Traffic, Drugs, Mental Health, and Disinfectants: Changes in Sewage Sludge Chemical Signatures During a COVID-19 Community Lockdown

The COVID-19 pandemic and related shutdowns have caused changes in everyday activities for many people, and signs of those changes are present in the chemical signatures of sewage sludge produced during the pandemic. We analyzed primary sewage sludge samples from a wastewater treatment plant in New Haven, CT USA collected between March 19 and June 30, 2020. This time period encompassed the first wave of the COVID-19 pandemic, the initial statewide stay at home order, and the first phase of reopening. We used liquid chromatography coupled with high resolution mass spectrometry and targeted and suspect screening strategies to identify contaminants in the sludge. We and found evidence of increasing opioid, cocaine, and antidepressant use, as well as upward trends in chemicals used in disinfectants and sunscreens during the study period. Benzotriazole, an anti-corrosion chemical associated with traffic pollution, decreased through the stay-at-home period, and increased during reopening. Hydroxychloroquine, a drug that received significant attention for its potential to treat COVID-19, had elevated concentrations in the week following the implementation of the United States Emergency Use Authorization. Our results directly relate to nationwide reports of increased demand for fentanyl, antidepressants, and other medications, as well as reports of increased drug overdose deaths during the pandemic. Though wastewater surveillance during the pandemic has largely focused on measuring SARS-CoV-2 RNA concentrations, chemical analysis can also show trends that are important for revealing the public and environmental health effects of the pandemic.