Q. What are high risk substances?
High risk substances are drugs with a potential for harm. High risk substances can be prescribed by physicians or obtained illegally, and they may cause addiction, overdose, and death.
Q. What substances do you currently test for?
Biobot offers 3 bundles of chemistry targets for purchase:
- Core high risk substances bundle
- Substance use disorder (SUD) treatment & intervention drugs
- Opioids and adjacent substances
Our high-risk substances bundle covers a broad set of common substances that pose a significant concern to public health departments and are suitable for wastewater testing. The bundle includes the following targets:
- Fentanyl & norfentanyl
- Methamphetamine & amphetamine
- Cocaine & benzoylecgonine
- Xylazine & 4-hydroxy xylazine
- Trans-3’-hydroxycotinine (nicotine metabolite)
The substance use disorder (SUD) treatment & intervention drugs bundle identifies common substances used in SUD treatment and overdose reversal. The bundle includes the following targets:
- Naloxone & 6α-Naloxol
- Buprenorphine
- Methadone & EDDP
The opioids bundle tests for a variety of prescription and illicit opioids and adjacent substances. Notably, naturally-derived opiate compounds such as heroin and morphine, metabolize rapidly to morphine within sewer systems. Therefore, this assay may be best incorporated at upstream sampling locations to maximize the specificity of estimates for each opioid. The following targets are included in the opioids bundle:
- Acetyl Fentanyl, acetyl norfentanyl
- Carfentanil
- Sufentanil, Norsufentanil
- Codeine
- Dihydrocodeine
- Heroin, 6-monoacetylmorphine
- Hydrocodone, Norhydrocodone
- Hydromorphone
- Morphine
- Oxycodone & Noroxycodone
- Oxymorphone
- Tramadol, N-Desmethyltramadol & O-Desmethyltramadol
- Tianeptine, Tianeptine MC5 Metabolite
If you are interested in adding any of these bundles to your wastewater testing, please contact support@biobot.io.
Q. How does Biobot choose what substances to test for?
Through internal research and development, literature reviews, and conversations with local communities, we choose substances that pose a significant concern to public health departments and are suitable for wastewater monitoring.
Q. Why do some selected targets have no metabolites or no parent drugs? Why do some parent drugs have multiple metabolites?
Biobot chooses targets where the chemical signature of a substance, called a biomarker, is consistently measurable in wastewater. In some cases, the biomarker for a parent drug or metabolite may not be consistently measurable in wastewater, but there is still public health value in reporting one of the biomarkers. Conversely, some parent drugs have multiple metabolites that are suitable for measuring in wastewater. By measuring multiple metabolites, we can gain a deeper understanding of the consumption of the parent substance.
Q. Why are some targets both a parent substance and a metabolite?
When testing for high risk substances in wastewater, it's common to encounter biomarkers that can be both parent compounds (the original drug) and metabolites (the byproducts formed when the body breaks down the drug). This dual role can make data interpretation challenging. Here’s why this happens and what it means for public health monitoring:
Understanding Parent Compounds and Metabolites
- Parent Compounds: These are the original forms of the drug that are consumed. For example, heroin itself is a parent compound.
- Metabolites: These are the substances that result from the body processing (metabolizing) the parent compound. For example, when heroin is metabolized, it breaks down into 6-monoacetylmorphine (6-MAM) and then further into morphine.
Why Some Biomarkers Serve Both Roles
- Sequential Metabolism: Some drugs are metabolized in steps. For example, heroin is first metabolized to 6-MAM, which then breaks down into morphine. In this case, 6-MAM is both a metabolite of heroin and a parent compound for morphine. Another example is amphetamine. Amphetamine is both a primary metabolite of methamphetamine as well as a commonly prescribed prescription drug, and thus a parent drug in its own right.
- Direct Excretion: Some drugs and their metabolites are excreted directly into the wastewater system without fully breaking down. This means you might find both the original drug and its metabolites in the wastewater.
- Environmental Stability: The stability of these compounds can vary. Some metabolites are more stable in wastewater, while others degrade quickly. This can affect what is detectable in samples. For instance, heroin rapidly degrades in wastewater.
Q. How does Biobot analyze chemicals in wastewater?
Because traces of high risk substances are excreted in urine and feces, wastewater is an ideal medium for capturing community trends in HRS consumption. Biobot employs highly sensitive laboratory assays to measure the concentration of HRS markers in wastewater, which enables estimates of community substance use.
Substances are appropriate wastewater-based epidemiology (WBE) targets if:
- a chemical signature of a substance, called a biomarker, is consistently measurable in wastewater, and;
- resulting data are easily interpretable, specific, and actionable.
Biobot measures parent drugs and metabolites as shown in the figure below. After ingestion of a parent drug, small amounts of the drug along with metabolites (chemical signatures of the parent drug being processed by the human body) are present in wastewater. By measuring both parent drugs and their respective metabolites, we can distinguish between changes in community substance use and environmental events such as flushing down the drain (which do not reflect substance use).
Prior to processing, quality control standards are added to each sample to correct for sample loss and deterioration during analysis. The method, termed “isotope-dilution quantitation”, is a gold standard for the identification and quantitation of organic substances in wastewater. After removing large particles by filtration, samples are concentrated using solid-phase extraction prior to quantitative analysis by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS).
Substance consumption is calculated by normalizing measured substance concentration (i.e., mass substance per volume wastewater) to the approximate influent flow and population served, which are both reported by the team collecting wastewater samples. By multiplying the measured concentration (ng/L) by the influent flow rate (mL/day) and dividing by catchment population, Biobot estimates community consumption in milligrams of substance per 1,000 people.
Q. What types of locations are eligible for high risk substances testing?
Per Biobot’s current protocol, eligible sampling locations are wastewater treatment plants or other sampling location types (e.g., pump stations) with regularly available data on volumetric flow rate. Flow rate data are necessary to characterize dilution rates (i.e., how quickly a substance may become diluted in wastewater), which affects the estimation of biomarker quantity. If you have questions about specific locations and whether flow data is complete, reach out to support@biobot.io.
Q. What is the recommended sampling cadence for high risk substances testing?
Biobot recommends sampling twice weekly. You can also collect a weekly sample, but it is helpful to have additional data points to capture variation in substance use across the week.
Q. What are the recommended sampling days for high risk substances testing?
We generally recommend that you sample on Mondays and Wednesdays. If you can only sample weekly, note that Monday sampling will generally capture higher levels of recreational substance use on weekends, while Wednesdays will capture lower levels of habitual substance use.
Q. What is the turnaround time for a high risk substance report?
Results are typically available on the Biobot customer platform within 10 business days of sample receipt. In rare cases, a rerun may be needed which may delay data delivery.
Q. Can Biobot identify individuals from wastewater samples?
No. Chemical analysis of samples does not produce any personally identifiable information. Wastewater aggregates all human waste in a community (one sample is usually representative of thousands of people), naturally anonymizing each sample. Please see our wastewater code of conduct for more information.
Q. Does Biobot make customer high risk substance wastewater data public?
No, Biobot does not publish location-level customers high risk substance wastewater data. The decision to make any customer-level data public is up to the customer. The only HRS data that Biobot makes public are through studies such as this one, where all data are aggregated and anonymized to the regional level. Any sub-regional data is published with the consent of the partner. Please see our wastewater code of conduct for more information.
Q. What is the importance of establishing a baseline?
We recommend establishing a 3-month baseline for high risk substance testing. This provides sufficient data to determine if any changes or trends are true increases or decreases in substance use, or whether changes represent normal variation that should be expected.
Q. Does weather impact HRS results?
Sewer systems that handle only sanitary flow will not have their HRS results impacted by weather. If you have a combined sanitary-and-stormwater system, Biobot can generally correct for events like heavy rainfall because we normalize our data using daily influent flow. There are, however, rare instances in which combined sewer systems receive so much rainfall that it dilutes the concentration of a substance below our limits of quantification or detection.If this occurs, it will typically impact substances which are present in wastewater at low concentrations, such as fentanyl or naloxone and their respective metabolites.
The impacts of other factors, such as the effects of extremely high or low temperatures or the effect of salts deployed during winter weather, require more year-to-year data to quantify. Biobot will provide updated guidance on these weather-related impacts as findings become available.
Q. Which community stakeholders can benefit from wastewater data on high risk substances?
Public health officials, community leaders, federal agencies, correctional facilities, opioid task force teams, and other stakeholders as well as members of the general public can benefit from collecting better data and enhanced insights on high risk substance use in their communities.
Q. Do you provide resources to help engage community stakeholders?
Yes. If you need assistance engaging with community stakeholders please contact support@biobot.io and we would be happy to assist you.