Month: May 2014

How much cosmic radition do you get from flying from Sydney to Texas, USA?

Posted on

Fletcher Best

Being the #hygienenerds that they are, #fletcherandbest were thinking about the hazards that they might encounter during their trip to Texas for #AIHce2014. They tell me that they might have gotten a little side tracked consuming some G&T’s in the Qantas lounge before their flight…especially when they were sitting next to Tim Cahill! ….But they did get back to business and thankfully bring us their first blog post on the hazards of cosmic radiation that they were exposed to during their long-haul flight!


Firstly, some background: The electromagnetic spectrum includes a variety of radiation types, dependent on their wavelength, for example, radio waves, microwaves, infrared, ultraviolet, x-rays and gamma rays. Low frequency, long wavelengths are considered non-ionizing, whereas higher frequency, shorter wavelengths are classed as ionizing radiation.  Ionizing radiation has enough energy to cause chemical changes by breaking chemical bonds. X-rays and gamma rays have very high frequencies and very short wavelengths, and have enough energy to remove electrons from an atom. This process is referred to as ionisation.

nonionising rad

On earth, we are constantly exposed to radiation from space; this invisible ‘shower’ of radiation contributes to our background radiation dose. These cosmic rays consist of both low and high energy charged particles. When we are on the earth’s surface, we are protected by these rays by the earth’s atmosphere, which acts as a shield. Those who live in high altitude areas are exposed to higher levels of cosmic radiation than those at sea level.

Exposure to ionising radiation can increase when travelling in an aircraft, as the earth’s atmosphere provides less protection from cosmic radiation at altitudes around 7000 – 12000 metres – the usual travelling altitudes of commercial aircraft. The exposure depends on the altitude of the flight and the latitude of the flight from the equator, the further the flight path is away from the equator, the higher the exposure.


The dose limit of 1 mSv/year applies for all members of the public. Occupational exposures have a dose limit of 20 mSv/year; in this case, this would include people such as pilots and aircrew. ARPANSA report that studies undertaken to determine cancer risk to pilots and aircrew, show that there is no significant increased risk of cancer due to radiation exposure.

We were lucky enough to borrow Tracerco Personal Electronic Dosimeters (PEDs) to use during our flight from Sydney to Dallas to measure our gamma radiation exposure.


The results measured our dose to be 23.57 µSv, or 0.024 mSv for the duration of our flight (well, the time we were allowed to have electronic equipment operating – about 14 hours). This equates to about 2.5% of the annual dose limit of a member of the public. To reach the dose limit for the public, someone would need to fly this route 42 times in a year!

In comparison, a chest CT provides a dose of 8 mSv, a mammogram (four views) 0.7mSv, chest x-ray 0.1 mSv, or dental x-ray 0.01 mSv.

So, in the scheme of things, radiation exposure from flying, does not result in a concerning risk, however, if you were concerned, you could apply the three radiation protection principles of 1) time; 2) shielding; and 3) distance. You could choose to fly more flights over shorter distances, thereby reducing your exposure time and increasing your shielding, as shorter haul flights fly at lower altitudes, or spend shorter amounts of time at altitudes of concern.

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) provides further information regarding radiation basics and cosmic radiation. Radiation doses for medical procedures can be found at the Health Physics Society Fact Sheet.

Thanks #fletcherandbest for going to the effort of measuring and assessing your dose of exposure to cosmic radiation!

Introducing our Guest Bloggers AIHce 2014

Posted on Updated on

The American Industrial Hygiene Conference & Exposition (AIHce) kicks off in a few days, and sadly I am not going. It is a massive conference for occupational and environmental health and safety professionals and this year it’s being held in San Antonio, Texas.

I am suffering from severe FOMO (fear of missing out), but although I may not be able to go, I happen to know three awesomely fantastic occupational hygienists that are!  They have graciously offered to share some of the highlights of this fantastic conference and put pen to paper so we can all learn about the latest & greatest information.

Our first guest blogger is Alex Wilson, who is attending the AIHce via winning the 3M Young Hygienist of the Year award at the BOHS Conference. Alex is based in the UK and works in the Steel industry. He has been lucky enough to attend the AIHce previously as part of attending the AIHA Future Leaders Institute, and has put his hand up to cover some of the social aspects of the conference…it’s going to be hard I can tell!


Holly Fletcher, and Brooke Best are teaming up to cover the Australian view of the world. Brooke is a HOTTIE and Holly is a casual HOTTIE, based in Sydney. Brooke’s background is in mining, and Holly is one of those hygienists who is into everything from mining, industry, and now, coal seam gas, so they’re sure to come up with some interesting reads!

Fletcher Best

All three guest bloggers are also going to present at the AIHce Ignite session which is sure to be fantastic…and I can’t wait to see them on YouTube! So for the next few weeks, please welcome your guest bloggers Alex Wilson, Holly Fletcher, and Brooke Best.

The ColorRun results are in. So is it hazardous to your health?

Posted on Updated on


Is the ColorRun hazardous to your health? That is the question I set out to answer, yet unfortunately, like most things in occupational hygiene, getting the answer wasn’t that simple!

I’ve provided details on the methodology I used to collect the samples previously (and what it looked like during the run), but I need to explain the limitations in the data I collected. It’s important to know the limitations of any study before you accept the conclusion…so going against the way that popular media typically reports scientific studies and I’m going to give you some of those limitations first:

  • Firstly, only five valid samples made it out of the run. This isn’t too bad, but I had hoped for at least 6 samples so I had greater confidence in the data. As it stands now, I have highly variable results and a relatively small data set…not what I really want. But like my 7-year old says, “you get what you get and you don’t get upset!”.
  • Then there was the case where some of us suffered a direct hit from a colour throw (when the Color Run volunteers threw the dust right in our face for example…which happened twice). This resulted in small chunks of dust being left on top of the sample filter. They would not be representative of what you would breathe in (you might swallow them perhaps…but not inhale). However those “chunks” of dust dried up and actually rolled off the filter, so they weren’t analysed. The NATA-accredited lab even reported that the samples, “contained large amounts of loose particulate matter that was not all able to be weighed with the filter. Results may be biased low”. So if anything, these results are lower than they probably are…not the other way around.
  • We only sampled for 2.5 hours on average, and the exposure standard is based on an average over an 8-hour workday. For direct comparison purposes, I have assumed that the remaining 5.5-hours or so were spent in a dust-free environment, but I didn’t measure it. So again, these results are biased low (so they are conservative).
  • We are not workers and so the “exposure standard” legally doesn’t apply to us as such. But it does apply to the volunteer workers throwing the colour around and standing in a haze of dust for 2.5-hours. If our results appear shocking to you, just imagine the dose that they are getting and the impact to their health.

So let’s get down to the good stuff…the sample results. I’ve listed them in the table below in relation to the exposure standard. Remember that exposure standards represent airborne concentrations, which according to current knowledge should not cause adverse health effects nor cause undue discomfort to nearly all people. They do not represent “no-effect” levels that guarantee protection for everyone because of the variability in susceptibility between individuals. Therefore there may be a small proportion of people who may suffer mild or transitory discomfort at concentrations around, or below, the exposure standard. An even smaller number may exhibit symptoms of illness. Exposure standards determine whether a potential exists for over exposure, and associated ill health effects.

Three out of five samples exceeded the exposure standard, so I wasn’t off to a good start.…but to answer my question, “is it hazardous to your health”? I wanted to use statistics. There is uncertainty in all data, yet I wanted to see 95% of the data be below the exposure standard. I won’t bore you with the statistics, but the 95th percentile was well over the exposure standard. This was due to both the high sample results and also the high degree of variability in the data set.

Runner Result (calculated over 8-hours, assumed no exposure for remaining time after the ColorRun) Exposure Standard
Kel (ran with 2 x four year old boys) 29.0 mg/m3 4 mg/m3
Kym (ran with 1 x three year old son) 1.1 mg/m3 4 mg/m3
Mel (ran solo) 22.5 mg/m3 4 mg/m3
Kristy (ran solo) 84.2 mg/m3 4 mg/m3
Me (ran with a 7 year old daughter) 0.8 mg/m3 4 mg/m3

So what does it all mean? These results demonstrated that participating in the Newcastle ColorRun was hazardous to our health.

Some of us as you can see fared better than others. We all ran the same course in roughly the same amount of time. The amount of flour dust we inhaled though was more due to luck (or lack of) more than anything else. It’s almost impossible to not get covered in dust if you run through a colour station or go to the colour throw at the end.

Like any good occupational hygienist I need to provide you with a list of recommendations based on the data collected. So here are some of my recommendations for future participants of the Color Run:

Seriously consider your need to participate in this event. If you suffer from allergies, or allergy-type symptoms such as coughing, wheezing, shortness of breath, or if you suffer from asthma, or if you are considering taking babies or small children, then this is especially important. 

If you do participate, then take caution when going through the colour throws at each kilometer, which includes skipping them entirely (run around them up wind), or wear respiratory protection. I also recommend skipping the final colour throw at the end and the optional trip to the “Cleaning Zone”.

It’s a pity that this event is targeted at families and for kids to #runwithmum and yet the health risks associated with participating in this event are understated. I have no problem with risky activities…I just think that people should be provided with all the information so they can weigh up the risks and make an informed decision for themselves. I would recommend that the organisers of the ColorRun provide the Safety Data Sheet for the “color” on their website and to engage a competent person to provide an updated commentary for the public on its meaning. It is not fair for parents to have to individually contact the organisers, only to be told thatbreathing small amount of this material is not likely to be harmful“. You should be told the health effects of the colour, the concentrations at which you may experience those health effects, and things you can do to reduce your exposure. Most importantly you should be made aware that some people are more susceptible to developing illness related to exposure.  That would be more useful than telling me it’sgluten free“.

Spare a thought also for the volunteers who were not provided with respiratory protection and stayed within those colour stations (dust clouds) for over 2-hours. If you think our results were high, then their exposures would be far greater. Of course this is only a guess as I didn’t measure them (but it’s based on an educated observation!). I’d suggest there is a significant risk of exposure to flour dust in excess of the Workplace Exposure Standard and controls are needed to reduce that exposure. I recommend that one of those controls should be to perform a personal exposure assessment for volunteer workers.

There were a lot of people running with tiny babies and small children (including us). It’s not worth it, seriously. It’s hard for me to say this as my daughter LOVES it, but sometimes it’s just not worth the risk. We’ll just find another mum-daughter bonding activity…one that isn’t hazardous to our health.

Still not convinced? Well it’s a big call to say all of this on just 5 samples, so I’m lucky that I’m not the only Occupational Hygienist out there with a bunch of sampling pumps. The more samples we can collect to add to the data set will provide more certainty and confidence in these results. I will update these results and recommendations with additional validated data as it comes in…so stay tuned!

Young Hygienist Snapshot: Liam Gunning

Posted on Updated on


Liam is a Certified Occupational Hygienist and a fellow graduate of the MSc OHP Program at the UOW. Liam and I sat the COH exam together on the same day last year (also known as the single most terrifying experience of your life) – and we have someone both survived to see the other side of it! Here is 5-mins with Liam:

Best location I have worked: I have worked in interesting places all around Australia. I find that the big sites with the highest risk are usually the most interesting. Some of the best places I have worked include off-shore oil facilities, UG mines, and oil refineries. Working off-shore was awesome, I was able to see and talk to nearly everyone on the facility and get to know what they do. Working in high risk environments where you can make a big difference through implementing controls is usually the most rewarding thing.

The best thing about my job is: That I get to learn about everyone else’s job and meet lots of different people.  

Career Highlight: Passing the COH exam was pretty special

If you want to be an Occupational Hygienist, you’d better get used to: Explaining to engineers why we do personal monitoring and not area monitoring. [Side note: story of my life!]

People normally think my job involves: I basically have the same conversation with everyone who asks me what I do.

Questioner:  What do you do for work?

Liam:  I’m an Occupational Hygienist.

Questioner:  *blank stare

Liam: I assess worker’s exposure to stuff like noise, chemicals, and dust….

Questioner: Oh, I thought you cleaned toilets, ha, ha, ha.

Liam: *blank stare

Any advice on how to change the flow of this conversation is welcome!

The worst thing I’ve been asked to do was: Back in the asbestos auditing days, auditing old and dingy places for asbestos was usually a drag.  One in particular was an old toilet block in a secluded location.  The toilet block was to be demolished as it had a reputation for attracting people using it as a place to meet up and conduct business other than what would normally be conducted in a toilet block.  The audit didn’t take long to complete.  However in that time there were way too many people disregarding the “do not enter” signage for my liking.


Young Hygienist Snapshot: Caitlin Purcell

Posted on Updated on


Caitlin is currently working as a District Safety, Health & Environment Manager in Canada – how’s that for a working holiday! She is a Health and Safety Graduate who has seen the light and is currently completing her Masters in Occupational Hygiene and Toxicology at ECU yay! Here is 5-mins with Caitlin:

The best thing about my job is:  The diversity! I love that one day I can be performing a noise survey, and the next I might be conducting ergonomic assessments or delivering various toolbox presentations. It’s great being able to keep things interesting with a mix of both field and office work.

Career Highlight: Reaching platinum Frequent Flyer status from all the FIFO work! And on a serious note, I have to say that working on a control strategy that saw silica exposures at a locomotive service shop drastically reduced was a great outcome for the health of the affected workers.

If you want to be an Occupational Hygienist, you’d better get used to: Crafting a good sales pitch. Any ‘Pump Jockeys’ out there who have ever tried to strap an exposure monitor to an unwilling worker will know the feeling!

People normally think my job involves: Cleaning of some description. My housemates can attest to the fact that I would make a really lousy Hygienist if that were the case.

The best thing I’ve been asked to do was: Conduct a heat stress survey on various track machine operators. Spending a day in the true outback riding on locomotives wasn’t such a bad day at the office!

The worst thing I’ve been asked to do was: I once had to assess formaldehyde exposure at a large scale chicken breeder farm in WA. It was great to get an insight into the industry, but I couldn’t help but want to scoop up all the chickens and set them free!


Instagram of the Week

Posted on

Instagram has been great to watch lately for the #occupationalhygienist.

We have two new posts today from people who have been busy posting some pics of their work travels. I love the video of the foundry…”walk with me”. It’s going to be my new phrase from now on at work. Love it.

Running the #happiest5k

Posted on Updated on

The Newcastle Colour Run was on yesterday, and once again it was great fun morning, albeit a bit dusty! A very big thank you goes to the five volunteers who graciously wore personal exposure monitors for the entire run as part of an exposure assessment.

It was a little awkward running with a pump on your bum, but it was in the name of science!

We managed to collect 5 valid personal exposure samples for inhalable dust (one sample was invalid ahh!). All the samples have gone in for analysis, so now the waiting game begins. We certainly had some colourful sample filters, all in varying shades and varying amounts of dustiness. It will be interesting to see what the results say…so check back here in a few weeks and I’ll let you know!

I also found another good use for the GoPro, so for those of you who have never seen a Colour Run before – check this out so you can see what it’s all about!