Solar Ultraviolet Radiation Risk Estimates-A Comparison of Different Action Spectra and Detector Responsivities

Disentangling the Role of the SnO Layer on the Pyro-Phototronic Effect in ZnO-Based Self-Powered Photodetectors

Self-powered photodetectors (PDs) have been recognized as one of the developing trends of next-generation optoelectronic devices. Herein, it is shown that by introducing a thin layer of SnO film between the Si substrate and the ZnO film, the self-powered photodetector Al/Si/SnO/ZnO/ITO exhibits a stable and uniform violet sensing ability with high photoresponsivity and fast response. The SnO layer introduces a built-in electrostatic field to highly enhance the photocurrent by over 1000%. By analyzing energy diagrams of the p-n junction, the underlying physical mechanism of the self-powered violet PDs is carefully illustrated. A high photo-responsivity (R) of 93 mA W-1 accompanied by a detectivity (D*) of 3.1 × 1010 Jones are observed under self-driven conditions, when the device is exposed to 405 nm excitation laser wavelength, with a laser power density of 36 mW cm-2 and at a chopper frequency of 400 Hz. The Si/SnO/ZnO/ITO device shows an enhancement of 3067% in responsivity when compared to the Al/Si/ZnO/ITO. The photodetector holds an ultra-fast response of ≈ 2 µs, which is among the best self-powered photodetectors reported in the literature based on ZnO.

Risk assessment of occupational skin cancer among outdoor workers in southern Spain: local pilot study

OBJECTIVE

Overexposure to ultraviolet (UV) radiation is the main preventable cause of skin cancer. Outdoor workers, exposed to the sun for many hours throughout their working lives, are at special risk. The aim of this study is to determine occupational photoexposure and photoprotection among outdoor workers employed by a municipality in southern Spain.

METHODS

Cross-sectional descriptive study focusing on outdoor workers employed by the municipality of Fuengirola (in areas such as construction, gardening, urban cleaning and beach maintenance). The participants were monitored by personal dosimetry, participated in a dermatological check-up and answered a validated questionnaire (CHACES) on their habits, attitudes and knowledge related to sun exposure.

RESULTS

The median effective erythema dose of exposure to solar UV radiation during the working day (n=20) was 379.4 J/m², equivalent to 3.8 standard erythema doses, almost 3 times higher than the recommended limits for an 8-hour workday. Skin examination (n=128) revealed the presence of actinic lentigines (79.7%), actinic keratoses (8.6%) and skin cancer (3.9%). The CHACES questionnaire (n=128) revealed a sunburn rate of 50.0%. Photoprotection practices were markedly deficient: only 16.7% of the survey respondents sought protection in the shade, 20.3% avoided exposure during the peak exposure hours and 33.1% applied sunscreen.

CONCLUSIONS

This is the first study to evaluate UV radiation exposure, occupational sun protection practices, sunburn and actinic injuries of different outdoor workers in one of the sunniest regions of Spain and underlines the need for effective interventions to protect outdoor workers' health.

Prevention of Health Risks Related to Occupational Solar Ultraviolet Radiation Exposure in Times of Climate Change and COVID-19 Pandemic

Occupational exposure to solar ultraviolet (UV) radiation is a recognized work-related risk, as is associated with the induction of long-term adverse health effects such as Non-Melanoma Skin Cancers and cataracts. Recent research provided new data suggesting an increased risk of specific forms of malignant melanoma, i.e., Lentigo Maligna Melanoma, for outdoor workers, while the relation of cumulative exposure to solar radiation with ocular diseases, such as uveal melanoma and macular degeneration, is still debated. Nowadays, one of the main focuses of prevention activities is the organization of multicomponent sun safety initiatives, which are proved to be effective, particularly when including technologies that are able to directly interact with individuals, such as phone apps, such as the recently released SunSmart Global UV App. Nevertheless, we should not forget that we are living in an era of profound changes, and phenomena such as climate change and the COVID-19 pandemic have an impact on all aspects of our lives, including how and when we perform, as well as the perception of, outdoor activities. In the future, this may result in possible changes in the scenario of occupational and leisure-time solar radiation exposure-related health risks.

Bringing Light into Darkness-Comparison of Different Personal Dosimeters for Assessment of Solar Ultraviolet Exposure

(1) Measuring personal exposure to solar ultraviolet radiation (UVR) poses a major challenges for researchers. Often, the study design determines the measuring devices that can be used, be it the duration of measurements or size restrictions on different body parts. It is therefore of great importance that measuring devices produce comparable results despite technical differences and modes of operation. Particularly when measurement results from different studies dealing with personal UV exposure are to be compared with each other, the need for intercomparability and intercalibration factors between different measurement systems becomes significant. (2) Three commonly used dosimeter types—(polysulphone film (PSF), biological, and electronic dosimeters)—were selected to perform intercalibration measurements. They differ in measurement principle and sensitivity, measurement accuracy, and susceptibility to inaccuracies. The aim was to derive intercalibration factors for these dosimeter types. (3) While a calibration factor between PSF and electronic dosimeters of about 1.3 could be derived for direct irradiation of the dosimeters, this was not the case for larger angles of incidence of solar radiation with increasing fractions of diffuse irradiation. Electronic dosimeters show small standard deviation across all measurements. For biological dosimeters, no intercalibration factor could be found with respect to PSF and electronic dosimeters. In a use case, the relation between steady-state measurements and personal measurements was studied. On average, persons acquired only a small fraction of the ambient radiation.