Monthly Archives: March 2011

Radiation, Cancer and Medicine

Lately everybody is talking about the Japanese nuclear accident, radiation and the risk of cancer. In the midst of one of these conversations, I was asked, “If radiation causes cancer, how come cancer is treated with radiation?” Another version is, “Since radiation breaks down DNA, which can cause cancer, how come we give radiation to treat cancer? Doesn’t it just break down more DNA?” That actually is a pretty good question.

Radiation therapy is commonly used to treat cancer. It is pretty effective for cancers that are localized (in one place). It is also very effective at treating more widespread cancers like Hodgkin’s Lymphoma.

For localized disease, it’s all in the focus. Radiation therapy can be focused like a laser flashlight beam. Very high levels of radiation are put in the area of the tumor and not much anywhere else. So any damage from radiation therapy is limited to the tumor – not exactly, of course, but pretty closely. Damaging tumor cells is the point, and we hardly need to worry about tumor cells becoming cancerous.

Some radiation treatments expose much more of the body to radiation. Treatments for Lymphoma are one example of this. People are given what would be concerning amounts of radiation if they got it working in a Japanese damaged nuclear facility. Here’s the interesting part: cancer cells and normal cells react differently to radiation. The way radiation damages cells is by causing breaks in DNA, the blueprint of life. It turns out that cancer cells are not very good at repairing their DNA. Normal cells are much better at successfully repairing the damaged DNA. So the damaged cancer cells die, and most of the damaged normal cells don’t.

If this sounds a bit imprecise, it is. Usually the difference between the cancer cell and the normal cell isn’t 100%. Most cancer cells don’t survive high-dose radiation, and most normal cells survive, repair themselves or die a clean death – just as long as they don’t turn into cancer.

This actually is the basis of cancer treatment of any kind. An important difference between the cancer and normal cells needs to be found and capitalized on.

But radiation is radiation. It damages DNA, and occasionally DNA is repaired badly – sometimes so badly it acquires something unpleasant like uncontrolled growth.

Studies do suggest to an increased risk of disease 20 or 30 years after radiation treatment. Cancer usually occurs in the middle years and later so many patients are cured of their cancer and are at the end of their natural life span before enough years have gone by to see any ill effects from the radiation treatment.

But ultimately, we worry about today and let tomorrow take care of itself. The prospect of not treating today’s cancer is so bleak that a future risk seems a small price to pay. Radiation, like so many other things in life, has its pros and cons.

Take care,

Dr. B

Dr. Bucklin: Radiation and Your Health on FOX Phoenix

This morning, our own Dr. Donald Bucklin appeared on KSAZ-TV (FOX Phoenix) to talk about radiation’s effects on health.

Check out his interview here

Radiation and Food – Are You What You Eat?

Just when we thought the Japanese nuclear disaster could get no worse, they announce the radioactive contamination of produce, milk and water. Is it not bad enough already?

There has indeed been some low level radioactive contamination of locally produced food, milk and water in Japan. The major radioactive isotopes involved are identified as Iodine 131 (I 131) and Caesium 137 (C 137).

First, how could such a thing happen? There has been persistent, low-level leakage of the products of nuclear fission since the disaster started. This could be from emergency venting of the reactors to avoid rupture or due to fire involving waste fuel rods. Conceivably, there might even be damage to the reactors. These are heavy elements, and they are unlikely to go very far from the nuclear plant.

Unlike Chernobyl, the amount of release has been quite small, and there have not been any raging fires to blow these things up into the stratosphere. Nevertheless, we have a bit of measurable radiation in water, spinach and milk very close to the plant.

cute little milkphoto © 2006 hobvias sudoneighm | more info (via: Wylio)

I-131 is the better known of the two radionucletides. It is a radioactive form of the element iodine. We buy iodinated salt to get the small amount of iodine we need to make thyroid hormone. Making thyroid hormone is basically the only use your body has for iodine. If there is I-131 in the environment, and you happen to eat food contaminated with it, it will head straight to the thyroid gland (the body thinks it is normal iodine). While the thyroid gland is busy making thyroid hormone out of it, it is quietly irradiating your thyroid. This can cause some genetic damage, and many years later it is possible this could lead to thyroid cancer. For the record: thyroid cancer is one of the most curable cancers out there.

The problem with I-131 is what doctors call “self limiting.” The half life of I-131 is only 8 days. That means 50% remains 8 days from now and 25% 16 days from now. By 5 half lives (40 days), the stuff is practically gone.

No discussion of I-131 is complete without discussing KI (potassium iodide) – the wonder pill. For all you hear about this stuff, it should be $100 a pill and a government secret. Alas, it’s just an easily-made type of iodine. If you are on supplemental iodine, the thyroid will be filled up and won’t hold on to any I-131 it comes across, which is helpful only when you are around I-131 (which we’re not).

Caesium 137 is another radioactive isotope that is in the area of the reactors. This is a much more troublesome substance. If being radioactive is not enough, it is also chemically poisonous, water soluble and tends to settle in bones. C137 has a half life of 30 years, so it takes 150 years (5 half lives) for the radiation to be manageable. No one is allowed near Chernobyl because of still highly radioactive Caesium 137 in the soil.

If C-137 gets into your body, the biologic half life is 70 days, rather than 30 years. So you will be effectively rid of it in just about one year (350 days). That’s at least one year too long for most people.

Food can get contaminated by radioactive dust falling on spinach leaves. Radioactive dust can contaminate grass and be eaten by dairy cows, producing radioactive milk. Now before we give ourselves osteoporosis from avoiding milk and anemia from avoiding spinach, we need too remember two things: 1) the damaged reactors are in Japan, not California, and 2) the radioactive contamination is so minor, there is no danger.

How much milk from next to the Japanese reactor do you think gets exported to the United States? Zero. Same goes for spinach. These are locally grown products that are consumed locally, and not even there these days. Even if the radiation was not in question, it would cost a ridiculous amount to fly milk and spinach around the world.

But you can bet that you are protected by more than just distance and the law of supply and demand. Export of Japanese agricultural products, few that they are, are carefully inspected for the least trace of radiation before being accepted in this country.

Radiation identified in the food chain is certainly dramatic news. It was a predictable and expected consequence of the Japanese nuclear reactor trouble. Thankfully, we are safely on the opposite side of the planet.

Take care,

Dr. B

Little to Fear in the U.S. As Radiation Concerns Abound

It’s easy to be afraid and nervous regarding the recent news from Japan when it’s described in such ominous terms. There is no question that the earthquake and resulting loss of life and property has been tragic and sudden.

The nature of news reporting often dwells on the negative and inflammatory. The repetition also sets an ominous and foreboding tone; however, closer examination of the facts is necessary to understand the implications to the rest of the global community and to each of us as individuals. The dread of something catastrophic over which you have no control serves to increase our fear and anxiety about the circumstances.

Radiation is one of those perils that is invisible and something that most people understand only through science fiction movies. Typically when it comes to the unknown, the average person is prone to be suspicious, confused, anxious and distrustful. The reality is the science of radiation, its capabilities and risks are well understood. The radiation released from a nuclear power accident is different than that of a nuclear bomb. Even allowing for the explosions that have occurred at Japanese nuclear reactors there is a vast difference in the type of radiation released. It is nothing like a nuclear bomb as seen on footage from testing in the Nevada desert or the old films of World War II.

Within 10 to 50 miles of the disaster, important risks both short- and long-term exist. Fortunately, we are some 5,000 miles away. For decades, a very good network throughout the U.S. monitors every day in real time the amount of radiation in the atmosphere. This was very effective in understanding the risks of the 1986 Chernobyl disaster and several other international nuclear power plant accidents. This is being supplemented by portable monitors along areas of the U.S. West Coast. Fear simply need not be part of the conversation.

What do you need to know and understand? The amount of radiation that is likely to reach the United States is very small compared to the amount of background radiation to which we are already exposed on a daily basis. No one needs to take any specific actions at this time. It is unlikely that anything will need to be done in the U.S. to protect ourselves as there is no particular risk from the events in Japan.

Of note is the distribution by the Japanese health officials of potassium iodide to individuals in local areas of possible contamination. Potassium iodide has limited usefulness for protection against thyroid cancer from exposure to radioactive iodide, a dangerous isotope commonly released in a nuclear power accident. Timing and dosing are critical. It should only be used by those most at risk, which include infants, children and young adults. It is not 100% effective and does not protect against other types of cancer. There are potential side effects even though it is sold without a prescription. The Center for Disease Control does not recommend any action of this kind at all for anyone in the U.S. nor do they anticipate this being necessary from the current disaster in Japan. Do not be fooled or misinformed on this point.

Events are still ongoing with a final chapter yet to come, however, considering the distance from the source of radiation in Japan to the U.S., there is little concern at this point. The dilution and scattering of radiation over long distances keeps the amount in the atmosphere rather low. Is any extra radiation to be avoided? Of course it is, however, there are more significant risks, which are actually trivial, much closer to home. As my colleagues have so aptly pointed out, there is greater risk from environmental radiation in Denver than in Tokyo, which is less than 150 miles from the disaster site.

Being mindful about disasters in the world while understanding the facts is the best thing you can do. If you have further questions or concerns, consult your primary healthcare provider or local health department for information. The Center for Disease Control remains a reliable resource for good current advice.

– Dr. Kaler

Dr. Bucklin Offers Insight on Radiation Exposure to CNBC, Wall Street Journal

In the wake of the nuclear disaster in Japan, U.S. HealthWorks’ Medical Review Officer Dr. Donald Bucklin appeared on CNBC‘s “Squawk on the Street” this morning to discuss what health effects, if any, there might be following the explosions. Check out his interview here, as well as his thoughts in the Wall Street Journal and Bloomberg.

Radiation Exposure in the Real World

Japan’s nuclear threats have us all thinking about radiation exposure; and I have an added interest since I was the medical director for 10 years at the Palo Verde Nuclear Generating Station, the largest nuclear plant in the nation.

But my first introduction to the hazards of radiation was as an elementary student. We, like all children around the U.S., were instructed to hide under our desks in the event of nuclear war. That seems a bit naive in retrospect.

Radiation is everywhere. The sun emits radiation, as does the earth, and probably the moon. The stars definitely do. Medical procedures like X-rays and CT scans involve radiation, as do TSA scanners. There is even a little radiation in the food we eat and the air we breathe. Like so many other things, radiation is all about dose.

Radiation is counted in millisievert (mSv), a word which keeps the non-PhDs like myself out of their field. Normally we are exposed to a background radiation total of 2.40 mSv per year. This is an additive scale. It’s like getting less than a penny’s worth of radiation per day and end up with $2.40 at the end of the year. This comes from solar radiation predominantly, and a small amount from man-made sources. Man-made sources range from the luminous hands on your watch, a chest X-ray, or nuclear testing from 60 years ago.

Some locations have higher normal background radiation due to more radioactive materials in the bedrock or simply high elevation like Denver. The normal range of background radiation is from 1 to 100, so a hundred-fold increase could still be in the normal range.

So why worry about radiation?

Radiation is bad because it can cause breaks in your DNA – the chain of life so to speak. You don’t go far with a broken chain. The body attempts to repair these breaks and is pretty successful, but nothing is 100%. Those few poorly repaired DNA chains may self-destruct and cause no mischief, or can code for unfriendly cells, like cancer.

Scientists have studied radiation exposure and calculated that normal background radiation will cause 1 person out of 100 to get cancer in his or her lifetime. Additional radiation exposure increases the risk.

There is also danger from large exposures to radiation that occur acutely, as opposed to 20 years of exposure. This is called radiation sickness. Here we are talking about nuclear accidents. Radiation sickness causes the most active cells to die first. The lining of your stomach and intestine are usually affected first, causing nausea, vomiting and bloody diarrhea. This might take 24 hours to develop in exposures of 3,500 mSv or 1 hour in more extreme exposures of 5,500 mSv. At 8,000 mSv acute exposure, the mortality rate is 50%. The cardiovascular system breaks down in high-level radiation exposure. If you survive those, the blood system is the next likely victim. Radiation can kill your blood-making cells. You would miss them.

These are the kind of dangers emergency workers who stayed at the damaged nuclear plant face.

What about people in Tokyo or the world?

“Dilution is the solution to pollution” was my organic chemistry’s professor’s favorite expression. The closer you are to the source, the higher the radiation exposure. Radiation goes down with distance. This assumes the radiation source doesn’t move.

The levels measured at the plant in recent days are high enough to cause radiation sickness. These are potentially dangerous in the short term as well as the long term. The levels measured 120 miles away in Tokyo are 10 times higher than normal, but you would get just as much radiation moving to Denver. Moving to Denver with its higher level of solar radiation (due to elevation) doesn’t seem like a particularly foolhardy thing to do.

But life gets more complicated if the radiation source moves around. Radioactive elements are rather dense and don’t move around too easily. All solids can be made liquid or gas, just like water. The fuel rods in the reactor are solids. They release huge amounts of heat energy because they are radioactive. If not cooled, this heat can build up to the point of making the uranium rods melt and become a liquid. This liquid is so dense and hot, it can melt though almost anything (picture trying to keep lava in a container).

The next step is going from liquid to gas. Uranium can be vaporized by explosion or intense heat. Now we have a cloud of highly radioactive material floating about. That is exactly what happened at Chernobyl 20 years ago. One of the radioactive elements to spread was radioactive iodine. Potassium iodide keeps your thyroid full and stops you from absorbing the radioactive variety. This helps prevent thyroid cancer, but nothing else.

So this triple (quadruple) meltdown is unprecedented in history, but the science is very well understood. Simply keeping distance between you and trouble, like so many other times in life, is all it takes. Today, you will get more radiation in Denver than in Tokyo.

Take care,

Dr. B

5 Steps to Survive Winter Allergies

Most of us associate allergies with spring and summer when things are in bloom. Even some of us who don’t have allergies seem affected by a vigorous bloom; however, folks who have spring allergies are also more prone to winter allergies. The human immune system’s sensitivity to different allergens is very individualized. But if one is prone to spring allergies then there is a greater chance that you may have problems in the winter even though the triggers are entirely different.

When the weather gets cooler, we close up the house and turn on the heat, making the perfect storm for allergy sufferers. Dust, mold, mildew and pet dander are the big winter culprits. The secret is these things are actually around all year long. In sensitive individuals, these factors may intensify allergies any time of year but really come into play in the cooler weather. Trying to minimize the amount of these allergens in your environment is helpful.

Even though you cannot truly be the master of your domain, you can improve the condition of your habitat by following these tips:

“Cats are magical. . .the more you pet them the longer you both live” ~photo © 2010 Nancy ~ | more info (via: Wylio)

1. Avoid known allergens: This means some regular house cleaning, probably weekly with a more vigorous attention to problem areas once per month. Keep pets out of the bedroom – this will make your sleeping area as a safe zone to keep down the amount of pet dander, dust and molds that animals also carry on them wherever they go. You spend a lot hours in your bedroom, so keep it as allergen-free as possible. Really sensitive individuals may consider showering more often to remove potential allergens from hair, skin and clothing.

2. Change your bedding weekly. Washing sheets, linens and towels helps keep the amount of dust, dust mites and mildew down to a minimum. Dust mites are microscopic organisms that exist everywhere. They thrive on dry skin cells that naturally slough off our bodies. Special bedding or mattress covers can be purchased that help contain this situation for individuals who need additional help. Allergy bedding and special mattress covers can be purchased at many department stores that handle regular bed linens.

3. Add moisture. The dry indoor air exacerbated by heating systems of any kind is irritating to airways and tends to make people with allergies even more vulnerable. Room humidifiers, liberal use of saline nasal spray, nasal irrigation systems, and simply staying well hydrated by drinking plenty of fluids can be very helpful.

4. Take allergy medicine regularly. If you suffer with allergies, you need to be proactive and take a preventive stance against your symptoms. Waiting until you feel bad is too late. It is much harder to gain control by that time. There are good non-sedating antihistamines that are available without prescription, very effective and still form the foundation of allergy control.

No273 13 Oct 2009 Sneezephoto © 2009 mcfarlandmo | more info (via: Wylio)

5. Consult your healthcare provider. If you still can’t gain control and a functional level of comfort with the above mentioned measures, there are additional prescription medications that can be effective. Discussing which choices are right for you and the severity of allergies would be time well spent.

Whatever you do, don’t give up. There is help. It is just a matter of identifying what your triggers are and how best to avoid them.

– Dr. Bruce Kaler

Urine Drug Screening 101

Pre–employment drug testingphoto © 2011 Francis Storr | more info (via: Wylio)I see a lot of drug screens. As the National Medical Review Officer for 36,000 companies, I spend a lot of time answering questions about them. The most frequent category of question involves the numbers seen on positive urine drug screens results. I will review what these numbers mean and what they can and cannot tell you. I will try to clear up the cloudy urine, so to speak.

We’ll start with cut off levels. There is a simple concentration level that determines the “line drawn in the sand.” Any value equal or above the limit is positive, and those below the limit are negative, kind of like Black Jack.

Now to complicate matters, every positive drug screen goes through two different testing procedures. The first is called an immunoassay – this test is highly sensitive and not very specific. They can detect several variations of a drug (drugs break down into several parts in the body). In the case of marijuana, the cut off of the immunoassay is 50 ng/ml. Either the test is positive (above 50 ng/ml) and goes on to further testing, or it’s below 50 ng and is reported as negative. There is never an immunoassay numeric result.

Any positive initial test (immunoassay) will undergo a second testing of a different type-GCMS confirmation. This stands for Gas Chromatography Mass Spectrogram (don’t worry – there won’t be a test later). This is an extremely specific test that identifies one single drug variant in the urine. Because it identifies a single molecule type, the cut off level is low, 15 ng/ml in the case of marijuana. The GCMS result is the only number reported. The lab reports the test as negative if it is below 15 ng/ml. If it is above 15 ng, a quantitative number is given, like 38 or 300.

That is a lot to write down, but we are just talking a cut off level. We see cut off levels everywhere in life – 90% in school gets you an “A,” 89% a “B.” Driving 75 mph on the highway gets you there, while 80 mph gets you a ticket.

So, let’s say we have a drug screen that is positive for cocaine at 300 ng/ml (the cut off cocaine is 100 ng/ml on GCMS). Every day a company wants to know if the donor was under the influence at the time of the drug screen. The simple answer is: “I have no idea.”

That information isn’t available with a urine drug screen. The reasons are several. The most important is the concentration of drug in the urine is not the same as the concentration of drugs in the brain. Drugs in the urine don’t affect you; drugs in the brain do. The other reason a drug screen won’t reveal impairment is there are too many variables (unknowns). Among these are the donor’s dose, timing, body weight, food and drink intake, kidney and liver function. All affect the level of the drug in the system. So for a given value in urine, the donor could have arrived at that by taking hundreds of different combinations of drug amount and timing before the drug screen. So we can say the cocaine was definitely present in the urine, and it was a positive drug screen. The positive result cannot tell you if the donor is a long-term cocaine user or used it once in his life right before the drug screen. And it can’t tell you whether he was impaired (high) at the time of the drug screen.

So a urine drug screen only places the person into a user or a non-user group. We unfortunately don’t have chronic users groups and tried-it-only-once user groups to pick from.

– Dr. B

Physical Therapy: The Medicine that Cures

When people are injured, it’s important to as soon as possible restore function and movement to some reasonable form.

Everyone is eager to get back to their life, job or recreational activities, but the pain of injury is difficult, disruptive and discouraging to one’s normal activities. And the longer the injury drags out, the more likely depression will ensue.

The ticket to success in overcoming an injury is early mobilization. But this has to be done within reason, with patience and with an understanding of the body mechanics relevant to the injured body part.

The plan tailored to the injury and level of conditioning is the physical therapy. It remains the cornerstone of recovery and preventing further injury. Coaching by a physical therapist is critical to planning the recovery and doing no further harm. A good plan and continued mentoring by the therapist will ensure a speedy recovery.

www.Army.milphoto © 2008 The U.S. Army | more info (via: Wylio)

The basics of therapy during the initial acute phase are well known: rest, ice, compression and elevation (R.I.C.E.). Early mobilization of the injured part within reason, as well as the rest of the body, is beneficial. It continues to maintain muscle tone, which starts to atrophy after 24 hours of inactivity. The additional weakness and stiffness needs to be minimized rather than creating an additional liability. Essentially, increased circulation helps promote healing.

Convalescence from a significant injury is often frustrating and has its ups and downs. During the recovery phase, it’s key to remain within certain boundaries to avoid over-training.

Nonetheless, several variables have to be monitored by a physical therapist and your healthcare provider to stay on course. Recapturing strength, endurance and range of motion are the goals for recovery. Although some common patterns emerge for certain injuries, we are all individuals who bring different considerations to the challenge. We often think of these as baby steps to recovery.

When the pain of the acute phase subsides, typically there is weakness that remains. Getting back to a functional level of activity can take more time than you wish. Listening to your body is important. Also, using the expertise of the physical therapist and maintaining an open dialogue with the therapist will get you to your goals as soon as possible.

Remember, it does take time to regain your normal level of endurance. Along the way, learning the best body mechanics for your activities, and getting and maintaining a level of strength suitable for the job are critical to getting better and staying that way. Physical therapy is the medicine that cures.

– Dr. Bruce Kaler