Towards a Cleaner Green: A Review of Microbial Testing of Medical Cannabis and Its Implications for Patient Health

Abstract

Abstract: The recent surge in medicinal cannabis uses globally, largely due to changes in supply laws, has necessitated a comprehensive examination of its safety and quality. Despite its legal use in over 40 countries, there is increasing concern about microbiological contaminants, notably fungi, in cannabis. While background (or normal levels) of microbes are considered harmless with proper growing and manufacturing practices, some can pose health risks, particularly in certain applications like smoking, tinctures, or edibles. This literature review aims to explore the occurrence, identification, and health implications of fungal pollutants in medicinal cannabis. It also examines the negative effects of specific mycotoxins and the testing standards for medical cannabis, contributing significantly to current medical practices and future policy development in this rapidly evolving field. The presence of moulds and fungi on cannabis can potentially make users sick, with Botrytis cinerea, Aspergillus, Penicillium, Fusarium and Alternaria being common contaminants. However, the evidence linking exposure to fungus in cannabis with illness after consumption is limited, and the risks seem to depend on individual factors and level of exposure. The medicinal use of cannabis and cannabinoids has been shown to control various biological processes related to cancer and other illnesses. Cannabis is being used as a supplement for chronic pain, anxiety, depression, and other neurological conditions. Nevertheless, solvents, pesticides, and fungal pathogens may contaminate therapeutic cannabis. Mycotoxins from these fungi have been detected in cannabis samples, but their health effects are unknown. In growing medicinal cannabis markets like Thailand, mycotoxins might cause considerable economic losses. To reduce supply chain risks, medical cannabis products require more research on practical microbiological safety recommendations for improved public health.