Wednesday, July 1, 2015

The Health Risks Of Radiation

Radioactivity


Non-Ionizing Versus Ionizing Radiation: Ionizing radiation is the greater concern; the World Health Organization writes: “Epidemiological studies on populations exposed to  radiation (for example atomic bomb survivors or radiotherapy patients) showed a significant increase of cancer risk at doses above 100 mSv.” It, however, adds: “If the dose is low or  delivered over a long period of time (low dose rate), there is greater likelihood for damaged cells to successfully repair themselves. However, long-term effects may still occur if the cell damage is repaired but incorporates errors, transforming an irradiated cell that still retains its capacity for cell division. This transformation may lead to cancer after years or even decades have passed. Effects of this type will not always occur, but their likelihood is proportional to  the radiation dose. This risk is higher for children and adolescents, as they are significantly more sensitive to radiation exposure than adults.”
Source: Teraphysics

An article, by Sarah Laskow, in Foreign Policy gives a comprehensive review on humanity’s use of radiation, with the intent of answering a couple of important question. What do we really know about the harmful effects to humans of ionizing radiation like gamma rays (γ) and medical x-rays? The question to ask is what is considered a safe dose?

In “The Mushroom Cloud and the X-Ray Machine” (March 26, 2015), Laskow writes about the history of determining safe radiation exposure, beginning with the United States testing of nuclear weapons on Ailuk Atoll in the Marshall Islands on March 1, 1954 (It detonated a thermonuclear bomb of 15 megatons, 1,000 times greater than was dropped over Hiroshima.) There was fallout:
In the 1950s, the U.S. government may have had the best of intentions when it told the residents of Ailuk that they were safe, but technically speaking, authorities weren’t in a position to offer those assurances. What U.S. government scientists said at the time was that below 25 roentgens, they could not see any effects on a person’s body. But they allowed for the possibility that, over time, small amounts of radiation exposure might cause genetic damage. In other words, the most reliable science of the era could not measure the effects of the relatively low levels of radiation that reached Ailuk.
Today, despite the 2,053 nuclear weapons tested around the world during the Cold War, the more than 430 nuclear power plants currently operating in 31 countries, and the skyrocketing use of radiation in medicine—annually, there are 20 million nuclear-medicine procedures in the United States alone—scientists are still uncertain about those risks. The estimated total levels of radiation that reached Ailuk were ultimately determined to be less than 10 roentgens. By today’s safety standards, such levels would be less than what is referred to as “low dose,” which is anything below 100 millisieverts (mSv), the metric measure now used, or roughly equal to 10 roentgens.
Over the past 17 years, the U.S. Energy Department has invested in more than 240 projects, at a cost of over $130 million, to discover the effects of low-dose radiation on humans and the environment, to no avail. This January, the House of Representatives passed a bill calling for a new road map for low-dose research to find a science-backed reason to end what are—in the words of House Science Committee Chairman Lamar Smith, a Texas Republican—“overly restrictive regulations” on nuclear industries.
Although the bill appears on its face benign, calling for coordinated efforts by scientists to finally get to the bottom of low-dose exposure risks, its goal is to discredit the so-called “linear no-threshold” (LNT) model, which has formed the basis for radiation safety policy for decades. This model assumes that radiation at any dose is harmful—an approach used by regulatory bodies, both in the United States and internationally. While most scientists agree that the LNT model offers a reasonably conservative guide for establishing standards, they know it’s based on an estimate—and they understand that, eventually, studies will pinpoint the exact effects of radiation at low doses.
This last point is particularly important to me, because in 1980 I worked as a summer engineering student at a research nuclear reactor; and like all employees who worked around or near the reactor, I received doses of radiation. Before the summer ended, I was given a whole-body scan in a machine similar to a CT scanner to see if I suffered any ill effects during my short four-month internship. None was detected; equally important, my radiation monitor (a thermoluminescent dosimeter, or TLD) registered a low dose. I think it was 17 millirems), which is equivalent to 0.17 mSv, well within safety standards. So I was “safe.” (Today, for example, the Canadian Nuclear Safety Commission lists the annual dose limit as 50 mSv).

But was I? To be sure, I was certainly within government and industry regulations. But, is this sufficient? Is it a surprise that I was diagnosed with colorectal cancer in 2012? Or was this a random non-correlating event? A mere coincidence? family history? the misfortune of a bad genes? I have no proof of any connection, nor am I willing or have any desire to look for any. The only question that concerns me today is what I can do to limit my exposure to ionizing radiation to only what is medically necessary.

Tomorrow, for example, I am going for a CT scan of my lungs and abdomen (expected dose of radiation: 102 mSv, a not-insignificant dose, but much lower than what an individual undergoing radiation treatment for cancer typically receives). This is will be my sixth CT scan in less than three years. It is important to remember that there is an cumulative effect to exposure to radiation.

There are important questions and concerns that many of us today face, One being that science has not yet obtained sufficient understanding of radiation and its effects to humans to know what is really a safe amount of radiation. Then there are the non-medical cases. As is the case with newer technologies, radiation has the ability to do both good and bad, the trick it seems is to determine and thus know the boundary lines between the two. This is important, because if we regularly use a technology like radiation for good purposes (like X-rays, cancer diagnosis and cancer treatment), we ought to know its full effects on the human body, including its risks to well-being and health.

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For more, go to [FP]

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Today is Canada Day, a celebration and recognition of our nation’s birth on July 1, 1867, a national holiday with the usual and expected fireworks and festivities. To all my fellow Canadians, Happy Canada Day.

Tuesday, June 30, 2015

Leonard Cohen: Come Healing (2013)



Leonard Cohen, with a beautifully sung intro by the Webb sisters (Charley and Hattie) performs “Come Healing,”at Dublin’s 02 Arena on September 12, 2013 as part of his Old Ideas world tour; it has a spiritual feeling of the need for redemption to it, a plaintive appeal—a “penitential hymn”— to the heavens to restore wholeness of body and mind (or at least some healing presence), which bears the collective burdens of its manifold experiences.

Can this song also apply to a nation’s collective consciousness, its body politic, as a call to national healing and reconciliation? Perhaps it can, but it begins with individuals.

And none of us deserving/The cruelty or the grace. What to make up of this powerful couplet, a commentary, perhaps, on the current (and past) state of world affairs? There is more than enough cruelty, and an insufficient level of grace. Whom or what is to blame

This song can be found on Live in Dublin (the ninth track on disc 1)released on December  2, 2014.

Come Healing
by Leonard Cohen & Patrick Leonard

O gather up the brokenness
And bring it to me now
The fragrance of those promises
You never dared to vow

The splinters that you carry
The cross you left behind
Come healing of the body
Come healing of the mind

And let the heavens hear it
The penitential hymn
Come healing of the spirit
Come healing of the limb

Behold the gates of mercy
In arbitrary space
And none of us deserving
The cruelty or the grace

O solitude of longing
Where love has been confined
Come healing of the body
Come healing of the mind

O see the darkness yielding
That tore the light apart
Come healing of the reason
Come healing of the heart

O troubled dust concealing
An undivided love
The heart beneath is teaching
To the broken heart above

Let the heavens falter
Let the earth proclaim
Come healing of the altar
Come healing of the name

O longing of the branches
To lift the little bud
O longing of the arteries
To purify the blood

And let the heavens hear it
The penitential hymn
Come healing of the spirit
Come healing of the limb

O let the heavens hear it
The penitential hymn
Come healing of the spirit
Come healing of the limb

Monday, June 29, 2015

Why Do Some People Have Allergies?

Immune System

Human Response: Zimmer writes: “This picture, built up in labs over the past century, answered the ‘how?’ part of the allergies mystery. Left unanswered, however, was ‘why?’ And that’s surprising, because the question had a pretty clear answer for most parts of the immune system. Our ancestors faced a constant assault of pathogens. Natural selection favoured mutations that helped them fend off these attacks, and those mutations accumulated to produce the sophisticated defences we have today.”
Image Credit: Sam Taylor
Source: Mosaic

An article, by Carl Zimmer, in Mosaic looks at the issue of human allergies and interviews an immunologist who has a controversial, but intriguing, theory that essentially says allergies are good for us. That is, they are a long-developed and resident evolutionary response to harmful chemicals, which in some people engender equally harmful or deadly reactions. That today there exist many more harmful or toxic chemicals, many man-made, and many that did not exist 50 years ago ago, might explain why there are many more persons worldwide suffering from allergies.

For example, “Worldwide, sensitization rates to one or more common allergens among school children are currently approaching 40%-50%,” reports the American Academy of Allergy, Asthma & Immunology. The same report says, “Worldwide, sensitization (IgE antibodies) to foreign proteins in the environment is present in up to 40% of the population.”

There are many questions on why this is so; equally important is why some persons have severe allergic reactions (sometimes fatal), while others’ reactions are comparatively mild. We are coming nearer to answering this important question, but we do not know how far we currently are from meeting this objective. We do know that in some persons, the human body’s immune system has an exaggerated, if not aggressive, response to allergens; the essential question is why this occurs? We know the mechanism of what happens; what we do not know is why some persons suffer from allergies—in some cases the response is deadly—and while others do not.

On a personal note, I for one have no known allergies; my wife, on the other hand, has asthma, and a number of allergens can cause an allergic reaction in her. Last week, we took our oldest son, aged 13, to an allergist for testing, who determined that he is highly allergic to horses, and mildly so to dandelions and maple trees. This piqued my interest on this subject.

In “Why Do We Have Allergies?” (April 7, 2015), Zimmer writes:
“That is exactly the problem I love,” Ruslan Medzhitov told me recently. “It’s very big, it’s very fundamental, and completely unknown.”
Medzhitov and I were wandering through his laboratory, which is located on the top floor of the Anlyan Center for Medical Research and Education at the Yale School of Medicine. His team of postdocs and graduate students were wedged tight among man-sized tanks of oxygen and incubators full of immune cells. “It’s a mess, but a productive mess,” he said with a shrug. Medzhitov has a boxer’s face – massive, circular, with a broad, flat nose – but he spoke with a soft elegance.
Medzhitov’s mess has been exceptionally productive. Over the past 20 years, he has made fundamental discoveries about the immune system, for which he has been awarded a string of major prizes. Last year he was the first recipient of the €4 million Else Kröner Fresenius Award. And though Medzhitov hasn’t won a Nobel, many of his peers think he should have: in 2011, 26 leading immunologists wrote toNature protesting that Medzhitov’s research had been overlooked for the prize.
Now Medzhitov is turning his attention to a question that could change immunology yet again: why do we get allergies? No one has a firm answer, but what is arguably the leading theory suggests that allergies are a misfiring of a defence against parasitic worms. In the industrialised world, where such infections are rare, this system reacts in an exaggerated fashion to harmless targets, making us miserable in the process.
Medzhitov thinks that’s wrong. Allergies are not simply a biological blunder. Instead, they’re an essential defence against noxious chemicals – a defence that has served our ancestors for tens of millions of years and continues to do so today. It’s a controversial theory, Medzhitov acknowledges. But he’s also confident that history will prove him right. “I think the field will go around in that stage where there’s a lot of resistance to the idea,” he told me. “Until everybody says, ‘Oh yeah, it’s obvious. Of course it works that way.’”
Or not; as theories go, this one has its share of controversy, it not only being counter-intuitive, but going against the accepted idea that allergies are not good or in no way beneficial to humans—a sentiment shared, no doubt, by the millions of allergy sufferers. The more-accepted theory invokes a combination of genetics or hereditary factors, environmental considerations, and an obsession with hygiene. Even so, Medzhitov defends his position on the protective value of allergies, not giving it any moral weight, but a scientific one, which is dispassionate as it is based on evolutionary theory and, in particular, on natural selection and on the findings of evolutionary biology.

In Medzhitov’s case, he is not looking so much for a cure as an explanation, one being why in some people, the body's human system reacts in such a heightened manner, Zimmer writes, zeroing in on the essential question: “Instead, allergists should be learning why a minority of people turn a protective response into a hypersensitive one.” If scientists and medical researchers can find the answer to this mystery, they will understand an important piece of the puzzle of human development from an evolutionary perspective. To understand is to know with a high degree of certainty; from this point a “cure” might be in sight. What this cure might entail is now hard to say.

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For more, go to [Mosaic]

Sunday, June 28, 2015

A Summer's–Day Visit To The Country

Leaving The City

Eli in Action: To effectively pick strawberries, it is necessary to get down low. Our youngest has the definite height advantage in our family.

A few days ago, we all drove 40 kiolometres (25 miles) northeast of Toronto to go strawberry picking to a farm in Newmarket (Strawberry Creek Farm); we then went to have lunch at a hamburger and fries joint (The Moose Caboose) another 17 kilometres (10 miles) northeast, to Mount Albert, before heading off further north for another 20 kilometres (12 miles) to Jackson’s Point for ice cream and sherbet (Maple Leaf Dairy Bar). Over the past couple of years, we have visited Jackson’s Point a number of times. A pleasant summer-resort harbor located on Lake Simcoe, it has that small-town feel with assorted shops and a pleasant small beach where you can bring your family.

On our return home, a few hours later, while stopping for gas (at a Shell station on Hwy 48), while we were looking for a coke or soda machine, we saw this instead (see the last photo in the series). After arriving home, the fresh berries that we picked became key ingredients in a summer salad and a tasty pie. There is something wonderful stepping into Nature after being cooped up in the city for so long; the change is refreshing.

We shall return.

Sarah & Josh: There are rows and rows of strawberries that seem to go on forever. I have resisted the temptation to call this Strawberry Fields Forever.
Strawberry-Spinach Salad with mandarin orange slices. It is as delicious as it is pleasing to the eyes.
Strawberry-Rhubarb Pie: One of my favourites.

Good pickings: Two kilograms (4 lbs) of strawberries. Besides eating them, some of these berries went into a strawberry-spinach salad and some into a strawberry-rhubarb pie that Sarah made— both of which we enjoyed as part of our Friday evening Shabbat meal. Both the rhubarb and the spinach were purchased from this farm.


Selling Live Bait: Yes, they sell live bait here. A few dollars can buy sufficient worms for a day's fishing. We did not have the chance, however, to test out the quality of these worms. Perhaps another time.


All Photos: ©Perry J. Greenbaum, 2015