Allergic and Respiratory Symptoms in Employees of Indoor Cannabis Grow Facilities

Should cannabis self-cultivation be part of a public health‒oriented legalization policy framework?

Cannabis control policies are increasingly being liberalized, including the legalization of non-medical cannabis use and supply in multiple settings, for example in Canada, with main policy objectives focusing on improved public health. An important while contested matter has been the appropriate design of legal cannabis supply structures and sources. These, in most Americas-based legalization settings, have included provisions for (limited) 'home cultivation'. Recent data suggest that about 8% of active consumers engage in cannabis home cultivation for their own supply, while approximately 14% are exposed to it in/around their home. Home cultivation commonly exceeds legal limits and/or occurs where not allowed, and is disproportionately associated with high-frequency and/or other risk patterns of cannabis use. In addition, home cultivation may facilitate exposure or diversion of cannabis to minors, as well as pose possible environmental exposure risks especially when occurring indoors. Given its placement in private spaces, related regulations are largely shielded from enforcement. Home cultivation, therefore, bears substantive potential to circumvent or work counter to public health‒oriented legalization policy objectives. Recent assessments of health outcomes from cannabis legalization show mixed-including multiple adverse-results, implying the need for regulatory revisions towards protecting public health outcomes. Especially in settings where extensive (e.g. commercial) retail systems were established to provide regulated, legal cannabis products to consumers, it is questionable whether home cultivation overall serves primary public health‒oriented objectives; relevant data should be expanded and used to review related provisions.

Bioaerosol Exposures and Respiratory Diseases in Cannabis Workers

PURPOSE OF REVIEW

This review investigates occupational inhalation hazards associated with biologically derived airborne particles (bioaerosols) generated in indoor cannabis cultivation and manufacturing facilities.

RECENT FINDINGS

Indoor cannabis production is growing across the US as are recent reports of respiratory diseases among cannabis workers, including occupational asthma morbidity and mortality. More information is needed to understand how bioaerosol exposure in cannabis facilities impacts worker health and occupational disease risk. Preliminary studies demonstrate a significant fraction of airborne particles in cannabis facilities are comprised of fungal spores, bacteria, and plant material, which may also contain hazardous microbial metabolites and allergens. These bioaerosols may pose pathogenic, allergenic, toxigenic, and pro-inflammatory risks to workers. The absence of multi-level, holistic bioaerosol research in cannabis work environments necessitates further characterization of the potential respiratory hazards and effective risk prevention methods to safeguard occupational health as the cannabis industry continues to expand across the US and beyond.

IgE-Mediated Allergy and Asymptomatic Sensitization to Cannabis Allergens-Review of Current Knowledge and Presentation of Six Cases

Cannabis allergy is a relatively new phenomenon described in the 1970s. Its increased frequency has been observed over the last years due to the increasing therapeutic and recreational use of cannabis-based products. Sensitization possibly leading to allergy symptoms can occur not only through the smoking of cannabis, but also through ingestion, the inhalation of pollen, or direct contact. The severity of symptoms varies from benign pruritus to anaphylaxis. There is scant information available to support clinicians throughout the entire therapeutic process, starting from diagnosis and ending in treatment. In this review, we present six cases of patients in whom molecular in vitro testing revealed sensitization to cannabis extract and/or cannabis-derived nsLTP molecules (Can s 3). Based on these cases, we raise important questions regarding this topic. The article discusses current proposals and highlights the importance of further research not only on cannabis allergy but also on asymptomatic sensitization to cannabis allergens, which may be ascertained in some percentage of the population.

Stress, Mental Health, and Coping Among Workers in the Northern California Cannabis Industry: A Qualitative Descriptive Analysis

California is home to a multibillion-dollar cannabis (marijuana) industry, but little is known about the occupational health and safety hazards faced by cannabis workers and even less of the stress, mental health, and coping mechanisms among these workers. Previous research has been based on long-term workers at legal businesses, but most California cannabis is produced and sold unlawfully. There are many seasonal workers whose experiences have not been studied. A qualitative study based on focus group discussions and key informant interviews was performed to understand cannabis workers' experiences, knowledge, and perceptions of occupational hazards. Participants reported sources of stress including production pressure and isolation, and mental health outcomes such as depression and mental fatigue. They described primarily maladaptive coping mechanisms. Unique characteristics of the cannabis industry, including criminalization and isolated, remote farms, make interventions challenging. However, policy approaches that involve community organizations could promote worker health.

Fatal Occupational Asthma in Cannabis Production - Massachusetts, 2022

Multiple respiratory hazards have been identified in the cannabis cultivation and production industry, in which occupational asthma and work-related exacerbation of preexisting asthma have been reported. An employee working in a Massachusetts cannabis cultivation and processing facility experienced progressively worsening work-associated respiratory symptoms, which culminated in a fatal asthma attack in January 2022. This report represents findings of an Occupational Safety and Health Administration inspection, which included a worksite exposure assessment, coworker and next-of-kin interviews, medical record reviews, and collaboration with the Massachusetts Department of Public Health. Respiratory tract or skin symptoms were reported by four of 10 coworkers with similar job duties. Prevention is best achieved through a multifaceted approach, including controlling asthmagen exposures, such as cannabis dust, providing worker training, and conducting medical monitoring for occupational allergy. Evaluation of workers with new-onset or worsening asthma is essential, along with prompt diagnosis and medical management, which might include cessation of work and workers' compensation when relation to work exposures is identified. It is important to recognize that work in cannabis production is potentially causative.

Epicutaneous Sensitization to the Phytocannabinoid β-Caryophyllene Induces Pruritic Inflammation

In recent years, there has been increased accessibility to cannabis for recreational and medicinal use. Incidentally, there has been an increase in reports describing allergic reactions to cannabis including exacerbation of underlying asthma. Recently, multiple protein allergens were discovered in cannabis, yet these fail to explain allergic sensitization in many patients, particularly urticaria and angioedema. Cannabis has a rich chemical profile including cannabinoids and terpenes that possess immunomodulatory potential. We examined whether major cannabinoids of cannabis such as cannabidiol (CBD) and the bicyclic sesquiterpene beta-caryophyllene (β-CP) act as contact sensitizers. The repeated topical application of mice skin with β-CP at 10 mg/mL (50 µL) induced an itch response and dermatitis at 2 weeks in mice, which were sustained for the period of study. Histopathological analysis of skin tissues revealed significant edema and desquamation for β-CP at 10 mg/mL. For CBD and β-CP, we observed a dose-dependent increase in epidermal thickening with profound thickening observed for β-CP at 10 mg/mL. Significant trafficking of CD11b cells was observed in various compartments of the skin in response to treatment with β-CP in a concentration-dependent manner. Mast cell trafficking was restricted to β-CP (10 mg/mL). Mouse proteome profiler cytokine/chemokine array revealed upregulation of complement C5/5a (anaphylatoxin), soluble intracellular adhesion molecule-1 (sICAM-1) and IL-1 receptor antagonist (IL-1RA) in animals dosed with β-CP (10 mg/mL). Moreover, we observed a dose-dependent increase in serum IgE in animals dosed with β-CP. Treatment with β-CP (10 mg/mL) significantly reduced filaggrin expression, an indicator of barrier disruption. In contrast, treatment with CBD at all concentrations failed to evoke scratching and dermatitis in mice and did not result in increased serum IgE. Further, skin tissues were devoid of any remarkable features, although at 10 mg/mL CBD we did observe the accumulation of dermal CD11b cells in skin tissue sections. We also observed increased filaggrin staining in mice repeatedly dosed with CBD (10 mg/mL). Collectively, our studies indicate that repeated exposure to high concentrations of β-CP can induce dermatitis-like pathological outcomes in mice.

Proteomics-Based Approach for Detailing the Allergenic Profile of Cannabis Chemotypes

Allergic sensitization to cannabis is an emerging public health concern and is difficult to clinically establish owing to lack of standardized diagnostic approaches. Attempts to develop diagnostic tools were largely hampered by the Schedule I restrictions on cannabis, which limited accessibility for research. Recently, however, hemp was removed from the classified list, and increased accessibility to hemp allows for the evaluation of its practical clinical value for allergy diagnosis. We hypothesized that the proteomic profile is preserved across different cannabis chemotypes and that hemp would be an ideal source of plant material for clinical testing. Using a proteomics-based approach, we examined whether distinct varieties of cannabis plant contain relevant allergens of cannabis. Cannabis extracts were generated from high tetrahydrocannabinol variety (Mx), high cannabidiol variety (V1-19) and mixed profile variety (B5) using a Plant Total Protein Extraction Kit. Hemp extracts were generated using other standardized methods. Protein samples were subjected to nanoscale tandem mass spectrometry. Acquired peptides sequences were examined against the Cannabis sativa database to establish protein identity. Non-specific lipid transfer protein (Can s 3) level was measured using a recently developed ELISA 2.0 assay. Proteomic analysis identified 49 distinct potential allergens in protein extracts from all chemotypes. Most importantly, clinically relevant and validated allergens, such as profilin (Can s 2), Can s 3 and Bet v 1-domain-containing protein 10 (Can s 5), were identified in all chemotypes at label-free quantification (LFP) intensities > 106. However, the oxygen evolving enhancer protein 2 (Can s 4) was not detected in any of the protein samples. Similarly, Can s 2, Can s 3 and Can s 5 peptides were also detected in hemp protein extracts. The validation of these findings using the ELISA 2.0 assay indicated that hemp extract contains 30-37 ng of Can s 3 allergen per µg of total protein. Our proteomic studies indicate that relevant cannabis allergens are consistently expressed across distinct cannabis chemotypes. Further, hemp may serve as an ideal practical substitute for clinical testing, since it expresses most allergens relevant to cannabis sensitization, including the validated major allergen Can s 3.

The Emerging Spectrum of Respiratory Diseases in the U.S. Cannabis Industry

While the cannabis industry is one of the fastest growing job markets in the United States and globally, relatively little is known about the occupational hazards that cannabis production workers face. Based on the closely related hemp industry and preliminary studies from recreational cannabis grow facilities, there is concern for significant respiratory exposures to bioaerosols containing microbial and plant allergens, chemicals such as pesticides, volatile organic compounds, and other irritant gases. Components of the cannabis plant have also recently been identified as allergenic and capable of inducing an immunoglobulin E-mediated response. Accumulating evidence indicates a spectrum of work-related respiratory diseases, particularly asthma and other allergic diseases. Disentangling causal relationships is difficult given the heterogeneity of mixed exposures, diagnostic challenges, and confounding by personal cannabis use. Despite and because of these uncertainties, better regulatory guidance and exposure controls need to be defined in order to reduce the risk of work-related disease.

California cannabis cultivation and processing workers: A qualitative analysis of physiological exposures and health effects

INTRODUCTION

Cannabis is a multi-billion-dollar California industry, but little is known about the occupational hazards or health experiences of cannabis cultivation workers. Respiratory and dermal exposures, musculoskeletal hazards, and other agricultural hazards have been identified in previous research. Even in a post-legalization framework, cannabis work is stigmatized and most cannabis is still produced illegally. Qualitative research is essential for establishing rapport with cannabis workers to understand their experiences and concerns.

METHODS

We conducted semi-structured discussions with four focus groups including 32 cannabis workers total, and 9 key informants who were workers, industry experts, and business owners or managers. Transcribed results were analyzed to identify key themes on physiological exposures and health effects.

RESULTS

The majority (81.3%) of focus group participants were seasonal migrant cannabis trimmers. Themes emerged of respiratory and dermal exposures and outcomes, musculoskeletal disorders, and physical hazards including living conditions. Workers reported respiratory symptoms and rashes from exposure to cannabis, mold, and pesticides. Musculoskeletal pain was ubiquitous due to inadequate seating and long shifts performing repetitive tasks. Seasonal workers experienced chronic exposure to cold conditions and unsanitary housing. Management-level interviewees and other industry stakeholders described concerns and experiences that differed from those of workers.

DISCUSSION

The results were consistent with existing research on cannabis worker health, with workers reporting respiratory and dermal exposure and symptoms, musculoskeletal hazards, and physical hazards associated with agricultural work. In addition, we found that workers were affected by substandard living conditions, remote and isolated work environments, and an absence of training.

A Pilot Study of Respiratory and Dermal Symptoms in California Cannabis Cultivation Workers

Cannabis (Cannabis sativa, marijuana) is the largest cash crop in California. While it is difficult to characterize the size of the industry, the total production is estimated at 15 to 16 million pounds per year, with total revenues exceeding $10 billion per year. Despite the huge size and rapid growth of the industry, there has been little research on the health and safety of cannabis workers. The goal of this pilot study was to explore the feasibility of collecting cannabis worker health data with a self-administered survey and to analyze the first systematically collected data on occupational health symptoms among California cannabis cultivation workers. We performed a cross-sectional survey of demographic and job characteristics as well as eye, nasal, respiratory, and dermal symptoms among 29 workers at two cannabis farms in the Sacramento area, California. Most participants were men aged less than 30 years, with 48% of participants self-identifying as non-Hispanic white and 58% reporting at least some college education. The most frequently reported work-related symptom was nasal irritation, and 38% of the participants reported symptoms suggestive of asthma. The participants had a demographic makeup distinct from traditional California agricultural workers, and a very high prevalence of current use of cannabis (93%). The high proportion of respondents with symptoms suggestive of asthma raises concern; sensitization to the cannabis plant has been reported among cannabis workers and users and there are many well-documented agricultural exposures causing asthma and asthma-like syndrome.

Establishing diagnostic strategies for cannabis allergy

INTRODUCTION

Cannabis is the most widely consumed illicit drug in the world and carries a risk of severe IgE-mediated allergic reactions, requiring appropriate diagnostic management. Currently available diagnostics are still relatively limited and require careful interpretation of results to avoid harmful over- and underdiagnosis.

AREAS COVERED

This review focuses on the most up-to-date understandings of cannabis allergy diagnosis, starting with the main clinical features of the disease and the allergenic characteristics of Cannabis sativa, and then providing insights into in vivo, in vitro, and ex vivo diagnostic tests.

EXPERT OPINION

At present, the diagnosis of IgE-mediated cannabis allergy is based on a three-step approach that starts with accurate history taking and ends with a confirmation of sensitization to the whole extract and, finally, molecular components. Although much has been discovered since its first description in 1971, the diagnosis of cannabis allergy still has many unmet needs. The lack of commercial standardized and validated extracts and in vitro assays makes a harmonized workup of cannabis allergy difficult. Furthermore, the epidemiological characteristics, and clinical implications of sensitization to different molecular components are not yet fully known. Future research will complete the picture and likely result in an individualized and standardized approach.

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

This review addresses knowledge gaps in cannabis cultivation facility (CCF) air emissions by synthesizing the peer-reviewed and gray literature. Focus areas include compounds emitted, air quality indoors and outdoors, odor assessment, and the potential health effects of emitted compounds. Studies suggest that β-myrcene is a tracer candidate for CCF biogenic volatile organic compounds (BVOCs). Furthermore, β-myrcene, d-limonene, terpinolene, and α-pinene are often reported in air samples collected in and around CCF facilities. The BVOC emission strength per dry weight of plant is higher than most conventional agriculture crops. Nevertheless, reported total CCF BVOC emissions are lower compared with VOCs from other industries. Common descriptors of odors coming from CCFs include "skunky", "herbal", and "pungent". However, there are few peer-reviewed studies addressing the odor impacts of CCFs outdoors. Atmospheric modeling has been limited to back trajectory models of tracers and ozone impact assessment. Health effects of CCFs are mostly related to odor annoyance or occupational hazards. We identify 16 opportunities for future studies, including an emissions database by strain and stage of life (growing cycle) and odor-related setback guidelines. Exploration and implementation of key suggestions presented in this work may help regulators and the industry reduce the environmental footprint of CCF facilities.

Surveillance of work-related asthma including the emergence of a cannabis-associated case series in Washington State

OBJECTIVE

We conducted surveillance for work-related asthma (WRA) in Washington State to identify the industry sectors and asthma exposures most commonly affecting injured workers and in need of prevention activities.

METHODS

Using workers' compensation data as the primary data source, valid cases were classified as work-aggravated asthma (WAA) or new onset asthma that includes occupational asthma (OA) and reactive airways dysfunction syndrome (RADS). The source of exposure that caused the worker's asthma, their industry and occupation were determined.

RESULTS

There were 784 valid work-related asthma cases identified for the period 2009-2016, WAA (n = 529) was most common followed by occupational asthma (n = 127) and RADS (n = 12). The Health Care and Social Assistance industry had the highest number of cases (n = 170) with 82% classified as WAA. The highest overall proportions of new onset asthma are occurring in Agriculture, Forestry, Fishing and Hunting (33% of work related asthma cases), Manufacturing (31%) and Construction (30%). The leading substances associated with new onset asthma across all industries include hop plant dust, wood and cedar dust, mineral and inorganic dust, mold, and cleaning materials. We describe ten cases of cannabis-associated asthma including seven from workers in the legalized cannabis industry, four of whom had OA.

CONCLUSION

State-based work-related asthma surveillance is critical in identifying the workers and exposures associated with this occupational disease, including the detection of a case-series in the cannabis industry.

Immunomodulation by cannabinoids: Current uses, mechanisms, and identification of data gaps to be addressed for additional therapeutic application

The endocannabinoid system plays a critical role in immunity and therefore its components, including cannabinoid receptors 1 and 2 (CB₁ and CB₂), are putative druggable targets for immune-mediated diseases. Whether modulating endogenous cannabinoid levels or interacting with CB₁ or CB₂ receptors directly, cannabinoids or cannabinoid-based therapeutics (CBTs) show promise as anti-inflammatory or immune suppressive agents. Herein we provide an overview of cannabinoid effects in animals and humans that provide support for the use of CBTs in immune-mediated disease such as multiple sclerosis (MS), inflammatory bowel disease (IBD), asthma, arthritis, diabetes, human immunodeficiency virus (HIV), and HIV-associated neurocognitive disorder (HAND). This is not an exhaustive review of cannabinoid effects on immune responses, but rather provides: (1) key studies in which initial and/or novel observations were made in animal studies; (2) critical human studies including meta-analyses and randomized clinical trials (RCTs) in which CBTs have been assessed; and (3) evidence for the role of CB₁ or CB₂ receptors in immune-mediated diseases through genetic analyses of single nucleotide polymorphisms (SNPs) in the CNR1 and CNR2 genes that encode CB₁ or CB₂ receptors, respectively. Perhaps most importantly, we provide our view of data gaps that exist, which if addressed, would allow for more rigorous evaluation of the efficacy and risk to benefit ratio of the use of cannabinoids and/or CBTs for immune-mediated diseases.