title: [Possible values of UV index in Serbia].
abstract: BACKGROUND
  UV Index is an indicator of human exposure to solar ultraviolet (UV) rays. The numerical values of the UV Index range from 1-11 and above. There are three levels of protection against UV radiation; low values of the UV Index--protection is not required, medium values of the UV Index--protection is recommended and high values of the UV Index--protection is obligatory. The value of the UV Index primarily depends on the elevation of the sun and total ozone column.
  
  
  OBJECTIVE
  The aim of the study is to determine the intervals of possible maximal annual values of the UV Index in Serbia in order to determine the necessary level of protection in a simple manner.
  
  
  METHODS
  For maximal and minimal expected values of total column ozone and for maximal elevation of the sun, the value of the UV Index was determined for each month in the Northern and Southern parts of Serbia. These values were compared with the forecast of the UV Index.
  
  
  RESULTS
  Maximal clear sky values of the UV Index in Serbia for altitudes up to 500 m in May, June, July and August can be 9 or even 10, and not less than 5 or 6. During November, December, January and February the UV Index can be 4 at most. During March, April, September and October the expected values of the UV Index are maximally 7 and not less than 3. The forecast of the UV Index is within these limits in 98% of comparisons.
  
  
  CONCLUSIONS
  The described method of determination of possible UV Index values showed a high agreement with forecasts. The obtained results can be used for general recommendations in the protection against UV radiation.
authors.forename: Milorad
authors.initials: M
authors.lastname: Letić
mesh_terms: D006801:Humans; D011829:Radiation Dosage; D012621:Seasons; D055771:Serbia; D013472:Sunlight; D014466:Ultraviolet Rays