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LABORATORIO DE FÍSICA DE LA ATMÓSFERA | |
Universidad Mayor de San Andrés - La Paz Bolivia |
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LABORATORIO DE FÍSICA DE LA ATMÓSFERA | |
Universidad Mayor de San Andrés - La Paz Bolivia |
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Ultraviolet Radiation Index (UVI)
Average december 2003
| Maximum exposure time in minutes | ||||
La Paz & Altiplano Region |
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| Skin type | Regional example | Cloudy sky | Semi-cloudy sky | Clear skies |
| Very Dark (Type IV) | Altiplanic | 26 | 17 | 14 |
| Medium (Type II & III) | Mediterranean | 14 | 10 | 8 |
| Very Fair (Type I) | Nordic | 7 | 5 | 4 |
Cochabamba & Valley Region |
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| Skin type | Regional example | Cloudy sky | Semi-cloudy sky | Clear skies |
| Very Dark (Type IV) | Altiplanic | 28 | 19 | 15 |
| Medium (Type II & III) | Mediterranean | 15 | 10 | 8 |
| Very Fair (Type I) | Nordic | 7 | 5 | 4 |
Santa Cruz & Eastern Region |
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| Skin type | Regional example | Cloudy sky | Semi-cloudy sky | Clear skies |
| Very Dark (Type IV) | Altiplanic | 30 | 20 | 16 |
| Medium (Type II & III) | Mediterranean | 17 | 11 | 9 |
| Very Fair (Type I) | Nordic | 8 | 5 | 4 |
The figures in the above table are measured in minutes and indicate the maximum time of continuous sun exposure, between the hours of 10:00 and 15:00, before skin burns and damage occurs.
To consult the index chose the skin type closest to your own and relate it to the data.
People who regularly spend prolonged time in the open-air should protect their eyes and sight by wearing sunglasses with an UV filter.
The Radiation Index is calculated taking the quantity of energy in the form of Ultraviolet Radiation (RUV) that reaches a surface in a particular measure of time. The equipment used to detect and measure RUV simulates the behaviour and reaction of a medium skin type and from this data determines the maximum exposure time before the occurrence of burning or skin damage on unprotected skin.
MED (Minimum Erythemal Dose) is the unit of biologically effective UV exposure, i.e. the minimum amount of UV that the skin can receive before burning occurs. This measurement is not very user friendly so we have converted the RUV index data to give the Maximum Time Exposure to the Sun.