UV Exposure of Elementary School Children in Five Japanese Cities¶

Occupational exposure to solar ultraviolet radiation in an eastern North Carolina university outdoor setting during the four seasons

Outdoor workers perform tasks throughout the year that expose them to solar ultraviolet radiation (UVR) and increase their risk of UVR-related adverse health effects. Multiple studies on occupational solar UVR exposures during summer have been published but similar investigations during other seasons are limited. The purpose of this study was to assess solar UVR exposure in an eastern North Carolina university setting during all four seasons (fall, winter, spring, and summer) to assess risk for outdoor workers, particularly groundskeepers, throughout the year. UVR effective irradiance (UVReff) was measured by area monitoring using a digital data-logging radiometer and a weatherproof UVR detector for 164 days from October 2020 to October 2021. Results showed that hourly and daily mean UVReff exceeded the 1-hr and 8-hr ACGIH Threshold Limit Values (TLVs), respectively, in all months and seasons at varying degrees. Winter had the lowest mean UVReff (3.4 × 10-3 ± 1.7 × 10-3 mW/cm2), but 91.1% and 100% of the hourly and daily UVReff measurements, respectively, still exceeded the TLVs. This study demonstrates the risk of overexposure to solar UVR among outdoor workers during cold months and seasons and the importance of implementing UVR protection throughout the year.

Combined Toxicological Effects of Di (2-Ethylhexyl) Phthalate and UV-B Irradiation through Endoplasmic Reticulum Stress-Tight Junction Disruption in Human HaCaT Keratinocytes

Di (2-ethylhexyl) phthalate (DEHP) is widely used as a plasticizer, and human exposure to DEHP is widespread and frequent. However, information about the combined effect of DEHP and ultraviolet (UV)-B on the skin are still limited. We investigated the cytotoxic effects of DEHP and UV-B on HaCaT keratinocytes and evaluated the related underlying mechanisms involving endoplasmic reticulum (ER) stress signals and the disruption of junction complexes as an effective target for skin inflammation. Our results revealed that co-treatment with DEHP and UV-B irradiation alleviated the cell cytotoxicity and markedly decreased X-box binding protein 1 (XBP1), endoplasmic reticulum oxidoreductase 1 alpha (Ero1α), and C/EBP homologous protein (CHOP) whereas a single dose of 40 mJ/cm² UV-B generated mild ER stress to slightly less or similar levels as that seen with DEHP. DEHP was also shown to inhibit tight junctions (TJs) after UV-B irradiation, increased apoptosis by altering apoptotic gene Bax and stress kinases, JNK, and p38 MAPK. Furthermore, exposure of HaCaT cells to DEHP and UV-B irradiation resulted in the marked suppression of the nuclear factor kappa B (NF-κB)/p65 signaling pathway. Taken together, our data suggest that nontoxic DEHP and UV-B irradiation regulated ER stress and epidermal TJ disruption with the induction of apoptosis activation and the secretion of proinflammatory cytokines such as interleukin 1 beta (IL-1β) and IL-6 in human keratinocytes. Further investigation is needed to confirm the mechanisms implicated in its toxicity and determine the effects of exposure to DEHP and UV-B irradiation on markers involved in this study.

Solar UV exposure of children in a summer school in Valencia, Spain

Ultraviolet (UV) exposure is the major environmental factor involved in the development of skin cancers and occurs mainly during outdoor activities. During summer schools, children receive regular and significant solar ultraviolet erythemal radiation (UVER) while practising outdoor activities. Personal dosimeters (VioSpor) were attached to the shoulders of schoolchildren and used to quantify their exposure to UVER. The study took place in Valencia, Spain, during July 2008, with three age groups (7-8, 9-10 and 11-12 years old) and involved about 15 schoolchildren. The median (25, 75 percentiles) twice-daily UV exposure values for all groups was 5.49 (3.59, 8.00) standard erythemal doses (SEDs), where 1 SED is defined as effective 100 Jm(-2) when weighted with the CIE erythemal response function. Exposure ratio (ER) is defined as the ratio between the personal dose on a selected body site and the corresponding ambient dose received on a horizontal plane during the same exposure period. The median (25, 75 percentiles) ER value for all groups in the study was 5.9% (4.1, 8.7).

Biological sensors for solar ultraviolet radiation

Solar ultraviolet (UV) radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

Diurnal variations in solar ultraviolet radiation at typical anatomical sites

OBJECTIVE

Solar ultraviolet (UV) radiation is an important environmental factor that affects human health. The understanding of diurnal variations of UV radiation at anatomical sites may be helpful in developing ways to protect humans from the harmful effects of UV radiation.

METHODS

In order to characterize the diurnal variations, the UV exposure values were measured at 30 min intervals by using Solar-UV Sensors and a rotating manikin in Shenyang city of China (41 degrees 51'N, 123 degrees 27'E). Measurement data for four representative days (in each of the four seasons respectively) were analyzed.

RESULTS

The diurnal variations in solar UV radiation at the shoulder, the forehead and the chest were similar to those associated with a horizontal control measurement. However, the diurnal variations at the eye and the cheek exhibited bimodal distributions with two peaks in spring, summer and autumn, and a unimodal distribution in winter. The UV exposure peaks at the eye and the cheek were measured at solar elevation angles (SEA) of about 30 degrees and 40 degrees , respectively.

CONCLUSION

The protection of some anatomical sites such as the eye from high UV exposure should not be focused solely on the periods before and after noon, especially in the places and seasons with high SEA.

Youth solar ultraviolet radiation exposure, concurrent activities and sun-protective practices: a review

To assist standardization of procedures, facilitate comparisons, and help guide research efforts to optimally inform development of appropriately targeted interventions, there is a need to review methods used to quantify child and adolescent solar ultraviolet radiation (UV) exposure, related outdoor activities and sun-protective practices. This holistic approach is essential for comprehensive research that will provide all-inclusive, informative and meaningful messages for preventive measures of harmful UV exposure. Two databases were searched and 29 studies were retrieved, and these studies report measurement or assessment techniques documenting UV exposure patterns and related outdoor activities. Polysulfone film badges were the main measurement instrument used in 10 studies, with questionnaire, survey data, observation, a model, electronic dosimeters, biological dosimeters, colorimeter and UV colouring labels used in the remaining studies. Methods used to record activities included self-report, parental report, a logbook and observation. Measurement duration and unit of UV exposure varied in most studies, but a method common to 15 studies was measured UV exposure as a percentage of ambient UV. The studies reviewed do not provide sufficient information for the development and evaluation of targeted youth sun protection programs. Studies are required which document precise UV exposure, concurrent activities and sun protection usage for children and adolescents.