Wastewater surveillance has been successfully employed to monitor pharmaceutical usage on a university campus. In this study, the usage patterns of antibiotics and disinfectants during the COVID-19 pandemic were evaluated. Firstly, the results showed that during COVID-19 waves, different pharmaceuticals correlated with normalized SARS-CoV-2 concentrations, suggesting that distinct medications may have been necessary to address the unique symptoms associated with each COVID-19 variant. Secondly, it was observed that both the total concentrations of antibiotics and disinfectants were higher during the peak of the COVID-19 pandemic compared to before the Delta Wave. Overall, this indicates an increased chemical usage associated with COVID-19, which raises concerns about its impact on the emergence of Antibiotic Resistance Genes (ARGs) during this period.@en

In this study, we report the implementation of a comprehensive wastewater surveillance testing program at a university campus in Singapore to identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infected individuals and the usage of pharmaceuticals and personal care products (PPCPs) as well as other emerging contaminants (ECs). This unique co-monitoring program simultaneously measured SARS-CoV-2 with chemical markers/contaminants as the COVID-19 situation evolved from pandemic to endemic stages, following a nationwide mass vaccination drive. SARS-CoV-2 RNA concentrations in wastewater from campus dormitories were measured using real-time reverse transcription-polymerase chain reaction (RT-qPCR) and corroborated with the number of symptomatic COVID-19 cases confirmed with the antigen rapid test (ART). Consistent results were observed where the concentrations of SARS-CoV-2 RNA detected in wastewater increased proportionately with the number of COVID-19 infected individuals residing on campus. Similarly, a wide range of ECs, including disinfectants and antibiotics, were detected through sensitive liquid chromatography with tandem mass spectrometry (LC-MS/MS) techniques to establish PPCPs consumption patterns during various stages of the COVID-19 pandemic in Singapore. Statistical correlation of SARS-CoV-2 RNA was observed with few ECs belonging to disinfectants, PCPs and antibiotics. A high concentration of disinfectants and subsequent positive correlation with the number of reported cases on the university campus indicates that disinfectants could serve as a chemical marker during such unprecedented times.@en