrolidine (NPYR; 3.4-19.6; 18%). At least one N-nitrosamine was detected in 70% (28/40) of sediments analyzed. Non-detect values in units of ng/g dw were obtained for N-nitrosodimethylamine (NDMA; <10.2), N-nitrosomethylethylamine (NMEA; <1.7), N-nitrosodiethylamine (NDEA; <3.9), N-nitroso-di-n-propylamine (NDPA; <1.7), and N-nitrosopiperidine (NPIP; <3.6). Principal component analysis specifically points to two of multiple potential pathways explaining N-nitrosamine occurrences in sediment: NDBA and NDPhA were positively correlated with bulk water ammonia and pH levels, and NPYR with sediment content of organic carbon and iron. Interestingly, N-nitrosamine occurrences up- and downstream of WWTPs were statistically indistinguishable (p>0.05). This is the first report on the occurrence of the carcinogenic N-nitrosamines NDBA, NDPhA, and NPYR in U.S. freshwater sediments. Discovery of this phenomenon warrants further research on the compounds' origin, environmental persistence, aquatic toxicity, and risks posed.