Yahoo Answers is shutting down on 4 May 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

What is the difference between UVA and UVB?

Summer is approaching the Northern Hemisphere and it's time to put on some sun block, but what is the difference between UVA and UVB sun rays?

Sources greatly appreciated

9 Answers

Relevance
  • 1 decade ago

    Sunscreen is a must for anyone who spends time outside. Your bottle probably mentions something about UVA and UVB rays. Since you care so much about your health, I thought I'd refresh your mind on the difference between the two.

    UVA rays: These are less likely to cause sunburn than UVB rays, but they penetrate your skin more deeply. Watch out because UVA rays can go through windows, lightweight clothing, and even your car windshield. Prolonged exposure cracks and shrinks the collagen and elastin in your skin, which is why UVA rays are responsible for signs of aging including wrinkles, saggy and leathery skin, and suns spots.

    UVB rays: These are responsible for tanning your skin, but they also cause sunburn. UVB rays are the main culprit when it comes to skin cancer. These rays also go through windows, and it doesn't matter if it's cloudy — you're still at risk for exposure.

    Although both types are responsible for different health risks, they're equally harmful to your skin. So if you're planning on enjoying the day outdoors, lube up with a sunscreen that protects against both UVA and UVB rays 20 to 30 minutes before heading out. Reapply at least every two hours.

  • 1 decade ago

    The sunlight that hits the earth’s atmosphere is made up of two different types of rays; Ultraviolet A (UVA) and Ultraviolet B (UVB) which affect your skin in different ways. UVB rays are the primary cause of sunburn and most skin cancers and can generally be blocked by window glass. UVA, on the other hand, can pass through window glass and is associated with skin ageing. UVA rays penetrate deeper into the base layer of the skin so even if you’re not getting burnt, you’re still likely to be ageing your skin. Just remember, A is for ageing and B is for burning.

    Source(s): Ask Jeeves
  • 6 years ago

    This Site Might Help You.

    RE:

    What is the difference between UVA and UVB?

    Summer is approaching the Northern Hemisphere and it's time to put on some sun block, but what is the difference between UVA and UVB sun rays?

    Sources greatly appreciated

    Source(s): difference uva uvb: https://tr.im/zxEE7
  • 1 decade ago

    UVA is 400 nm - 320 nm

    UVB is 320 nm - 290 nm

    (UVC is 290 nm - 100 nm)

    UVA (320-400 nm) radiation constitutes >90% of the environmentally relevant solar UV radiation and is thought to be the most relevant with regard to cancer risks.

    Source(s): GP for more years than I care to remember
  • 1 decade ago

    UVA rays:

    These are less likely to cause sunburn than UVB rays, but they penetrate your skin more deeply. Watch out because UVA rays can go through windows, lightweight clothing, and even your car windshield. Prolonged exposure cracks and shrinks the collagen and elastin in your skin, which is why UVA rays are responsible for signs of aging including wrinkles, saggy and leathery skin, and suns spots.

    UVB rays:

    These are responsible for tanning your skin, but they also cause sunburn. UVB rays are the main culprit when it comes to skin cancer. These rays also go through windows, and it doesn't matter if it's cloudy — you're still at risk for exposure.

    Although both types are responsible for different health risks, they're equally harmful to your skin. So if you're planning on enjoying the day outdoors, lube up with a sunscreen that protects against both UVA and UVB rays 20 to 30 minutes before heading out. Reapply at least every two hours.

    http://www.fitsugar.com/3181946

    Just noticed Brainiac has same answer ... lol.

    He also has the link to this website:

    All You Need to Know About UVA Rays

    UVA rays:

    make up the majority of the suns UV light. Unfortunately, humans are almost never safe from these rays as they can pass through windows, windshields, and even some light clothing. Basically, anytime you are outdoors your skin is being exposed to UVA rays.

    Although UVA rays are less likely to cause severe sunburn and skin cancer, these rays do play a large role in the breakdown of elastin, thus making them directly responsible for aging. Basically, UVA rays are the driving force behind wrinkles in the skin. Excessive and prolonged exposure to UVA rays breaks down and cracks the collagen and elastin of our skin, which in turn causes wrinkles. 75% of our skin is made of collagen, the protein of skin, cartilage, bones, tendons and other connective tissues in our body. UVA rays are capable of penetrating the skin deeper than UVB rays. After excessive exposure to them, the skin (collagen and elastin) looses elasticity and the ability to resume its shape after stretching which is why wrinkles occur. Outside of aging and leathery skin, UVA rays are also known to exacerbate the negative effects of UVB rays and can directly cause some forms of skin cancer, including melanoma.

    UVA rays are the primary rays used in tanning beds and salons. In moderation, UVA rays can help your body produce its own vitamin D, and vitamin D is important for protecting against certain cancers, diabetes, osteoporosis, and other diseases.

    UVB rays:

    are the primary cause of sunburn and skin cancer. Although they have the nickname of "tanning ray", they are more intense and carcinogenic than UVA rays. Fortunately these rays cannot pass through glass and clothes.

    UVB rays are known to directly contribute and cause Basal and Squamous cell carcinomas and Melanoma (skin cancers). These rays stimulate the melanocyte cells located on the bottom layer of skin. When these cells are stimulated they produce melanin, which is the brown pigment of a suntan. This is the skin's natural defense against harmful ultraviolet rays. However, when overexposure occurs, the rays can mutate skin cells causing sunburn, blistering, scarring, moles, and in severe cases, skin cancer!

    UVB rays are classified as having a wavelength between 290-320 nanometers.

    http://www.homesunburnremedies.com/difference-betw...

  • 5 years ago

    Diabetes is among the most common disorders in the world today. Here are a few natural remedies that can be helpful in reducing the sugar levels in a diabetic patient https://tr.im/W89qR

    Despite various researches done and precautions taken, one cannot predict who will suffer from diabetes. Depending on the type and severity, every diabetic patient should be given medications.

  • ?
    Lv 4
    5 years ago

    Hmm... I have never owned an iguana but I know people who have... I would get a round screw in one with a special reptile fixture and put it over a basking spot... I'm not sure which would be better, but you could always get one with both... Sorry I couldn't help more...

  • 4 years ago

    2

    Source(s): 1 Month Diabetes Treatment http://reversediabetestoday.enle.info/?6A7U
  • ?
    Lv 4
    4 years ago

    1

    Source(s): Hair Fall Solution http://enle.info/HowToStopHairLoss/?Z5Hj
Still have questions? Get answers by asking now.