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UV Protection after a Nuclear War
by Bruce Beach
Radiological Scientific Officer

Table of Contents


Because I have been asked about this subject several times, and because there will be a need for this information after a nuclear war, and because there does not appear to be anywhere that I can find a document on this subject - I have decided to write up this material myself. For any who may decry my lack of expertise in this area, I will certainly accept their reservations and only ask that they provide me with a better article for posting.

Why there is little information on nuclear UV

Between the opposite extremes of Greenhouse Effect and Nuclear Winter many dire threats encircle mankind and many of these threats are not by any means mutually exclusive. While we will not concern ourselves here with the environmentalists' pet concern of Greenhouse Effect and shall confine ourselves to one particular subject associated with Nuclear Winter let us note that the non-availability of survival information is created by two extremes of thought.

One extreme of thought is characterized by the governments and their many bureaucracies that for the most part, for two reasons, sneeringly and condescendedly reject any requests for information. The first reason is that they hold it ridiculous that anyone would think after all these years without there having been a nuclear war that nuclear weapons would actually be used and that anyone should prepare for that eventuality. The second reason is that they become annoyed that a civilian (in their terminology not meaning someone who is non-military, but rather simply someone who is not representing a government agency) would encroach upon their domain and ask for information. These government attitudes are passing strange in that they are the ones who are supposed to be concerned about the well being of the public and they are ones who spend seemingly endless billions of dollars in building nuclear weapons and the means of their delivery while saying that they will never use them - so that we need not worry about them.

The other extreme of thought holds that use of nuclear weapons will be so disastrous that there is no need to make preparation for survival.

The rational for this latter doctrine is that the holders of it equate "survivability and therefore fightability" and therefore anyone who advocates 'survivalism' receives also their sneers, and more than that - their downright anger because to them we seem to be advocating nuclear war. While this latter accusation couldn't be further from the truth we still end up with the same result - the academic and technical talent on both sides give us no assistance in making preparation for nuclear survival.

The Meaning of Nuclear Winter

Ninety-nine percent of the sunlight being absorbed would make it rather dark so that we may say that these are literally dark days that are anticipated. Anyway, so much for statements regarding the threat of Nuclear Winter. However, two caveats may be made here from a survivalist's point of view. In the first place we do not know how intense it may or may not be. Some event or intervention may occur to ameliorate the final outcome.

The other caveat is that because this shall be an unique event we really have no experience to tell us how and it what way other factors may interplay. Consequently, while it may be a severe challenge to agriculture and survival - it may not be an insurmountable one and thought should be given to strategies to combat its effects. That, however, is beyond the scope of the present study and will have to be treated of elsewhere. Here we are concerning ourselves with one particular phenomena that may accompany nuclear winter and that is the intensifying of UV (ultraviolet rays) from the sun.

Intensified UV

This last quote does not clearly delineate why nuclear war survivors will not live long enough to concern themselves about the effect of UV in causing skin cancer but I thoroughly cover elsewhere my projections of the effects of an all out nuclear war on the world's population and in point of fact I am more pessimistic about the number of casualties than are most other sources who put them at about one billion people, or about 20% of the world's present population, whereas I put them at 80% or four billion of the world's present population. This still leaves 20% long term survivors or one billion people which is more population than the world had in 1800.

I shall now turn to one summary source of scientific literature that I do have available and the following quotes, unless otherwise indicated, are from that source - which is:

An Authoritative Scientific Review of Environmental and Health Effects of UV,
with Reference to Global Ozone Layer Depletion
Published under the joint sponsorship of the United Nations Environment Programme,
the International Labour Organisation,
and the World Health Organization Geneva,

The document itself is very long (hundreds of pages), often very technical, and involves many chapters. It is mainly concerned with two areas of inquiry one being what we have referred to as the Greenhouse effect and the other being industrial uses of UV. The document concerns itself extensively with biological and medical studies. There is, however, little in the document relating directly to nuclear war and its effects.

While the above quote refers to the environmentalists' concern about the Greenhouse effect, speculated as being caused by present human activity, the effects of a nuclear war on UV penetration could be much more substantial.

Technical Explanation of UV

UV is split into three categories or wavelengths:

Collectively they are all-adjacent in the electromagnetic spectrum and are just referred to as UV. It is the longer wavelengths that concern us and when in this article I refer to UV I am really referring mostly to UVA although sometimes UVB will be discussed.

Optical Radiation Spectral Bands
Ultraviolet radiation 100 - 400 nm
UVA 315 - 400 nm
UVB 280 - 315 nm
UVC 100 - 280 nm
Visible radiation (light) 400 - 760 nm
Infrared radiation (IR) 760 - 10 / 6 nm = 1 mm

Methods for measuring UV

The National Weather Service method for measuring UV

A very kind gentleman at:

has provided me with the following information:

If you have questions about health aspects contact the U.S. EPA at 1-800-296-1996. If you have questions about scientific aspects contact the NWS at (301) 713-0622.

Other methods for measuring UV

MEDs (minimum erythemal doses)

Of the two useful means of measurement of the intensity of UV described above the second appears most practical for our use and is calibrated in a unit called a MED.

Number of MEDs in a 3 h exposure period for a sensitive skin type (1 MED = 200 J m-2 effective) for the erythemally effective UVB irradiances are given in the following as a function of latitude (°) and time of year for the Northern Hemisphere (Driscoll 1992). We might think of this as being what is 'normal' in the a pre-nuclear holocaust period.

0 12 14 14 12 11 11 12 13 15 13 12 12
5 11 13 13 13 12 12 12 13 14 12 11 11
10 11 12 12 13 12 12 13 14 13 12 11 9
15 8 11 11 12 12 12 13 13 12 11 8 7
20 7 10 10 12 13 13 13 12 11 10 7 6
25 5 7 9 10 11 12 12 11 10 8 5 5
30 4 6 8 10 10 12 11 10 10 6 5 3
35 2 4 6 8 9 10 10 9 8 5 3 2
40 2 3 5 8 8 10 9 9 7 4 2 1
45 1 2 4 6 7 9 8 7 5 2 1 1
50 1 1 3 5 6 8 8 6 4 2 1 0
55 0 1 2 4 5 7 6 4 3 1 0 0
60 0 1 1 3 4 6 5 4 2 1 0 0
65 0 0 1 2 3 5 4 2 1 0 0 0
70 0 0 1 1 3 4 3 2 1 0 0 0
75 0 0 0 1 2 3 2 1 0 0 0 0
80 0 0 0 1 1 2 1 1 0 0 0 0
85 0 0 0 0 1 1 1 0 0 0 0 0
90 0 0 0 0 1 1 1 0 0 0 0 0

As an extrapolation of this last statement might we then say that as a worst case - a 100% depletion of the Ozone layer would result in a 200% increase in the UV exposure and from the table above - the worst case would be 45 MEDS (in the 3 hours centered on noon) or 15 meds per hour - or that one could receive a sunburn from being outside just 4 minutes at that time even on a dark cloudy day. Mind you, that is the worst case extrapolation of the maximum ozone depletion combined with the most critical geographical location and the time of day for the most intense exposure. Nevertheless, starting with this most extreme case we can then work downward in developing our defenses. Those who do not like my methodology can propose their own.

Variables affecting UV intensity

There are many variables that affect UV intensity.

There are many other variables such as:

grassy surfaces
high altitudes

all of which increase the intensity of the UV reflected.

Snow, sand and water are all reflective surfaces and will intensify UV exposure to varying degrees. Grass reflects from 2.5 to 3 percent, sand reflects 20 to 30 percent, snow and ice 80 to 90 percent. Depending on the angle of reflection, water can reflect up to 100 percent of rays striking the surface.

Speculation as to how much UV may be presented or present is largely useless. What will be needed is a reliable method of measure. We shall examine both methods of measure and methods of defense in later sections, but first let us look at the effects of intensified UV.

Medical Effects of Intensified UV

Excessive UV, even under 'normal' conditions, can cause serious serious physical problems. We can only speculate what it might do under the extreme conditions of Nuclear Winter.

Agricultural effects of Intensified UV

Beneficial effects of UV

Some amounts of UV are beneficial in the same way that some amounts of arsenic are beneficial (in fact necessary).

Instruments for measuring UV

The criteria that I have established for selecting proper instrumentation is as follows:

I have found some possible equipment solutions and present them on a
separate page.

Strategies for combating excessive UV

There come to mind several strategies for combating excessive UV.


First and foremost would be that of timing. Those individuals who have to work outside might try to do so in the twilight periods (before sunrise and after sunset) during the most serious circumstances. They should definitely avoid the midday hours if the situation is serious. The southern hemisphere custom of a midday siesta could certainly be considered everywhere.


A high protection factor is associated with a tightly woven (not knitted) material. UV is transmitted and scattered through the interstices of the material itself rather than penetrating the fabric.

Brimmed Hats


Eye protection is extremely important. Long term effects in the way of eye cancer and blindness can be very detrimental.

Dark sunglasses are NOT the answer. They can have the OPPOSITE effect that one might suppose. The reason is that if they are not special polarized UV protective their being dark will cause the pupil to open wider and the optic nerve will be exposed to MORE UV. Be WARNED about this.



Sun Screens

Surprisingly, while millions of dollars are spent marketing sunscreens and the pharmaceutical companies, medical associations, and weather bureaus all combine to promote them, the scientific studies themselves indicate that they are contra-indicated. That is to say - you should not use them. The reason is - UVB darkens the upper layers of the skin, and the creams and lotions enhance this darkening so that one does not as readily burn if they develop a tan (and some tanning is beneficial for that reason). HOWEVER, the tan does not prevent the UVA from penetrating through to the deeper cells where the DNA is affected and the detrimental causes of cancer occur. For this reason sunlamps and sun tanning are generally non-beneficial.

So - you can decide for yourself.


Most of the descriptions of Nuclear Winter and the concomitant effects of intensive UV come from non-governmental sources which we might well also characterize as anti-survivalist. They hold out little hope, and give little encouragement for survival.

As with dozens of other papers that I have provided on the subject of nuclear survival I do not doubt but that this one will also be subjected to ridicule. I find it strange that the government can take down the nuclear survival shelter signs, scrap the civil defense radiation detection equipment, ridicule the researchers and teachers of survivalist techniques - such as myself - and still spend billions upon billions in developing nuclear weapons and their means of delivery. But that is the way that it is.

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