Skin temperature during sunbathing--relevance for skin cancer

The influence of climate change on skin cancer incidence - A review of the evidence

BACKGROUND

Climate change is broadly affecting human health, with grave concern that continued warming of the earth's atmosphere will result is serious harm. Since the mid-20th century, skin cancer incidence rates have risen at an alarming rate worldwide.

OBJECTIVE

This review examines the relationship between climate change and cutaneous carcinogenesis.

METHODS

A literature review used the National Institutes of Health databases (PubMed and Medline), the Surveillance, Epidemiology, and End Results and International Agency for Research on Cancer registries, and published reports by federal and international agencies and consortia, including the Australian Institute of Health and Welfare, Climate and Clean Air Coalition, U.S. Environmental Protection Agency, Intergovernmental Panel on Climate Change, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, United Nations Environment Programme, World Health Organization, and World Meteorological Organization.

RESULTS

Skin cancer risk is determined by multiple factors, with exposure to ultraviolet radiation being the most important. Strong circumstantial evidence supports the hypothesis that factors related to climate change, including stratospheric ozone depletion, global warming, and ambient air pollution, have likely contributed to the increasing incidence of cutaneous malignancy globally and will continue to impose a negative on influence skin cancer incidence for many decades to come.

CONCLUSION

Because much of the data are based on animal studies and computer simulations, establishing a direct and definitive link remains challenging. More epidemiologic studies are needed to prove causality in skin cancer, but the evidence for overall harm to human health as a direct result of climate change is clear. Global action to mitigate these negative impacts to humans and the environment is imperative.

Covid-19 screening: are forehead temperature measurements during cold outdoor temperatures really helpful?

Background

Body temperature control is a frequently used screening test for infectious diseases, such as Covid-19 (Sars-CoV-2). We used this procedure to test the body temperature of staff members in a hospital in Tyrol (Austria), where the Covid-19 disease occurred in March 2020. The hospital is located in a mountain area at 995 m above sea level with low outdoor temperatures during early spring season. Under these conditions, we analyzed whether forehead temperature control offers a sufficient screening tool for infectious diseases.

Methods

Forehead temperature of 101 healthy male and female employees was measured with an infrared thermometer directly after entering the hospital (0 min), followed by further controls after 1 min, 3 min, 5 min and 60 min. We also tracked the outside temperature and the temperature at the entrance hall of the hospital.

Results

Complete data of body temperature were available for 46 female and 46 male study participants. The average forehead temperature measured directly after entrance to the hospital was the lowest (0 min) 33.17 ± 1.45 °C, and increased constantly to 34.90 ± 1.49 °C after 1 min, 35.77 ± 1.10 °C after 3 min, 36.08 ± 0.79 °C after 5 min, and 36.6 ± 0.24 °C after 60 min. The outside temperature ranged between −5.5 °C and 0 °C, the indoor temperature had a constant value of 20.5 °C.

Conclusion

Our results indicate that forehead infrared temperature control is not an appropriate tool to screen for infectious disease directly at the entrance of a building, at least during early spring season with cold outdoor temperatures.

Impact of physiologically relevant temperatures on dermal absorption of active substances - an ex-vivo study in human skin

Skin temperature plays a certain role in the dermal absorption of substances, but the extent and mechanisms of skin temperatures-induced modulation in ranges caused by physiological thermoregulation or environmental conditions are largely unknown. The influence of dermal temperature on the absorption of the model lipophilic compound (anisole) and the model hydrophilic compounds (1,4-dioxane, ethanol) through human skin was investigated at three dermal temperatures (25, 32 and 39 °C) in an ex-vivo diffusion cell model. The substances were applied to the skin and transdermal penetration was monitored. All substances showed temperature dependent variations in their penetration behavior (3 h: 25-39 °C: 202-275% increase in cumulative, transdermally penetrated amounts). The relative differences in absorption in relation to temperature were greatest within 45 min after exposure (25-39 °C: 347-653% rise in cumulated penetration), although absolute amounts absorbed were small (45 min vs. 3 h: 4.5-14.5%). Regardless of blood circulation, skin temperature significantly influences the amount and kinetics of dermal absorption. Substance-dependent, temperature-related changes of the lipid layer order or the porous pathway may facilitate penetration. The early-stage modulation of transdermal penetration indicates transappendageal absorption, which may be relevant for short-term exposures. For both, toxicological evaluation and perfusion cell studies, it is important to consider the thermal influence on absorption or to perform the latter at a standardized temperature (32±1 °C).

Balance between Health Risks and Benefits for Outdoor Workers Exposed to Solar Radiation: An Overview on the Role of Near Infrared Radiation Alone and in Combination with Other Solar Spectral Bands

Near infrared or infrared A (IRA) accounts for over 40% of the solar spectrum (SS) and is able to reach subcutaneous tissue as well as the retina. Outdoor workers are occupationally exposed to solar radiation (SR), but the level of exposure may differ widely depending on the job performed, time spent outdoors, latitude, altitude, season, personal protection, etc. Until now, risk assessment and management for outdoor workers has focused on the prevention of both acute and long-term effects on the eye and the skin due to solar ultraviolet radiation (UVR) with little consideration of the other components of the SS (a possible exception is represented by visible radiation with reference to the eye). A growing body of evidence coming from in vitro studies indicates that IRA is involved in cellular reactive oxygen species (ROS) production and may interfere with the respiratory chain in the mitochondria. Moreover, it can modulate gene expression and some metabolic pathways. The biological action of IRA is only partly attributable to a thermal mechanism, should it be also involved in photochemical ones. The cellular and molecular pathways affected by IRA are partly similar and partly different with respect to those involved in the case of visible ultraviolet A (UVA) and ultraviolet B (UVB) radiation. Consequently, the net effect of the SS is very difficult to predict at different levels of the biological organization, making more difficult the final balance of health risk and benefits (for the skin, eye, immune system, blood pressure, etc.) in a given exposure situation. Moreover, few in vivo studies and no epidemiological data are presently available in this regard. Investigating this topic may contribute to better defining the individual exposome. More practically, it is expected to bring benefits to the risk assessment and management for outdoor workers exposed to SS, contributing to: (1) better definition of the individual profiles of susceptibility, (2) more focused preventive and protective measures, (3) better implementation of the health surveillance and (4) a more effective information and training.

Assessment of temperature and ultraviolet radiation effects on sunburn incidence at an inland U.S. Beach: A cohort study

BACKGROUND

Increases in outdoor temperature may lead to increases in sunburn, outdoor exposure, and skin cancer in human populations.

OBJECTIVE

This study aimed to quantify sunburn incidence and risk for Ohio beachgoers exposed to varying outdoor conditions.

METHODS

Sunburn incidence data were obtained through a prospective cohort study at East Fork Lake (Cincinnati, Ohio, USA). Recruitment occurred over 26 weekend days. Beach interviews and follow-up telephone interviews obtained exposure and health information. New sunburns were self-reported 8-9 days post-enrollment. Survey data were paired with ultraviolet radiation (UVR) index and temperature data for statistical analysis.

RESULTS

Among 947 beachgoers, new sunburns were reported in 18% of swimmers. Sunburn incidence was associated with temperature (odds ratio = 1.2; 95% CI: 1.1 - 1.4) and UVR index (odds ratio = 1.6; 95% CI: 1.0 - 2.5) in models adjusted for water exposure, arrival time, and beach visit frequency. Some evidence of a temperature+UVR interaction was observed.

LIMITATIONS

Exposure and sunburn data were self-reported without clinical diagnosis and date of onset. The follow-up period enabled sunburns to be reported from a variety of days rather than only the beach visit day thereby limiting interpretation. Sun protection behaviors were not evaluated.

CONCLUSIONS

Temperature and UVR influence sunburn frequency. Temperature, however was more strongly associated with sunburn in beachgoers than the nearest measured UVR index, suggesting future investigations are needed to better understand how temperature effects sunburn development. Interventions for decreasing sunburn are needed.