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!
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
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.
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.
How to Keep Safe from UV Radiation
Sun damage to your skin from UV radiation can increase your chances of skin cancers like melanoma. Some tips:
- Limit sun exposure. Attempt to avoid the sun's intense rays between 10am and 4pm.
- Avoid tanning beds. Just because it's an artificial light source doesn't make UV radiation any less dangerous. Those who begin indoor tanning at a young age increase their risk of melanoma.
- Apply sunscreen every day. Use a sunscreen with sun protection factor (SPF) of at least 30, both before and every 60 to 80 minutes during outdoor exposure. You may need to apply it more often if swimming or sweating heavily. Select "broad-spectrum" products that filter both UVA and UVB light.
- Use enough sunscreen. Most people apply only 25 to 50 percent of the recommended amount by the National Council on Skin Cancer Prevention. Apply at least one ounce (a palmful) when applying it.
- If you are likely to sunburn, wear a long sleeved shirt, pants and a wide brimmed hat. Make use of shade as often as possible.
- Conduct monthly self exams. The best time to do these is right after a shower or bath, using a full length mirror and a hand held mirror in a bright room.