Here is a quote from an article I read about this topic...........
"They must also be taught how to effectively shelter in place for a brief time while the radioactive fallout loses 90 percent of it's lethal intensity in the first seven hours and 99 percent of it in two days. For those requiring sheltering from fallout, the majority would only need a couple or three days of hunkering down, not weeks on end."
I've attached a document from the Department of Homeland Security (DHS) about how to best survive a nuclear attack. It appears the article that you read must have gotten its numbers from the attached DHS document.
I was a nuclear trained submarine officer for my first career. I was trained to calculate the radiactive dosage that a person would receive in different scenarios and what the potential health affects would be. It is my opinion that the article you drew a completely incorrect conclusion from the data. Let me explain.
Here is the source quotation from the attached DHS article:
During the first hour after a nuclear explosion, radioactivity levels drop precipitously. Radioactivity levelsare further reduced by about 90% after another 7 hours and by about 99% after 2 days. This quotation is describing radioactivity levels that result
within the near vicinity a nuclear blast during the first couple of days. A nuclear blast is an uncontrolled chain reaction as neutrons bombard isotopes of uranium or plutonium atoms and split them and release enormous amounts of energy. The splitting of the atoms in turn release more neutrons that bombard other atoms and split them to release even more energy. During the first hour or hours the nuclear fuel will become used up so the new radioactivity that is generated will drop off significantly. Radioactivity levels near the blast will drop off dramatically as the force of the blast disperses the radioactive materials as seen in a mushroom cloud. As the radioactive materials are dispersed due to air pressure from the blast and wind, the radioactive levels near the blast will drop as the materials are being carried away from the area. Please keep in mind that even though the radiactivity levels have dropped to 1% of the initial amounts in the vicinity of the blast, that 1% is still deadly and will very likely kill you if you are not already dead.
Now, let's talk about the radioactivity that is disbursed by the air pressure from the blast and the prevailing winds. The materials that get contaminated by the radiation will stay contaminated at lengths of time determined by the half-life of the radioactive sources (uranium and plutonium isotopes). Many of the isotopes of these elements have half-lives of thousands of years. For example, plutonium 239 which was used to destroy Nagasaki, Japan during WWII has a half life of 24,100 years. What that means, it will take 24,100 years for radiactive plutonium 239 to become half as radioactive as it was at the beginning of the 24,100 years. If an area has enough radioactivity to be deadly, it will take many years, decades, or centuries for that area to ever be safe again. Just look at Chernobyl (
Chernobyl disaster ). So if you happen to live down-wind of a city that was destroyed by a nuclear blast, over the next several days, weeks, or months, the radioactivity levels where you live may actual be increasing as more of the contamination from the city reaches you.
Here are the conclusions I believe you should draw. If you are near enough to a nuclear blast that the radioactivity levels drop by 99% within 2 days, then you are so close to the blast that you may not be alive 2 days later even if you are in a shelter. If you do survive those first 2 days, you will probably receive lethal radiation doses when you leave the shelter, even if your exit occurs weeks later.
Please keep in mind that in event of a catastrophy, the goverment will place a high priority on preventing panic. As such, governing officials will likely paint a rosie picture to prevent widespread panic that could occur if people understood the actual depressing facts. While the DHS document could make it appear that you would be ok after 2 days, anyone with a nuclear background can recognize what the results will really be.
For those requiring sheltering from fallout, the majority would only need a couple or three days of hunkering down, not weeks on end."
I'm afraid that the article's conclusion is not even close to being accurate based on the reasons I have stated above. I have to wonder what the interests are of the person who wrote this article. Is this person just misinformed or do they have something to gain by misrepresenting the facts?
