Sun-induced production of vitamin D3 throughout 1 year in tropical and subtropical regions: relationship with latitude, cloudiness, UV-B exposure and solar zenith angle.

This study evaluated the differences in vitamin D3 synthesis in two different latitudes throughout 1 year using an in vitro model, which simulates cutaneous vitamin D photoproduction. Borosilicate ampoules containing 7-dehydrocholesterol (7-DHC) were exposed to sunlight hourly throughout the daylight hours, 1 day per month for a year, in Fortaleza (latitude 03° 43' 01" S-LAT3° S) and Sao Paulo (latitude 23° 32' 53" S-LAT23° S). Later, vitamin D3 and photoisomers of 7-DHC (tachysterol and lumisterol) were measured by a high-performance liquid chromatography system (HPLC). Vitamin D synthesis weighted UV radiation (UVBVitD) and solar zenith angle (SZA) were calculated during the same periods for both latitudes. Vitamin D3 synthesis occurred throughout the year in both locations, as expected in latitudes lower than 35°. Median of photoconversion to vitamin D3 through the year was higher in LAT3°S [median (IQR): LAT 3°S 4.1% (6.0); LAT 23°S 2.9% (4.5); p value = 0.020]. Vitamin D3 production strongly correlated with UV-B (LAT3° S, r = 0.917; p < 0.0001 and at LAT23° S, r = 0.879; p < 0.0001) and SZA (LAT3° S, r = - 0.924; p < 0.0001 and in LAT23°S, r = - 0.808; p < 0.0001). Vitamin D3 production starts later in LAT23° S, especially in winter. Lowest percentages were observed in June in both cities, although, compared to LAT3° S, in LAT 23° S the conversion was over 50% lower in the winter period. Cloudiness impaired photoproduction of Vitamin D3 even in summer months in both latitudes. Our results provide data to help guide medical recommendations for sensible sun exposure to promote the cutaneous production of vitamin D3 at different latitudes, seasonality, time of day and cloudiness status in Brazil.

Daily Maximum Erythemal Dose Rates in the Tropics.

The maximum erythemal dose rate (EDRmax ) at the Earth's surface tends to occur at local noon. However, clouds can make the timing of EDRmax significantly away from local noon. In fact, EDRmax and its time of occurrence depend mainly on the solar zenith angle at noon (SZAn ), site's altitude, the total ozone column (TOC), cloud cover, cloud genera and aerosols. This work depicts the daily incidence of EDRmax for Belo Horizonte (19.92°S, 43.94°W, 858 m a.s.l.) in the Southern Hemisphere tropics for a period of five years (2005-2010). Daily values of EDRmax ranged from 0.063 W m-2 (1σ > 6.9%, Moderate UV-Index of 3, winter) to 0.486 W m-2 (Extreme UVI of 19, summer). Indicative values of EDRmax for cloudless days were 0.336 W m-2 (summer, TOC = 258 Dobson Units), 0.311 W m-2 (fall, 260 DU), 0.253 W m-2 (spring, 274 DU) and 0.143 W m-2 (winter, 246 DU). Radiation enhancement events by clouds made EDRmax up to 45% higher than the reference EDRmax for cloudless summer skies at a time resolution of a few minutes. The main cloud genera to be associated with such events are Cumulus, Altocumulus, Altostratus and Stratocumulus. The EDR can also be significantly affected by aerosols, which attenuated on average 0.031 W m-2 (22%) of the erythemal UV in a case study at the site.

A Semiempirical Approach to the Determination of Daily Erythemal Doses.

The maintenance of ground-based instruments to measure the incidence of ultraviolet radiation (UVR) from the Sun demands strict and well-developed procedures. A piece of equipment can be out of service for a couple of weeks or months for calibration, repair or even the improvement of the facilities where it has been set up. However, the replacement of an instrument in such circumstances can be logistically and financially prohibitive. On the other hand, the lack of data can jeopardize a long-term experiment. In this study, we introduce a semiempirical approach to the determination of the theoretical daily erythemal dose (DEDt ) for periods of instrumental absence in a tropical site. The approach is based on 5 years of ground-based measurements of daily erythemal dose (DED) linearly correlated with parameters of total ozone column (TOC) and reflectivity (RPC ) from the Ozone Monitoring Instrument (OMI) and the cosine of solar zenith angle at noon (SZAn ). Seventeen months of missing ground-based data were replaced with DEDt , leading to a complete 5-year series of data. The lowest and the highest values of typical DED were 2411 ± 322 J m-2 (1σ) (winter) and 5263 ± 997 J m-2 (summer). The monthly integrated erythemal dose (mED) varied from 59 kJ m-2 (winter) to 162 kJ m-2 (summer). Both of them depended mainly on cos(SZAn ) and RPC . The 12-month integrated erythemal dose (12-ED) ranged from 1350 kJ m-2 to 1546 kJ m-2 , but it can depend significantly on other atmospheric parameter (maybe aerosols) not explicitly considered here.

An estimate of the cost of treating non-melanoma skin cancer in the state of São Paulo, Brazil.

BACKGROUND: The most common form of cancer in Brazil is non-melanoma skin cancer, which affects approximately 0.06% of the population. There are no public policies for its prevention and the economic impact of its diagnosis has yet to be established. OBJECTIVES: To estimate the costs of the diagnosis and treatment of non-melanoma skin cancer in the state of São Paulo between 2000 and 2007 and to compare them with the costs associated with skin melanoma in the same period. METHODS: The Clinical Practice Guidelines in Oncology (National Comprehensive Cancer Network) was used as a procedure model, adapted to the procedures at the SOBECCan Foundation at the Ribeirão Preto Cancer Hospital in São Paulo. The estimated costs were based on the costs of medical treatment in the public and private sectors in 2007. RESULTS: The mean annual costs of each individual treatment of non-melanoma skin cancer were much lower than those estimated for the treatment of skin melanoma. Nevertheless, when the total costs of the treatment of non-melanoma skin cancer were taken into consideration, it was found that the total cost of the 42,184 cases of this type of cancer in São Paulo within the study period was 14% higher than the costs of the 2,740 cases of skin melanoma registered in the same period within the Brazilian National Health Service (SUS). However, in the private sector, the total cost was approximately 34% less for the treatment of non-melanoma skin cancer compared to melanoma. CONCLUSION: The high number of cases of non-melanoma skin cancer in Brazil, with 114,000 new cases predicted for 2010, 95% of which are diagnosed at early stages, represents a financial burden to the public and private healthcare systems of around R$37 million and R$26 million annually, respectively.

Estimativa do custo do tratamento do câncer de pele tipo não-melanoma no Estado de São Paulo - Brasil / An estimate of the cost of treating non-melanoma skin cancer in the state of São Paulo, Brazil

FUNDAMENTOS: O câncer de maior incidência no Brasil é o de pele não-melanoma, que afeta aproximadamente 0,06 por cento da população. Não existem políticas públicas para sua prevenção e o impacto econômico do seu diagnóstico não tem sido avaliado. OBJETIVOS: Estimar os custos do diagnóstico e tratamento do câncer de pele não-melanoma no Estado de São Paulo entre 2000 a 2007 e compará-los com os do melanoma cutâneo no mesmo período. MÉTODOS: Foi utilizado como modelo de procedimento o projeto diretriz Clinical Practice Guidelines in Oncology, (National Comprehensive Cancer Network), adequado aos procedimentos da Fundação SOBECCan - Hospital do Câncer de Ribeirão Preto - SP. Os custos estimados baseiam-se nos valores do tratamento médico pagos pelos setores público e privado em 2007. RESULTADOS: Os valores médios de custo individual do tratamento anual do câncer de pele não-melanoma são muito mais baixos do que os estimados para o tratamento do melanoma cutâneo. Entretanto, observados os gastos totais no tratamento do câncer de pele não-melanoma, percebe-se que os 42.184 casos deste câncer em São Paulo, no período estudado, fazem com que o custo total do seu tratamento seja 14 por cento superior ao dos 2.740 casos de melanoma cutâneo registrados no mesmo período para o SUS. Porém, para o sistema privado, o gasto total é, aproximadamente, 34 por cento menor para o tratamento do câncer de pele não-melanoma. CONCLUSÃO: O elevado número de casos de câncer de pele não-melanoma no Brasil - com 114 mil novos casos previstos para 2010, sendo 95 por cento diagnosticados em estágios precoces - representa um impacto financeiro ao sistema público e aos sistemas privados de saúde de cerca de R$ 37 milhões e R$ 26 milhões ao ano, respectivamente.

BACKGROUND: The most common form of cancer in Brazil is non-melanoma skin cancer, which affects approximately 0.06 percent of the population. There are no public policies for its prevention and the economic impact of its diagnosis has yet to be established. OBJECTIVES: To estimate the costs of the diagnosis and treatment of non-melanoma skin cancer in the state of São Paulo between 2000 and 2007 and to compare them with the costs associated with skin melanoma in the same period. METHODS: The Clinical Practice Guidelines in Oncology (National Comprehensive Cancer Network) was used as a procedure model, adapted to the procedures at the SOBECCan Foundation at the Ribeirão Preto Cancer Hospital in São Paulo. The estimated costs were based on the costs of medical treatment in the public and private sectors in 2007. RESULTS: The mean annual costs of each individual treatment of non-melanoma skin cancer were much lower than those estimated for the treatment of skin melanoma. Nevertheless, when the total costs of the treatment of non-melanoma skin cancer were taken into consideration, it was found that the total cost of the 42,184 cases of this type of cancer in São Paulo within the study period was 14 percent higher than the costs of the 2,740 cases of skin melanoma registered in the same period within the Brazilian National Health Service (SUS). However, in the private sector, the total cost was approximately 34 percent less for the treatment of non-melanoma skin cancer compared to melanoma. CONCLUSION: The high number of cases of non-melanoma skin cancer in Brazil, with 114,000 new cases predicted for 2010, 95 percent of which are diagnosed at early stages, represents a financial burden to the public and private healthcare systems of around R$37 million and R$26 million annually, respectively.