More samples from the #happiest5k – will it still be hazardous to our health?

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Following on from the exposure assessment we performed on runners in the Newcastle ColorRun, we are lucky enough to have some more volunteers who ran the #happiest 5k in Brisbane recently and took some more samples.

So will the results be the same? Will they continue to show that participating in the ColorRun is hazardous to your health? The samples are in with the lab at the moment so we will just have to wait and see…our newest guest blogger, Kristy will bring us the news as we get it!


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

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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!

Running the #happiest5k

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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!




Is the #ColorRun hazardous to your health?

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The Color RunTM is in Newcastle this weekend, and I’ll be running the #happiest5k for the third time. It’s a great event with a warm and friendly atmosphere, and because it’s so family-friendly and kids are encouraged to #runwithmum, one of my young daughters will be running alongside me. There’s just one thing that I’m not sure of about this whole event, and that’s whether the “color”, which is the name they give to the coloured corn-starch (which is what we Australian’s call corn-flour) thrown at you throughout the run, is hazardous to your health.

When occupational hygienists are unsure whether workers are being over-exposed, they can perform what’s known as an “exposure assessment” to determine if the hazard presents a significant risk to health….so that’s what I plan to do!

The first step in the exposure assessment process involves information gathering. The Color RunTM website tells me that the colour is made from corn-starch and natural plant based food dyes…with the added bonus of being gluten free. That’s fine, except that corn-starch and natural plant based food dyes aren’t typically thrown into the air at you and then inhaled.

I contacted the Color RunTM and asked them for a copy of the Safety Data Sheet. I also told them that my daughter has asthma and asked if there was any advice against doing the run in her case. “Color Support” were quick to get back to me with the following information (sans SDS and reference to the question on asthma):

Thank you for your email! The color is a cornstarch base and is dyed with food grade dyes. It is even Gluten free. 🙂  Here is a list of the ingredients in our color: Blue Thank – FD and C Blue 1 Lake Low, Melojel Starch. Green – FD and C Blue 1 Lake Low, FD and C Yellow Lake 36-42 PCT, Melojel Starch. Pink – FD and C Red 40 Lake 36-42PCT, Melojel Starch. Yellow – FD and C Yellow 5 lake 36-42 PC, Melojel Starch. Our color has gone through extensive testing. In the Material Safety Data it says there could be some irritation since the color can form dust, but in all of the testing it states that there is nothing The MSD sheets show the Potential Health effects are as follows: Oral Exposure – Swallowing this material is not likely to be harmful. Dermal Exposure – Unlikely to cause skin irritation or injury. Inhalation Exposure – This material is a dust or may produce dust. Breathing small amount of this material is not likely to be harmful. Eye Exposure – Dust can cause eye irritation Symptoms may include stinging, tearing redness and swelling of eyes. Symptoms of Exposure – No data Other Health Effects – The material can form dust, which may cause skin or mucous membrane irritation. Symptoms may include redness, burning, and swelling. Although they may cause respiratory tract irritation, nuisance dusts do not form scar tissue or affect the structure of air spaces in the lungs. Their effects on the tissues are potentially reversible.

Whilst I like the smily face touch in their email, according to their information the dust may be irritating, but breathing in a small amount of material is not likely to be harmful. Have a look at the picture below. Do you think this meets the definition of a “small amount of material”?

I think the health risks might be a bit understated, hence the reason for performing an exposure assessment. As a preventative measure, our youngest daughter (the asthmatic) probably won’t run with us this weekend…and if she does, then she won’t be taken into the color throw at the end which is where the above picture was taken.

I then did a bit of background research on the health effects of corn-flour in general to understand the health impact: It’s relatively harmless when you buy it in the packet at Coles and use it to thicken your gravy, but when you get it as a dust in the air it causes irritation of the respiratory tract which can range from allergy-type symptoms, coughing, wheezing, shortness of breath, eye irritation, through to asthma. Some people are what’s known as “sensitised”, which means that they are more likely to show some of the above symptoms when they are exposed to lower levels. Sensitisation can occur from previous exposures that may have happened many years after their initial exposure.

The next step in this exposure assessment is to define what’s termed, “Similar Exposure Groups” or SEGs. These are groups of workers that are expected to have the same general exposure because of the similarity and frequency of the tasks they perform, the materials and processes which they work, and the similarity of the way they perform the tasks. In this case, my SEG will be “runners” participating in the Newcastle Color RunTM. As part of this, I also need to identify the exposure scenarios, which in this case, will be focused only on the potential inhalation of corn flour to color runners.

I then need to make a judgement about the exposure, which in this case, based on my experience doing two previous Color RunsTM, I’m going to call the exposures “uncertain”. I need to also decide how I’m going to determine if it’s hazardous. In this case, as it’s not practical to sample all the color runners, I’m going to select a sub-set of runners and collect enough samples to at least perform inferential statistics…so I’m going to sample exposure from at least six runners. I do have a slight limitation here, as these statistics rely on the samples being randomly collected, and I plan on sampling a targeted group of people (including 3 hygienists and 3 willing participants). However, we are all at different levels of fitness and won’t all run at the same pace or at the same time, so I’m trying my best to make this randomised.

I then need to decide on an exposure standard (ie: a limit) for the assessment, and also a metric to use to compare the data to that standard. I’m going to use the value recommended by Safe Work Australia for grain dust (oats, wheat, and barley) of 4mg/m3. That value was designed to reduce the effect of respiratory symptoms, but it would not be sufficient to prevent sensitisation or occupational asthma in the long-term. However, as the exposure period is expected to last for around an hour, and I’m going to assume that participants (well, us at least) are not exposed on an ongoing basis, I think that this value is fit for purpose.

I also need to set the methodology and sampling parameters for the measurement approach. I’ll be measuring inhalable dust via IOM samplers in accordance with AS3640 (2009) with the measurement period starting from when we first line up at the “start line” and finishing just before we leave the venue of the Newcastle Jockey Club.

I’m going to use a simplified approach and go with the method recommended by the AIHA and use the Exposure Rating Categorisation System which is based on the estimate of the 95th percentile relative to the exposure standard. In every-day language, this just means that I want 95% of my data to be below the recommended limit.

If this were a work site in NSW, then I’d want to see 95% of the data below half of that limit, as anything over half of the limit typically means that the process may not be under reasonable control to protect the workers. Further to that, you already know that exposure standards are not a dividing line between safe and unsafe, they are designed to protect most workers, but not all workers…so you need some leeway in there also.

The next step is to put in some preliminary temporary controls to prevent over exposure. During the last Color RunTM my daughter wore goggles to prevent the colour going into her eyes, she wore a bandana around her face to prevent breathing in the dust (hygienists everywhere are rolling their eyes as they no how ineffective these are!), and we don’t go through the voluntary “air blown cleaning zone” which is promoted so you are, “totally good for the drive home”. We’ll use the same controls this time also.


It will be a few weeks until the results are in, but I’ll keep you posted on the outcome. If it turns out that doing the Color RunTM poses a risk of developing harmful health effects due to dust exposure, then sadly this weekend will be the last Color RunTM we will attend. That will be a pretty sad thing, as my daughter absolutely loves it. It’s currently on par with the One Direction concert at this point…yes it’s that sad…so fingers crossed!