Developmental PFOS exposure alters lung inflammation and barrier integrity in juvenile mice.

Emerging epidemiological evidence indicates perfluorooctane sulfonic acid (PFOS) is increasingly associated with asthma and respiratory viral infections. Animal studies suggest PFOS disrupts lung development and immuno-inflammatory responses, but little is known about the potential consequences on respiratory health and disease risk. Importantly, PFOS exposure during the critical stages of lung development may contribute to disease risk later in life. Thus, we hypothesized that developmental PFOS exposure will affect lung inflammation and alveolar/airway development in a sex-dependent manner. To address this knowledge gap, timed pregnant Balb/cJ dams were orally dosed with a PFOS (1.0, or 2.0 mg/kg/d) injected mealworm or a vehicle control daily from gestational day (GD) 0.5 to postnatal day (PND) 21, and offspring were sacrificed at PND 22-23. PFOS exposed male offspring displayed increased alveolar septa thickness. Downregulated protein staining of occludin were also observed in the lungs after PFOS exposure in male mice compared to vehicle controls, indicative of barrier dysfunction. BALF macrophages were significantly elevated at 2.0 mg/kg/d PFOS in both sexes compared to vehicles, while BALF cytokines (TNF-α, IL-6, KC, MIP-1α, MIP-1ß, and MCP-1) were suppressed in PFOS exposed male offspring compared to vehicle controls. Multiplex nucleic acid hybridization assay showed male-specific downregulation of cytokine gene expression in PFOS exposed mice compared to vehicle mice. Overall, these results demonstrate PFOS exposure exhibits male-specific adverse effects on lung development and inflammation in juvenile offspring, possibly predisposing them to later-in-life respiratory disease. Further research is required to elucidate the mechanisms underlying the sex-differentiated pulmonary toxicity of PFOS.

Correction: Lamb et al. Nose-Only Exposure to Cherry- and Tobacco-Flavored E-Cigarettes Induced Lung Inflammation in Mice in a Sex-Dependent Manner. Toxics 2022, 10, 471.

In the original publication [...].

Nose-Only Exposure to Cherry- and Tobacco-Flavored E-Cigarettes Induced Lung Inflammation in Mice in a Sex-Dependent Manner.

Flavoring chemicals in electronic nicotine delivery systems have been shown to cause cellular inflammation; meanwhile, the effects of fruit and tobacco flavors on lung inflammation by nose-only exposures to mice are relatively unknown. We hypothesized that exposure to flavored e-cigarettes would cause lung inflammation in C57BL/6 J mice. The mice were exposed to air, propylene glycol/vegetable glycerin, and flavored e-liquids: Apple, Cherry, Strawberry, Wintergreen, and Smooth & Mild Tobacco, one hour per day for three days. Quantification of flavoring chemicals by proton nuclear magnetic resonance spectroscopy (1H NMR), differential cell counts by flow cytometry, pro-inflammatory cytokines/chemokines by ELISA, and matrix metalloproteinase levels by western blot were performed. Exposure to PG/VG increased neutrophil cell count in lung bronchoalveolar lavage fluid (BALF). KC and IL6 levels were increased by PG/VG exposure and female mice exposed to Cherry flavored e-cigarettes, in lung homogenate. Mice exposed to PG/VG, Apple, Cherry, and Wintergreen increased MMP2 levels. Our results revealed flavor- and sex-based e-cigarette effects in female mice exposed to cherry-flavored e-liquids and male mice exposed to tobacco-flavored e-liquids, namely, increased lung inflammation.

Novel Δ8-Tetrahydrocannabinol Vaporizers Contain Unlabeled Adulterants, Unintended Byproducts of Chemical Synthesis, and Heavy Metals.

Cannabis e-cigarettes containing Δ8-tetrahydrocannabinol (Δ8-THC) produced synthetically from hemp-derived cannabidiol (CBD) have recently risen in popularity as a legal means of cannabis consumption, but questions surrounding purity and unlabeled additives have created doubts of their safety. Herein, NMR, GC-MS, and ICP-MS were used to analyze major components of 27 products from 10 brands, and it was determined none of these had accurate Δ8-THC labeling, 11 had unlabeled cutting agents, and all contained reaction side-products including olivetol, Δ4(8)-iso-tetrahydrocannabinol, 9-ethoxyhexahydrocannabinol, Δ9-tetrahydrocannabinol (Δ9-THC), heavy metals, and a novel previously undescribed cannabinoid, iso-tetrahydrocannabifuran.

Cannabis Vaping: Existing and Emerging Modalities, Chemistry, and Pulmonary Toxicology.

The outbreak of e-cigarette or vaping product use-associated lung injury (EVALI) has been cause for concern to the medical community, particularly given that this novel illness has coincided with the COVID-19 pandemic, another cause of severe pulmonary illness. Though cannabis e-cigarettes tainted with vitamin E acetate were primarily associated with EVALI, acute lung injuries stemming from cannabis inhalation were reported in the literature prior to 2019, and it has been suggested that cannabis components or additives other than vitamin E acetate may be responsible. Despite these concerning issues, novel cannabis vaporizer ingredients continue to arise, such as Δ8-tetrahydrocannabinol, Δ10-tetrahydrocannabinol, hexahydrocannabinol, and cannabichromene. In order to address cannabis e-cigarette safety and vaping in an effective manner, we provide a comprehensive knowledge of the latest products, delivery modes, and ingredients. This perspective highlights the types of cannabis vaping modalities common to the United States cannabis market, with special attention to cartridge-type cannabis e-cigarette toxicology and their involvement in the EVALI outbreak, in particular, acute lung injurious responses. Novel ingredient chemistry, origins, and legal statuses are reviewed, as well as the toxicology of known cannabis e-cigarette aerosol components.

Identifying a role for the interaction of homocysteine and copper in promoting cardiovascular-related damage.

Observations that copper and homocysteine levels are simultaneously elevated in patients with cardiovascular disease has generated interest in investigating the interactions between copper and homocysteine. Several prior studies have shown that complexes of copper and homocysteine are toxic, leading to cardiovascular damage in vitro. It is not clear, however, why related effects do not occur with other structurally similar, more abundant cellular thiols such as glutathione and cysteine. Herein, a mechanism for a selective redox interaction between copper and homocysteine is demonstrated. It involves a kinetically favored intramolecular hydrogen atom transfer that results in an alpha-amino carbon-centered radical known to promote biomolecular damage.

The influence of terpenes on the release of volatile organic compounds and active ingredients to cannabis vaping aerosols.

Dabbing and vaping cannabis extracts have gained large popularity in the United States as alternatives to cannabis smoking, but diversity in both available products and consumption habits make it difficult to assess consumer exposure to psychoactive ingredients and potentially harmful components. This work studies the how relative ratios of the two primary components of cannabis extracts, Δ9-tetrahydrocannabinol (THC) and terpenes, affect dosage of these and exposure to harmful or potentially harmful components (HPHCs). THC contains a monoterpene moiety and has been previously shown to emit similar volatile degradation products to terpenes when vaporized. Herein, the major thermal degradation mechanisms for THC and ß-myrcene are elucidated via analysis of their aerosol gas phase products using automated thermal desorption-gas chromatography-mass spectrometry with the aid of isotopic labelling and chemical mechanism modelling. Four abundant products - isoprene, 2-methyl-2-butene, 3-methylcrotonaldehyde, and 3-methyl-1-butene - are shown to derive from a common radical intermediate for both THC and ß-myrcene and these products comprise 18-30% of the aerosol gas phase. The relative levels of these four products are highly correlated with applied power to the e-cigarette, which indicates formation of these products is temperature dependent. Vaping THC-ß-myrcene mixtures with increasing % mass of ß-myrcene is correlated with less degradation of the starting material and a product distribution suggestive of a lower aerosolization temperature. By contrast, dabbing THC-ß-myrcene mixtures with increasing % mass of ß-myrcene is associated with higher levels of HPHCs, and isotopic labelling showed this is due to increased reactivity of ß-myrcene relative to THC.

Pine rosin identified as a toxic cannabis extract adulterant.

Pine rosin (colophony) has been identified as a potentially new adulterant in cannabis oil. Its inhalation toxicity poses a significant health concern to users. For example, pine rosin fumes are released during soldering, and have been cited as a causative agent of occupational asthma. Symptoms also include desquamation of bronchial epithelium, which has also been observed in e-cigarette or vaping product used-associated lung injury (EVALI) patients. The sample analyzed herein was acquired from a cannabis industry source, also contains medium chain triglycerides and oleamide, the latter of which is a hypnotic that is commonly found in the synthetic marijuana product Spice, or K2. A combination of proton nuclear magnetic resonance (1H NMR) and high pressure liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESIMS) was used to unambiguously identify major pine rosin ingredients such as abietic and other resin acids. Comparison to commercial samples of pure pine rosin confirmed the assignment.

Aerosol Gas-Phase Components from Cannabis E-Cigarettes and Dabbing: Mechanistic Insight and Quantitative Risk Analysis.

Consumption of cannabis by nontraditional methods has surged since the advent of legalization in North America and worldwide. Inhaling cannabis extracts using vaporizers and via dabbing has risen in popularity, while concerns over product safety have not hindered their proliferation. The work herein is the first step toward assessing the safety of vaporizing and dabbing concentrated cannabis extracts as a function of gas-phase reaction products. The gas-phase thermal degradants of Δ9-tetrahydrocannabinol (THC) have not been previously investigated. It was found that users may be exposed to concerning degradants such as methacrolein, benzene, and methyl vinyl ketone when using cartridge vaporizers and dabbing. It was shown that THC alone and mixed with terpenes generated similar degradation products and, most notably, elevated levels of isoprene. Importantly, it was shown that added terpenes led to higher levels of gas-phase products compared to THC alone. To estimate cancer and noncancer risks associated with exposure to these and other degradants, quantitative risk assessment was applied to experimentally determined values for dabbing and vaping and literature-sourced levels of hazardous components in cannabis smoke. Overall, gas-phase aerosol products had significantly lower values in dabbing and vaporizing compared to cannabis smoking, although these results should be interpreted in light of potential variations in degradant levels due to disparate usage patterns and the dangers of the higher aerosol concentration of THC.

Cannabis Inhalation and Voice Disorders: A Systematic Review.

IMPORTANCE: Widespread legalization of cannabis throughout the United States has created a knowledge gap that leaves practitioners who manage voice disorders uninformed about this substance, commonly referred to as marijuana. The association of cannabis inhalation and voice disorders is rarely reported. However, studies on the association between cannabis inhalation and respiration have been published; therefore, these studies may serve as a surrogate for studies on the association between cannabis and phonation. OBJECTIVE: To review the literature on the association of cannabis-only consumption via smoking and vaping with the health and function of the vocal mechanism to aid clinical recommendations for patients with voice disorders. EVIDENCE REVIEW: This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. An electronic search in MEDLINE via PubMed, CINAHL, Scopus, and Cochrane Library databases for original research on inhaled cannabis was performed from January 1, 2007, through August 10, 2018. The search strategy included Medical Subject Heading terms and keywords marijuana, cannabis, respiratory, lungs, larynx, voice, phonation, and vocal with Boolean operators (AND, OR). Studies of participants of legal age (≥18 years) who had cannabis-only clinical data and used nonsynthetic cannabinoids were included in the review. FINDINGS: This systematic review identified 6 clinical science studies and 13 basic science or animal studies. The only study to date that has evaluated the association between laryngeal symptoms and inhaling cannabis found that human smokers assessed by indirect laryngoscopy with mirror examination exhibited dark vocal folds. Analyses of 6 other clinical science articles indicated an association between cannabis inhalation and respiratory problems that were reduced with smoking cessation or switching to vaporizing. Lung function was maintained in light cannabis smoke exposure after long-term use. Analyses of basic science and animal articles indicated that cannabis smoking was associated with lung and throat injuries attributable to smoking degradation by-products, similar to injuries seen in human tobacco smoking. CONCLUSIONS AND RELEVANCE: The findings suggest that cannabis-only smoking is associated with changes in vocal fold appearance, respiratory symptoms, and negative lung function changes, especially in heavy smokers. Details about patterns of cannabis consumption appear to be relevant to gather in patients with voice disorders. Results further suggest that cannabis smokers presenting with a voice disorder should undergo laryngeal imaging and complete pulmonary function testing when indicated and receive education about consumption methods and their association with voice disorders.

Free-Base Nicotine Is Nearly Absent in Aerosol from IQOS Heat-Not-Burn Devices, As Determined by 1H NMR Spectroscopy.

Heat-not-burn products, eg, I quit ordinary smoking (IQOS), are becoming popular alternative tobacco products. The nicotine aerosol protonation state has addiction implications due to differences in absorption kinetics and harshness. Nicotine free-base fraction (αfb) ranges from 0 to 1. Herein, we report αfb for IQOS aerosols by exchange-averaged 1H NMR chemical shifts of the nicotine methyl protons in bulk aerosol and verified by headspace-solid phase microextraction-gas chromatography-mass spectrometry. The αfb ≈ 0 for products tested; likely a result of proton transfer from acetic acid and/or other additives in the largely aqueous aerosol. Others reported higher αfb for these products, however, their methods were subject to error due to solvent perturbation.

E-cigarettes can emit formaldehyde at high levels under conditions that have been reported to be non-averse to users.

E-cigarette aerosol emission studies typically focus on benchmarking toxicant levels versus those of cigarettes. However, such studies do not fully account for the distinct chemical makeup of e-liquids and their unique properties. These approaches often conclude that there are fewer and lower levels of toxins produced by e-cigarettes than by cigarettes. In 2015, we reported the discovery of new hemiacetals derived from the reaction of formaldehyde and the e-liquid solvents. The main finding was that they constituted a significant proportion of potentially undetected formaldehyde. Moreover, unlike gaseous formaldehyde, the hemiacetals reside in the aerosol particulate phase, and thus are capable of delivering formaldehyde more deeply into the lungs. However, the findings were criticized by those claiming that some of the results were obtained under conditions that are averse to vapers. A "reinvestigation" of our study was recently published addressing this latter issue. However, this reinvestigation ignored major details, including no mention of the formaldehyde hemiacetals. Herein, we isolated both gaseous formaldehyde and formaldehyde hemiacetals at an intermediate power level claimed, in the "reinvestigation", to be relevant to "non-averse," "normal" usage. The results were that both gaseous formaldehyde and formaldehyde from hemiacetals were produced at levels above OSHA workplace limits.

Toxicant Formation in Dabbing: The Terpene Story.

Inhalable, noncombustible cannabis products are playing a central role in the expansion of the medical and recreational use of cannabis. In particular, the practice of "dabbing" with butane hash oil has emerged with great popularity in states that have legalized cannabis. Despite their growing popularity, the degradation product profiles of these new products have not been extensively investigated. The study herein focuses on the chemistry of myrcene and other common terpenes found in cannabis extracts. Methacrolein, benzene, and several other products of concern to human health were formed under the conditions that simulated real-world dabbing. The terpene degradation products observed are consistent with those reported in the atmospheric chemistry literature.