In addition to being illegal, “street weed” can be contaminated with multiple substances that result in unnecessary risks and possibly even injury. A comparison can be found in alcohol: All alcohol can get you buzzed, but alcohol contaminated with methanol will make you blind.
Fungal contamination (Aspergillus and Penicillium species) in marijuana samples has been demonstrated. Contamination with fungal or bacterial pathogens could increase risk of pneumonia and other respiratory problems (McPartland and Pruitt 1997, McLaren et a l 2008). Lack of ventilation and high humidity increase the likelihood of mold growth in indoor growing operations (Martyny et al 2013). Unregulated storage, such as on the black market, permits mold growth.
There are concerns that pesticides may pose risks in cannabis products (McLaren et a l 2008). Arsenic and other heavy metals have been identified in unregulated growing operations.
Contamination with methamphetamine, fentanyl, crack cocaine, formaldehyde (embalming fluid) and unusual new synthetic compounds with unpredictable side effects have also been seen. Typically, cannabis becomes laced with other compounds to enhance its hallucinogenic potential or to increase profitability to the distributor.
Cannabis should be treated with respect, just like any other substance you would put in your body. Don’t take risks with your health. For your safety, stick to reliable product sourcing, whether you grow your own or use a branded dispensary.