This is taken from the IAEA News Channel (Nuclear & Radiological Events)
Overexposure of a worker (I-131)
|[28 February 2013, Finland, MAP Medical Technologies Oy, posted 08 April 2013, INES = 2(Final)]
A laboratory worker was contaminated with I-131 in a radiopharmaceutical company on February 28 2013. The worker was wearing two pairs of gloves and, when changing gloves, had noticed a break in the right inner glove, but not any obvious break in the outer latex glove.
Only 3-4 hours later, routine monitoring revealed heavy contamination of the dorsal part of the right hand. Immediate actions to decontaminate the hand were undertaken on site. On the next day, besides persisting heavy contami-nation of the hand, activity was also found in the thyroid gland, and the Finnish Radiation and Nuclear Safety Authority (STUK) was notified. Stable iodine had not been administered.
Based on original measurements on site and later follow-up at STUK, including surface contamination measurements and whole body counting, the original activity of the hand was estimated at 11 MBq and the equivalent skin dose at 25 Sv, affecting an area of about 10 cm2. The estimated equivalent dose to the thyroid was 430 mGy and the estimated effective dose 22 mSv.
On her first visit at STUK, the worker was advised to wear a glove and change it frequently in order to protect the surrounding and promote decontamination by sweating and washing. Three days later little activity was left in the hand. 11 days after the incident the skin was dry and slightly desquamating. After 15 days the skin was intact with no desquamation left. No further signs of skin damage have occurred.
The incident log for the above event can be read at the following link: IAEA News Channel.
I think this is quite a shocking case. Just look at the headline figures here: 25 Sv to part of the hand, dose to the thyroid 430 mGy and effective whole body dose estimated at 22mSv. (Personally I think the units used are a little wonky, but I will put that aside).
It is very important to note that this is not a nuclear incident (even though it's reported on the IAEA news event channel). This is very unlikely to hit the media - will be missed by most - but the doses received in this incident ARE NOT common in the nuclear industry (far from it) - under routine or accident situations to workers or members of the public.
According to their website, Map Medical Technologies develop and manufacture radiopharmaceutical for nuclear medicine professionals. There are many similar companies like this located all over the world doing similar work. Looking at the report of this case it makes me wonder how many similar exposures of this type might go undetected. There appears to have been a PPE (double glove) failure, combined with a lack of monitoring so that the hand contamination went unnoticed (for up to four hours). It is not clear if the thyroid contamination is a result of transfer from the hand, or due to direct intake at the workplace (during the initial contamination incident). I am inclined to think that latter - clearly radiological hygiene standards were considerably below expectations.
A lack of radiation / contamination monitoring (again)
If you look at other incidents I have commented on in this blog, many being very different to this latest one, you will nevertheless see a common theme. Lack of monitoring. I spend considerable time during my training courses - drilling into delegates the fact that monitoring (passive, active, direct and in-direct) are the ‘eyes, ears - indeed all the senses combined' -and the only way to understand the radiological environment surrounding you. Without adequate monitoring you are effectively ‘blind' - and when blind significant radiation exposures can be delivered leading to events of this type.
Is 25 Sv local dose really possible?
I was curious to see if the estimated dose delivered to the hand was realistic (since 25 Sv is a massive localised dose, and 11MBq is a modest activity used in the medical sector). I ran my Varskin 3 code (a dosimetry model for surface / skin contamination). I used a skin density thickness of 7 mg / cm2, a 2-d disk (10 cm2), skin averaging over 10cm2, 11 MBq of I-131 with an exposure time of 4 hours. My results were around 8 Sv (Gy) which is about a 1/3 reported above. I re-ran the code with different geometry and skin thickness and you can approach 25 Sv (Gy) so I presume the dose calculations run for this individual would have been very specific. So the basic findings are that a localised radiation dose of 25 Sv is most certainly possible under the conditions outlined in this incident.
I then wanted to explore using gloves. I have no idea what type of gloves were worn so I used neoprene gloves with the following specification: density 1.23 g/cm3 with the thickness of 0.4mm. Assuming these gloves were worn intact with the contamination on the outer surface, then the skin dose over four hours is reduced by about a factor 8. With two pairs of gloves the dose to the skin over the exposure time reduces by a factor of about 50 (so using the original supplied data you might be looking at a hand dose of 0.5 Sv rather than 25) - still considerable, but considerably less.
The results of the calculations show that regular monitoring of the gloves during the work is a key measure to reducing exposures.
This is taken from the IAEA News Channel (Nuclear & Radiological Events)
Overexposure of workers (Ir-192)
|[18 October 2012, Pakistan, Wajedo International, Karachi, posted 10 January 2013, INES = 3(Prov)]
On October 18, 2012, three workers were overexposed during industrial radiography at Phool Nagar near Lahore. The event took place due to detachment of Ir-192 source (67 Ci) which remained stuck in the Guide Tube. The workers could not notice this and loaded the Gamma Projector and Guide Tube in the vehicle and traveled for almost 30 minutes from work site to office while placing the Guide Tube very close to the leg of one worker (‘worker A' sitting on rear seat of the vehicle).
After reaching the office, ‘worker A' unloaded the Gamma Projector to place it in storage pit. ‘Worker B' performed radiation survey and found that the source was still in the Guide Tube. ‘Worker B' and ‘worker C' (‘worker C' was not a designated radiation worker) conducted the recovery operation and brought the source to shielded position.
‘Worker A' reported headache and vomiting within 24 hours and severe burns appeared on his left leg in about 15 days which later developed into open wounds. ‘Worker A' is currently under medical treatment.
The event came into the knowledge of Pakistan Nuclear Regulatory Authority (PNRA) by the end of November 2012. The matter was investigated and investigations found certain violations of regulatory requirements and certain steps of safety procedures. PNRA has served work stoppage notice to the company and further actions are under way.
Calculations were made to assess the dose received by the workers. The whole body dose to the ‘worker A' sitting near to the source in the vehicle is estimated to be 2.02 Sv and for the other two workers sitting at front seats of the vehicle is 0.81 Sv each.
The incident log for the above event can be read at the following link: IAEA News Channel.
Yes another sad case of bad practice in industrial radiography. It does not report the local dose to the leg, it would have been significant.
I just thought I would upload part 2 of this three part blog series regarding the recent radiation protection training trip to Abu Dhabi. Of course, the most important part of the trip is the training – running a Radiation Protection Officer (RPO) session over 3 days. However, every trip is a learning experience in other ways – culture, architecture and of course food. So I now present a few pictures of my time in UAE relating specifically to observations away from the training.
Grand Millennium Al Wahda Abu Dhabi
I stayed at the Grand Millennium Al Wahda hotel in Abu Dhabi. I requested this from the client specifically – partly so I was not staying at the training venue (held at the Le Méridien Abu Dhabi). At the end of a long day training it is nice to get outside and travel somewhere else to stay rather than simply ‘go up to your room’. Secondly, due to my work being all over the place (re the chaos at home over last few weeks), I wanted somewhere I could quietly knuckle down and get some work done. Therefore it allowed emails, reports and finances to be conducted without feeling I should be spending the evening with delegates.
It was a nice hotel – very nice staff and with a fantastic restaurant called Toshi. Those who have followed my trips to Dubai will know I also rave about Toshi in Dubai. Toshi is an Asian themed place serving freshly prepared and cooked food from Japan, Thailand, China and related areas.
Oh the traffic !!
The journey between the Grand Millennium and the training venue took about 30 minutes. What I noticed immediately is that rush hour in Abu Dhabi is no different to any other large city in the UK. I did find the U-turns performed at major intersections / traffic lights rather alarming (I just closed my eyes and hoped!).
The Toshi Restaurant
So to the food. As many of you will know I rather like my food. I have been on a campaign to lose weight since the 1/1/2012 eating nothing but Asian related foods (mostly cooked by myself). As of 28 November I am hovering around 22.5 kg reduction – not really getting rid of any more at the moment – rather I am maintaining. The main thing I have learnt is that you can cook exciting foods – controlling the sugar and oil is the key to controlling the healthy (or not so healthy) dish. If someone is going to cook for me I like to know what is going into the dish. What I like about Toshi is that much of the food is Japanese style (sushi, raw fish related) and you can pick and choose so you know what you are getting. Most of the cooked dishes are prepared in front of you so that you can see what is going in, and in my fussy case, control that oil!
Here is an example of the stir-fry which was cooked for me on the night of my arrival. Being tired I did not want to eat much so just grabbed a basket, picked all the ingredients, and gave to the chef to cook right there are then. Was fabulous (and note the chilli!).
Another night I wanted a curry so opted for duck curry with vegetables. Not quite as healthy I know (!) – but I made up for it by avoiding the rice. It was fabulously aromatic and not too hot – normally I do go for heat but the delicate spicing enhanced the tender duck meat.
On my last night in UAE I opted almost exclusively for Sushi – making up the dishes from scratch and going for raw fish, no rice and plenty of salad. I have never really been into Sushi but I must say it was fresh and felt very healthy to eat! So, with that in mind I was not at all guilty (much) to have just one pudding during my stay. Now take a close look at what follows – black pepper ice-cream in a crispy basket with ‘things’. No idea what has gone into this dish but it tasted fantastic!
So that ends part 2 of this blog about UAE. Not much radiation protection I know, I will discuss the RPO course during the final part 3 – coming up soon!
Well, after quite a lot of stress and certainly some heart searching (illness in the family), I finally started my latest trip to UAE (19-23 November). All previous trips to UAE had been based in Dubai, so travel to Abu Dhabi was a new experience. Ionactive is again working with RNA Safety International to provide a general Radiation Protection Officer (RPO) courses for UAE. The course is based directly on the requirements of UAE Federal Authority for Nuclear Regulation (FANR) – but also encompasses IAEA standards and best practice from the UK.
Care when talking radiation monitoring equipment up in the air!
Security at Heathrow on the morning of travel was not as smooth as I was expecting (generally I find it quite quick). Ushered through Fast Track I was expecting it to take minutes. Indeed within 60 seconds my bags were going through the x-ray machine, but then I spent the next 20 minutes having my bags taken apart, swabbed and then x-rayed again. Nothing was found (as expected) but I do wonder if the PED (Personal Electronic Dosimetry) aroused their suspicions. Either that or I just look a dodgy guy!
Etihad - nice service
I had not flown Etihad before and first impressions were excellent. The lounge was calm and peaceful with lots of food and drink if that takes your fancy. Despite all this being freely available I never have the will to pig-out for the sake of it, in fact I am not a fan of eating or drinking much at all when flying.
The seat I had was like a little pod and almost totally enclosed – lots of privacy and space. For my trip out I was using it as a mobile office. For my trip back to the UK (leaving 0300 on Friday morning – UAE time), I intended to take advantage of a fully flat bed and sleep the entire trip. The flight has was mostly calm but noted the sound of ‘wind’, the feeling of turbulence, and the image of the aircraft (see picture) tracking against a cross wind (those fly lessons were some use after all !).
[Aside – written later in the flight out. At 1750 UAE time they came around and closed all the window blinds. I was going to ask why – but then a red glow was produced in the cabin. I believe this ambience is supposed to be sunset? Why not just look for the real one? I kid you not – the stars then come out – yep the entire cabin roof was full of stars. Being the pain that I am, I was still working so I had my own cabin light on – sorry folks]
The wonders of the world below
There were some great views from out of my window – a couple are shown below but the camera just does not do them justice. The wonders of the vastness of the earth. Amazing to see how the topography and vegetation changes so radically from place to place. As I was about to fly over Saudi Arabia the expected rocky sandy brown colour throughout appeared as expected.
Radiation and food - what did you expect?
As you might expect the trusty PED (which got me into trouble early in the morning) was also featured by some food (yes I know it’s not the best monitor to use for these measurements, and it’s not measuring neutrons, but its small). Here are a couple of captures.
Holiday or a work trip (get real!)
One or two colleagues (and perhaps some family?) raise an eyebrow regarding these trips .. “Going on your hols for a bit of warmth?”. I can assure you these are no jolly. 0430 start on day 1 will finish at 2330 UAE time (1930 UK time). I am then up and showered by 0600 UAE time (0200 UK time) on Tuesday morning. Then I have a full day of training which is rewarding but tough going, especially where there are language issues. That was repeated Wednesday and Thursday. I then left my hotel about 0030 on Friday morning UAE time (2030 UK time, Thursday) for a 0300 flight back to the UK (arriving 0645 UK time Friday).
Going away from home is never easy
The delay to this whole trip was caused by family illness (as noted early on). My wife having been diagnosed with cancer is doing really well post op. Despite the worry she is holding it together brilliantly. Going away is never good for her, the boys or indeed myself – it’s just one of those things when you’re a consultant. Going abroad when things are not exactly ideal back at home is never going to be easy. Anyway, with the operation out the way it is time for the treatment regime to begin. Whilst the treatment is not welcomed (it’s a necessity), at least it has some routine about it – enabling me to reschedule all those clients meetings.
[Aside – by and large my clients have been fabulous over the last few weeks, really do appreciate their good wishes and allowing the diary to be significantly reorganised.]
[Second Aside – I could not capture on camera (was too quick) but the PED alarmed at 8 micro Sv/h (currently the average is about 3 micro Sv/h). Wonder that that was about?]
Music for the flight out
For those of your into music, I played ‘The Fierce and the Dead’, ‘The Enid’ and NOSOUND during the flight out.
Next up will be Part 2 where I will say some words about the actual training – it was a great experience!