Canadian Drug and Substance Watch: Understanding the data

On this page

---

What the data can tell us

The Canadian Drug and Substance Watch (CDSW) provides critical information for early intervention and decision-making. The CDSW can provide early warnings by detecting new and emerging psychoactive substances and trends of those substances over time.

The CDSW does not currently quantify:

• the amounts of a detected substance
• the purity of substances
• the co-occurrence of other substances with those identified

Drug early warning systems differ from traditional reporting of drug use. They allow us to track and analyze shifting patterns of drug use across multiple data sources. This is not a drug alert system, which aims to prevent immediate harm by sharing information about the location and appearance of drugs.

Definitions

Explanations of terms used in the CDSW.

New psychoactive substances

New psychoactive substances are drugs that have recently appeared on the illegal drug market. They are not currently controlled under the Controlled Drugs and Substances Act and their sale is regulated under the Food and Drugs Act. An example of a new psychoactive substances is 5-MeO-DMT (from the hallucinogen pharmacological class).

Emerging psychoactive substances

Emerging psychoactive substances are drugs that have recently appeared or re-appeared on the illegal drug market. These substances are controlled under the Controlled Drugs and Substances Act. An example of an emerging psychoactive substance is protonitazene (from the opioids pharmacological class). For more information on controlled substances status determination: Health Canada’s Controlled Substances Status Determination Process - Canada.ca

Metabolites

Metabolites are substances that are formed when a drug is broken down by the body. There can be more than one metabolite associated with each drug. In some cases, metabolites can be used as drugs themselves. An example of a metabolite is normephedrone (metabolite of mephedrone, from the stimulant pharmacological class). If a metabolite is identified, the CDSW will flag it in the data.

Pharmacological class

A pharmacological class is a way to group drugs based on their effect on the body. Drugs in the same class cause the same or similar effects. For definitions of the pharmacological classes in this tool, visit Health Canada's Drug Analysis Service (DAS).

For reports and data, visit the Drug Analysis Service and Cannabis Laboratory.

Precursors

Precursors are chemicals that are used in the production of other chemicals. The precursors reported in the CDSW are used in the production of psychoactive substances which may or may not be controlled.

An example of a precursor is BMK glycidic acid. For more information on precursor chemicals of controlled substances: Controlled substances and precursor chemicals - Canada.ca

Data sources

The CDSW is a surveillance tool that integrates data from the sources described below.

Drugs samples from law enforcement

Health Canada’s Drug Analysis Service operates laboratories across Canada that analyze drugs and substances submitted by Canadian law enforcement and public health officials. DAS analyzes suspected drug samples to identify whether or not they contain controlled substances under the Controlled Drugs and Substances Act. DAS data provides information about the composition of drugs circulating in Canada. It also shows changes in the types of drugs and substances submitted by law enforcement and public health officials.

Data are from January 2023 to December 2024. Substances that were identified for the first time on or after January 2023 are included in this tool. Currently, the CDSW only includes samples submitted by law enforcement.

Wastewater monitoring

Health Canada analyzes untreated wastewater (sewage) for the presence of drugs. Wastewater data helps us detect emerging trends in drug use. These trends may be missed by traditional surveillance methods. Wastewater analysis also allows drug use to be compared between regions and municipalities.

Wastewater samples were provided by partners participating in the program. Currently, wastewater samples are provided by Statistics Canada's Canadian Wastewater Survey and Environment and Climate Change Canada.

The wastewater data presented in the CDSW is a subset of data collected as a part of Health Canada's National Wastewater Drug Surveillance (NWDS) Initiative. This subset is intended to highlight new and emerging psychoactive substances.

Wastewater samples are collected from wastewater treatment plants. Samples are screened using mass spectrometry. We screen for over 500 drugs and drug metabolites. The screening list was compiled using:

• scientific literature and data from Health Canada’s national surveys, such as
  • Canadian Substance Use Survey
  • Canadian Student Alcohol and Drugs Survey
• substances of public health concern

Data are available from January 2023 to December 2023 and April 2024 to December 2024.

Web monitoring

Online discussion of new drugs often happens months before those substances are connected to poisonings or intoxications. Health Canada scans online discussion forums looking for words that are similar to known drug names. Possible drug names are compared against a list of known drug names. This helps us determine if drugs are new or emerging. Web monitoring provides insights into the dynamics of the illegal drug market. Data are available from January 2023 to December 2024.

Data limitations

Limitations of drug samples analysis

DAS’ data is solely based on samples submitted to its laboratories for analysis. As such, samples analyzed by DAS may not be completely representative of drug seizures in Canada, including substances circulating on the market. DAS data should therefore be used with caution when determining trends or drawing conclusions about the type and nature of substances circulating in the market.

Findings presented here may differ from other data from the Health Canada Drug Analysis Service as these data are presented and analyzed in a different manner.

For more information, visit the Drug Analysis Service and Cannabis Laboratory.

Wastewater monitoring limitations

Only drugs that are on our screening list can be identified in the wastewater. This list is updated frequently based on other surveillance data. However, creating an exhaustive list is difficult. When new substances are added to the screening list, they may be identified for the first time in the data. This does not mean that the substance was not previously in the wastewater.

A substance is identified in wastewater when it’s at a level that’s detectable by the measurement instrument (mass spectrometry). Substances may be present, but at levels too low for identification.

The population coverage of the wastewater program is limited. It includes only communities and municipalities with participating wastewater treatment plants. The number of participating sites varies between provinces and territories. The number of sites may vary month-to-month. Therefore, the drugs identified do not represent all of Canada. Trends over time should be interpreted with caution.

The mass spectrometry technique we use can sometimes be insufficient to distinguish between positional isomers that have the same molecular mass. A known instance of this is para-fluorofentanyl and meta-fluorofentanyl. In instances where this limitation is known, we have reported data in a position-agnostic manner (i.e., “fluorofentanyl”). In instances where this limitation is unknown, the data will be reported as separate positional isomers and updated when we discover the limitation.

Regions and time periods where no wastewater samples were collected are indicated as “Not collected”.

Web monitoring limitations

Web monitoring identifies mentions of substances in online forums. We do not know if the substances mentioned are being used, sold, or synthesized. Web monitoring data typically cannot provide information on the exact region where the drugs are being sold or used. No geographic information can be provided in the CDSW for this data source.

Not all web data can be monitored. Only select areas are chosen for monitoring to maintain a manageable volume. Continuous monitoring is especially difficult for dark web platforms due to high turnover rate and inconsistent access. A single substance may have multiple names and spellings. Although the machine learning algorithm captures several of these, there are some that may be missed.

International drug early warning systems limitations

This is not a comprehensive list of all early warning systems or national drug observatories around the world. This list will be reviewed with each update to the CDSW. Links are external and are subject to change.

Acknowledgements

Health Canada would like to thank all collaborators who have contributed wastewater samples including Statistics Canada's Canadian Wastewater Survey, Environment and Climate Change Canada and other participating sites. A special thank you to the Public Health Agency of Canada’s National Microbiology Laboratory (NML) for their continuous support with wastewater monitoring, including onboarding of participating sites and assisting with pre-processing of samples for analysis by Health Canada’s Drug Analysis Service and Cannabis Laboratory.