Ambient measurements of monoterpenes near Cannabis cultivation facilities in Denver, Colorado

Abstract

� Measurements near cannabis facilities increased background concentrations of monoterpenes by four times. � The types of monoterpenes that were measured varied widely across Denver, suggesting a diverse set of emission profiles. � Composition of measurements near emission sources were dominated by d-limonene, bmyrcene, and a-pinene.

Cannabis Cultivation Facilities: A Review of Their Air Quality Impacts from the Occupational to Community Scale

“…The same compounds are the dominant BVOCs in the grow room sampled by Knights, but the rank composition followed a different order: myrcene (68%), d -limonene (14%), α-pinene (13%), and β-pinene (5%). Due to the rarity of myrcene in cleaning and coating products, the author also proposed that it could be used as a sensitive tracer of cannabis operations, in agreement with Wang et al Furthermore, Knights observed a steady increase in concentrations of all compounds from months 3 to 4 and an abnormal peak of myrcene in the seventh month, indicating emissions rates are different due to growth stages or for different strains. BVOCs collected and analyzed from male and female plants of two cannabis species during the flowering stage showed the most abundant compounds to be β-myrcene, ( E )-β-ocimene, and terpinolene .…”

“…Initially, a literature search was conducted in December 2020 in Web of Science using the keywords “cannabis cultivation” and (“emissions” or “odor”), which returned few results. ,, Likewise, “hemp cultivation” and (“emissions” or “odor”) did not return studies of interest for this review. Given the difficulties encountered with the initial steps of a systematic review, the authors changed the approach.…”

“…Inverse dispersion modeling can also be used to link the concentration of a particular compound to its source by estimating its back trajectory to the point of emission. , Knowledge of the air parcel passing through an industrial cluster allows for particular compounds to be targeted against background concentrations. Because most terpenes emitted by CCFs have a short lifetime in the troposphere, Wang et al modeled only 3 h prior to the observations. Wang et al used the HYSPLIT model, but other models such as CALPUFF and TRAJ2D , are also viable options.…”

“…Because most terpenes emitted by CCFs have a short lifetime in the troposphere, Wang et al modeled only 3 h prior to the observations. Wang et al used the HYSPLIT model, but other models such as CALPUFF and TRAJ2D , are also viable options. While modeling air pollutant concentrations could be a cost-effective approach compared to monitoring, the lower spatial and/or temporal resolution of models and a lack of validation with ground-level monitoring data could lead to large errors.…”

The Cannabis Terpenes

“…Figure 5 a illustrates a chromatogram of the terpene extract from the floral tissue of cannabis. Among others, the major monoterpene components are limonene, β-myrcene, α-pinene, and linalool with traces of α-terpinolene and tran-ocimene [ 54 , 55 ] ( Figure 5 b), while predominate sesquiterpenes are E- caryophyllene, caryophyllene oxide, E -β-farnesene, and β-caryophyllene [ 56 ]. The cannabinoids are biologically synthesized from diterpene structures to form phenol terpenoids, which account for almost a quarter of all metabolites [ 26 ].…”