Radioactive isotopes found in conjuction with Nuclear plant accidents

The 1962 Sedan nuclear test formed a crater 100 m (330 ft) deep with a diameter of about 390 m (1,300 ft), as a means of investigating the possibilities of using peaceful nuclear explosions for large-scale earth moving.

Apart from their use as weapons, nuclear explosives have been tested and used for various non-military uses, and proposed, but not used for large-scale earth moving. When long term health and clean-up costs were included, there was no economic advantage over conventional explosives.^[29]
Synthetic elements, such as einsteinium and fermium, created by neutron bombardment of uranium and plutonium during thermonuclear explosions, were discovered in the aftermath of the first thermonuclear bomb test. In 2008 the worldwide presence of new isotopes from atmospheric testing beginning in the 1950s was developed into a reliable way of detecting art forgeries, as all paintings created after that period may contain traces of cesium-137 and strontium-90, isotopes that did not exist in nature before 1945.<sup>[30]
end quote from wikipedia.

In the process of trying to find out more about plutonium I discovered this section on peaceful uses of 
nuclear weapons or energy. For example, one of the ways art forgeries are detected is by finding traces of cesium-137 and strontium-90 isotopes in the paint. What this means in real time is that everyone and everything now has cesium-137 and strontium-90 in them as well as everything now on the surface of the earth.

And now there are new elements like einsteinium and fermium that are bi-products of nuclear explosions.

next quote under the heading "plutonium" from wikipedia:</sup>
Plutonium is the heaviest primordial element, by virtue of its most stable isotope, plutonium-244, whose half-life of about 80 million years is just long enough for the element to be found in trace quantities in nature.^[3] But plutonium is a regular byproduct of a reactor’s splitting uranium atoms in two. Some of the speeding subatomic particles of the fission process turn uranium into plutonium. ^[4]
The most important isotope of plutonium is plutonium-239, with a half-life of 24,100 years. Plutonium-239 is the isotope most useful for nuclear weapons. Plutonium-239 and 241 are fissile, meaning the nuclei of their atoms can break apart by being bombarded by slow moving thermal neutrons, releasing energy, gamma radiation and more neutrons. These can therefore sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors. end quote.

So, what is in reactor number 3 is therefore plutonium-239 with a half life of 24,100 years.

Since this is the biggest long term problem that humanity (and all life will experience the next almost 25,000 years from the Fukushima Nuclear plant partial or complete meltdowns) this might be something that warrants further study.
next quote under the heading radioactive iodine from wikipedia:
Iodine-131 (¹³¹I), also called radioiodine (though many other radioactive isotopes of this element are known), is an important radioisotope of iodine. It has a radioactive decay half life of about eight days. Its uses are mostly medical and pharmaceutical. It also plays a role as a major radioactive hazard present in nuclear fission products, and was a significant contributor to the health effects from open-air atomic bomb testing in the 1950s, and from the Chernobyl disaster, as well as being a threatening presence today in the Japanese nuclear crisis. This is because I-131 is a major uranium, plutonium and indirectly thorium fission product, comprising nearly 3% of the total products of fission (by weight).
end quote.

Even though thyroid, some types of breast cancer and some types of cancers occurring in the sexual organs can be prevented from taking potassium iodide pills, the half life of Iodine 131 or "Radioactive Iodine which can travel in the air only has an 8 day half life (which means that it is only active for 8 days.

Also, when I first went and looked at the areas near Area 51 in the Nevada Desert on Google Earth I found hundreds of nuclear bomb test craters still visible by satellite pockmarking that section of Nevada. From these tests einsteinium and fermium were found caused by thermonuclear explosions.

Begin quote from "radioactive cesium" in wikipedia subheading

"Health risk of radioactive caesium"

Caesium-137 is water-soluble, and the biological behavior of caesium is similar to that of potassium and rubidium. After entering the body, caesium gets more or less uniformly distributed throughout the body, with higher concentration in muscle tissues and lower in bones. The biological half-life of caesium is rather short at about 70 days.^[6] Experiments with dogs showed that a single dose of 3800 μCi/kg (approx. 44 μg/kg of caesium-137) is lethal within three weeks.<sup>[7]
end quote.

A Nuclear expert on CNN TV said that radioactive cesium in Shellfish and fish in the area of Fukushima could be very serious if people tried to eat them because of radioactive cesium.
next quote on Caesium-137</sup>

Accidental ingestion of caesium-137 can be treated with Prussian blue, which binds to it chemically and then speeds its expulsion from the body.^[8]
The improper handling of caesium-137 gamma ray sources can lead to release of this radio-isotope and radiation injuries. Perhaps the best-known case is the Goiânia accident, in which an improperly-disposed-of radiation therapy system from an abandoned clinic in the city of Goiânia, Brazil, was scavenged from a junkyard, and the glowing caesium salt sold to curious, uneducated buyers. This led to multiple serious injuries from radiation exposure.
Caesium gamma-ray sources that have been encased in metallic housings can be mixed-in with scrap metal on its way to smelters, resulting in production of steel contaminated with radioactivity.<sup>[9]
 end quote:

For many years likely into the present many people were cautioned for example of buying silverware or stainless steel cooking utensils from China because often they contained disposed of radiation which might harm unsuspecting buyers.


So, to sum up, radioactive iodine has a half life of only 8 days. So, one would have to be exposed to it through the air, water, dust within 8 days to have it give a person thyroid or other types of potentially fatal cancers.

However, radioactive Cesium has 70 Days to give a person a fatal dose. And the worst doses are like radioactive iodine from breathing it into ones lungs or eating it or accidentally having the dust in one's mouth. However, far more serious long term is the radioactive plutonium-239 which is actually 7% or more of the mox fuel mix at Reactor number 3 which will kill  creatures or make them sick or genetically alter them for 25,000 years wherever those particles go on earth in any form of air, water or earth. So, even one radioactive particle of plutonium-239 could kill or injure or maim many many creatures and humans over those 25,000 years since it doesn't degrade during that time no matter what is going on.</sup>