Application of the Environmental Relative Moldiness Index in Indoor Marijuana Grow Operations

Details

• Personal Author:
  Magzamen S ; Reynolds SJ ; Root KS ; Schaeffer JW ; Sharp JL ; Van Dyke M
• Description:
  Objectives: Indoor marijuana grow operations (IMGOs) are increasing due to legalization of recreational and medicinal cannabis at the state level. However, the potential exposures of IMGO workers have not been well studied. Mold exposure has been identified as a major occupational health concern. Mold-specific quantitative polymerase chain reaction (MSQPCR) can provide quantitative exposure data for fungi at the species level. The purpose of this study was to characterize the airborne fungal burden using MSQPCR and to evaluate the applicability of an airborne Environmental Relative Moldiness Index (ERMI) in IMGOs. Methods: Air and dust samples were collected inside and outside the IMGOs and then analyzed via MSQPCR. These data were then used to calculate IMGO-specific ERMI scores. Culturable air samples were collected on agar plates and analyzed via microscopy. Differences were evaluated between indoor and outdoor concentrations, as well as between air and dust samples. The agreement between MSQPCR and culture-based methods was also evaluated. Results: Based on the geometric means for non-zero values of each fungal species across all IMGOs, the total airborne concentration was approximately 9100 spore equivalent (SE) m-3 with an interquartile range (IQR) of 222 SE m-3. The indoor/outdoor ratio of geometric means across all 36 species per IMGO ranged from 0.4 to 6.2. Significantly higher indoor concentrations of fungal species, including Aspergillus spp., were observed. An average airborne ERMI score of 7 (IQR = 7.6) indicated a relatively high burden of mold across a majority of operations. The ERMI scores were driven by the high concentrations of Group 1 species with a mean of 15.8 and an IQR of 13. There were 63 additional species identified in the culturable air samples not included in the ERMI. Conclusions: High concentrations of airborne fungi were identified in IMGOs. Our evaluation of the ERMI based on MSQPCR as a rapid diagnostic and risk assessment tool for industrial hygienists in the IMGO setting is equivocal. ERMI did not identify all relevant fungal species associated with this specific occupational environment. We identified several issues with using the ERMI calculation. At this time, the catalog of fungal species needs to optimized for the occupational setting to ensure adequate coverage, especially for those species expected to be found in this burgeoning industry. Further research is necessary to elucidate the link between the ERMI score of airborne samples, worker exposure and health effects in grows to generate an acceptable index score for use in occupational exposure assessments. [Description provided by NIOSH]
• Subjects:
  Air Pollution Air Pollution, Indoor Atmosphere Coal Coal Mining Computers Environmental Monitoring Mining Occupational Health Safety Software

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• Keywords:
  Agriculture Airborne Particles Air Sampling Author Keywords: Cannabis Cannabis Deoxyribonucleic Acids Diagnostic Techniques DNA Environmental Relative Moldiness Index ERMI Exposure Assessment Fungi IAQ IMGOs Indoor Air Quality Indoor Marijuana Grow Operations Industrial Hygiene Laboratory Techniques Marijuana Mold Molds Molecular Biology MSQPCR Occupational Exposure Outdoors Plants Quantitative Analysis Risk Assessment Sampling

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• ISSN:
  2398-7308
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  64
• Issue:
  7
• NIOSHTIC Number:
  nn:20060391
• Citation:
  Ann Work Expo Health 2020 Aug; 64(7):728-744
• Contact Point Address:
  Joshua W. Schaeffer, Department of Environmental and Radiological Health Sciences, Colorado State University, 1681 Campus Delivery, Fort Collins, CO 80523, USA
• Email:
  Joshua.Schaeffer@colostate.edu
• CAS Registry Number:
  Cannabis (CAS RN 8063-14-7)
• Federal Fiscal Year:
  2020
• Performing Organization:
  University of Colorado, Denver
• Peer Reviewed:
  True
• Start Date:
  20070701
• Source Full Name:
  Annals of Work Exposures and Health
• End Date:
  20250630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:64998d9f245e25d9720011d9010142802ca5f762972bd4d0cd68d7138782325d9b2c1f0cc3cf006be4ef27f1bc3a95ee5e7c52ba5e1a1d18c938df6ba17ddcd7
• Download URL:
  https://stacks.cdc.gov/view/cdc/224318/cdc_224318_DS1.pdf
• File Type:
  [PDF - 2.46 MB ]