A novel clinical method to measure skin staining reveals activation of skin damage pathways by cigarette smoke.

BACKGROUND: Long-term use of cigarettes can result in localised staining and aging of smokers' skin. The use of tobacco heating products (THPs) and electronic cigarettes (ECs) has grown on a global scale; however, the long-term effect of these products' aerosols on consumers' skin is unknown. This pilot clinical study aimed to determine whether THP or EC aerosol exposure results in skin staining or activation of biomarkers associated with oxidative stress. MATERIALS AND METHODS: Eight areas were identified on the backs of 10 subjects. Two areas were used for air control, and two areas exposed to 32-puffs of cigarette smoke (CS), THP or EC aerosols, which were delivered to the skin using a 3-cm diameter exposure chamber and smoke engine. Skin colour was measured using a Chromameter. Squalene (SQ), SQ monohydroperoxide (SQOOH) and malondialdehyde (MDA) levels were measured in sebum samples by mass spectrometry and catalase colorimetry. RESULTS: CS exposure significantly increased skin staining, SQOOH and MDA levels and SQOOH/SQ ratio. THP and EC values were significantly lower than CS; EC values being comparable to air control. THP values were comparable to EC and air control at all endpoints, apart from skin staining. SQ and catalase levels did not change with exposure. CONCLUSIONS: CS stained skin and activated pathways known to be associated with skin damage. THPs and ECs produced significantly lower values, suggesting they could offer hygiene and cosmetic benefits for consumers who switch exclusively from smoking cigarettes. Further studies are required to assess longer-term effects of ECs and THPs on skin function.

Enamel staining with e-cigarettes, tobacco heating products and modern oral nicotine products compared with cigarettes and snus: An in vitro study.

PURPOSE: To evaluate the effect of cigarette smoke, smokeless tobacco (e.g. snus), tobacco heating products (THP), electronic cigarettes (EC), and modern oral nicotine products on tooth staining. METHODS: In this in vitro study, staining was assessed for 86 days following exposure of bovine enamel samples to a scientific reference cigarette (1R6F), a THP (glo), an EC (ePen 3), a reference snus product (CRP1.1), and a modern oral product (LYFT). Red wine and coffee were used as positive controls and DMSO and complete artificial saliva as negative controls. Whether brushing could reduce staining levels was also assessed. Changes in staining levels were assessed using the Commission Internationale de L'éclairage L*a*b* method. RESULTS: Enamel staining increased with incubation time, and cigarette smoke, snus, coffee and wine induced statistically higher staining levels. THP, EC and modern oral exposure induced minimal staining levels that were also comparable to negative control samples. At day 86, ΔE mean and SD values were 28.50 ± 3.14, 19.76 ± 1.26, 17.35 ± 3.44, 16.22 ± 2.07, 18.30 ± 3.82, 4.10 ± 1.99, 11.30 ± 2.60, 49.56 ± 2.44 for cigarette, glo, EC with blended tobacco, EC with rich tobacco, reference snus product, modern oral product, coffee or wine. The control ΔE mean and SD values at day 86 were 18.68 ± 3.89 for DMSO and 2.17± 0.78 for complete artificial saliva. The ΔE values for all DMSO extracted samples and control increased from day 1 to 86, which suggests that the DMSO used to extract the samples contributes to the enamel sample staining levels. Staining levels were reduced by brushing. CLINICAL SIGNIFICANCE: Cigarette smoke, red wine, snus and coffee stained enamel. Exposure to THP, EC or modern oral product extracts for 86 days resulted in minimal enamel staining. Further studies are required to assess the long-term impact on staining and the oral cavity following consumer exclusive use of EC, THP or modern oral products.

Development of a novel method to measure material surface staining by cigarette, e-cigarette or tobacco heating product aerosols.

Tobacco smoke (CS) may visually stain indoor surfaces including ceilings, walls and soft furnishings over time. Potentially reduced risk products (PRRPs) such as e-cigarettes (EC) and tobacco heating products (THP) produce chemically less complex aerosols with significantly reduced levels of toxicants, particles and odour. However, the potential effects of EC and THP aerosols on the staining of indoor surfaces are currently unknown. In this study, an exposure chamber was developed as a model system to enable the accelerated staining of wallpaper and cotton samples by a scientific reference cigarette (3R4F), three THP (glo™, glo™ pro, glo™ sens) and an e-cigarette (iSwitch Maxx). Exposure to 3R4F reference cigarettes caused the greatest level of staining, which was significantly higher than glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols, all of which showed relatively little colour change. Exposure to 200-1000 puffs of 3R4F cigarette smoke resulted in a visible dose response effect to wallpaper and cotton samples which was not observed following exposure to glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols. Aging of the samples for 4 weeks post-exposure resulted in changes to the staining levels, however PRRP staining levels were minimal and significantly lower than 3R4F exposed samples. For the first time, diverse PRRPs across the tobacco and nicotine products risk continuum have been assessed in vitro for their impact on surface staining. CS exposure significantly increased the level of wallpaper and cotton staining, whereas exposure to glo™, glo™ pro, glo™ sens or iSwitch Maxx aerosols resulted in significantly reduced levels of staining, staining levels were also comparable to untreated control samples.