check your hygiene
Respiratory Protection in Asia – The Truth About Masks Used
Do you want the truth? Think you can handle the truth?
Well, the truth is the following three methods used to protect yourself from breathing in contaminated air will not provide you any protection at all!
Sorry to be the bearer of bad news, however, this blog is not all about sunshine and rainbows
This blog is intended to shed some light on the “masks” commonly used to protect people from airborne hazards in Asia, and tell you why they don’t work.
NOTE: The information presented below is not based on rigorous filtration efficiency testing repeated in a laboratory. The information presented answers one simple question i.e. “will that mask protect me?” It’s pretty simple to answer, either it will or it won’t protect you.
In Part 3 of this Respiratory Protection in Asia Series, we explored the Principals of Protection. We now know that a mask will only protect you when all of the air that goes into your lungs passes through a filter that removes all of the bad stuff from the air. To achieve these two fundamental things need to occur:
1. the filter media has to be designed and tested to prove that the contaminants you are protecting yourself from will be removed from the air; and
2. all of the air has to pass through the filter before it reaches your lungs – that is, no bad air is can pass through the filter or travel through any gap.
So let’s apply these principles to the mask most commonly seen to be worn in Asia……the good old Medical Mask.
Firstly what is a medical mask?
In the 1890’s a German bacteriologist and hygienist, by the name of Carl Flügge discovered infectious diseases such as tuberculosis and cholera could be transmitted through droplets released from people’s mouths and noses (AKA Flügge droplets) . This discovery lead to the development of the first medical masks consisting of gauze strips placed over the wearer’s mouth. It is believed French surgeon Paul Berger was the first to wear a surgical mask while operating in 1897.
These days, despite the introduction of immunisation and antibiotic drugs, used to control communicable diseases and infection such masks continue to be used for purposes of:
– limiting the transmission of infective agents from staff to patients during surgical procedures;
– protecting the wearer against splashes of potentially contaminated liquids; and
– reducing the risk of spreading infections, particularly in epidemic or pandemic situations.
Okay, so let’s apply the respiratory protection principles to test the Medical Mask:
Will the mask filter remove the airborne contaminants?
No, the mask will not filter airborne contaminants. Why? because fundamentally the medical mask is designed to stop germs released by the wearer from reaching the outside world – – they are not designed to stop airborne contaminants from the outside world getting in!
Will the mask fit the wearer’s face so no gaps between the mask and the wearer’s face are possible?
What about the designer masks you ask? Surely they must protect you, they look so good.
I am told that the designer masks are preferred over the medical masks, however, they are more expensive and, therefore, are less common. I have also been told that an added benefit of these masks is you can wash them and they will last up to 3 or 4 months.
So what are the masks made up of?
So let’s apply the respiratory protection principles to test the Designer Mask:
Will the mask filter remove the airborne contaminants?
The simple answer is no
Why’s that you ask? Well, the material the masks are made of allows airborne contaminants to pass through and into your lungs. In Part 3 of this series, we demonstrated the size of airborne particles (PM10 and PM2.5) in comparison to a human hair. The photo on the left shows a human hair that has been pushed through the mask to demonstrate how big the holes are in the material are. The photo on the right shows how the large holes can be seen with the naked eye.
Will the mask fit the wearer’s face so no gaps between the mask and the wearer’s face are possible?
What about covering your and mouth and nose with your hand for protection?
It’s actually quite difficult to apply the respiratory protection principles to this method of protection. The human hand is not pervious, i.e. air cannot pass through your hand.
Now, hypothetically speaking just say you were able to seal off your mouth and nose with your hand, then how would you actually breathe? Let’s face it, to breathe in clean air we need to remove the bad contaminants, to do this we need a filter. The hand is not a filter. Once you remove your hand away from your face you will continue to breathe in the contamination.
Don’t miss the final blog in this 5 part series where we take a look at the real challenges for protecting persons lungs in Asia.
Respiratory Protection in Asia – Principles of Protection
Last year the World Health Organisation (WHO) reported that sufficient evidence now demonstrates air pollution to be the world’s single largest environmental health risk, contributing to 1 in every 8 deaths globally (approx 7 million people per year).
I have been working in Asia for some months now and have certainly noticed the significant environmental pollution. The other thing I have noticed is the “face masks” worn by the Asian population.
With all due respect, I do have some concern regarding the “masks” I have witnessed in use, particularly as the general perception is they will protect against dusts, chemicals and other biological hazards.
This blog is intended to simply explain how a “mask” works and how it actually protects you from all of the bad stuff in the air!
Let me provide you with a simple explanation of how clean air gets into your lungs and how bad air can be kept out.
Now, imagine billions of tiny little pollution particles that continue to float around in the air. Under a microscope, they usually look like this little creature
Now the aim of protection is to stop these little creatures from getting into your lungs
Sounds easy enough, right? Well, let me tell you it’s not!
You see when you wear a protective mask there will be a myriad of things that influence whether or not those little creatures will get into your lungs. Fundamentally to provide you with protection, the mask must:
— remove creatures of all sizes;
— remove creatures of all chemical states (gas, solid or liquid); and
— fit your face.
Let’s have a look at these more closely.
Whoever said size doesn’t matter was wrong! You see the tiny creatures that get into your lungs and hurt you are typically not visible to the naked eye, that is you won’t be able to see them!
Dust (or “particulate matter” as occupational hygiene nerds like to call it) comes in many sizes. The fact that it is floating in the air demonstrates how small it really is, you see the heavy particles will fall out of the air leaving us to deal with the small ones.
Now here’s two facts for you to consider:
1. the smaller the creature, the deeper it will go into your lungs
2. the deeper the creature goes into your lungs the less likely it will be for the creature to ever come out
Well, how small does it have to be you ask?
Let’s look at the pictures below. For us to even breathe in a creature it would have to be around about 10μm (AKA PM10), for a creature to get deep into our lungs it will need to be around 2.5μm (AKA PM2.5). Now let’s compare these sizes to the size of a human hair.
The microscopic image of the hair on the left below demonstrates the diameter of a human hair to be 60μm. Now looking at the diagram on the right we can compare the size of each creature to the cross section of human hair. Pretty small right?
So for a mask to even work it would need to include filter media that would capture even the smallest particle.
CHEMICAL STATE (GAS, SOLID OR LIQUID):
Creatures that “float around” in the air don’t just include particulates. Creatures come in many different forms and include liquids (think of vapours coming from a petrol tank) and gases. It is important to understand how the mask will actually adsorb the creatures made up of liquids or gases so that they don’t pass through and travel into your lungs. The discussion above regarding size continues to be relevant even when discussing the chemical state of each creature.
Think of the protection you need in the form of an umbrella that you were standing underneath. Your goal is not to get wet! If your umbrella was made of cotton (similar to the shirt on your back) and it started raining, would you get wet? Have a think about it.
It’s important to understand what you are protecting yourself from, whether it be a gas, solid (particulate) or vapour (liquid) so you know that the mask you are wearing is actually not going to let the little creatures travel across to the other side so they can get into your lungs. This is the very reason why different filters are used to capture different types of creatures. It is also important to note that sometimes no matter how good your mask is there are just some creatures that cannot be captured with a filter, for example, carbon monoxide (CO).
Sometimes people say to me that they don’t like wearing a mask because it makes their glasses fog up. Well, I can tell you there is only one reason for that – – – – the mask actually doesn’t fit!
So your still a little confused when I talk about a mask “fitting” you? Well it is simple, the mask you wear is designed to cover both your mouth and nose as these are the two locations air will go in and out of your body (other than farting of course!). We know that all of the air needs to pass through a filter to remove all of the bad creatures, therefore if there is a gap between your mask and your face, then bad air will enter your lungs, its that simple!
Mask seal against the wearer’s face
What’s not simple is actually getting a seal between the mask and your face, that is getting your mask to fit! Remember the picture showing the tiny size of the creatures in comparison to a human hair? Well, the picture below demonstrates how something as simple as facial hair will create a gap between a mask and a person’s face resulting in a broken seal. Once this seal is broken it is easy for the little particles to travel through the gap and into the lungs.
— the material the mask is made from;
— the shape of the persons face;
— features such as a persons nose;
— the size of the mask; and even
— chewing and talking!
So what do I need to remember?
The only thing I want you to remember from this blog is never assume a mask will protect you.
A mask will only protect you when all of the air that goes into your lungs passes through a filter that removes all of the bad creatures. To achieve this two fundamental things need to occur:
1. the filter media has to be designed and tested to prove that the creature you are protecting yourself from will be removed from the air; and
2. all of the air has to pass though the filter before it reaches your lungs – that is, no bad air is can pass though the filter or travel though any gap.
Don’t miss the next blog in this 5 part series where we take a look at and apply the above principles to the following three types of respiratory protection or “masks” commonly used in Asia to protect against all sorts of airborne health hazards.
Respiratory Protection in Asia – Do we actually need protecting?
Okay, so Part 1 of this series introduced you to “masks” I have observed to be used in Asia to protect against contaminated air. I must admit I have never seen so many people wearing respiratory protection in some form or another in my life. Which raises the questions “is there really that much contaminant (AKA “bad stuff”) in the air?” and “do we actually need protection?”
Since working in Laos, I have noticed significant changes in seasonal air quality. I arrived in October, the end of the rain season. It is now the dry season and rural populations are preparing land to plant rice by slashing and burning all vegetable matter (termed by scientists as “biomass burning”). It is obvious to anyone with eyes that the burning activities significantly burdens the air with contaminants. The pictures below, taken at the same location show the visible difference in the seasonal air quality (October 2014 and April 2015).
Smoke-filled air from biomass burning 05.04.2015
So what are the facts?
Well, the World Health Organisation (WHO) reports:
– in 2012, 1 in 8 of all global deaths (approx 7 million ppl) was resultant of air pollution exposure; and
– sufficient evidence now demonstrates that air pollution is the world’s single largest environmental health risk.
So what is “Air Pollution” then?
Indoor Air Pollution – The Facts:
Pollution and Exposure Source: Pollutants generated from open fires and simple stoves used to cook and heat the home using solid fuels such as wood, crop wastes, charcoal, coal and animal dung. Such fuels produce small soot particles that penetrate deep into the lungs. In poorly ventilated dwellings, indoor smoke can be 100 times higher than acceptable levels.
Population Affected: Approx. 3 billion globally. Exposure is high among women and young children in low and middle-income countries, who spend the most time near the domestic fire.
Health Outcomes: 4.3 million premature deaths annually.
Outdoor Air Pollution – The Facts:
Pollution and Exposure Source: Pollutants arise from household solid fuel fires, motor vehicles, agricultural waste incineration, forest fires, certain agroforestry activities (e.g. charcoal production) and power plants. Exposure concentrations differ by geographic areas and time spent in various settings.
Population Affected: Persons who live in the Western Pacific and South-East Asia regions disproportionately experience the burden of outdoor air pollution accounting for 88% of all premature deaths globally.
Health Outcomes: 3.7 million premature deaths annually.
NOTE: In 2013 an assessment by the International Agency for Research on Cancer (IARC) concluded that outdoor air pollution is carcinogenic to humans, with the particulate matter component of air pollution most closely associated with increased cancer incidence, especially cancer of the lung.
Okay, air pollution is a real issue for people who live in the Western Pacific and South-East Asia regions:
When combined, the population of the Western Pacific and South East Asian regions approximates to 3.2 billion people. Almost half of the world’s population!
Do we need protecting? Yes! or as the Laos would say “man lao”!
READ MORE FROM THE RESPIRATORY PROTECTION IN ASIA SERIES:
Respiratory Protection in Asia – What’s the Deal?
Okay, so I have been working in Asia long enough now to recognise that many people of the general public and workers get around wearing makeshift respiratory protection.
So I asked one of my Lao colleagues “what are those things people wear on their faces”? She simply replied “masks”.
So when you try to protect yourself from “bad air” in Asia what do you use? Well I have observed three typical methods that include:
1. Wearing a medical “mask”
2. Wearing a “designer mask” purchased at the local village
3. My personal favorite – Covering your mouth and nose with your hand
Apparently the last method is quite effective when riding a motorbike!
Firstly I have to acknowledge the willingness of the Asian population to wear some form of protection in an attempt to stop them from breathing in all the bad stuff that fills the air. A cultural characteristic I rarely witness in Australia!
However and with all due respect I do have some concern regarding the “masks” I have witnessed in use, particularly as the general perception is they will protect against dusts, chemicals and other biological hazards.
So what’s the big deal and why would I be blogging about this? Well, to reduce harm to persons requires controls to be implemented. Firstly, no control will be bullet proof unless the hazard is eliminated. Secondly, to actually know if a control will work (or not) requires an understanding of its limitations.
This 5 part blogging series aims to promote awareness of the limitations of controlling exposure to “dirty air” in Asia when using the three methods described above. Tune in tomorrow for Part 2 to learn if we actually do need protecting!
I remember attending the AIOH Conference a few years ago when a colleague said to me “imagine what it would be like to be diagnosed with an occupational illness” my response was that I would at least like to choose which occupational illness I was diagnosed with.
So I few days ago I found myself in a situation that took me back to that discussion, and just to put your beating hearts at rest I haven’t been diagnosed with any crazy illness. I did find myself in a situation however where I was exposed to a contaminant that I would have much preferred to substitute with another, I would even go as far to say that I would have rather copped a lung full of ammonia or even benzene!
Currently I work in Laos. To get to work I travel by Company bus from the Laos capital, Vientiane. I am not the best at travelling on buses in Laos (I quickly realised) so I break the torturous exercise up into 3 segments:
1 – Leave civilisation – travel for 1.5 hrs – stop at a service station for break;
2 – Drive on dirt that resembles a road for 1.5 hrs – stop at a Company office for break;
3 – Navigate a goat track for 1.5 hrs – arrive at work.
So here’s me returning to work and decide to have one last iced coffee in Vientiane before I return to civilisation 4 weeks later, I get on the bus and we stop at the service station, I decide I need to go to the toilet.
Reluctantly I know I will have to use the symbolic Asian ‘squatter toilet’. Being the prepared hygienist I am, I take with me a packet of Dettol hand wipes so I can “wash” my hands afterwards. I go in; close the door and find somewhere to put my hand wipes (a dry spot on the floor near the door), I then navigate the use of the hole in the ground. After I finish my business I use my wipes, then put the packet under my arm and walk across the service station to see my colleagues sitting down at a table.
When I arrived at the table I put the packet of wipes down on the table only to see the packet contaminated with shi*t!! Nooooo!
Yep, you guessed it! I look down and find I have someone else’s excretion on my shirt and down the inside sleeve of my arm. Is this seriously happening to me? The situation only to be compounded by the fact that the airline lost my luggage so I couldn’t even change my shirt.
Good hazard identification Fletcher! Seriously, I didn’t just throw the packet of wipes on the floor. I strategically selected a place that didn’t appear to be dirty and seriously, how did someones business end up near the door?
What’s the big deal right? It’s only on my shirt, it’s not like I ingested it. It begs the question however, if I didn’t recognise the hazard in the most obvious place where else would I not see it? I hate to think.
Well, this is the deal.…… The following diseases have been listed by the world health organisation (WHO) as a High infection and transmission risk in Laos due to less than adequate sanitation and hygiene practices:
Hepatitis A – viral disease that interferes with the functioning of the liver; spread through consumption of food or water contaminated with fecal matter;
Hepatitis E – water-borne viral disease that interferes with the functioning of the liver; most commonly spread through fecal contamination of drinking water; and
Typhoid fever – bacterial disease spread through contact with food or water contaminated by fecal matter or sewage.
I am lucky I am vaccinated against Hepatitis A and Typhoid. However, there is no approved Hepatitis E vaccination currently available. Quite scary, especially when the WHO report that globally over 60% of all hepatitis E infections and 65% of all hepatitis E deaths annually occur in South East Asia. Oh my Buddha!
health poverty action laos
What is it? Dusts Not Otherwise Specified (known as “Dust NOS”) are quite simply just dusts, that are insoluble or poorly soluble in water and have not been classified due to their toxicity (eg: they don’t have any toxic impurities such as quartz or lead etc). Dust NOS may come from vehicle traffic, drilling, blasting, grinding, screening etc.
What does it do? Whilst there are still information gaps for health aspects of Dust NOS, workers may still be susceptible to eye/nose/throat irritation or dust-related diseases such as Chronic Obstructive Pulmonary Disease (COPD).
What is the “safe limit”? Interestingly, Safe Work Australia does not specify a Workplace Exposure Standard for Dust NOS in the Work Health and Safety (WHS) Regulations in Australia. Dust NOS would be one good example of how simply complying with the WHS Regulations is not enough to prevent occupational illness and disease in your workplace.
The Australian Institute of Occupational Hygienists (AIOH) has just published their Position Paper on Dust NOS and their associated health issues. That Position Paper recommends two Dust NOS “trigger values” to protect workers from potentially serious health effects. These are:
- 5mg/m3 for inhalable dust; and
- 1mg/m3 for respirable dust.
You need to figure out which dust fraction (inhalable or respirable) is likely to have the greatest likelihood of exceeding the associated trigger value…or potentially look at both.
What is the difference between “inhalable” and ‘respirable”?
Inhalable dust is basically all of the dust that you can breathe in through your nose and mouth, while Respirable Dust is the dust that makes its way down deep into your lungs into the unciliated airway (the alveolar region). You can find more info in Australian Standard AS3640 for inhalable dust and AS2985 for respirable dust.
What do these new trigger values mean? This is a big deal in the world of dust. Previously in 2013, Safe Work Australia recommended that Dust NOS (as inhalable dust) should be maintained below 10mg/m3 and they made no mention of respirable dust. It turns out that that magic number was introduced back in 1990 and wasn’t reviewed or updated since that time. Think back to 1990…I was in Year 7; perms were in, I think I had a pair of mustard coloured jeans. It wasn’t a good year. Times have changed. More studies have been performed, and we are better informed on many things, including perms….so with new information comes new recommendations.
In the world of mining (which have different Regulations), there are exposure standards for Respirable Dust ranging from 2.5mg/m3 to 5mg/m3, and you’ll note that this new trigger value is even lower than that.
So these new trigger values mean that as hygienists we want to put more control measures in place a bit earlier than Safe Work Australia recommended previously. This might include more dust suppression, more ventilation, containment, or the use of respiratory protection as a last resort. The Position Paper lists some practical control measures that can be used to reduce exposure to Dust NOS that would be considered on a case-by-case basis.
Why do you care? Why recommend even more stringent requirements than the WHS Regulations? Ultimately, occupational hygienists are focused on protecting worker health and preventing occupational illness and disease. Implementing these trigger values in your workplace is one example of how you can reduce exposure to workers and therefore reduce the associated occurrence of illness and disease associated with Dust NOS.
Need an Occupational Hygienist? The AIOH has a Consultant Directory here.
I had a nice break from cooking while I was in the UK. It was so nice, that I extended that break by a few more weeks…until we all really got sick of not eating home-cooked food and it was time to break out the pots and pans again. So reluctantly, I reached down to grab a saucepan from the kitchen cupboard and bam….mould smell. Even worse than the smell was the realisation that my pans were mouldy…eew! The next hour was spent decontaminating the entire cupboard and washing the pots and pans…and speed dialling for Mexican take out…again.
Now mould is serious stuff. Granted, I had a very minor mould problem which was resolved easily enough, but if you don’t take care of it quickly, you can end up with a multitude of health problems such as eye irritation, sneezing, coughing, nausea, diarrhoea, headaches, fatigue…the list goes on and on.
Occupational hygienists perform inspections and sampling (when needed) to assess mould damage and develop remediation action plans, and sometimes perform the remediation themselves (or they’ll specify exactly what needs to be done for a contractor). They also perform clearance testing to show that the remediation was successful.
So today I thought I’d go through some of the common questions asked about mould from an occupational hygienists perspective.
How do you identify mould indoors? This involves looking for signs of water damage through a visual inspection and collecting moisture readings, especially focussing on porous materials or hidden growth in less-commonly tracked places (such as behind the sofa). Sampling for mould is not always required…as it can be pretty obvious if you see it. If sampling is needed (for eg: legal or investigative reasons) it may include surface samples, bulk samples, or air samples…or a combination of all three.
How do you know if the mould is hazardous to my health? Whilst no Australian Standard exists containing values that you can say are “safe” or “unsafe”, there are commonly used guidelines that we can refer to. The Australian Mould Guideline is one of those guidelines and provides health risk guides for viable and non-viable fungi in indoor air and on indoor surfaces. These guidelines provide a point of reference to which an assessment of health risk can begin to be made.
How do I get rid of it? Well whenever you have mould growth indoors, you need to make sure that you fix the underlying cause of the moisture causing the problem in the first place. In the case of my mouldy pots and pans…my crappy oven is the cause. It doesn’t vent correctly and moisture is transferred to the adjacent cupboards. I’d love to tell you that I fixed the problem immediately…but it’s a work in progress!
Mould remediation can be a complex task and best left to the experts. Apart from fixing the source of the moisture, it can involve removing free water, vacuum cleaning with a HEPA filter, wet removal (such as using a damp cloth with detergent), mechanical drying and dehumidification. Mould remediation contractors will wear PPE during the remedial works to prevent them getting sick during the process.
How can I be sure it’s gone? This brings us to clearance testing. This is essentially the same process as collecting samples as part of the initial investigation, and is performed to (hopefully) show that the removal was successful.
Where can I go for more information? Speak to your friendly occupational hygienist for advice. The AIOH has a consultant directory here, if you don’t already have on on speed dial!