The fungi "Aspergillus flavus", "Aspergillus fumigatus", "Aspergillus niger", "Aspergillus parasiticus", "Aspergillus tamarii", "Aspergillus sulphureus", "Aspergillus repens", "Mucor hiemalis" (not a human pathogen), "Penicillium chrysogenum", "Penicillium italicum" and "Rhizopus nigricans" have been found in moldy cannabis. "Aspergillus" mold species can infect the lungs via smoking or handling of infected cannabis and cause opportunistic and sometimes deadly aspergillosis. Some of the microorganisms found create aflatoxins, which are toxic and carcinogenic. Researchers suggest that moldy cannabis should thus be discarded to avoid these serious risks.