Wastewater as an Indicator of the Physical and Mental Health of Pennsylvania Communities
Wastewater-based epidemiology is increasingly being viewed as a powerful tool for providing information about the health of a community because each person in a treatment plant’s service area inevitably contributes to the wastewater. Here, we partnered with two wastewater treatment plants in the Commonwealth of Pennsylvania – Derry Municipal Water Authority (WWTP A) and a facility with the PA Department of Corrections (WWTP B) to monitor the weekly occurrence of: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); two pain medications (acetaminophen and naproxen), one cough suppressant (dextromethorphan); four antibiotics (ampicillin, ofloxacin, sulfamethoxazole, and trimethoprim); two therapeutic agents (remdesivir and dexamethasone); hydroxychloroquine; and four anti-anxiety medications (alprazolam, buspirone, citalopram, and clomipramine). By analyzing wastewater, the well-being of an entire community can be gained without the need to interview, survey, or test individuals.
Pain medications were observed frequently in the wastewater influent samples. At WWTP A, acetaminophen concentrations were found to be positively correlated with SARS-CoV-2 concentrations in the wastewater, while naproxen was not found to correlate with SARS-CoV-2. Acetaminophen is the active ingredient in Tylenol®, and naproxen is the active ingredient in Aleve®; therefore, these results may suggest that Tylenol® was more actively used to treated COVID-19 symptoms in the WWTP’s service area than Aleve®. At WWTP B, no correlations were found between acetaminophen or naproxen and SARS-CoV-2. However, when the concentrations were converted to equivalent tablets or doses, the number of equivalent tablets observed in WWTP B influent was higher for acetaminophen compared to naproxen.
Sulfamethoxazole and trimethoprim were the most frequently detected antibiotics in the wastewater influent samples collected at both WWTPs. Higher concentrations of sulfamethoxazole were observed in fall 2020 through winter 2021 compared to the spring and summer of 2021 at both WWTPs, with concentrations increasing again with the colder months in fall 2021. These seasonal patterns are common for antibiotics in wastewater treatment plants and were also observed for trimethoprim in WWTP A; however, these trends were not observed for trimethoprim in WWTP B.
Dexamethasone, which is a corticosteroid that treats inflammation, was also frequently detected at both WWTPs. In hospital settings, dexamethasone has been used to treat patients on ventilators. In WWTP A, dexamethasone concentration patterns coincided with the number of hospitalized patients on ventilators but were not as well aligned with only the number of COVID-19 patients on ventilators. At WWTP B, the detection of dexamethasone in the WWTP influent was not correlated to SARS-CoV-2. Because dexamethasone is a corticosteroid that it is used to treat a much broader array of conditions that cause inflammation, including skin conditions and allergies, its high frequency of detection is likely due to other approved uses of dexamethasone by inmates and/or staff at the PA DOC facility.
The two mental health-related medications that were detected most frequently as part of this project were citalopram and buspirone. At WWTP A, citalopram concentrations were found to be highest in mid-winter 2021 and to generally decrease through the remainder of the project’s sampling period (Fall 2021). However, it is unclear if these results are typical seasonal variations in citalopram occurrence in WWTP influent (i.e. associated with seasonal depression symptoms), or if the changes were related to various phases of the pandemic. Without pre-pandemic data to compare, we were unable to disentangle the effects of the pandemic on mental health using wastewater data. Citalopram was detected in nearly all of the samples collected at WWTP B, while buspirone was detected in less than half of the samples. These results are consistent with the typical courses of treatment for each of these medications. Whereas courses of treatment with citalopram are for long-term depression symptoms and may span as long as six months to two years, buspirone is used to treat shorter-term episodes of anxiety and is not recommended for chronic anxiety. Therefore, its lower frequency of detection appears to be consistent with its less common usage compared to citalopram and its shorter treatment course.
Overall, this project provided data that could serve as human physical health indicators over the course of the pandemic, including SARS-CoV-2, the pain medications/fever reducers acetaminophen and naproxen, the antibiotics ampicillin, ofloxacin, sulfamethoxazole, and trimethoprim, COVID-19 related therapeutics (remdesivir and dexamethasone), and hydroxychloroquine to wastewater treatment plant operators. Additionally, pharmaceutical data that could serve as human mental health indicators over the course of the pandemic, including the anti-depressant citalopram and the anti-anxiety medication buspirone, were also shared with WWTP operators. SARS-CoV-2 data were generally shared over email within 48 hours of sample collection with our project partners. Pharmaceutical data was shared as it became available, but generally monthly or bi-monthly due to longer processing times and lab constraints at Penn State. We hope that these data were useful to our project partners and believe that the results further demonstrate the utility of wastewater surveillance efforts to address human health concerns at the community scale.