Radiation-Seeking Fungus

In Chernobyl, wildlife is thriving. In fact, in the old reactor, a new radiation-seeking fungus is thriving:

In 1999, a robot sent to map the inside of the reactor returned with samples of a particularly black fungi, indicating an abundance of the biological pigment melanin, which also colours your skin.

Though melanin is typically associated with 'protective' properties – absorbing and safely transforming different electromagnetic wavelengths, such as DNA-damaging ultraviolet light – the researchers had an inkling that a more extraordinary phenomenon was allowing the fungi to prosper; something still involving the combination of melanin and radiation, but beyond the bounds of radioactive protection.

After all, even without melanin, many fungi are intrinsically radiation-resistant.

Their hunch was bolstered by findings of melanised fungi, happily congregating in the cooling pools of functional nuclear reactors, and by studies of dark, 'radiation-seeking' fungi, purposefully growing towards radioactive particles in soil, particularly around Chernobyl.

The team looked to the example of photosynthesis as a model, said Casadevall. If plants can use the green pigment, chlorophyll, to absorb energy from the Sun and produce a usable form of chemical energy, they reasoned, fungi might be able to use their melanin pigment and radiation energy in a similar way. They even devised the snazzy moniker, 'radiosynthesis', for the process.

To test their idea, the group analysed three different types of fungi, including Cladosporium sphaerospermum, the species abundant in and around Chernobyl. Using ionising radiation from the radioactive isotope, caesium-137, they exposed the fungi to radiation doses similar to those inside the damaged reactor, and about 500 times greater than the Earth's normal background level.

Melanin-containing fungi exposed to the radiation – even when nutrient-starved on purpose – grew significantly larger and up to 2.5 times faster than fungi without melanin and those not exposed to radiation.

'How we made the Chernobyl rain'

Russian military pilots explain 'How we made the Chernobyl rain':

Russian military pilots have described how they created rain clouds to protect Moscow from radioactive fallout after the Chernobyl nuclear disaster in 1986.

Major Aleksei Grushin repeatedly took to the skies above Chernobyl and Belarus and used artillery shells filled with silver iodide to make rain clouds that would "wash out" radioactive particles drifting towards densely populated cities.

More than 4,000 square miles of Belarus were sacrificed to save the Russian capital from the toxic radioactive material.

"The wind direction was moving from west to east and the radioactive clouds were threatening to reach the highly populated areas of Moscow, Voronezh, Nizhny Novgorod, Yaroslavl," he told Science of Superstorms, a BBC2 documentary to be broadcast today.

"If the rain had fallen on those cities it would've been a catastrophe for millions. The area where my crew was actively influencing the clouds was near Chernobyl, not only in the 30km zone, but out to a distance of 50, 70 and even 100 km."

In the wake of the catastrophic meltdown of the Chernobyl nuclear reactor, people in Belarus reported heavy, black-coloured rain around the city of Gomel. Shortly beforehand, aircraft had been spotted circling in the sky ejecting coloured material behind them.

Moscow has always denied that cloud seeding took place after the accident, but last year on the 20th anniversary of the disaster, Major Grushin was among those honoured for bravery. He claims he received the award for flying cloud seeding missions during the Chernobyl clean-up.

A second Soviet pilot, who asked not to be named, also confirmed to the programme makers that cloud seeding operations took place as early as two days after the explosion.

Alan Flowers, a British scientist who was one of the first Western scientists allowed into the area to examine the extent of radioactive fallout around Chernobyl, said that the population in Belarus was exposed to radiation doses 20 to 30 times higher than normal as a result of the rainfall, causing intense radiation poisoning in children.

Mr Flowers was expelled from Belarus in 2004 after claiming that Russia had seeded the clouds. He said: "The local population say there was no warning before these heavy rains and the radioactive fallout arrived."

Imagine Earth without people

Bob Holmes, perhaps too gleefully, asks us to Imagine Earth without people:

Though modern buildings are typically engineered to last 60 years, bridges 120 years and dams 250, these lifespans assume someone will keep them clean, fix minor leaks and correct problems with foundations. Without people to do these seemingly minor chores, things go downhill quickly.

The best illustration of this is the city of Pripyat near Chernobyl in Ukraine, which was abandoned after the nuclear disaster 20 years ago and remains deserted. "From a distance, you would still believe that Pripyat is a living city, but the buildings are slowly decaying," says Ronald Chesser, an environmental biologist at Texas Tech University in Lubbock who has worked extensively in the exclusion zone around Chernobyl. "The most pervasive thing you see are plants whose root systems get into the concrete and behind the bricks and into doorframes and so forth, and are rapidly breaking up the structure. You wouldn't think, as you walk around your house every day, that we have a big impact on keeping that from happening, but clearly we do. It's really sobering to see how the plant community invades every nook and cranny of a city."

With no one to make repairs, every storm, flood and frosty night gnaws away at abandoned buildings, and within a few decades roofs will begin to fall in and buildings collapse. This has already begun to happen in Pripyat. Wood-framed houses and other smaller structures, which are built to laxer standards, will be the first to go. Next down may be the glassy, soaring structures that tend to win acclaim these days. "The elegant suspension bridges, the lightweight forms, these are the kinds of structures that would be more vulnerable," says Masterton. "There's less reserve of strength built into the design, unlike solid masonry buildings and those using arches and vaults."

But even though buildings will crumble, their ruins — especially those made of stone or concrete — are likely to last thousands of years. "We still have records of civilisations that are 3000 years old," notes Masterton. "For many thousands of years there would still be some signs of the civilisations that we created. It's going to take a long time for a concrete road to disappear. It might be severely crumbling in many places, but it'll take a long time to become invisible."

Wildlife defies Chernobyl radiation

Wildlife defies Chernobyl radiation:

The exclusion zone around the Chernobyl nuclear power station is teeming with life.

As humans were evacuated from the area 20 years ago, animals moved in. Existing populations multiplied and species not seen for decades, such as the lynx and eagle owl, began to return.

There are even tantalising footprints of a bear, an animal that has not trodden this part of Ukraine for centuries.

"Animals don't seem to sense radiation and will occupy an area regardless of the radiation condition," says radioecologist Sergey Gaschak.

"A lot of birds are nesting inside the sarcophagus," he adds, referring to the steel and concrete shield erected over the reactor that exploded in 1986.

"Starlings, pigeons, swallows, redstart — I saw nests, and I found eggs."

There may be plutonium in the zone, but there is no herbicide or pesticide, no industry, no traffic, and marshlands are no longer being drained.

There is nothing to disturb the wild boar — said to have multiplied eightfold between 1986 and 1988 — except its similarly resurgent predator, the wolf.

Pripyat Ghost Town

Pripyat Ghost Town tells a peculiar story, in broken English (with an almost audible Russian accent), about one young lady's peculiar motorcyle tour — "a story about town where one can ride fast, with no stoplights, no police, no danger to hit some cage or some dog..." The town? Pripyat — four kilometers north of Chernobyl.

Very eerie. (Hat tip to Todd for the link.)

Edit: The original link has died. Here's a newer link.