Major celebrations in New Orleans earlier this year may have been accompanied by a troubling rise in the use of powerful synthetic opioids, according to new research that analyzed the city’s wastewater.
Scientists found that during the period surrounding Super Bowl LIX and Mardi Gras in early 2025, traces of several emerging drugs — some far stronger than morphine — increased in sewage samples, offering a snapshot of hidden drug trends in the community.
The study, published in Environmental Science & Technology Letters, used wastewater monitoring as a noninvasive way to detect drug use across a large population.
Instead of relying on hospital reports or law enforcement data, researchers tested sewage from a treatment plant serving roughly 300,000 people.
This approach can reveal patterns of drug consumption in near real time without identifying individuals.
Opioid misuse remains a major public health crisis in the United States, with substances such as heroin, oxycodone, and fentanyl responsible for many overdose deaths.
In recent years, a new group of synthetic opioids known as nitazenes has appeared on the illegal drug market. Originally developed in the 1950s as potential painkillers, these compounds were abandoned because they were considered too dangerous.
They resurfaced around 2019 and have since been linked to overdoses in several countries.
Researchers collected wastewater samples from late January through the end of March 2025, covering the weeks before, during, and after the major events. Laboratory tests detected seven different nitazene compounds, including metonitazene, which can be about 1,000 times more potent than morphine.
Some substances were found at similar levels during the events and the following weeks, while others appeared only after Mardi Gras had ended, suggesting ongoing use beyond the festivities.
Although wastewater data cannot determine exactly how many people used these drugs, it can show whether their presence is increasing or decreasing. Scientists say this early detection is valuable because many regions are not yet testing for nitazenes in overdose cases. In Louisiana, for example, official reports have not listed these drugs despite national data showing they are becoming more common.
The researchers emphasize that monitoring sewage could help public health officials respond more quickly to emerging threats. If dangerous substances are detected early, authorities can increase awareness, expand testing, and prepare medical services for potential overdoses. This is especially important during large events that attract visitors and strain local resources.
The findings highlight how new technology can reveal hidden aspects of the opioid crisis. By analyzing wastewater, scientists can track trends that might otherwise go unnoticed until after harm has occurred.
As communities continue to confront the evolving drug epidemic, tools like sewage monitoring may play a crucial role in prevention efforts. The study suggests that even celebrations known for music and joy can carry unseen risks, underscoring the need for vigilance and proactive public health strategies.
