[UV-radiation--sources, wavelength, environment]

Area of Science:

• Environmental Science
• Dermatology
• Physics

Background:

• Solar radiation encompasses ultraviolet (UV) radiation, a portion of optical radiation ranging from 290-4,000 nm.
• UV radiation is internationally classified into UVC (200-280 nm), UVB (280-320 nm), and UVA (320-400 nm) based on wavelength.
• Global radiation, or solar radiation reaching Earth's surface, is modified by atmospheric conditions, geographic factors, and time-dependent variables.

Purpose of the Study:

• To define ultraviolet (UV) radiation and its environmental sources.
• To explain the factors influencing solar radiation reaching the Earth's surface.
• To describe the determinants of cumulative UV exposure.

Main Methods:

• Review of international definitions for UV radiation classification.
• Analysis of factors affecting solar radiation penetration and modification in the atmosphere.
• Identification of variables contributing to cumulative UV dose.

Main Results:

• UV radiation is categorized into UVC, UVB, and UVA, with specific wavelength ranges.
• Atmospheric conditions (ozone, pollution), geographic latitude, elevation, season, time of day, cloudiness, and indirect radiation modify global radiation.
• Cumulative UV exposure is significantly influenced by outdoor activities, occupation, sunbed use, and phototherapy.

Conclusions:

• Understanding the characteristics and environmental modulation of UV radiation is crucial.
• Biologically effective radiation is a complex interplay of solar output and Earth's atmospheric/geographic factors.
• Cumulative UV exposure is multifactorial, involving environmental and behavioral components.