Contact allergy and electronic cigarettes (and eyelash curlers)

Metal Concentrations in E-Cigarette Aerosol Samples: A Comparison by Device Type and Flavor

BACKGROUND

The rapid evolution of electronic cigarette (e-cigarette) products warrants surveillance of the differences in exposure across device types-modifiable devices (MODs), cartridge ("pod")-containing devices (PODs), disposable PODs (d-PODs)-and flavors of the products available on the market.

OBJECTIVE

This study aimed to measure and compare metal aerosol concentrations by device type and common flavors.

METHODS

We collected aerosol from 104 MODs, 67 PODs (four brands: JUUL, Bo, Suorin, PHIX), and 23 d-PODs (three brands: ZPOD, Bidi, Stig) via droplet deposition in a series of conical pipette tips. Metals and metalloids [aluminum (Al), arsenic (As), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), tin (Sn), and zinc (Zn)] were measured using inductively coupled plasma mass spectrometry (ICP-MS), results were log-transformed for statistical analysis, and concentrations are reported in aerosol units (mg / m 3 ).

RESULTS

Of the 12 elements analyzed, concentrations were statistically significantly higher in MOD devices, except for Co and Ni, which were higher in PODs and d-PODs. Of the POD brands analyzed, PHIX had the highest median concentrations among four metals (Al, Ni, Pb, and Sn) compared to the rest of the POD brands. According to POD flavor, seven metals were three to seven orders of magnitude higher in tobacco-flavored aerosol compared to those in mint and mango flavors. Among the d-POD brands, concentrations of four metals (Al, Cu, Ni, and Pb) were higher in the ZPOD brand than in Bidi Stick and Stig devices. According to d-POD flavor, only Cr concentrations were found to be statistically significantly higher in mint than tobacco-flavored d-PODs.

DISCUSSION

We observed wide variability in aerosol metal concentrations within and between the different e-cigarette device types, brands, and flavors. Overall, MOD devices generated aerosols with higher metal concentrations than PODs and d-PODs, and tobacco-flavored aerosols contained the highest metal concentrations. Continued research is needed to evaluate additional factors (i.e., nicotine type) that contribute to metal exposure from new and emerging e-cigarette devices in order to inform policy. https://doi.org/10.1289/EHP11921.

Formaldehyde in Electronic Cigarette Liquid (Aerosolized Liquid)

BACKGROUND

Aerosolized liquid (e-liquid) of electronic cigarettes can be toxic. Beyond the solvent (propylene glycol, vegetable glycerin) and nicotine, little is known about the liquid composition. Formaldehyde, a carcinogen and source of contact dermatitis, has been reported in the vaporized e-liquid, but no studies have assessed the actual e-liquid.

OBJECTIVE

The aim of the study was to evaluate e-liquid products for the presence of formaldehyde.

METHODS

Sixteen e-liquid products were purchased and analyzed for the release of formaldehyde using the chromotropic acid method of detection.

RESULTS

Of the 16 e-liquids purchased, 4 (25%) were positive for the presence of formaldehyde; 2 were flavored and 2 were nonflavored. All positive e-liquids were in pods or disposable electronic cigarette devices, and 2 were purchased from local vape shops. The average nicotine content in the positive e-liquids was 3.85% versus 4.03% in the negative e-liquids.

CONCLUSIONS

The e-liquid products contain toxic chemicals not declared on product labels, as shown in this study with 25.0% of e-liquids containing formaldehyde. All positive e-liquids were within pods or disposable devices. Continued analysis of e-liquids and increased product regulation are needed.

A Systematic Literature Review of E-Cigarette-Related Illness and Injury: Not Just for the Respirologist

Following the recent electronic cigarette (e-cigarette) illness outbreak, the current review aimed to collect all related clinical cases for study and analysis and provide a critical synopsis of the proposed injury mechanism. Adhering to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines, e-cigarette-related clinical cases were identified via Google Scholar and PubMed databases. Additionally, references of published case reports and previous review papers were manually searched, revealing 159 publications presenting e-cigarette-related case reports and 19 reports by the Centers for Disease Control and Prevention. 238 individual cases were identified; 53% traumatic injuries due to e-cigarette explosion or self-combustion, 24% respiratory cases, and 12% poisonings. Additional cases pertained to oral, cardiovascular, immunologic, hematologic, allergic reactions, infant complications, and altered medication levels. Case reports were mainly published between 2016-2019 (78%). The oldest case, a lipoid pneumonia, was published in 2012. The current review showed that e-cigarette-related health effects extend beyond the acute lung injury syndrome, including traumatic, thermal injuries and acute intoxications. Physicians should be aware of the distinct clinical presentations and be trained to respond and treat effectively. Regulators and public health authorities should address the regulatory gap regarding electronic nicotine delivery systems (ENDS) and novel tobacco products.

Metal/Metalloid Levels in Electronic Cigarette Liquids, Aerosols, and Human Biosamples: A Systematic Review

BACKGROUND

Electronic cigarettes (e-cigarettes) have become popular, in part because they are perceived as a safer alternative to tobacco cigarettes. An increasing number of studies, however, have found toxic metals/metalloids in e-cigarette emissions.

OBJECTIVE

We summarized the evidence on metal/metalloid levels in e-cigarette liquid (e-liquid), aerosols, and biosamples of e-cigarette users across e-cigarette device systems to evaluate metal/metalloid exposure levels for e-cigarette users and the potential implications on health outcomes.

METHODS

We searched PubMed/TOXLINE, Embase®, and Web of Science for studies on metals/metalloids in e-liquid, e-cigarette aerosols, and biosamples of e-cigarette users. For metal/metalloid levels in e-liquid and aerosol samples, we collected the mean and standard deviation (SD) if these values were reported, derived mean and SD by using automated software to infer them if data were reported in a figure, or calculated the overall mean (mean ± SD) if data were reported only for separate groups. Metal/metalloid levels in e-liquids and aerosols were converted and reported in micrograms per kilogram and nanograms per puff, respectively, for easy comparison.

RESULTS

We identified 24 studies on metals/metalloids in e-liquid, e-cigarette aerosols, and human biosamples of e-cigarette users. Metal/metalloid levels, including aluminum, antimony, arsenic, cadmium, cobalt, chromium, copper, iron, lead, manganese, nickel, selenium, tin, and zinc, were present in e-cigarette samples in the studies reviewed. Twelve studies reported metal/metalloid levels in e-liquids (bottles, cartridges, open wick, and tank), 12 studies reported metal/metalloid levels in e-cigarette aerosols (from cig-a-like and tank devices), and 4 studies reported metal/metalloid levels in human biosamples (urine, saliva, serum, and blood) of e-cigarette users. Metal/metalloid levels showed substantial heterogeneity depending on sample type, source of e-liquid, and device type. Metal/metalloid levels in e-liquid from cartridges or tank/open wicks were higher than those from bottles, possibly due to coil contact. Most metal/metalloid levels found in biosamples of e-cigarette users were similar or higher than levels found in biosamples of conventional cigarette users, and even higher than those found in biosamples of cigar users.

CONCLUSION

E-cigarettes are a potential source of exposure to metals/metalloids. Differences in collection methods and puffing regimes likely contribute to the variability in metal/metalloid levels across studies, making comparison across studies difficult. Standardized protocols for the quantification of metal/metalloid levels from e-cigarette samples are needed. https://doi.org/10.1289/EHP5686.

Dermatologic manifestations associated with electronic cigarette use

BACKGROUND

Electronic cigarette use continues to rise, yet there are no reviews summarizing dermatologic manifestations associated with electronic cigarettes in the literature.

OBJECTIVE

To review the literature regarding cutaneous manifestations associated with electronic cigarette use and increase awareness of side effects associated with this rapidly developing public health epidemic.

METHODS

The PubMed database was searched for related literature. All studies involving the effects of electronic cigarette use on the skin or mucosa were obtained and reviewed for evidence.

RESULTS

Contact dermatitis, thermal injuries, and oral mucosal lesions have been reported with the use of electronic cigarettes.

LIMITATIONS

The conclusions presented in individual case reports or series are not based on randomized controlled trials.

CONCLUSION

Electronic cigarettes can present with harmful dermatologic manifestations.

The moderating effect of gender on the association between E-cigarette use and smoking status: A cross-sectional study

INTRODUCTION

The novel features of e-cigarettes in the recent vaping boom are appealing to females. Given increasing concerns about using e-cigarettes among females, understanding the patterns of using e-cigarettes in females compared to males is critical. We investigate the moderating effect of gender on the association between ever vaping and smoking status and gender differences in reason for ever vaping and in having ever stopped smoking.

METHODS

We used population data (n = 38,661) from the 2015, 2016, and 2017 Texas Behavioral Risk Factor Surveillance System (BRFSS) to examine a gender difference in ever vaping associated with smoking status. Additionally, we restricted the sample to current smokers who have ever vaped (n = 4733) to examine the association of gender with quitting smoking as reason for ever vaping and with having ever stopped smoking.

RESULTS

We found a significant association between ever vaping and gender (OR = 0.77, 95%CI = 0.65, 0.91). When smoking status was considered, female never-smokers had a significantly lower likelihood of ever vaping than male never-smokers (OR = 0.43, 95%CI = 0.27, 0.76). No significant gender difference was found in ever vaping to quit smoking (OR = 1.12, 95%CI = 0.73, 1.74) and having ever stopped smoking (OR = 1.41, 95%CI = 0.95, 2.10).

CONCLUSIONS

The findings of this study provide evidence of gender differences in vaping patterns. Female never-smokers are less likely than male never-smokers to experiment with e-cigarettes. However, there is no evidence of a gender difference in both ever vaping to quit smoking and having ever stopped smoking. Consistent monitoring of gender differences in using e-cigarettes and stratified policy approaches tailored for genders are necessary.