Last June, a joint investigation by The Los Angeles Times and WeedWeek revealed that despite California’s regulation of cannabis, the Golden State had not been successful in keeping pesticide-contaminated cannabis from reaching shelves. Over half of the products tested (25 out of 42 products) showed concentrations of pesticides higher than either the federally required levels for tobacco or California’s local state-required levels for cannabis. However, the concentrations were low enough that harmful symptoms might not be immediately visible. Although in high enough concentrations, inhaled pesticide residue can cause skin irritation, headaches, dizziness, nausea, vomiting, diarrhea, fatigue, and other symptoms, in low concentrations inhaled repeatedly over time, the pesticide residue can continue to do damage while the consumer remains unaware of the harm.
“The contaminants include chemicals tied to cancer, liver failure, thyroid disease and genetic and neurologic harm to users and unborn children,” reporters from the Times and WeedWeek concluded. “Most of the pesticides found were in low concentrations that risk long-term harm by repeated use, though the extent of the health threat may not be known for years.”
While long-term studies of the effects of inhaled pesticides from cannabis don’t exist yet, the June 2024 report and similar exposés have led to growing awareness among both growers and consumers about the health risks of exposure to pesticides while smoking cannabis. This is prompting more growers to pursue clean cultivation techniques.
The Move Toward Zero-Spray Farming
Clean cultivation methods that are getting more popular include integrated pest management (IPM) and zero-spray farming. IPM is a preventative method that focuses on addressing the conditions that typically attract pests. When pests do infest a crop, IPM farmers will use biological controls first, introducing beneficial insects like ladybugs that are natural predators to most pests. However, IPM does include chemical pesticides as a last resort.
Truly zero-spray farming requires a commitment to manage crops without any use of synthetic pesticides or herbicides. Zero-spray farmers rely on crop rotation to disrupt seasonal infestations, companion planting to pair crops with other plants that deter pests or attract ladybugs and other natural predators, and weed management. The practice has its challenges (it takes more labor and can generate a lower yield), but it does ensure a healthier crop, and some small and mid-sized cannabis farmers in California have made the leap.
Autumn Brands is one example. A medium-sized, family-run California farm with a zero-spray philosophy, Autumn Brands focuses on cultivating a thriving natural ecosystem in which ladybugs control local pest populations. The farm also invests in slow, hand-processed production. “We don’t even hold a spray license because we don’t need one,” says Hanna Brand, co-owner of Autumn Brands. “We feel we’re not harming our consumers in that way, and we give them that guarantee.”
The Push for Change
Both growers and consumers have also been pushing for change on the state level, calling for state-supported programs that will certify pesticide-free cannabis. While there are third-party certifications on the market, these are pay-to-play, which can be an obstacle for smaller farms. Many family-run farms hope that as the cannabis market expands and more research emerges on the effects of inhaled pesticides, growing consumer pressure will prompt policymakers to establish a state-backed system for clearly disclosing what’s in the products people are smoking.
