Contaminants of Concern in Cannabis : Microbes, Heavy Metals and Pesticides John M. McPartland and Kevin J. McKernan in S. Chandra et al. (eds.), Cannabis sativa L. - Botany and Biotechnology, Chapter 22, 2017, 457-474. Doi : 10.1007/978-3-319-54564-6_22 Abstract Microbiological contaminants pose a potential threat to cannabis consumers. Bacteria and fungi may cause opportunistic infections in immuno-compromized individuals. Even dead organisms may trigger allergies and asthma. Toxins from microbial overloads, such as Shigla toxin and aflatoxins, may pose a problem—unlikely, but possible. The Cannabis plant hosts a robust microbiome; the identification of these organisms is underway. Cannabis bioaccumulates heavy metals in its tissues, so avidly [...]