10th April 2011 Sievert

A sievert is a measure of the response of the body to radiation.
It's measured in J/kg.

The initial dose is measured in grays.   They are weighed depending on the type of radiation and the type of tissue. Since α is the most damaging, it has a weighting of about 20 whereas γ, which mostly just passes through us, has a weighting of 1. Gonads, breast and thyroid tissue, for example, are more likely to have a negative effect than, say, bone so different weighting for different tissues.

Receiving 1 Sv over a lifetime gives about a 5% chance of getting a fatal cancer.  In the UK, the radiation we get from rocks, cosmic rays and the carbon and potassium in our bodies, we receive about 2.5 mSv per year.  Of course, if we have medical x-rays, we get more.

http://www.sixtysymbols.com/videos/radiation.htm

9th April 2011 Carbon Dating & Heart Disease

Due to the nuclear tests in the last century, the date fat has been laid down in arteries can be measured. Tests have been done which determine the year of birth of people born in the 1960s onwards, in a particular region of USA, to within about 18 months by looking at tooth enamel.

 How Cold-War Nuclear Tests Are Giving Hope to Heart-Disease Patients

Measuring atomic bomb-derived 14C levels in human remains to determine Year of Birth and/or Year of Death

4th April 2011 The Discovery as Radiation as a Cancer Treatment

Since I read the an article a few days ago on the Radiation Girls, I've been wondering how on earth anyone thought of using radiation to treat cancer.  Well today my luck was in as  Orac mentioned it in his blog.

A young man by the name of Emile Grubbe was so impressed by Roentgen's discovery of x-rays that he began to experiment himself. He began to suffer from radiation dermatitis of his hands and neck.  He linked these lesions to the radiation.  One of his colleagues suggested he try to use them to treat carcinoma, which he did with almost immediate success. In February of 1896, he founded the first radiation therapy facility in Chicago.

31st March 2011 Radiation Effects

There are several models of possible radiation effects at different levels. Because the effects with small amounts of radiation are small, it is hard to quantify them, so do small amounts of radiation 1) do nothing 2) cause harm 3) have a positive effect?  The jury is out.

Putting radiation exposure in context

Orac: 'Ann Coulter Versus Physics - Guess Who Wins'

30th March 2011 - Radium

Today I finished reading a series of articles on Radium and the Radium Girls.

Radium was hailed as a wonder element, with radium sweets, tonics and so on being produced. It was found within a couple of years of its discovery that it could be used to shrink cancer tumours.  What I'd like to know is how they managed to spot that radiation shrinks tumours, or rather why they would be treating people with it in order to see this.

According to the ACS, the discovery of radiation in 1896 by Wilhelm Conrad Roentgen was a huge advancement in cancer therapy. Within months of the discovery, X-rays were being used for diagnosis, and within three years, radiation was used in cancer treatment. According to the ACS, radiation therapy began with radium and low-voltage diagnostic machines. French doctors discovered that daily doses of radiation over several weeks would greatly improve therapy results. In the early 20th century, radium was being used in small tubes for insertion directly into tumors or body cavities containing cancer, which allowed for treatments of inoperable areas, like the cervix and larynx, according to the American Society of Radiation Oncology. [Source: The History of Cancer Therapy]

The Radium Girls were women who worked in a factory painting watch dials with Radium.  They suffered horrible disfigurements and ultimately death from radiation poisoning.  Radium acts like calcium in the body, and is used by the body in place of calcium.  Instead of making bones strong, it shoots them with alpha particles, causing holes so that the bones become brittle and break.

Part 1: The Radium Girls
Part 2: Life in the Undark
Part 3: A Dazzle in the Bones