Scientists from the U.S. Geological Survey (USGS) and researchers from the Integral Ecology Research Center (IERC) worked with U.S. Forest Service Law Enforcement and Investigations to conduct research on the impact of illegal cannabis cultivation sites on California’s federally managed lands. The study published in the Science of The Total Environment sheds light on the negative ecological footprint caused by “trespass grows.” Although California legalized recreational cannabis use in 2016, roughly 90% of cannabis is produced illegally.
The study provided a comprehensive analysis of how pesticides, pharmaceuticals, and other organic pollutants continue to impact land after illegal cultivators abandon grow sites. Sometimes the negative effects persist long after a site is shut down by law enforcement. The researchers conducted surveys of three former illegal cannabis cultivation sites located in Shasta-Trinity National Forest, San Bernardino National Forest, and Six Rivers National Forest. They conducted quantitative analysis of pesticides in topsoil, as well as surface water and sediment from streams adjacent to the grow sites.
The findings revealed significant levels of pesticides. The research team detected imidacloprid, malathion, and myclobutanil in the topsoil. Cannabinoid compounds, including tetrahydrocannabinol (THC) and cannabidiol (CBD), persisted in water, soil, and bed sediments. Analysis also showed that plasticizers associated with irrigation systems and personal care products used by growers contaminate surrounding ecosystems.
Illegal cultivation sites harm critical habitats and taint drinking water, wildlife, and fisheries. The researchers emphasized how illegal grow operations jeopardize endangered species.
The study highlights the need to monitor public lands to prevent and remediate the long-term ecological risks caused by illegal grow operations. The findings can inform policy development for more effective wildlife protection, forestry practices, and water quality.
Sources: Eureka News Alert, Science of The Total Environment
