California: 77% cannabis clones contaminated with pesticides

While California prepares to open up legal sales of cannabis for anyone over the age of majority in January 2018, today's industry suffers from a «slight» problem: 77% of Cannabis plant clones are contaminated with pesticides, according to an recent report of Steep Hill, a cannabis testing lab.

The same laboratory had already warned last October that 84% Californian weed was «unfit for human consumption», prompting him to investigate the reason for the contamination.

Traditionally plants are contaminated by pesticides in different ways:

• inputs containing pesticides, used with full knowledge of the facts
• products used without knowing what's inside, but containing pesticides
• a crop subject to «drift» of pesticides from the neighboring field, carried by wind, water, soil, insects or animals.

«When we released our first study in October 2016, several growers contacted Steep Hill to say that they didn't use pesticides, that they only used organic fertilizers, We were told that they were doing the best they could for their patients and consumers,» explains Jmîchaeĺe Keller, CEO of Steep Hill. «After hearing this several times, we realized there was a problem in the supply chain. It just hit me: it's in the clones.».

And Keller asked his lab to confirm his theory. The company purchased 124 clones from several growers around Los Angeles. Of the 124 plants, 17 contained no trace of pesticide. And only 22% of the cannabis clones complied with California's pesticide limit.

However, the report points out that some of the pesticide levels found were very low and will not be a concern once the plant has fully matured and been harvested.

According to the report, the source of the contamination could be the growing substrates, rather than the direct application of pesticides.

«In some cases, the large amount of systemic pesticide (such as myclobutanil ) in the culture medium would likely provide a long-term application reservoir if the clone culture medium were transplanted and remained in contact with with the root system »notes the report.