Which UV is bad for you....All UV !

[colinbm]

Which UV is bad for you....All UV !

https://www.news-medical.net/news/20190822/New-study-reveals-mechanism-of-ultraviolet-induced-skin-breakdown.aspx

[dabateman]

Well they look at 3 wavelengths and then concluded that all three are damaging. These being 265nm, 302nm and 365nm.

Would have been better to treat the cells with broader range of light and IR light. The amount of even 365nm in sunlight is very low compared to IR. If there mechanical stress test scales with light as they claim then IR would also be damaging.

 

They need a better test with more controls in my opinion before making general claims.

 

Link to paper;

https://www.sciencedirect.com/science/article/pii/S1751616119305892

[JMC]

I get very concerned about the validity of an article when one of the section in bold says "all types of UV radiation are equally harmful" when talking about UVA, B and C. Be interesting to know whether paper discussed anything about the requirement of UV for Vitamin D production, or perhaps they consider that to be harmful too. I really hope they got someone with some skin knowledge to proof read the article before it got published.

[Andrea B.]

.....no one UV range is more damaging than another. Rather, the magnitude of absorbed UV energy governs the degradation of tissue mechanical integrity.

 

For equivalent incident dosages, UVC damages human stratum corneum the most.

 

Perhaps one should not go by the popular report on a medical news site. The abstract seems to indicate that because we absorb more UV-A than UV-B and more UV-B than UV-C, the absorbed amounts are all equally damaging. If absorbed in equal amounts, then UV-C is the most damaging.

 

 

 

 

Edit: C --> A and clarification.

[OlDoinyo]

This is oversimplifying. The pattern of damage is wavelength-dependent. The shorter wavelengths are more energetic, but also not very penetrating, so their consequence tends to be more superficial. UV-A and far blue light are much more penetrating, and more capable of causing deeper tissue damage. UVB and UVC are especially hard on the cornea of the eye, because it is very vulnerable to superficial damage. UVA is harder on the lens of the eye, because it can reach there.

[Andrea B.]

The paper only addressed damage to the the outer skin layer.

[linuxmaster]

Everything is bad for you out reasonable limits ^__^

[photoni]

good morning. I ask you a basic question, I use a tanning lamp with 6 neon tubes to print the BW negatives with the ancient techniques; they are 10 cm from the sandwich: glass over negative over sensitized 100% cotton paper.

Is the light reflected from the paper bad for the eyes?

my eyeglasses have a slight UV treatment, in fact in portraits with wet collodion the lenses are not transparent but a little gray

Is it enough or better to add Polaroid mobile lenses (which are uncomfortable and heavy)?

Thank you

Toni

[colinbm]

Polycarbonate safety goggles at the minimum & you need your face & skin covered.

[ulf]

Polycarbonate safety goggles at the minimum & you need your face & skin covered.

It is all about exposure intensity and time.

If you are doing this for a long time you should be careful, but I assume the process can be running without you very close for most of the time.

 

The intensity in typical tanning bed tubes is not very high and the wavelengths are mainly in the UV-A region that is less dangerous.

Just as you should be careful with exposure to strong sunshine those tanning lamps are emitting harmful UV if exposuring you for a long time even from some distance.

Compare the typical usage during normal tanning.

 

It is still a good practice to protect your eyes, but If the exposure time is reasonably limited, there would not be much risk from the reflected light from the paper to your skin.

Many normal plastic materials used in eyeglasses limit UV rather well, but polycarbonate protection glasses like the ones Stefano showed are even better. https://www.ultravioletphotography.com/content/index.php/topic/4441-odd-polycarbonate-goggles/page__fromsearch__1

There are types like those specifically designed for UV-protection.

[Andrea B.]

UV light is particularly bad for the eyes. At a certain age we all begin to get cataracts unless we have been exceptionally careful to protect our eyes our entire lives while outdoors. This is, of course, impossible. So I will suggest that when dealing with more direct UV light than sunlight, you must add some eye protection. Damage is cumulative.