Uploaded January 2026 | Updated September 2026, 1 week ago
Hidden Health Hazards to Recreational Users and Medical Patients
A Speaker Series: Toxicology and Societies - The Impacts of Chemicals in Our Lives
Brought to you by:
WWU Institute of Environmental Toxicology and Chemistry
WWU Alumni Association
As cannabis and cannabis-based products are becoming more popular for symptomatic relief in patients with medical conditions, including autism, cancer, PTSD, seizures, epilepsy, as well as Parkinson’s disease, contaminant exposure in medical use is now a concern for public health. In order to inform further research and provide solutions to the public health risk of cannabis contaminants at a national level, we examined the current landscape of state-level contaminant regulations, cannabis contaminants of concern, as well as patient populations susceptible to contaminants.
As of May 18, 2022, 36 states and the District of Columbia listed a total of 679 cannabis contaminants as regulated in medical or recreational cannabis, including 551 pesticides, 74 solvents, 12 inorganics, 21 microbes, five mycotoxins, and 16 other contaminants. Different jurisdictions showed significant variations in regulated contaminants and action levels ranging up to four orders of magnitude. A failure rate of 2.3% was identified for flowers and 9.2% for extracts in the California samples.
Insecticides and fungicides were the most prevalent categories of detected contaminants, with boscalid and chlorpyrifos being the most common. The contaminant concentrations fell below the regulatory action levels in many legalized jurisdictions, indicating a higher risk of contaminant exposure. Cannabis use reports indicated usage in several patient populations susceptible to contamination toxicity, including cancer (44,318 patients) and seizure (21,195 patients).
This study demonstrates the urgent need to mitigate the public health risk of cannabis contamination by introducing national-level guidelines based on conventional risk assessment methodologies and knowledge of patients’ susceptibility in medical use. Further studies will use adverse outcome pathway models to predict how medical use guidance, contaminant regulations, and risk communication can affect patients’ health in different jurisdictions in the U.S.
Hidden Health Hazards to Recreational Users and Medical Patients
A Speaker Series: Toxicology and Societies - The Impacts of Chemicals in Our Lives
Brought to you by:
WWU Institute of Environmental Toxicology and Chemistry
WWU Alumni Association
As cannabis and cannabis-based products are becoming more popular for symptomatic relief in patients with medical conditions, including autism, cancer, PTSD, seizures, epilepsy, as well as Parkinson’s disease, contaminant exposure in medical use is now a concern for public health. In order to inform further research and provide solutions to the public health risk of cannabis contaminants at a national level, we examined the current landscape of state-level contaminant regulations, cannabis contaminants of concern, as well as patient populations susceptible to contaminants.
As of May 18, 2022, 36 states and the District of Columbia listed a total of 679 cannabis contaminants as regulated in medical or recreational cannabis, including 551 pesticides, 74 solvents, 12 inorganics, 21 microbes, five mycotoxins, and 16 other contaminants. Different jurisdictions showed significant variations in regulated contaminants and action levels ranging up to four orders of magnitude. A failure rate of 2.3% was identified for flowers and 9.2% for extracts in the California samples.
Insecticides and fungicides were the most prevalent categories of detected contaminants, with boscalid and chlorpyrifos being the most common. The contaminant concentrations fell below the regulatory action levels in many legalized jurisdictions, indicating a higher risk of contaminant exposure. Cannabis use reports indicated usage in several patient populations susceptible to contamination toxicity, including cancer (44,318 patients) and seizure (21,195 patients).
This study demonstrates the urgent need to mitigate the public health risk of cannabis contamination by introducing national-level guidelines based on conventional risk assessment methodologies and knowledge of patients’ susceptibility in medical use. Further studies will use adverse outcome pathway models to predict how medical use guidance, contaminant regulations, and risk communication can affect patients’ health in different jurisdictions in the U.S.
