Friday, 6 February 2015

Veritasium - "The Most Radioactive Places on Earth" review.

By Mark Williams

YouTube.com is a great place to learn some science (see end of article for a few of my favourites), here we take a critical look at a recent video on radiation.






Since its upload more than 1 month ago over 1.5 million people have already viewed Veritasium’s new video measuring radioactivity around the world. Armed with a neat Geiger counter, Derek visits many of the most infamously radioactive places on Earth: Trinity Site, Hiroshima, Fukushima and Chernobyl as well as a Uranium mine, Marie Curie’s office and the stratosphere.

The table below is based on the information provided in the video, but here I’ve kept the units at per hour, instead of per year, for each example.

Place
Approximate dose, in ┬ÁSieverts per Hour
Usual background dose
0.1 to 0.2
Eating a banana
0.1 (per banana)
Peace Dome, Hiroshima, Japan.
0.3
Uranium mine
1.7
Marie Curies lab door knob
1.5
Trinitite at Trinity, US, nuclear bomb test site.
2.1
33,000 feet (The stratosphere)
2.2
Cruising altitude (long haul flight)
3.0
Chernobyl, Ukraine
5.0
Fukushima, Japan
10
Basement of Pripyat Hospital, Ukraine
2000
Permitted US radiation worker limit.
~5.7 (based on 50,000 per annum)
At the space station
~18.25 (based on 80,000 per 6 months)
Smokers lungs
~18.25 (based on 160,000 per annum)

Making ionising radiation relatable is difficult, and this video has highlighted a few important problems that arise with doing just that. For example, the Sievert does not just consider the radioactive material, but also its proximity and likely effect on the human body. This video talks about the equivalent dose, in other words the dose in a fairly homogenous field, like a city. But it also looks at the dose on a specific organ, in this case the lungs, which must consider a ‘weighting factor’ - here radioactive smoke comes into direct contact with the tissue and you have what is known as an ‘effective dose’. 

For example, smokers are much more likely to develop lung cancer than non-smokers, but being a smoker may not mean that the chance of developing other cancers is so severely increased. The dose received on the space station, also mentioned in the video, will act on the entire body.

Different radionuclides (unstable elements) give off different ionizing radiation at different rates. There are countless books (and trust me when I say countless!) defining and equating the physics of dosimetry and suitable protective measures. We are lucky to have this knowledge today as it guides our use of radioactive material within research and dictates strict commercial practices. However, its complexity makes it seem like scary jargon.

Using the banana equivalent dose, as in the video and a previous article, is at least a little bit relatable, but it doesn’t portray the complexity of ionising radiation and can, I feel, mislead our understanding. Is that a problem? Does the public need to understand the reasons behind the risk? Do people really have the time? Or are we missing something in our explanations, is there not a better more relatable parallel than bananas…


Some of my favourite YouTubers:

Veritasium - 'The science video blog from atoms to astrophysics!' These are usually about common misconceptions and debunking myths. Some videos are pretty funny, but you'll often learn something new.

VSauce - 'Our World is Amazing.' In my opinion, this is one of the most well informed channels on Youtube. Michael Stevens is able to discuss any issue, be it scientific, artistic, historical etc... and often digresses into fascinating detail.

Periodic Videos / Sixty Symbols - Brady Haron asks professors and experts from (usually) The University of Nottingham questions relating to chemistry or physics, respectively. Any regular viewer of these channels will come to adore the professors and lecturers as they explain their fields with passion.

Minute Physics - As the name suggests, this is physics heavy. But it is generally good at explaining a lot of physical concepts with a whiteboard in a short space of time.

Kurzgesagt - With one upload per month, this channel is small, but dense with interesting content. It's also occasionally hilarious.


4 comments:

  1. Great little video.I was sceptical about tobacco containing polonium, the same stuff that was used to poison Alexander Litvinenko, but it true!

    http://scienceblog.cancerresearchuk.org/2008/08/29/radioactive-polonium-in-cigarette-smoke/

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    Replies
    1. Thanks for the link, although it's the same radionuclide there isn't enough polonium-210 in cigarette smoke to cause acute radiation sickness, which is what was so fatal for Litvinenko.

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    2. Heh, actually, if you're talking "thirdhand smoke" you can get the Litvinenko dose if you lick ten square feet of smokers' flooring absolutely clean every single day. For 2.3 TRILLION years. Seriously. See my whole analysis on it if you want in my comment and extended discussion at:

      globalhealthlaw.wordpress.com/2009/01/11/third-hand-smoke/#comment-52

      You'll note that you also need to suspend the normal laws of physics because of that annoying half-life thing, but hey, Antismokers generally don't care about details like that! LOL!

      - MJM

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  2. He stayed out of the whole LNT/Hormesis/Cancer rate argument and just covered stuff pretty well. Not bad.

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