Monday, September 29, 2014

Radiotrophic Fungi Thrive on Gamma Radiation

In 1986 the Chernobyl Nuclear Power Plant suffered a catastrophic meltdown which irradiated thousands of square miles. The Chernobyl Exclusion Zone is the area around the reactor in a 30 kilometer (18 mile) radius also known as the Zone of Alienation, an area of mandatory resettlement. This disaster spread 200 times more radioactivity than the bombs that were dropped on Hiroshima and Nagasaki combined.
In 1991, five years after the meltdown, slimy, black molds were discovered on the walls inside the Chernobyl Nuclear Power Plant. Samples of the fungi were collected and studied at the Albert Einstein College of Medicine in New York City. They discovered that the mold was a collection of several fungi which contained melanin, a natural pigment found in most organisms. In order to test the effect of radiation on these bacteria the team exposed colonies of them to gamma rays 500 times as intense as the normal radiation background on Earth's surface. The colonies grew up to three times as fast as normal. In order to have a control group with which to compare the rate of growth, the created a mutant "albino" form of the fungus, which produced no melanin. This white fungus grew at a normal pace. Extrapolating their results, scientists discovered that the melanin in these fungi was used to convert gamma radiation into chemical energy to enhance the growth of these organisms. Co-researcher Ekaterina Dadachova  stated that, "Just as the pigment chlorophyll converts sunlight into chemical energy that allows green plants to live and grow, our research suggests that melanin can use a different portion of the electromagnetic spectrum - ionizing radiation - to benefit the fungi containing it”.
This was an enormous discovery, the radiation levels in the heart of the reactor were so great that scientists never expected to find any life inside of it, much less a group of organisms that were strengthened by it! Until now, melanin's biological role in fungi - if any - had been a mystery. This discovery has great potential and far-reaching implications. In space, ionizing ration is very prevalent, using this discovery, astronauts may be able to grow and rely on fungi like this as a self-replenishing food source for long missions bringing interplanetary travel that much closer.
 The melanin in these fungi is chemically identical to that contained in our own skin cells begging the question, does the melanin in our skin harvest energy from background radiation as well? This and many other questions are still being analyzed and may someday change the world we live in.

Tuesday, June 18, 2013

Dirty Bombs: What are they and how they could affect you?

It is human nature to fear things that we don’t understand. One of these things is how radiation exposure actually works. There is an incredible amount of misinformation about radiation and its effects on human beings. Truthfully small quantities of radiation are negligible, and in fact we are exposed to small amounts of various kinds of radiation all the time.

One concern that has been raised by the public is that terrorists will escalate from explosive or shrapnel bombs to bombs with hidden dangers as well as physical ones. In fact, one of the major worries in the aftermath of the recent Boston Marathon bombings was whether or not the shrapnel bombs were also radiological dispersion devices (RDDs) also known as dirty bombs.

Explosives Plus an Easily Dispersed Radioactive Source

First, an overview of dirty bombs and how they work.

Dirty bombs go a step beyond traditional explosives and add a radioactive component in the form of pellets or powder to the mix. One thing to note is that devices containing materials classified as radioactive does not equate them to a nuclear or atomic bomb. The violent fission reactions found in atomic bombs are not present in RDDs. Dirty bombs are meant to foment chaos and disruption instead of mass destruction. Terrorists count on public misinformation to help create further panic in a crisis situation.

When an RDD explodes, it coats everything nearby including people and objects with radioactive particles which can travel beyond the initial blast radius. Because of this, in addition to immediate contamination, secondary contamination can occur well beyond the radius of the blast.

What should I do if I find myself within the blast radius of one of these bombs?

First of all, don’t panic. While exposure to the types of radioactive material that would be found in these bombs could be an issue eventually if not properly cleaned up, the strength of the material used is not going to cause immediate radiation sickness, cell damage, or instant cell mutation1.

Because radiation cannot be felt or seen, the cautious thing to do is assume that there was a radioactive component to the bomb and respond accordingly. The Nuclear Energy Institute (NEI) has listed some general guidelines to follow if you find yourself in this situation and you are not seriously injured by the initial explosion.
  • Leave the immediate area on foot—do not take public transportation.
  • Go inside the nearest building. Seeking immediate shelter will reduce exposure to any radioactive material at the scene of the explosion.
  • Remove clothing as soon as possible and seal it inside a plastic bag. Save the clothing so that emergency response personnel can test it. Removing clothing will eliminate 90 percent of the radioactive contamination, according to the Centers for Disease Control and Prevention.
  • Take a shower or wash yourself as completely as possible. This will reduce the amount of radioactive contamination.
  • Seek more information from emergency response personnel who respond to the explosion. 

What if I live nearby? Should I evacuate or stay where I am?

If emergency responders have not made their way to your area, unless your building is damaged, it is recommended that you stay put. Many of the radioactive materials that are likely to be used in dirty bombs have a short half-life and decay quickly. They are also unlikely to penetrate building walls. If you are instructed to or choose to shelter where you are in the absence of instruction, it is recommended that you turn off your heating/air conditioning and any other device that draws air from the outside temporarily. As the situation becomes more organized, you should be able to get feedback from emergency personal by radio or in person for instructions on how to proceed.

In a particular event, who determines whether or not a bomb contains radioactive material?

The National Guard has a Civil Support Team (CST) whose members are deployed to most major events. Included in the gear that they have on hand is a portable radiation detector. As these individuals scan the area for various threats, they will determine whether or not radioactive material was mixed with the explosives. The CSTs will then alert the nearby population with the results of their testing.

Portable Radiation Detector with a Belt Clip

The best defense against these kinds of terrorist actions is to be informed. Knowing what to do if you find yourself in this situation robs them of their goal to spread chaos and fear. Better yet, spread the knowledge you’ve gained and together we can stand against those that want to harm us and take away our freedoms.
D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world.

1    Information provided by NEI


Steps for Public Safety Against a ‘Dirty Bomb’, Nuclear Energy Institute  
Boston Marathon Bombings Raises New Concerns of “Dirty Bombs,” Emergency Film Group  
Dirty Bomb, National Terror Alert Response Center

Wednesday, May 15, 2013

The Mysteries of Dark Lightning

The pursuit for the understanding of the world around us is one of man’s greatest obsessions. Entire fields of study have been formed to explain everything from the inner workings of tiny particles to the awesome power of phenomena such as storms and lightning. There are those among us that build their careers on finding the reason ‘why’ things behave the way they do. These are the fearless, the bold, and maybe just a little bit crazy research scientists.

XKCD's Depiction of Scientific Curiosity
One such group of scientists from the Florida Institute of Technology, led by Joseph Dwyer, is studying a newly observed type of lightning called ‘dark lightning’ or terrestrial gamma-ray flashes (TGFs). Currently there are conflicting opinions about the specific properties of dark lightning. What is not disputed is that this type of wave exists and it is one of the most powerful energy forms composed of light that scientists have observed here on Earth. 

First a brief explanation of visible lightning

Lightning is nature’s way of equalizing the polarization between two clouds, within a single cloud, or between a cloud and the surface of the Earth. As the electric field within a cloud increases, the air around the cloud begins to ionize. That is, electrons are pulled away from the surrounding air molecules. These fragments of molecules form a conductive plasma pathway between two objects. The positive ions travel upward through this path and the negative ions (electrons) travel downward. When they meet, a complete pathway is formed. Lightning is the result of the charge transfer between cloud and cloud or cloud and ground through that pathway.

Basic Principles of Visible Lightning

So exactly what is dark lightning and how is it related to regular lightning?

Periodically energy outbursts are observed in high energy thunderstorms. The theory is that certain conditions cause the electric field built up by the storm to discharge in a different way. Storms can discharge energy by converting it into a flash of intense ionizing (x-rays and gamma rays) radiation that travels upward rather than channeling that energy downward in the form of heat and light. These waves are radiated upward in all directions instead of formed into a directed bolt. As such, this cloud of energy dissipates quickly.

(From left to right) Start of energy transferal, energy discharged up as 'dark lightning', energy discharged down as visible lightning (Credit: Studio Gohde)

Gamma rays? Those are only man-made or found around black holes and supernovas right? 

Scientists previously assumed that this was the case.  After some extensive research, Professor Dwyer and his team have a theory that the thunderstorm acts as a giant particle accelerator. Electrons are accelerated almost to the speed of light by the strong electrical fields in the storm.  More study is needed to define the method of generation and properties of this phenomenon. The advantage to further research in this field is that there are many devices already designed that detect and analyze gamma radiation.

Is dark lightning dangerous to humans?

Any kind of ionizing radiation is harmful to humans on some level. However, the likelihood of being close enough to absorb enough rays to be harmed is pretty slim. Dark lightning occurs in the neighborhood of 16,000 feet. Commercial airplanes cruise at an altitude of about 30,000 to 40,000 feet so at most the plane would pass through the height in question twice during their flight. Also pilots try to avoid flying through the heart of a thunderstorm.  Even if the timing was just right, the amount of radiation emitted by a flash of dark lightning is maybe up to the equivalent of 10 chest X-rays around the edges and up to 1 full-body CT scan in the very center of the radiation burst according to research scientist, Joseph Dwyer. Dwyer also indicated that dark lightning seems to be fairly rare; he and his team have figured that dark lightning occurs maybe once for every thousand visible lightning flashes.

So next time a storm rolls in, think about all of the amazing properties that come along with that storm. This discovery shows just how much exploring we have to do even in our own backyards. Imagine what future generations of research scientists will find.

D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world.

Thunderstorms Generate Mysterious 'Dark Lightning', Rick Pantaleo,
Dark Lightning Linked to its Luminous Twin, Becky Oskin, Live Science
Scientists detect dark lightning linked to visible lightning, Nikolai Østgaard, AGU
Florida Institute of Technology
Wikipedia (Overview of Lightning)

Friday, April 19, 2013

Deciphering Hazmat Symbols

Have you ever wondered what those large tanker trucks are carrying? How do you know if a given truck is carrying anything radioactive? Would the truck be glowing green like in cartoons?

'Radioactive' Glowing Green Tanker Truck
Radioactive Cartoon Truck

While fun to think about, radioactive materials can’t be identified in such an obvious way. However there is a labeling standard detailed by the US Department of Transportation (DOT) that requires trucks to post what type of material they are carrying. The label found on these trucks is a symbol in a colored diamond. These signs may seem really cryptic but they can tell you a lot about what is in that truck. These signs or placards comply with DOT regulations for trucks shipping within the United States and Canada. 

What do all those symbols and numbers mean?

There are four relevant items indicated by these signs as noted by the diagram below.

Diagram defining hazard placard parts
Class 7 Hazard Placard

Hazard Symbol: An alternate method for identifying the material contained in the tank

Class Name: A one or two word description of the contents of the tank

Color Classification: The color of the placard provides some detail relating to the type of material
Red: Flammable Material
Red and White: Flammable Solid or Spontaneously Combustible Material
Orange: Explosives
Yellow: Oxidizer
Green: Nonflammable Material
Blue: Dangerous when Wet
White: Inhalation Hazard and Poisonous
White and Yellow: Radioactive
Black and White: Corrosive
White with Black Stripes: Misc Hazardous Material

Hazard Class: Shipped materials are categorized in one of 9 classes

Class 1: Explosives
Class 2: Gases – Compressed or Refrigerated
Class 3: Flammable and/or Combustible Liquid
Class 4: Flammable Solids – Spontaneously Combustible and/or Water Reactive
Class 5: Oxidizing Materials – Organic Peroxide
Class 6: Poisonous and/or Infectious Substances
Class 7: Radioactive Materials
Class 8: Corrosive Materials
Class 9: Misc. Hazardous Materials

Sometimes in place of the class name, a classification number is used. This is called the United Nations identification number. These numbers are listed on a chart that further classifies the contents of the tank. This number can also be denoted separately from the hazard placard in the form of a rectangular orange label.

Two Versions of Labeling for Shipping Petroleum Gases
Petroleum gases, liquefied
More information and a complete list of these numbers can be found here:

For those of you with a smart phone on hand, there is an app available that provides a database search for the UN numbers. You can get a general description and if you want more information you can click on the listing for more details. The app for Android is called DOT Placards and the app for Apple is called Placard+.

Should I be concerned if I see a truck hauling radioactive material?

There are many regulations dictating how radioactive material can be shipped. Depending on the radiological strength, these materials fall into 4 different categories:

  • Exempt (not strong enough to pose a health hazard)
  • Low-level Waste (LLW)
  • Intermediate-level Waste (ILW)
  • High-level Waste (HLW)
Each of these categories requires a certain type of container and shielding for transport. As summarized by the World Nuclear Association:

“The objective of the regulations is to protect people and the environment from the effects of radiation during the transport of radioactive material.

Protection is achieved by:

  • containment of radioactive contents;
  • control of external radiation levels;
  • prevention of criticality; and
  • prevention of damage caused by heat.

The fundamental principle applied to the transport of radioactive material is that the protection comes from the design of the package, regardless of how the material is transported.”

So rest assured that even in the event of an accident, the radioactive material is securely packed to prevent accidental radiation exposure.


World Nuclear Association, “Transport of Radioactive Materials”
San Bernardino County Fire Dept, Hazardous Materials Division, “Emergency Response Program”