9th Feb 2011 

The Most Informative Q&A Site covering nearly all complexion flaws

By: Dr. Pierre

Questions & Answers On 
UV Rays Effect on the Skin

Images of Sunburn blisters, peeling, inflammation

Sun Blisters Peeling

Images of Suntan skin in various degrees



UV Radiation is the electromagnetic spectrum between x rays and visible light, i.e., between 40 nm and 400 nm. 

The UV spectrum is divided into Vacuum UV (40-190 nm), Far UV (190-220 nm), UVC (220-290 nm), UVB (290-320), and UVA (320-400 nm).  

The natural source of UVR is from the sun. Artificial sources include tanning beds, black lights, germicidal lamps, curing lamps, mercury vapor lamps, high-intensity discharge lamps, halogen lights, fluorescent and incandescent sources, and some types of lasers (excimer lasers, nitrogen lasers, and third harmonic Nd:YAG lasers).  

Depending on the wavelength range of the emitted UVR each source has its own unique hazards. 

UVC, Far UV and Vacuum UV are absorbed in the atmosphere.  

Germicidal lamps are designed to emit UVC radiation because of their ability to kill bacteria.  

Our epidermis absorbs UVC.  

UVB is the most destructive form of UV radiation because of its high energy level in causing photochemical damage to cellular DNA, sunburn, delayed pigmentation and skin cancer. 

Reductions in atmospheric ozone could increase the prevalence of skin cancer. 

UVA, the most commonly encountered by us is the tan causing ray followed by erythema if the exposure is excessive.  

While UVA is needed by us for synthesis of vitamin D, overexposure thickens and toughens the skin (leading to premature aging), and suppresses our immune system. Photography and tanning booths use UVA lamps. 

Noting on the rising number of men and women suffering from delayed pigmentation, pre-mature aging and skin cancer, this has become my motivation in pioneering the world’s first anti-UV day cream. The Dr Pierre line has 6 non-sensitizing and highly moisturizing variations to suit every skin need – i.e. Product #s 070, 70, 74-P, 76-P, 076 and 79-P. 


I read an article several years ago regarding sun tanning.

It stated that the sun would continue to burn your skin for a while after you are through tanning, and that you needed to take a shower to wash "it off".

Several of my friends think I am crazy, and I cannot find the article to prove it.

One wants to bet me that who ever is wrong has to bungie jump..I need help.

ASAP, Is it true what I read? Thank you for your help.

(submitted by alias: CJ)

Hi CJ, when you suntan under natural sunlight(i.e. not salon tanning beds which emits only artificial UV-A rays) you are receiving both UV-A and B rays.

UV-A rays radiate deep into the dermis layer, but has lower energy than the B rays.

Both the epidermal and the dermal layers contain melanin(black) cells which give us our skin tone, depending on their concentration level.

UV rays cause a chemical reaction to the melanin cells, which then lead to rapid melanin cell multiplication.

Because A rays penetrate both layers of melanin cells the multiplication of melanin cells in two layers produces a dark tone(i.e. the tan look) very quickly.

The B rays, on the other hand, do not penetrate as deep as the A rays.

B rays penetrate only up to the epidermal layer, and therefore will cause only the epidermal layer's melanin cells to multiply.

So, the skin won't tan as fast as if exposed to the A rays.

However, the B rays have much higher energy than the A rays, and because of this, it burns.

The B rays energy will not deplete as fast as the A rays, and will accumulate on the skin.

Over time, the accumulated energy causes the melanin cells to multiply gradually.

This slow process of multiplying the melanin cells is termed delayed pigmentation, appearing on the skin as uneven brown patches usually.

For people who love tanning, usually they do not want to get burned.

So they apply a cream that contains anti-UVB agents to block off the B rays, and to allow only the A rays to pass through in order to get a quick tan.

If such a cream is applied, then it is less likely to get any burn during or after a tan, provided of course the person doesn't over-expose to the sun by exceeding the limit the cream can protect.

However, if no cream is applied, then the person is receiving both the A+B rays.

In such a case, the high B rays energy will not deplete immediately but will retain and accumulate.

So, it is true that it will burn the skin for some time(even up to a few days after say, a 3 to 5 hours exposure under the hot afternoon sun).

Taking a shower, however, will not wash away the burn, but it does help a little by cooling off the temperature left by the B rays.

Soaking in a cold bath tub of water will cool off the body temperature better, but it will not deplete all the accumulated B rays energy.

Regards: Pierre  


I would like to know what treatments/products you would suggest using for my skin problems.

I have a pigmentation problem on the right side of my face that has worsened progressively over the past five years.

It started as a small spot on my cheek and has increased to most of the right side and has moved to my forehead.

I have had numerous glycolic peels, used Renova, RetinA and other bleaching cream.

I think all of these things have just worsened my skin condition and made it extremely sensitive to any sunlight and resulted in more acne type problems.

I do take birth control pills, but the pigmentation problem started and progressed long before I started taking them.

Your recommendations would be greatly appreciated.

Thank you.

Laura (submitted by alias: laura)

Hi Laura, with your current condition, the first thing you must avoid is exposure to the sun.

Using a good sunscreen with SPF 8 to 15 is sufficient.


Do not use one that's higher.

Sunscreens with higher SPF can cause lots of other complications to the skin.

More on SPF here.

Artificial peels often caused more harm than good.

After a fresh peel, the skin temporarily appears soft and fair but, actually, it is due to the disappearance of some of the epidermal sub-layers which have been peeled off.

With the loss of some sub-layers, naturally the skin has a much thinner epidermal skin, thus less protective capability against the sun's harmful UV rays.

I advise that you stop receiving such treatment altogether.

Birth control pills can also cause a hormonal imbalance in your body over time, and leading to some melanin cells to over-multiply themselves.

Although your pigmentation problem started and progressed long before you started taking them, it does not necessarily mean that it is not one of the current additional causes to your pigmentation problem.

If, after having avoided the sun and having used a good sunscreen for some time, there's still no improvement, then the primary cause of your pigmentation now is due to the pills.

Of course your skin peels and past exposure to the sun are most likely the early causes to your pigmentation problem, but your pills could have become a later problem contribution source.

Bleaching creams can only work, provided the source of the problem can be controlled.

Nevertheless, all other daily/nightly skincare products used also play a role to some extent in your resulting skin condition.

I urge you to try our samples.

For your convenience I have pasted a copy of our text version Sampleset Request Form below here for your completion.

(Note: Actual form contents are removed from here to save space)

Best Regards: Pierre  

I have used a tanning bed 3 times for 10 minutes each time; I am beginning to see white spots on my legs; Is this being caused by the tanning bed and is there anything I can do to get rid of them.

Thanks (submitted by alias: waterbaby)

Hi Waterbaby, the Answer is yes and no.

The white spots are melanin cells that have been depigmented, and cannot multiply themselves when stimulated by UV rays.

This is of course not natural, but it happens to most people.

All other normal melanin cells when exposed to the UV rays will automatically multiply themselves, thus becoming more in numbers and more concentrated, and appearing darker in shade(i.e. Tan) so as to shield and protect the skin better against UV penetration.

This is a natural physiological phenomena(a great creation of our good God) to protect our skin from further damage by the harmful effects of UV rays.

So when cells that are normal and when exposed to UV rays became darker, the remaining abnormal cells that do not multiply and remain the same obviously appear as if they are white spots in the darker cells surrounding area.

So these white spots were not caused by the UV rays to become white, but were caused by the surrounding cells which became darker through UV exposure, and highlighting them as if they are white spots.

I don't encourage this kind of treatment.

Tanning beds emit artificial UV-A rays which possess deep penetration ability, up to the dermis layer, causing both layers of melanin cells to multiply.

Although UV-A rays energy is lower than that of UV-Bs, we are all already exposed daily to the sun's natural UV-A and B rays as well.

So everyone of us have enough absorption of UV-B rays every day.

UV-B rays that accumulated on our skin can be highly activated by additional UV-A rays to cause serious harmful effects on skin, leading to skin cancer in the long run.

Stop this treatment for a while and let the tanned cells get back to their normal concentration level, and the white spots will disappear gradually.

Regards: Pierre  

I really appreciate that evrey time you Answer my Question.

You are the real expert of the skincare.

I think I will keep using the UV cream with jojoba oil.

I have another Question 

(Sorry to bug you again) which is " Is it better for the skin to take sun, properly, once in a while?" I stop taking sun since this Summer (before I was taking sun until I get suntun every year) because I realize that I am getting more spots on my arms.

sincerely, Sachiko Sueki (submitted by alias: Sachiko)

You are welcome, Sachiko, with your Questions always.

I'm always glad to see that someone receives proper help when needed.

The UV rays from the sun is very harmful, and is the main cause to your spots.

In Australia, the peoples' love for sunbathing in the past has contributed to the country's skin cancer rate as being the highest in the world.

Today, instead of seeing people around naked, bareback, or in bikinis at the beach, more and more people are aware of the danger now, and are wearing large straw hats, and having more clothings on for protection.

By the way straw hats(or even umbrellas) won't really help much.

Lot's of UV rays are reflected from walls, ground, and every surface onto a person's skin.

Yes, a bit of sunlight is good for your skin. 


However, even without having to go out directly under the sun for a sunbath, you are already receiving and absorbing lots of UV rays in the day.

UV ray is just next to the 'visible rays' in the light spectrum of rays.

Visible rays are rays that when present allow us to see an object. Without visible rays will mean complete darkness, and we can't see anything.

So you can safely assume that as long as there are visible rays around, there are also UV rays present(since these two rays are just next to one another).

You can therefore go further to assume that so long your eyes can still see something(i.e. not complete darkness), there are UV rays present.

So even when you are at home or in the office (indoors), so long there is still good visibility, you are already absorbing UV rays reflected from the outside into your home/office.

So avoid sunbathing totally.

There's no need for that.

You are already receiving adequate amount of UV rays daily naturally.

Regards: Pierre  

I have a Question.

Isn't a suntan just a precursor to a sunburn? In other words, wasn't every sunburn a suntan a few hours earlier.

What does suntan lotion do? My theory is that it does nothing more than lengthen the amount of time before everything happens.

If you would get a tan in 40 minutes and a burn in 60 w/o lotion, then wouldn't putting on #2 just make it take 80 minutes to tan and 120 to burn? Please help me.

If you have a web page i could reference it would be great thanks cameron (submitted by alias: Cameron)

Hi Cameron, A suntan may usually appear as a precursor to a sunburn, but not always, and not under all circumstances.

The sun's rays comprise a portion of spectrum classified by scientists as Ultra-Violet(UV) rays.

These are further divided into UV-A, UV-B and UV-C.

UV-C is mostly shielded by the earth's ozone layer, leaving UV-A and UV-B to penetrate our atmosphere.

UV-A penetrates both our epidermis and dermis skin layers.

Since the basal layer(the last layer) of the epidermis and the prickle-cell layer(the first layer) of the dermis both contain melanin cells(melanocytes), these two layers of cells are stimulated simultaneously by the UV-A rays to produce more melanocytes - a natural chemical reaction ingeniously created by our God Almighty - to prevent the harmful effects of the UV rays against the underlying cells.

In other words, the hyper-production of more melanin (melanin means black) cells is to provide a more opaque skin layer(which otherwise would be more translucent) in order to obstruct penetration of the UV rays. 


It is for this reason (that is, two layers of skin containing melanin cells being stimulated to multiply melanocytes simultaneously), that UV-A causes sun-tanning.

Tanning-beds in beauty salons also emit UV-A rays to produce quick tans.

However, the energy in UV-A is weaker than in UV-B.

That is why the tan doesn't last long (usually disappeared after one to three weeks), and that is also why UV-A doesn't cause sun-burn on its own.

On the other hand, UV-B's energy is much greater than UV-A's, and thus, it causes the burning sensation very quickly.

However, the penetration level of UV-B is only up to the epidermis.

Thus, UV-B causes only the epidermal layer(that is, only one layer) to multiply the production of its melanin cells.

That is why a tan is not produced as instantly as exposure to UV-A rays.

Due to its high energy, UV-B rays once absorbed into the skin do not deplete quickly, but retained for a long time.

UV-B accumulates to cause a slow 'tan' which results in delayed pigmentation of the skin(that is, those unsightly brown blocky patches).

Since both UV-A and UV-B are found in the sun's rays, exposure to the sun will cause the skin both to tan and to burn - the tan manifesting faster than the burn as explained above - appearing as if a tan always precedes a burn.

But one can obtain a tan without a burn(or less degree of burn) by the following methods:  

1. By exposure to a salon's sun-tanning bed(which emits only UV-A rays).

2. By applying a sunscreen that blocks out only the UV-B rays(that is preventing a burn caused by the UV-B rays but allowing the UV-A rays to penetrate the skin to cause the tan).

Some screens even contain active ingredients to speedify the tanning effect, by amplifying the UV-A rays penetration.

There are also suntan products which can amplify tanning - and within 10 to 15 minutes - under room lighting, without exposure to the sun.

Such products are often named as suntan lotions(milk, or the like).

Note that if one doesn't want to have a tan as well, then he/she should not apply a suntan lotion, but a broad spectrum sunscreen lotion instead(meaning a sunscreen with total block action - blocking UV-A and UV-B).

So do not get mixed up between suntan and sunscreen products.

Sunscreens are available in various strengths, measured in SPF terms.

SPF stands for Sun Protection Factor.

The SPF of a sunscreen is determined by sampling a group of people by the following steps(usually not less than 25 people of various skin color tone):  

1. The human samples are made to expose their back to the sun.

Most parts of the body are covered, except the parts which are to be tested and measured.

Let's say there are 5 sunscreen products(named A, B, C, D, and E) of varying anti-UV strengths which need to be measured.

Then the person's back will have 6 holes, cut out from the shirt(or any covering) exposed to the sun.

One hole will have nothing applied on it.

The other five holes will each have one of the five sunscreens applied, and marked.

2. After every 5 or 10 minutes, the back of the human samples are examined to determine if a burn has occurred.

To elaborate, let's say after examining one of the human samples, the unprotected part was found to blister in 10 minutes, while the other 5 parts(on the back of the same person) each took 100, 150, 180, 200 and 220 minutes respectively to form the first sign of blisters.

The SPF is then computed by dividing each of these 5 values by 10 minutes(when it was unprotected).

Thus, the SPF value for the 5 sunscreens will be: Sunscreen A = 100/10 = SPF 10 " B = 150/10 = SPF 15 " C = 180/10 = SPF 18 " D = 200/10 = SPF 20 " E = 220/10 = SPF 22 It can be comprehended clearly that SPF is therefore a measure of the number of times a sunscreen will be able to protect a person before blister occurs as compared to his/her exposure to the sun if unprotected.

3. The readings of all the human samples are noted, averaged and compiled, to provide the SPF values for the respective sunscreens measured.

Since SPF is a measure of the number of times(and not absolute hours or minutes), and since such measurement is conducted on sampling of a small group of people, and taking their mean value(averages), note that a darker complexioned person may apply, say, an SPF 10 sunscreen and yet is better and more effectively protected than one who is fairer-skinned and wearing an SPF18 sunscreen.

Why so? Well, if the darker complexioned person were to take 30 minutes to blister under unprotected exposure, then applying an SPF 10 sunscreen will enable him/her to expose for 300 minutes before blistering occurs.

On the other hand, the fair-skinned person may get blisters after only 10 minutes of unprotected exposure.

So, an SPF 18 sunscreen will only protect him/her for 180 minutes.

Moreover, every person is different constitutionally.

A person's skin, although applying the same sunscreen, may not react exactly in the same manner as that which was determined from the small group of human samples.

Yet another factor.

The sampling that was conducted in a cold 4-seasonal climate(even if done during summer time with lots of sunlight) may not apply well to people living in the tropical and sub-tropical climates.

Therefore, one may find an SPF sunscreen good for protecting him/her up to, say, 200 minutes of exposure in a colder country, but realized that the same sunscreen could not last longer than 100 minutes at one of the beaches in Singapore, Malaysia, or Australia.

Different times of the year within one country will also have different amount of UV-A and UV-B rays, and as such, a sunscreen's protection time will vary according to the time of the year.

UV-rays are also absorbed and retained in swimming pools and in sea-water for some time even after the sun has set.

Therefore, swimming immediately after sunset may not be all that safe as most people presumed.

I would recommend early morning swim instead.

Staying at home or carrying an umbrella does not mean that one is not exposed to any UV rays absolutely.

The ground, the walls, the glass, the surroundings, all reflect light and UV-rays.

So long we are able to see any object(that is objects are visible to our eyes), there are UV rays present, though in different degree depending on the time of the day and year.

This is so because we can see only when there's visible ray, and visible ray is just next to the UV-ray spectrum.

Therefore, whenever there is visible ray, there are UV-rays.

Moreover, higher SPF sunscreen doesn't necessarily mean better and more effective(especially those containing inorganic substances).

Higher SPF requires higher concentration of UV absorbers in the sunscreen, and thus a higher risk of developing skin reaction and allergy.

Sunscreens using organic substances such as TiO2(Titanium Dioxide) is safer, not only in that it is organic and less susceptible to allergy, but it also works by deflecting the UV-rays, rather than absorbing them and retaining on the skin's surface as in cases of inorganic UV absorbing agents.

I believe such retention of UV-rays on the skin's surface(especially those with higher SPF) will in the long run promote skin complications too.

However, unfortunately, organic substances alone do not seem to work more effectively than the synergistic effect of skillfully combining both organic and inorganic substances.

I hope the above explanation will help you and others in buying sun care products and in the choice of their relative SPF values more intelligently and more rationally.

Best Regards: Pierre