Cannabis is green, but that doesn't mean it's always environmentally friendly. In fact, growing cannabis indoors within urban areas could pose a significant threat to the environment according to a new study.
Setting up indoor cannabis grow-ops in cities could be deadly for the earth as cultivation sites release an alarming amount of ozone into the atmosphere. Those are the results of the first study to look at the potential atmospheric impacts of growing cannabis plants, and although the results are highly preliminary, they show that the government should pay more attention to the environmental impact of growing cannabis indoors.
The study was led by researcher William Vizuete, who examined the volatile organic carbons (VOCs) that cannabis plants emit into the air. Those VOCs aren't particularly harmful to people or the environment on their own, but when exposed the sun and combined with other gases, particularly nitrogen oxides (NOx) produced by combustion in cars and stoves, they can produce ground-level ozones that accumulate in the atmosphere and contribute to smog and other types of pollution.
“If I was going to do an experiment, and I wanted to increase the ozone or particulate matter in Denver, what I'd do is I'd put a bunch of VOCs right in the middle of downtown Denver,” Vizuete noted.
And that’s exactly what the city has done by letting cannabis grow ops set up shop in downtown Denver's heavily trafficked warehouse areas.
'They were just air samples, nothing illegal about that'
Biogenic VOCs - volatile carbons found naturally in plants - are everywhere. In fact, that fragrant scent you get from slicing an orange is actually a biogenic VOC. Common VOCs include alpha-pinene, which gives fir trees their pine scent; limonene, which is the scent found in a peel of a citrus fruit; and myrcene, which is found in wild thyme.
Since VOCs are ubiquitous, studying them wasn't a problem for Vizuete until he started studying cannabis, which is difficult for American researchers to get their hands on since marijuana is still prohibited at the federal level. Vizuete couldn't bring cannabis to work even while conducting research at the National Centre for Atmospheric Research in Colorado, which legalized recreational cannabis back in 2012.
“I can go to Colorado, I can go buy plants, and bring them home to my house, it's perfectly legal,” he told Civilized. “But since it's a federally illegal substance, I cannot bring this plant into the federal lab at NCAR, which is really unfortunate.”
Instead, he set up a mini-lab in his garage, where he grew 12 small cannabis plants using three different strains. He then took air samples from the area around the plants and brought it to the federal lab to analyze, which was legal.
"They were just air samples," he explained, “there's nothing illegal about that.”
When he analyzed the samples, he found that his little plants were, in fact, emitting biogenic VOCs. His plants ranked in the mid-range on the scale for biogenic VOC emissions, which means they weren't releasing a high level of gas, but it wasn't a low level either. And that's concerning because a grow op producing hundreds or even thousands of plants could be generating a staggering level of hazardous chemicals.
'We need to understand if this is a problem or not'
Now, Vizuete hopes to use his preliminary findings to calculate how many potential VOCs are being produced inside Denver warehouses, and how much is interacting with the NOx in the environment to produce ozone.
“We really need to understand if this is a problem or not,” he told Civilized.
If it is, there's no need to panic since we have already developed technology to trap VOCs before they have a chance to escape into the atmosphere and react with NOx. That tech is currently being used in places like gas stations, which use a lot of solvents (man-made VOCs) to degrease engines. Since cars are one of the big producers of NOx, they have to make sure they catch those VOCs and trap them in carbon or charcoal filters before they get into the atmosphere and have a chance to react with the NOx.
“This is not a problem that we haven't dealt with in the past, and I think we have lots of precedence and technology to address the issue if it is an issue.”
But first, researchers need to figure out the extent of the potential problem, and then regulators need to step in to make sure that cannabis grow ops are safe. Those steps are already being taken in areas like Metro Vancouver, which has responded to complaints over smog and unpleasant smells emitting from licensed grow ops by working with the cannabis industry and stakeholders on regs to keep the air clean. With the help of researchers like Vizuete, those regs will likely become more common as experts and insiders work toward keeping the cannabis industry green.