The silent UVA.

The effects of UVA on the skin are well documented in the literature. Sunscreens were originally developed to protect against erythema and consequently against UVB. Even today, most sunscreens on the market provide much higher UVB than UVA protection. By looking at the transmission profile of 3 different sunscreens on the market and making a theoretical calculation, we show that users in the past and even today are being exposed to a huge amount of UVA in a silent way. This is what we define as silent UVA. There is a need to develop a new generation of sunscreens with higher UVA protection to reduce Silent UVA exposure.

A novel method for evaluating sun visible light protection factor and pigmentation protection factor of sunscreens.

INTRODUCTION: The role of visible light (VL) in the process of skin pigmentation by solar radiation has been demonstrated. Sunscreens with the presence of pigments, particularly iron oxide (IO), have a greater protective effect against VL and are, therefore, highly recommended for prevention and treatment of hyperpigmentation disorders. This study aimed to evaluate 33 sunscreen formulations, and through spectrophotometric measurements, proposes new methods to evaluate the VL protection factor and the pigmentation protection factor. METHODS: 33 sunscreen formulations marketed in Brazil were evaluated, including 17 products containing pigments and 16 products with no pigments. Spectrophotometric measurements were taken to determine solar VL protection factor and the pigmentation protection factor, based on the absorption curve of the product, the pigmentation action spectrum and sun spectrum. RESULTS: Sunscreen with pigments presented a higher solar VL protection factor and pigmentation protection factor compared to products without pigment. The statistical analysis showed a strong correlation between the solar VL protection factor and the integral of the absorption curve in the VL range and the transmittance reduction (%) in the same range. The correlation between the VL protection factor and the pigmentation protection factor was also demonstrated. CONCLUSION: The VL protection factor and the pigmentation protection factor showed to be adequate metrics to estimate the effectiveness of sunscreens in the prevention of the pigmentary effect of solar VL and the pigmentary effect of the complete spectrum of immediate pigmentation.

Using wearable devices for assessing the impacts of hair exposome in Brazil.

Previous studies have shown that physicochemical properties of hair can be impacted by internal and environmental exposures ranging from chemical stressors to weather. Besides the effects on hair, these exposures, termed "exposome", can act on specific organs including skin, as a synergistic damaging effect of UV exposure and pollution on human surfaces. The combination of several environmental factors such as sun exposure, temperature, relative humidity, air pollution and photo-oxidation caused by ground level ozone impacts hair properties such as melanin oxidation, protein content, surface quality and structural components. Therefore, exposome studies can reveal new hypotheses on how epithelia and hair could be affected by daily life environment and routine. The aim of this study was to evaluate the impact of several environmental aggressors on human surfaces, using portable and wearable devices for monitoring exposome. To better understand the underlying mechanisms associated with environmental factors, two subjects wore multiple sensors to capture the meteorological conditions biking through urban areas in summer and winter. Temperature, humidity, UV radiation and ozone concentration were recorded and hair swatches of different types, including natural, bleached/colored, colored and gray, were exposed on the helmets. Silicon wristbands were used on skin to identify main chemical aggressors. After exposure, hair swatches were analyzed by surface microscopy analysis, oxidation markers and more than 1,500 chemicals were evaluated on the bracelets. Correlated with GPS and monitoring data, all these results provide insights on how environmental stressors affect the quality of different hair types and body surface according to exposure routine. Our results suggest extreme climate conditions associated with hair damage and photo-oxidative marker linked to the environmental aggressors. Polycyclic aromatic hydrocarbons (PAH) indicate possible causes of hair damages. This is the first meteorotropic study of its kind, combining environmental aggressors related to hair damage, opening new research hypothesis further studies on exposome.

Association between non-melanoma and melanoma skin cancer rates, vitamin D and latitude.

Vitamin D synthesis takes place in the skin due to solar ultraviolet-B (UVB) radiation. Several studies have shown the association between low sun exposure, non-melanoma skin cancer (NMSC) and a lack of vitamin D synthesis. Since such synthesis in the body depends on the exposure of the skin to solar UVB radiation (290-320 nm), experimental measurements of this type of solar radiation are important. Tarapaca University in Arica, Chile, established a solar UV radiation laboratory in 2006 and since then this laboratory has performed systematic experimental solar UVB measurements using a calibrated biometer instrument. The results, which are presented in the current study, showed the association between NMSC and MSC rates, and the time required to produce 1,000 IU vitamin D with latitudinal variation. Solar UV index (UVI) levels reported in 6 cities from the north to the south of Chile indicated that the UVI ratio of monthly mean values was 1.8 times higher in Arica than in Punta Arenas in January (summer in Chile), whereas it was 14 times higher in June (winter). This factor is an important consideration, since vitamin D synthesis is directly associated with the exposure of individuals to solar UVB radiation. A similar trend was observed in Antofagasta, Santiago, Concepcion, Valdivia and Punta Arenas. It can be concluded from these data that there is a direct association between NMSC rates and mortality, and UVB radiation, meaning that this type of cancer would not depend on vitamin D synthesis and therefore on calcium uptake. By contrast, MSC rates increased with decreased levels of vitamin D, and thus calcium uptake, in all cities, with the only exception being Punta Arenas.

Hotspots of black carbon and PM2.5 in an urban area and relationships to traffic characteristics.

Three instrumented bicycles were used to measure black carbon (BC) and PM2.5 concentrations in a midsized city in southern Brazil. The objective of this study was to map the spatial distribution of BC and PM2.5, to identify air pollution hotspots and to assess factors that may affect the concentrations of these pollutants, e.g. traffic volume, number of heavy-duty diesel vehicles (HDDV), position of traffic signals and street incline. The cyclists collected data in the city centre along streets of different traffic density during nine sampling sessions in the weekday morning and afternoon rush hours, between March 13 and April 28, 2015. The sampling by bicycle covered an area of 2.70 km2, over variable elevation, and travelled a total distance of 215 km. BC and PM2.5 exhibited a large spatial variability on a scale of tens of metres and the concentrations were positively correlated with traffic counts, but exhibited a stronger relationship with the number of HDDV. These results imply that older buses and diesel-powered trucks may be the main driver behind the high pollution levels in the city's inner core. We observed a strong relationship between BC concentrations at junctions managed by traffic signals and the quantity of HDDV. The mean BC concentration was found to be 8.10 µg m-3 near traffic signals located on an inclined street (HDDV > 100 vehicles h-1) compared to traffic signals on flat terrain (6.00 µg m-3), which can be attributed to the higher acceleration required at the start of motion. This pattern was less evident for PM2.5 concentrations.

Hypovitaminosis D association with disease activity in relapsing remitting multiple sclerosis in Brazil.

Multiple sclerosis (MS) onset is believed to result from a combination of environmental and genetic factors. A prevailing theory addresses the influence of hypovitaminosis D in the development of MS. This research aimed to study the association between vitamin D serum levels and MS, as a prognostic and risk factor for the development and progression of the disease. A cross-sectional multicenter study was conducted in patients with relapsing-remitting MS (n=67), according to the revised McDonald criteria (2010), accompanied in three MS centers in different Brazilian states. A control group consisted of healthy volunteers (n=61). Blood collections were carried out in late summer and late winter. This seems to be the first study of this kind in Latin America. The vitamin D serum levels for MS patients (29.63±8.08) in summer were similar to the controls (29.71±8.28); however, in winter they were lower than the healthy individuals (24.05±7.47 vs 26.56±8.01). No significant difference between the three cities was observed. No association was noted between vitamin D serum levels and gender, race and age, nor correlation of these levels with the EDSS or disease duration. In contrast, a significant association was seen between deficient vitamin D serum levels in late winter with disease activity, characterized by the onset of relapses (19.73±5.69 vs 25.30±6.22) or Gd+ lesions (17.22±3.11 vs 22.79±7.22).

Doses of erythemal ultraviolet radiation observed in Brazil.

Non-melanoma skin cancer represents a quarter of the new cancer cases detected in Brazil. Despite the importance of this issue to public health, there are deficits in knowledge on the local UV radiation levels among physicians. In this work, we evaluate a set of daily erythemal UV doses measured in different Brazilian locations. Very high erythemal UV doses that often exceeded safe amounts were observed over almost the whole year, even during the time interval usually recommended as safe (before 10:00 h and after 16:00 h). These findings will hopefully enable foreign tourists, dermatologists, and decision-makers to implement new measures for solar protection according to South American standards.

Solar ultraviolet radiation measurements in one of the most populous cities of the world: aspects related to skin cancer cases and vitamin D availability.

A number of studies published in the scientific literature have shown the relationship between sun exposure and nonmelanoma skin cancer (NMSC) and vitamin D synthesis. However, the paucity of medical data, particularly in developing countries, hampers a global assessment of the impact of sun exposure on NMSC and vitamin D. To improve knowledge on this subject, this paper presents UV index (UVI) measurements performed in São Paulo City (SPC) in the period 2005-2008. It was found that 65% of the UVI measured 2 h around local noon during the summer show very high (8 < UVI < 10) and extreme (UVI > 11) levels according to the World Health Organization (WHO) classification. During the winter, 40% of the measurements around noontime show high or very high levels. In spite of worrisome recent statistics from SPC, showing that NMSCs make up about 28% of over a million of new cases of cancer in 2008, sun protection is not considered a real problem in these urban areas. UV measurements also show that every month of the year UV levels are high enough to ensure vitamin D production in human skin from incidental sun exposure.