Cannabis vs VOC – USA learnings
Cannabis VOC first remarks started in the US. Since Colorado stores began legal sales of recreational marijuana in 2014, air quality concerns have arisen regarding emissions. Over 600 licensed cultivation facilities in Denver could be the reason. Research by William Vizuete has shown that cannabis plants produce volatile organic compounds (VOCs) that can produce harmful pollutants. Prof. Vizuete is associate professor at the Gillings School of Public Health at the University of North Carolina.
“When a plant produces VOCs, there is a high probability that its cultivation under certain conditions may affect the ozone presence” explains Vizuete.
What VOCs are in cannabis plants?
Cannabis emits type of VOCs called terpenes. These, when mixed with nitric oxide and sunlight, form aerosols that break down the ozone layer. Terpenes are naturally-occurring compounds, playing huge role in a cannabis plant’s growth. Terpenes produce aromas, enrich color and pigmentation in leaves and buds, and contribute to the plant’s flavor. In short, terpenes help to enhance the plant’s attractiveness to some creatures, while deterring others that can do harm. High concentrations of VOCs can also cause number of human health problems, from nausea and fatigue to liver damage and the presence of cancer.
The research on cannabis VOC
Professor Vizuete outlines the concern that a significant number of cannabis crops may become a regular source of VOCs. To test the potential effects, Vizuete grew four cannabis strains (out of more than 600 strains available in Colorado) for 90 days and measured terpenes at each stage of plant development. The results showed that, assuming the current growing conditions, cannabis can more than double the existing annual VOC emission rate. Vizuete believes the research is underestimated, explaining:
“We selected four strains based on their popularity, and their VOC emissions may not be representative of all strains. Additionally, in commercial properties with optimized conditions for growth, emissions can be even higher. “
However, Van Butsic, co-director of the Cannabis Research Center at the University of California, Berkeley, says there are many technologies that trap volatile organic compounds before they enter the atmosphere. Such systems are necessary in other places such as gas stations.
“Before [emission] standards can be set for cannabis, we need problem recognition and long-term data to develop regulatory laws.”
Some states have relevant directives for cannabis growers – for example, in Washington, the Puget Sound Clean Air Agency requires growers to provide information about their air pollution monitoring and control plans. Europe can control the market and emissions in the future, drawing on the experience of the US.