Cannabis Cultivation Facilities May Be Negatively Impacting Air Quality, Researchers Say
The strongly scented, volatile chemical compounds given off by growing cannabis plants may be contributing to poor air quality around cannabis cultivation facilities, according to a new study from researchers at the Desert Research Institute (DRI), supported by the Washoe County Health District (WCHD) in Nevada.
The study, published in the Journal of the Air & Waste Management Association, investigated airborne levels of biogenic volatile organic compounds (BVOCs) around four cannabis growing facilities in Nevada. Researchers determined the level of BVOCs to be “concerning,” but said that further study would still be needed to properly assess whether these levels might be presenting any health risk to facility workers.
Cannabis plants produce ingredients for dangerous ground-level ozone
The BVOCs being produced by growing cannabis plants, predominantly terpenes like 𝛽-myrcene and D-limonene, are generally not considered dangerous to inhale. In fact, many consider it beneficial to human health — with some terpenes thought to boost emotional wellbeing in a similar way to aromatherapy.
However, in urban areas where cannabis facilities are common, these BVOCs can react with nitrogen oxide and hydroxyl radicals in vehicle or fuel combustion plant emissions to form ozone. Although ozone is helpful to the planet in the upper atmosphere, where it protects Earth from UV rays, at ground-level it presents a safety hazard to humans. Even at relatively low amounts, long-term ground-level ozone exposure can cause lung irritation, coughing and chest pain. For people with respiratory conditions such as asthma, ground-level ozone presents an even greater risk.
“Here in our region, unfortunately, we already exceed the national air quality standard for ground-level ozone quite a few times per year,” says lead author Vera Samburova, PhD, who is also an associate research professor of atmospheric science at the DRI.
“That’s why it is so important to answer the question of whether emissions from cannabis facilities are having an added impact.”
Across the four facilities, levels of BVOCs in the air ranged between 110 and 5,500 μg m−3. Additionally, the researchers calculated that for a single cannabis plant, the amount of BVOCs being produced could be enough to trigger the formation of on average 2.6 grams of ozone per day. The significance of this number is yet to be determined, Samburova says, but the researchers feel that this is high enough to warrant further study.
As well as the BVOCs, researchers also detected noticeably high levels of the volatile compound butane at facilities which also carried out cannabis extraction operations, sparking further concerns over the air quality in and around these facilities.
“The concentrations of BVOCs and butane that we measured inside of these facilities were high enough to be concerning,” Samburova asserts.
Concerns over the growing cannabis industry and air quality
As the cannabis industry expands, the number of cultivation facilities will grow exponentially to meet demand. If these facilities are found to be substantially adding to local air pollution, consequent expansion of this industry could pose a large risk to the local air quality, and the health of workers and nearby residents.
“With so much growth in this industry across Nevada and other parts of the United States, it’s becoming really important to understand the impacts to air quality,” Mike Wolf, permitting and enforcement branch chief for the WCHD Air Quality Management Division, said in a press release.
“When new threats emerge, our mission remains the same: Implement clean air solutions that protect the quality of life for the citizens of Reno, Sparks, and Washoe County. We will continue to work with community partners, like DRI, to accomplish this mission.”
The DRI research team hopes to be able to secure funding to carry out a larger-scale study, so that they can build recommendations for growing facilities and local health departments on what the best strategies might be for tackling this problem.
“This really hasn’t been studied before,” Samburova said. “We would like to collect more data on emission rates of plants at additional facilities. We would like to take more detailed measurements of air quality emissions outside of the facilities and calculate the actual rate of ozone formation. We are also interested in learning about the health impacts of these emissions on the people who work there.”