Search This Blog

Tuesday, May 24, 2011

Radioactive Fossils!

Last week one of our engineers took a trip down to Moab, Utah which is about a 4 hour drive south from our facility. For those of you who have never visited southern Utah, Moab is a world-famous mountain biking destination. It’s also known for dinosaur bones – the bright red sandstone in the area has produced some amazing ancient remains. While checking out one of the shops in town, our engineer noticed that the MiniRad-D (a portable radiation detector) he brought with him alarmed when he passed a row of fossils. I was surprised to find that this isn’t an anomaly: fossils often have radiation levels much higher than the environment around them. Robert Bekker, a world famous paleontologist, referred to this phenomenon when he said "you wouldn't want to leave some bone fragments in your pocket all day long."

An enthusiast checks the radiation levels of a dinosaur bone near Denver (source).

So why are fossils so ‘hot’? The reasons for this are not completely known, but one possible reason is that naturally-occurring radiation tends to concentrate in the living tissue of plants and animals. This is especially true with ocean-dwelling creatures such as shellfish and snails. Particles containing  isotopes such as U-238 and Th-232 and other isotopes often coalesce on the seafloor where the living organisms are exposed to them. Over long periods of time, the collected isotopes decay into other radioactive isotopes, making even small concentrations stand out. Also, In a process known as permineralization, living materials are replaced at times by deposits of denser materials with greater concentrations of radioactive isotopes.

These concentrations are usually fairly low, however, and it’s easy to see why people miss them. There’s often no visual difference between a rock containing a fossil and other ancient rocks. And because Geiger counters respond slowly to radiation, they would be ineffective at finding radiation at such low levels unless the operator knows what they are looking for. Scintillation detectors like the Cesium Iodide crystal used in the MiniRad-D will have a much better chance of finding these materials because they react quickly to radiation and can be up to 100 times more sensitive to radiation.

Also found in southern Utah, this rock contains measurable levels of Th-232.

Has anyone else had luck finding fossils or bones with a radiation detector? All this talk has made me want to get out into the late-spring sunshine and go searching. Who knows how many hot dino bones are still down there?  

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

Wednesday, May 18, 2011

D-tect Systems Video

To give a better idea of what we do here at D-tect Systems, we shot this short film on site here at our Draper, Utah facility. It gives a short introduction to the radiation and chemical detection field and then gives a short description of each of our products. We hope it can give you a sense of what D-tect is all about!



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

Monday, May 16, 2011

Putting Radiation in Perspective

Due to the recent nuclear crisis in Japan, we've seen much more technical jargon than usual on major news stories. A reason for this is that radiation physics is a highly technical field and even quantifying radiation can be very complicated: a shift of a few decimal places can mean the difference between no risk and a major radiological hazard. Even the units are new - how many people have ever used 'becquerel' or 'half-life' in a casual conversation?

In conjunction of the new language hitting newspapers and TV screens, we've seen a great push to put radiation in perspective. This basic education goes a long way to help people make choices on how much they should worry about what is going on in Japan and what they can do to protect themselves. Visual examples are popular such as this one on xkcd.com, as well as thorough explanations discussed here by Harvard Medical School.

In supporting this movement, we recently released a Radiation Basics Sheet that we put together with data from the World Nuclear Association and US Environmental Protection Agency. We included some relative doses such as how much radiation you'll get from watching a year of TV, how much from a chest x-ray, and how much you'll get from flying across the US. We hope that this information can be used to turn dispel fears and boost confidence. 

Our sheet was recently featured on the blog of STORMWATER (a journal for surface water quality professionals). The post What do the Numbers Actually Mean? is very informative and talks about radiation contamination in Tokyo's tap water. We're excited that someone is putting this information to good use, and we're grateful to STORMWATER for the coverage.

If you would like more information to help you put radiation risks in perspective, we here at D-tect Systems have experts in the radiation detection field who can provide more information by email (info@dtectsystems.com) or even on the phone (801.495.2310). 

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

Friday, May 13, 2011

My Trip to Japan

While in Japan, I was paired with a group that was sent to check on the structural integrity of several church buildings in several cities. My role was to show them how to use the equipment and gauge the levels of radiation at each site. To check on these levels I went armed with two different radiation detectors: the MiniRad-D (a small, pager-sized detector) and the Rad-ID (a portable radiation identifier).

In my visits to cities from Tokyo to Iwaki I checked radiation levels and talked with the local church officials about what those levels meant. Radiation levels in downtown Tokyo were near natural background levels but the closer I got to Fukushima, the higher the radiation levels rose. The cities I visited showed readings of anywhere from 0.35 µSv/hr to 2 µSv/hr above background radiation, which are elevated levels, but definitely not dangerous. Using the Rad-ID, I found out that most of the radiation came from the radioactive isotopes Co-60, I-131, I-132, and Cs-137, which are commonly given off in nuclear processes.


An interesting observation that I made was that storm drains in the areas I visited showed higher levels of radiation than the surrounding areas. I surmised that rainfall had carried down and collected some of the radioactive dust in the air and deposited the contamination as it flowed down these drains.


Although the Japanese have shown amazing resilience and are working as hard as they can to solve these enormous problems, there is still much uncertainty about health risks and what the future will bring. We’ll be back soon to check on the radiation levels again. If you’d like to brush up on your radiation basics, you can check out this sheet we’ve complied. It has basic conversions, safety levels, and doses to put radiation exposure in perspective. An interesting chart on radiation dose rates can be found here.

Wednesday, May 4, 2011

Radiation Contamination in Food and Water: What's the Risk?

As Japanese emergency workers continue to pump out thousands of gallons of contaminated water from the damaged reactors of the Fukushima Power Plant, radiation contamination in food and water has emerged as a new focus of the international media.  

Before explaining the risks of food and water contamination, it’s important to understand the difference between radiation exposure and radiation contamination.  The United States Center for Disease Control (CDC) defines exposure and contamination with the following:

A person exposed to radiation is not necessarily contaminated with radioactive material. A person who has been exposed to radiation has had radioactive waves or particles penetrate the body, like having an x-ray. For a person to be contaminated, radioactive material must be on or inside of his or her body. A contaminated person is exposed to radiation released by the radioactive material on or inside the body. An uncontaminated person can be exposed by being too close to radioactive material or a contaminated person, place, or thing.”


As the CDC implies, there are many ways that radiation can enter the body for contamination to occur.  Radioactive materials that enter into digestive tract can do damage while they reside in the body, but most of these materials pass through quickly. Radiation that gets trapped in other areas of the body, such as radioactive dust being breathed in and lodged in the lungs, can cause serious threats because the longer the radiation resides in the body, the more harm it can do.

So what are levels of radiation we actually need to worry about in food or water? The unit of measurement used for quantifying radiation in food and water is the Becquerel (Bq) and defined as the activity of a radioactive material in which one nucleus decays per second. More dangerous sources of radiation give off higher readings, and amounts decrease as radioactive isotopes decay. The Becquerel is a very small quantity of radiation; the human body itself produces over 4000 Bq per second. The standards set by the United States Food and Drug Administration (FDA) for food and water is about 375 Bq/lb (170 Bq/kg).

Recently Japan reported a reading of 463 Bq/lb (210 Bq/kg) in Tokyo’s tap water, leading to widespread fear and a government advisory against giving tap water to children (who are more susceptible to radiation and have lower exposure limits). Since this incident, the radiation in Tokyo’s tap water has returned to safe limits. Radiation in food has also been a problem, especially since much of the Fukushima Prefecture near the crippled nuclear plant is dedicated farmland.  Widespread bans have gone into place on the sale and consumption of crops from affected areas, as well as seafood caught in the ocean near the plant. Much of the radiation present in the contaminated food and water is Iodine-131, which has a half-life (meaning that half of a quantity of the material has broken down and is not longer radioactive) of only 8 days. This means that this type of radiation won’t be around for long, but the fear of radiation is more likely to hurt the Japanese economy as buyers shy away from food that they think might still have some contamination.

Source: Associated Press

Although the fear that Japanese radiation in dangerous amounts will end up in other countries is often unfounded, we can’t let down our guard just yet. Japan provides 4% of US food imports, including many seafood products that can have concentrated levels of radiation, such as shellfish and seaweed.

So how can we assure that our food and water is contamination free? Finding trace amounts of radiation in food and water is often difficult because products are usually shipped in large containers that shield radiation. Common radiation detectors such as Geiger Counters just aren’t sensitive enough to detect radiation at these levels. The FDA works to safeguard our food supply by using the MiniRad-D, a hand-held radiation detector, to search for radiation. The MiniRad-D uses a scintillation detector, which is over 100 times more sensitive than a Geiger counter, and because it can pick up radiation from tens of meters away, it can be used to scan whole containers of food at once. 

The MiniRad-D radiation detector

The procedure of scanning food is becoming increasing popular as Japan increases its exports. According to a recent New York Times article, even some fish markets and high-end restaurants have begun radiation detection procedures to ensure the safety of their customers. Knowing for sure that food and water is clean is a big draw for these businesses as Japan’s nuclear clean-up continues to make headlines.

So, although the direct danger of radiation contamination in food and water is very low, the effects of the nuclear crisis are sure to be felt for years to come. And as many companies involved with food imports are discovering, peace of mind is not only attainable, but extremely valuable. With the right equipment, good information, and correct procedures, this peace of mind is truly available to everyone.

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