How did the experiment on irradiating forests with cesium-137 end in the USA⁠⁠ (7 photos)

Mankind first learned about radiation at the end of the 19th century thanks to the French physicist Becquerel. For a long time, no one even thought about the dangers of this phenomenon. It is enough to recall the craze for radium at the beginning of the 20th century, when it was added to toothpaste, chocolate, cosmetics, advertised as a cure for impotence, and "miracle drugs" were produced on its basis.





Scientists began to seriously analyze the effects of radiation on living organisms only by the middle of the 20th century, when the nuclear era began in the history of the Earth. In 1945, the destructive power of the new weapon was obvious to everyone, but the consequences that its use could lead to were yet to be studied. And it was desirable to do this in practice, and not with the help of theoretical assumptions.



Radioendocrinator - a plate with radium that had to be carried in the pocket of the trousers to increase potency. The product was produced in the mid-20s of the last century

Gamma Forest

This is how the idea of ​​​​special irradiation of a certain biocenosis was born in order to test the long-term effects of radiation on living organisms. The idea arose in the early 1960s in the depths of the Brookhaven National Laboratory in the United States, which dealt with issues of peaceful use of the atom and fundamental nuclear physics.

It was not possible to work in tandem with the military - they carried out nuclear explosions at a test site in Nevada, poor in vegetation and fauna. It was much more interesting to test the effect of ionizing radiation on the ecosystem of temperate latitudes. For example, on the coniferous-deciduous forest that was located next to the laboratory. It was located on Long Island near New York, right in its wooded part.





Brookhaven National Laboratory complex on Long Island, USA

The experiment was called the "gamma forest" and began in 1961. At first, scientists fenced off an experimental area of ​​20 hectares. Two rows of wire fences allowed small animals to move freely, but large mammals had to be caught and taken out of the zone. The radioactive area was the center of the experiment, but the experiment itself affected a forest area of ​​5 square meters. km — it was this area that was fenced off not for animals, but for people, with warning signs hung generously everywhere.

A structure was erected on a metal platform in the center of a small clearing on the experimental site. It was a four-meter pole, on top of which was a container with 14 ounces (almost 400 grams) of cesium-137. A chamber was buried under the platform, securely shielded with lead plates and concrete blocks. The container with cesium was periodically lowered into it using drives to make it possible to safely study the effects of radiation.



Forest irradiation facility in Brookhaven Forest

Interim summary

The facility's operating mode was as follows: 20 hours of operation, four hours of break. And so on for 17 years until 1978. However, the effects of radiation exposure were visible after just one year.

At the epicenter of the experiment, a hundred meters from the source, all living things completely died out. At the same time, no signs of decomposition of dead biomass were observed, because the radiation killed not only trees, bushes and grass, but also microorganisms responsible for the processes of natural decay. The forest area around the cesium container was a gray-brown spot with bare posts and withered grass. The bark had fallen off some of the trunks, and the dead trees stuck out around the pole like ugly peaks, not much different in appearance from it.

As we moved away from the container, the forest began to come to life little by little. The first green islands appeared already a hundred meters from the source. It was sedge, and, interestingly, its oblong spots grew behind the dead trees. As in the case of sunlight, the trunks shaded the grass from the effects of radiation.

In general, Brookhaven Forest looked most impressive from above. Around the epicenter of death, a green ring of sedge first appeared, then a ring of bushes, then a deciduous forest - oaks and maples, and only at the very edges of the site did conifers grow - pines and spruces.



Results of the forest irradiation experiment

These trees turned out to be the most susceptible to radiation - pines suffered from irradiation much more than sugar maple or oak. And of the deciduous trees, the weakest tree was the linden. Even at a distance of a kilometer from the source, it shed its leaves, although it received a fairly low dose.

As for animals, scientists did not detect any noticeable impact on them. Small animals and birds simply left the contaminated area, and insects, worms and protozoa died after the first cycle of irradiation.

The second phase of the experiment

In 1978, the cesium source was dismantled, the second phase of the experiment began, during which specialists monitored how nature was recovering in the contaminated area. The forest did not return to its previous state soon. This was clearly visible from above - only maples and young oaks had mastered the epicenter of radiation. On the rest of the land, the forest, although restored, lost its diversity - there are practically no coniferous trees left in it.



The epicenter of Brookhaven forest after the end of the experiment

The above picture was taken in 1998 after 20 years of observation. Well, at present, such a bald spot is no longer there - nature has completely taken its toll, although the forest within a radius of three kilometers from the tower has become predominantly deciduous instead of mixed - pine trees have not grown in it.

Simultaneously with the scientists from Brookhaven Laboratory, their colleagues from Canada and Puerto Rico conducted similar experiments. It turned out that the tropical ecosystem recovers much faster than the vegetation of temperate latitudes. And the taiga is most exposed to radiation - in Canada, and today the epicenter of the experiment is clearly visible from above.

In the USSR

The same kind of experiments were conducted in the Soviet Union. Only here no one deliberately irradiated nature, and the impact of radiation on the biocenosis was studied after two nuclear accidents. As a result of each of them, the zone that received the strongest radiation became a radiation reserve.



East Ural Reserve

The first such reserve appeared on maps in 1966, nine years after the accident at the Mayak plant in the Chelyabinsk region. It is called the East Ural Radiation Reserve, and is still closed to tourists. However, according to measurements and assurances from ecologists, it is quite safe to stay there for a short period of time. As for species diversity, Soviet scientists have fully confirmed the findings of their American colleagues - deciduous trees are more easily affected by radiation. Only in the East Ural Reserve, the place of the dead pines and firs was taken not by oaks and maples, but by birches.