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

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.

Firefighter noise exposure during training activities and general equipment use.

Multiple noise measurements were taken on 6 types of fire station equipment and 15 types of emergency response vehicle-related equipment used by firefighters during routine and emergency operations at 10 fire stations. Five of the six types of fire station equipment, when measured at a distance of one meter and ear level, emitted noise equal to or greater than 85 dBA, including lawn maintenance equipment, snow blowers, compressors, and emergency alarms. Thirteen of 15 types of equipment located on the fire engines emitted noise levels equal to or greater than 85 dBA, including fans, saws, alarms, and extrication equipment. In addition, noise measurements were taken during fire engine operations, including the idling vehicle, vehicle sirens, and water pumps. Results indicated that idling fire-engine noise levels were below 85 dBA; however, during water pump and siren use, noise levels exceeded 85 dBA, in some instances, at different locations around the trucks where firefighters would be stationed during emergency operations. To determine if the duration and use of fire fighting equipment was sufficient to result in overexposures to noise during routine training activities, 93 firefighter personal noise dosimetry samples were taken during 10 firefighter training activities. Two training activities per sampling day were monitored during each sampling event, for a mean exposure time of 70 min per day. The noise dosimetry samples were grouped based on job description to compare noise exposures between the different categories of job tasks commonly associated with fire fighting. The three job categories were interior, exterior, and engineering. Mean personal dosimetry results indicated that the average noise exposure was 78 dBA during the training activities that lasted 70 min on average. There was no significant difference in noise exposure between each of the three job categories. Although firefighters routinely use equipment and emergency response vehicles that can produce hazardous levels of noise, this study showed that the average noise levels experienced by firefighters was below generally accepted guidelines.