A Wastewater Data Source on Drug Use for Proactive Public Health

May 9, 2023

Wastewater analysis to monitor SARS-CoV-2 has become commonplace over the course of the COVID-19 pandemic, providing valuable insights on disease prevalence and trends to help inform public health responses. Biobot is a global leader in this space, working at hundreds of locations to deliver crucial data insights from sewage in partnership with local, county, and state public health departments and enterprises across the United States.

Founded in 2017, Biobot is well known for its infectious disease efforts. However, its first wastewater monitoring platform was actually built to help tackle the opioid overdose epidemic. In early 2020, Biobot paused its opioid work to focus on the COVID-19 pandemic, but never lost sight of the important work to be done within the high-risk substance space. In 2021, the U.S. saw a record-breaking number of fatal overdoses, worsening a harrowing epidemic during the COVID-19 pandemic. In response, last fall Biobot launched its new and improved High Risk Substance Wastewater Platform (HRS Platform) to help communities better understand and respond to high-risk substance use.

Biobot’s High Risk Substance Wastewater Monitoring Platform 

Biobot’s High Risk Substance (HRS) platform provides naturally anonymized data on community use of fentanyl, methamphetamine, cocaine, and nicotine, addressing a critical gap in nationwide substance use data. Public health systems currently rely on survey data, emergency medical services (EMS) data, mortality data, and hospitalization data to estimate substance use. These sources tend to vastly undercount substance use in communities for a number of reasons. For example, lack of access to health services and stigmatization of substance use can impede hospitalization records and survey results. These data sources are also frequently delayed, meaning that public health responses rely on outdated data.

Biobot’s HRS platform, by contrast, reflects the levels of fentanyl, methamphetamine, cocaine, and nicotine that are present in a community’s wastewater, and estimates the amount of each drug consumed by tracking their most prominent chemical metabolites. Wastewater samples represent the entire community and are naturally aggregated, meaning they are anonymous. Wastewater data also do not rely on contact with the health system or law enforcement, therefore they are more comprehensive than data from current systems. And, since Biobot can produce results on the scale of days, data are available soon enough to inform a real-time public health response, compared to lagging EMS, mortality, and hospitalization data.

Insights from One Year of HRS Wastewater Data

Thanks to 72 wastewater treatment plants across the U.S. that participate in Biobot’s research, we analyzed data from their locations for a full year. From April 2022 to April 2023, our analyses led us to some powerful insights:  

1. We can distinguish between consumed and flushed drugs in wastewater 

When individuals consume a drug, their bodies metabolize the drug and produce a marker that is chemically different from the drug in its pre-metabolized form. This post-metabolic marker is then excreted in their waste. For drugs, these markers, called “metabolites,” are then excreted in urine, enter the wastewater system, and can be tested for and quantified in the lab. Because of these differences in the chemical makeup of the consumed drug – or “metabolite” – compared to the unmetabolized chemical – or “parent drug” – we can identify both of these concentrations via wastewater analysis. While drug metabolites enter the wastewater system through urination post drug consumption, parent can drugs enter the wastewater system through environmental dumping events, including drug flushing, and any other disposal of drugs that enter the wastewater stream.1

Below, we plot consumption estimates across 72 nationwide locations by parent drug and metabolite. We use flow and population to normalize the concentration of parent drugs and metabolites in wastewater to estimate consumption in milligrams per 1,000 people per day. The visualization shows the distribution of sample measurements that fell at each consumption level for each parent drug and metabolite pair. Higher peaks at a particular consumption level mean that more samples were measured at that particular consumption level. The vertical line in each distribution represents the median consumption level across samples of each metabolite or parent drug.

Through wastewater analysis, we can see distinctions across the distributions of parent drugs (methamphetamine, fentanyl, cocaine) and their metabolites (amphetamine, norfentanyl, benzoylecgonine). For example, we tend to see higher concentrations of norfentanyl than fentanyl in wastewater most of the time, which makes sense; more of the metabolized fentanyl would make it into the wastestream than unmetabolized fentanyl, due to their expected excretion proportions. Deviations from this trend tend to indicate an environmental dumping event. 

Testing for both the parent drug and metabolite in Biobot’s HRS panel allows us to compare trends across parent drugs and metabolites. Wastewater analysis is one of the only ways we can capture these data and produce nuanced information about the rates of use and discarding of different drugs in a community. At a community level, distinguishing between the amount of drugs consumed versus the amount of drugs disposed of provides greater granularity into the patterns of drug use and availability in a community. Gaining clarity on these dynamics can better inform public health responses; for example, a dumping event may signal a contaminated drug supply. 

2. We can compare drug use estimates across locations

We can see differences in distributions of methamphetamine and norfentanyl consumption use estimates across the West and Northeast, as shown in the visualization below. The dataset of samples that we used for this research and development analyses included 39 locations in the Northeast and 10 locations in the West. 

Studies have shown that age-adjusted overdose rates involving methamphetamine have tended to be higher in the West, and age-adjusted overdose rates involving fentanyl have tended to be higher in the Northeast (Mattson et al., 2021; Hedegaard et al., 2019). In the visualizations above, we see that the medians of each drug type – visualized by the vertical lines in each density plot – correspond to what we would expect, per these studies.2 Specifically, we see a higher median methamphetamine consumption value across locations in the West, and a higher median norfentanyl consumption value across locations in the Northeast. Substance use epidemiology that utilizes the power of wastewater data to explore geographic patterns informs how substance use changes across drug types in different areas. 

3. We can monitor trends in consumption estimates over time

Through wastewater analysis, we can also see differences in drug use across time in different locations. The plot below shows data on benzoylecgonine, the primary metabolite for cocaine,  across three sites in one East Coast state.

The plot shows how levels of benzoylecgonine, which estimate community cocaine use, were consistently highest in Site 2 from April 2022 to April 2023. We also see a pronounced downward trend in Site 1 from June 2022 to April 2023 that data from Site 2 and Site 3 do not reflect. Granular data across sampling location types provide insight into how the respective baselines of drug use may differ, and when trends in use may differ. We may also be able to track when a trend begins in one area, and then follows in another. This information helps communities better understand local trends, and will be increasingly useful when sharing intervention outcomes between surrounding communities. 

Case Study: Identifying Nicotine Environmental Dumping Through Wastewater

As mentioned above, Biobot’s HRS platform enables us to distinguish between parent drugs and metabolites. Sometimes, we see stark deviations in the amount of parent drug and the amount of metabolite present in a sample. At one of our locations, we noticed repeated spikes in nicotine, and wondered why this pattern (which was different from what we’d observed at other locations) continued to occur.

This stark increase was only observed in nicotine, the parent drug, and not in its metabolite, trans-3-hydroxycotinine. Since nicotine spikes were not mirrored in trans-3-hydroxycotinine concentrations, we inferred that the spikes did not confer a change in nicotine consumption; rather, the spikes suggested a nicotine dumping event.  

When we spoke with the location, we confirmed that it was near a tobacco plant — we were able to witness the effects of the tobacco plant’s deposits in wastewater through spikes of nicotine in our wastewater data!  

Harnessing HRS wastewater data to tackle the drug overdose epidemic and improve substance use interventions

Overdose deaths are at an all time high in the U.S.. Oftentimes, state and local officials rely on months- or year-old overdose and/or mortality data to piece together the nuance and severity of drug use in their communities. Without timely data to inform effective and proactive public health responses, we cannot stop, or better yet, reverse these upward trends. 

Wastewater analysis is timely, providing crucial data to inform targeted public health interventions to help prevent overdoses and save lives. We can use wastewater monitoring to gain a rich understanding of how drug use changes between locations and across time. We can also see what enters the wastewater system through consumption versus what enters the system environmentally (i.e., is flushed or dumped). Through wastewater analysis, we can gain valuable insights on drug use within communities.

Interested in learning more about analyzing wastewater for high-risk substances? Click here to talk to an expert.

1 Small amounts of the parent drug may also be excreted by the body after a drug is used, but we tend to see much larger amounts of parent drugs in wastewater when an environmental dumping event occurs.

2 We plot methamphetamine and norfentanyl here because methamphetamine is a special case of parent drug. Even though amphetamine is a metabolite of methamphetamine, amphetamine is also a parent drug itself. Amphetamine is prescribed as, for example, Adderall and Ritalin, so increases in amphetamine can reflect dumping events of those prescribed drugs. Additionally, even when methamphetamine is used, nearly half of the dose used is excreted as unmetabolized methamphetamine. We therefore refer to methamphetamine consumption, instead of amphetamine consumption, as a proxy for methamphetamine community use.

Written by Biobot Analytics

Biobot provides wastewater epidemiology data & analysis to help governments & businesses focus on public health efforts and improve lives.