Two men from Rochester, New York, died after using bat guano as a fertilizer for their cannabis plants. The men contracted histoplasmosis, a rare lung infection caused by the fungus Histoplasma capsulatum, which is found in bat excreta.
One man, 59, bought bat guano online to use as fertilizer in his home grow, while the other man, 64, had found guano in his attic following a heavy bat infestation. It’s unclear if he used it before getting sick.
The doctors who treated them warned that using bat guano as a fertilizer can be hazardous, especially for cannabis growers. Bat guano is permitted as a soil amendment with certain restrictions, but users must follow USDA Organic Regulations and take precautions to avoid inhaling airborne fungal spores.
Several online products claim to offer bat guano fertilizers, each with varying nutrient values. However, the risks associated with using bat guano are well-documented. The National Institutes of Health has linked bats to several zoonotic diseases, including histoplasmosis.
To minimize risks, those interested in purchasing commercial guano fertilizer should contact the manufacturer and ask about their sourcing practices and compliance with NOP and OMRI standards. Wearing a dust mask when handling bat guano can also help protect against airborne fungal spores.
Source: https://www.cannabisbusinesstimes.com/home/news/15710577/2-men-dead-after-using-bat-poop-to-grow-cannabis