Study Shows Cannabis Might Be Impacting Air Quality

Nov 7, 2019

The same chemicals that give cannabis its distinct smell may be contributing to air pollution and affecting human health. Recent tests of four cannabis grow facilities in Nevada and California found that the plants naturally release compounds that, when they accumulate in the air, create smog.

The Desert Research Institute (DRI) and Washoe County Health District recently contributed to the study, which was published in September in the Journal of the Air & Waste Management Association.

Plants naturally produce what are called biogenic volatile organic compounds (BVOCs) to attract pollinators and defend themselves against predators; however, cannabis plants in grow facilities are releasing BVOCs at a concerning rate.

“We need to put the red flag there because we did see high concentrations of volatile organic compounds in the facilities, inside,” said Vera Samburova, lead author of the study and an associate research professor of atmospheric science at DRI.

“These facilities [are] usually built around the highways. When we have combination with the volatile organic compounds from the cannabis facilities and emissions from the cars: this is when we can generate ozone. It's toxic for people when it's around us. It's not toxic, and it's important to help, in the upper atmosphere,"  Samburova said. 

When VOCs combine with nitrogen oxide emissions, like from cars and fuel combustion, and are exposed to the sun, they create ozone. When it’s in the ozone layer, it’s helpful in providing protection from ultraviolet (UV) rays from the sun. But at ground level, ozone can be harmful to humans.

Ozone at ground level can make it difficult to breathe, cause shortness of breath and coughing, inflame airways, aggravate lung diseases (like asthma and chronic bronchitis), and make lungs more susceptible to infection. Washoe County has already exceeded ozone air-quality standards multiple times this year and in 2018.

There are also concerns for the individuals working inside cannabis grow facilities. 

"These concentrations are huge and, definitely, their health effects must be studied in these facilities,” Samburova said.

She was surprised to see that workers in the facilities she visited did not wear protective gear. She spoke with KUNR media partner Bob Conrad, of ThisisReno, who has been following this issue.

"We've never really had legalized cannabis up until a few years ago in the United States, at the state level. This might be raising a concern for those employees, and protective gear might be in order if health impacts are going to be determined or found out as a result of this research and other research being done,” said Conrad.

Suggested personal protective equipment for individuals working in cannabis grow facilities include respirators, eye and face protection and skin-covering clothing.

Moving forward, Samburova and her team are in search of funding for a larger study. This area of study is new because large-scale cannabis growing has only been legal in some states for less than a decade.

Learn more at ThisisReno.

This story had editorial support from UNR’s Hitchcock Project for Visualizing Science.