Typically, festival atmosphere increases the accessibility and affordability of substances, thereby elevating the risk of adverse outcomes. Analysis of drug residues in wastewater at mass gatherings help identify the scale and temporal dynamics of substance use, enabling more informed risk management and resource allocation. However, drug use among event attendees may not represent a drug use pattern in a typically community; therefore, findings need to be cautiously extrapolated. Closed-door events present unique opportunities for WBE, including better estimation of restroom user populations, reduced uncertainty in wastewater dilution, and enhanced detection of emerging or novel psychoactive substances. However, short event durations, variable attendee turnover, and difficulties in estimating total wastewater discharge create challenges for accurate normalization and comparative assessment. Overall, evidence-based characterization of substance use at mass gatherings can predict spectator behavior, improve preparedness, guide harm-reduction strategies, and strengthen emergency medical planning. Recent applications of WBE at special events, methodological limitations, interpretation challenges, and future directions for advancing wastewater monitoring as a public health surveillance tool for mass gatherings will be discussed.
Dr. Bikram Subedi is an analytical chemist and Assistant Professor in the Department of Environmental Science at Louisiana State University. For the past 15 years, he has conducted wastewater-based epidemiology research in U.S. communities in collaboration with law enforcement agencies and public health officials. His work has characterized substance use trends during a wide range of special events, including basketball and football games, Solar Eclipse celebrations, cultural festivals, highway rest areas, and national holidays.