Potential Regional Air Quality Impacts of Cannabis Cultivation Facilities in Denver, Colorado

Chi-Tsan Wang, Christine Wiedinmyer, Kirsti Ashworth, Peter C. Harley, John Ortega, Quazi Z. Rasool, William Vizuete
2019 Atmospheric Chemistry and Physics Discussions  
<p><strong>Abstract.</strong> The legal commercialization of cannabis for recreational and medical use has effectively created a new and almost unregulated cultivation industry. In 2018, within the Denver County limits, there were more than 600 registered cannabis cultivation facilities (CCFs) for recreational and medical use, mostly housed in commercial warehouses. Measurements have found concentrations of highly reactive terpenes from the headspace above cannabis plants that, when released in
more » ... t, when released in the atmosphere, could impact air quality. Here we developed the first emission inventory for cannabis emissions of terpenes. The range of possible emissions from these facilities was 66&amp;ndash;657 metric tons/year of terpenes across the state of Colorado; half of the emissions are from Denver County. Our estimates are based on the best available information and highlight the critical data gaps needed to reduce uncertainties. These realizations of inventories were then used with a regulatory air quality model, developed by the State of Colorado to predict regional ozone impacts. It was found that most of the predicted changes occur in the vicinity of CCFs concentrated in Denver. An increase of 362 metric tons/year of terpene emissions in Denver County resulted in increases of up to 0.34&amp;thinsp;ppb in hourly ozone concentrations during the morning and 0.67&amp;thinsp;ppb at night. Model predictions indicate that in Denver County every 1,000 metric tons/year increase of terpenes results in 1&amp;thinsp;ppb increase in daytime hourly ozone concentrations and a maximum daily 8-hour average (MDA8) increase of 0.3&amp;thinsp;ppb. The emission inventories developed here are highly uncertain, but highlight the need for more detailed cannabis and CCFs data to fully understand the possible impacts of this new industry on regional air quality.</p>
doi:10.5194/acp-2019-479 fatcat:5xmhnp2ayjbghfm73bzg6wd4qy