UV Safety Awareness Month: UV Radiation

You know all about UV radiation in sunlight, but did you know that there are plenty of artificial sources of UV rays that can impact your skin and eyes? And not just tanning beds--many industrial occupations involve exposure to UV rays. Read on to learn more about how UV radiation works and how it works for us!

UV Radiation

Ultraviolet (UV) radiation is the term for certain rays of energy given off by the sun, as well as artificial sources like tanning beds. UV radiation comes in multiple types, determined by their wavelength:

• Ultraviolet A (UVA): Longer wavelengths that are not absorbed by the ozone layer. Penetrate deeper into your skin and can be present year-round, even in winter. About 95 percent of the sun's UV rays that reach the ground are UVA rays.
• Ultraviolet B (UVB): Shorter wavelengths that are largely absorbed by the ozone layer. Stronger than UVA but much less present throughout the year.

So what does this radiation do? UV radiation has many effects, some beneficial and some harmful:

• Produces vitamin D, a necessary mineral that helps the body absorb calcium and phosphorus from food.
• Damages skin and causes sunburns.
• Prematurely ages skin.
• Causes different types of skin cancer, such as many melanomas.
• Causes vision problems and eye damage.
• Excessive exposure can suppress the immune system, enhancing the risk of infections.

It's important to get some sun exposure in order to produce vitamin D, and you don't need much.. The World Health Organization (WHO) recommends 5 to 15 minutes of sun exposure 2 to 3 times per week.

Sources of UV Radiation

Sunlight

You know that sunlight contains UV radiation, but don't forget that the strength of the UV rays that reach the ground varies depending on many factors:

• Altitude: Higher elevations receive more UV rays.
• Atmosphere: UV rays can get through clouds. Ozone in the upper atmosphere filters out some of this radiation.
• Latitude: UV exposure reduces the farther you get from the equator.
• Reflection: UV rays can bounce off surfaces, even if they're not obviously reflective. Water, sand, pavement, grass, and snow can reflect rays and lead to an increase in UV exposure.
• Season: Spring and summer months have stronger UV rays.
• Time of Day: UV rays are at their strongest from 10 a.m. to 4 p.m.

Man-Made Sources

UV radiation is present in many technologies, including industrial processes. If you work around these devices, make sure you wear eye protection!

• Tanning beds and booths: Frequency and duration of use affect how much UV radiation you absorb from sunlamps and sunbeds. Most modern UV tanning beds only emit UVA rays, but older ones also emit UVB.
• Xenon and xenon-mercury arc lamps: These are typically used to disinfect, simulate sunlight (for solar panel testing), in some car headlights, or for UV "curing" (drying of ink and other coatings).
• Plasma torches and welding arcs.
• UV Therapy: UV-based treatment for skin conditions in which the drug psoralen is taken to increase UV sensitivity, and then the skin is exposed to UV light.
• Black-light lamps.
• Mercury-vapor lamps: only if the outer bulb is broken. Most of these lamps now have safeguards against this.