According to Associated Press, 9 out of every 10 illegal cannabis farms shut down in California in 2018 showed traces of potentially deadly pesticides, which are poisoning natural life and could also jeopardize human water supplies. This constitutes a major leap with regards to the chemicals found in approximately 75% of the illicit plantations discovered on public land a year earlier, and it is 6 times higher than in 2012.
In August 2019, Californian police discovered that Mexican drug dealers were using a dangerous pesticide banned in the United States to grow marijuana in remote areas of the Sierra Nevada mountains, in California. This pesticide was carbofuran, which is toxic to humans and can cause permanent damage to the reproductive system. These marijuana-growing sites are on federal land which is being systematically destroyed through tree felling, stream diversion, and the use of chemicals and pesticides.
Experts claim that the carbofuran found on those sites is so dangerous that a mere teaspoonful could kill an adult bear. Traces of this deadly chemical have been found in streams and rivers and in live and dead animals, including endangered species such as the fisher. The EPA (The Environmental Protection Agency) estimated that back then carbofuran was killing between 1 and 2 million birds each year in the United States. What's more, in 2008 the BBC informed that herdsmen in Kenya were using carbofuran to kill the lions threatening their herds.
For many years, carbofuran was sold under the Brand Furadan by FMC Corporation, and was being sprayed over fields of corn, cotton, potatoes, sunflowers, and other food crops. Regulators withdrew carbofuran from the US market in 2008, and nowadays it is also banned in the European Union, Canada, and most recently in Brazil too. But despite the ban, carbofuran is still affecting California as it is the favorite pesticide of illegal cannabis growers. Let's not forget that California represents more than 90% of the US illegal cannabis cultivation.
Researchers suspect that some illegal crops are now being moved to farming areas where they are being blended in with legal marijuana crops, which can in turn endanger farming as a whole. Authorities believe that, due to legalization, it is much easier for illegal growers to set up a greenhouse somewhere in a valley than having to set up a crop in a remote national forest.
Most of the illegal marijuana grown in California is sent out of the state as it cannot meet the strict Californian standards for legal cannabis due to its traces of toxic chemical products. Meanwhile, environmentalist groups are fighting to decontaminate the many areas where illegal crops containing carbofuran were set up in the past. As of August 2018, 160 toxic areas had been cleaned, but 830 were still awaiting decontamination. And we are only talking about the ones that are publicly known.
The United States Forest Service estimated that 1200 million gallons (4500 million litres) of water are deviated from aquifers to illicit crops in the Californian national forests every year. The toxic chemicals from these illegal cannabis farms are appearing in rivers and streams that feed directly into the state's water supply, which has led to fears that people might be at risk as a result of this.
And California is not alone. Illegal drug traffickers are present in 72 national forests in 21 states, which turns this into a major national issue. In addition, marijuana's semi-legal state (it is still banned by federal law) also impedes the study of any related environmental impact and hinders the creation of solutions from a purely environmental point of view.
The use of pesticides in cannabis cultivation has health implications for growers, users, and for the environment as a whole. The District of Columbia and some states like Connecticut, Maine, Minnesota, New Hampshire, and Massachusetts have already adopted regulations that are focused on less toxic approaches to medical cannabis cultivation, to ensure growing practices that avoid or ban the use of pesticides. And it is precisely this 'federal limbo' that brings an important opportunity for the development of an industry based on production practices that do not depend on pesticides, as for example organic cannabis growing.