An Unrecognized Hazard in E-Cigarette Vapor: Preliminary Quantification of Methylglyoxal Formation from Propylene Glycol in E-Cigarettes

Up to 95% of the liquid volume in an e-cigarette consists of propylene glycol. Previous research has shown that propylene glycol can generate diacetyl and formaldehyde when heated. New research shows that propylene glycol can also generate methylglyoxal, an alpha di-carbonyl compound recently shown to cause epithelial necrosis at even lower concentrations than diacetyl, the flavoring chemical associated with bronchiolitis obliterans ("Popcorn Lung"). We analyzed chemical emissions from 13 JUUL pod flavors. Diacetyl and methylglyoxal was detected in 100% of samples with median concentration (range) of 20 µg/m3 (less than limit of quantification: 54 µg/m3) and 4219 µg/m3 (677-15,342 µg/m3), respectively. We also detected acetaldehyde (median concentration: 341 µg/m3) and propionaldehyde (median concentration: 87 µg/m3) in all samples. The recent evidence that methylglyoxal is more cytotoxic to airway epithelial cells than diacetyl makes this an urgent public health concern. Current smokers considering e-cigarettes as a smoking cessation tool, and never users, who may be under the impression that e-cigarettes are harmless, need information on emissions and potential risks to make informed decisions.

The contribution of physical working conditions to sickness absence of varying length among employees with and without common mental disorders

Aims: The aim was to examine whether the contribution of physical work exposures to the risk of sickness absence (SA) is different between those with and without common mental disorders (CMD). Methods: We used questionnaire data on four work exposures and CMD from 6159 participants of the Helsinki Health Study cohort with 12,458 observations from three surveys (2000–2002, 2007 and 2012). We formed combination exposures for the work exposures (hazardous exposures, physical workload, computer and shift work) with CMD. Associations with SA of different length were examined with negative binomial regression models. Results: We observed stronger associations for CMD with SA than for the individual work exposures. The strength of the associations for hazardous exposures and physical workload increased with length of SA, especially when the participant also had CMD. The strongest associations for the combined exposures were observed for SA ⩾15 days, the rate ratios being 2.63 (95% CI 2.27–3.05) among those with hazardous exposure and CMD, and 3.37 (95% CI 2.93−3.88) among those with heavy physical workload and CMD. Conclusions: Employees with hazardous exposures or physical workload combined with CMD were at the highest risk of SA compared with those without these exposures or with only one exposure.

The assessment of environmental and occupational exposure to hazardous substances by biomonitoring

BACKGROUND

Modern biomonitoring has expanded beyond its origins in occupational medicine to cover a wide variety of diagnostic procedures and assessments of environmental pollution, ranging from exposure to heavy metals and chemicals to the effects of pesticides and environmental tobacco smoke. In biomonitoring, the overall pollutant load and hazardous exposure of an organism is quantitatively determined, by monitoring the pollutants themselves, their metabolic products and/or conjugates with protein or DNA, in either serum, urine or other body fluids, as well as tissue samples in exceptional circumstances.

METHODS

A selective survey of the current literature is exemplified by our recent scientific and clinical experience.

RESULTS

Biomonitoring is an excellent way to monitor potentially hazardous substances, especially for the assessment of systemic uptake from chronic exposure and the evaluation of subsequent health risks. Investigative biomonitoring can highlight incidental/accidental intoxication in individuals and provide new categories of problematic pollutants relevant to the general population.

CONCLUSIONS

In combination with diagnostic procedures, biomonitoring provides an important contribution to the rational assessment of currently recorded pollutants and resulting health risks. It is as an evaluation tool available in daily practice as well as in health and environmental research applications. Legislation is already implemented that incorporates biomonitoring within the remit of specified occupational health screening.