Silicosis – a multi-disciplinary approach

Andrew:

Eve Speyers and Dr June Sim from WorkSafe Western Australia, welcome to both of you. The floor is yours.

Eve:

Thank you. I just thought I’d introduce myself but obviously, that was done really well by Andrew. I am Eve. I am the Principal Scientific Officer here at WorkSafe WA and also, the Occupational Health Hygiene and Noise Team Manager. The silica work that we’ve been doing proactively like the other States and Territories in Australia falls within my team specifically. With me, I have my co-presenter, Dr June Sim, who is one of our Occupational Physicians here at WorkSafe.

Andrew:

We’ll just swap over slide screens and you’ll be away and going.

[Asides not transcribed]

Eve:

June and I are going to be co-presenting today as I just mentioned. The presentation is actually going to focus on the work that WorkSafe Western Australia has been doing through our internal occupational physicians here at WorkSafe and also, in partnership with some external medical experts and researchers and we’ve been looking into the diagnostic testing for silicosis.

I’m going to be covering the proactive campaign very briefly. I’ll look at the key issues that we’ve identified, the initial business that we conducted and how we then decided to take on a project coordinator to look at consistency across those inspections and also, the verification visits that we’ve been conducting more recently. And then, I’ll move on to health surveillance and the process here in WA as it is a little bit different to other States and Territories. And then, I’ll hand over to June and June will be looking at the health surveillance Recall Project which as I said, was done internally and that’s partnering with medical specialists as well through a multi-disciplinary team. And she will also be talking about the WA silicosis screening program which we refer to as WASSP.

Let’s move onto the next slide. Our proactive campaign commenced in 2018 at the beginning of that financial year and at that stage, it was conducted within my team. Essentially, my occupational hygienists looked at – like other regulators, engineered stone fabrication and this was off the back of the number of cases in silicosis that were identified in Queensland.

We conducted probably about 20 to 25 visits in that year and it was a bit of a snapshot because we didn’t actually know what we were going to find, we didn’t know whether the situation here in WA would be similar to what they were finding in Queensland or not. After that initial year, we decided to expand that across the inspectorate to have three teams of inspectors involved, just to have a broader reach so that we could visit more workplaces.

What we found quite quickly was as this project actually expanded, we really needed some level of consistency in regards to the inspections that were being conducted, even though we’d provided training and information to all of the inspectors involved in the project. We were finding that our backgrounds obviously were different and forming opinions were slightly different. There was some consistency, but we needed to be a little bit better in that space.

As a result, what we ended up doing was appointing a project coordinator and that inspector was from my team. What she did was she reviewed all of the data that was coming in, in terms of the inspection activities and the enforcement activities that were taken and where necessary, she would actually conduct revisits to workplaces to ensure that there was that level of consistency across the inspectorate.

More recently, what that has meant for us is that we’ve been looking at verifications of about 10% of those visits that were conducted initially, just to see if systems of work had been maintained adequately and controls are still effective. That was done in about 10% of the visits that we conducted.

More recently, the project has expanded a little bit within our team to focus on occupational hygiene exposure monitoring. What we decided there was we wanted to look beyond the reach of the engineered stone fabrication project. We decided to not just do it within that environment but also, within benchtop installation, so in domestic properties and commercial properties as well and also, in sample preparation in our laboratories. Our laboratories in WA are usually used to look at core samples for mining applications and in the processes related to the analysis of those core samples, crushing and grinding activities occur and that’s where this respirable crystalline silica can be generated as a result of those systems.

We looked there as well and also in wall chasing. And again, wall chasing is a bit unique to WA because of our double brick construction in the housing industry. What we were looking at is the activity of actually cutting a channel into the brick in order to lay conduit and cable and things like that. Obviously, that cutting can actually generate RCS.

In regard to that side of our project, we’re almost at the end of that and we’re slowly getting in the results so that we can actually formulate those and see where we think exposure might be initial across those industries.

I just wanted to bring up the stats. We’ve done about 136 visits to date with about 932 improvement notices issued and 13 prohibition notices issues. The majority of the notices were actually related to the controls or lack of controls in regard to RCS exposure. And in the prohibition space, the majority of those were issued due to uncontrolled dry cutting, which is an issue for us obviously, in regards to exposure and the development of the disease.

The key issues that we found with the initial visits, not the verifications but just the initial visits were those ones that you can actually see there on the screen. And what we found is that many workplaces had incomplete controls in place for controlling workplace exposure tasks when working with engineered benchtops. Health surveillance was sometimes provided but not always and we found some of the key employees, for example, contractors might not have been provided with health surveillance.

We were pretty firm on our enforcement activity in that space. Essentially, about 45% of workers were not clean shaven. That, I believe, is an issue for us regulators across Australia because obviously, facial hair reduces the effectiveness of respirators and therefore, exposure could be a potential issue. About 66% of workplaces hadn’t implemented health surveillance. 47% of respiratory protection was inadequate so that means it wasn’t fitted properly, it wasn’t used correctly and maybe not stored or not maintained correctly. 66% of workplaces hadn’t completed risk assessments for hazardous substances and about 34% of workplaces had poor housekeeping with an accumulation of respirable crystalline silica dust.

Some of the issues related to our verification visits and as I mentioned, we did about 10% of the businesses that we’d originally visited in regard to verification. Whilst we did see some improvements, what we saw was that health surveillance wasn’t always conducted, despite our really strong enforcement activity in the original visits. The issue related to workers not being clean shaven continues to be an issue for us again, despite enforcement activity being taken.

We often get the comment that my wife or my partner doesn’t want me to shave it off. Hipster beards are obviously a real big thing at the moment and very popular so that’s something we’re focusing on and continue to focus on. The other area that we saw water recycling issues. In regard to this area, we saw mixing of clean and dirty water. Sometimes, flocculants were added, sometimes they weren’t. Sometimes, filtration wasn’t adequate, and we’d see cloudy water and obviously, as that dries out, we have the risk for respirable crystallised liquid to be released into the environment depending on what the cleaning process is.

We also found that workers were not going home clean. Depending on the work activities and working engaged at the business, we found workers would be covered in slurry and basically, taking that home with them. And as I mentioned before which was an issue in the main visit part of our project, we found some noncompliant RPE and use of RPE.

One of the things I just wanted to speak about now before I hand over to Dr Sim is the health surveillance process in WA. It is a little bit different to other States and jurisdictions that have health monitoring and have adopted the WHS. Here in WA obviously, the duty holder is the employer as the PCBU elsewhere but the other duty holder here in WA is also the appointed medical practitioner. That’s the occupational physician or the doctor that conducts the health surveillance. They’re actually required under our legislation to provide the health surveillance results to WorkSafe where risk to health is consistent with exposure.

And we receive about 6000 health surveillance notifications every year for a variety of hazardous substances, so not just silica, so things like lead, organophosphates, isocyanates, those sorts of things. They then come into it, so they’re reviewed by our occupational physicians. I have obviously, Dr Sim with me here today but we also have another occupational physician, Dr Evelyn Lee. They review those health surveillance notifications and where they have concerns, obviously they check the data and the history related to those notifications previously and where they have concerns, they will refer those on to this team and an occupational hygienist will then go out to the workplace to ensure that the controls that are being used are still effective in regards to controlling exposure.

We have a good system here that is working. We also have an AMP forum and that’s an Appointed Medical Practitioner’s forum yearly to provide information to the doctors that are providing health surveillance in Western Australia. That facilitates the discussion around key topics. We also provide information, information sessions and a bit of training as well on the most relevant topics at that time. As a result of the silica health surveillance notifications that have come into WorkSafe, that’s actually driven the work that Dr Sim and Dr Lee have been involved in, in regard to that stakeholder engagement.

Those two projects there that I spoke about initially, there are the two project spinoffs from the enforcement campaign led by the WorkSafe inspectorate. We have the silica Recall Project there, which was conducted in-house at WorkSafe and focused on identifying high-risk workers that have been provided with health surveillance as a result of the proactive campaign.

And then also, the WASSP project, which is the WA silicosis screening program. That’s a partnership with Respiratory West and its focused on providing scans to workers that hadn’t had health surveillances yet. That might be people that have worked in the industry previously but have left, or self-employed people, for example.

I’m now going to hand over to Dr Sim and she’s going to talk about those projects in more detail.

Dr Sim: Thank you, Eve. As Eve stated, I’m an occupational physician with WorkSafe but I also have my colleague, Dr Evelyn Lee that works very closely. We job share this role and I’m presenting this on behalf of our team. One of the first projects we started with regards to silica from a health surveillance perspective was the silica Recall Project. WorkSafe invested heavily in this project and also, employed a part-time occupational medicine registrar to facilitate and run this project together with us.

As part of the silica Recall Project, it was offered to those who have had health surveillance prior to January this year. The reason that we decided to do a Recall Project was because as part of our legislation, only chest x-rays are required and not the key scans of chests. From the experience in Queensland, we realised that we could potentially be missing silicosis in individuals while exposed with the stone benchtop industry.

And WorkSafe decided that to facilitate this, they would fund low-dose HR or high-resolution chest CT scans to be completed on those who have completed the health surveillance but have only had chest x-rays. The funding was for 100 health surveillances. At WorkSafe, we also developed a silica health surveillance form and you can see a copy of that on your screen, which asks for patient’s details, exposure and also, the imaging section of the form.

Under the legislation, they can do a chest x-ray. We try and promote that AMP, so the Appointed Medical Practitioners actually do request a low-dose CT scan, but a lot of these employers are reluctant due to the costs involved. Some people are reluctant because of the radiation dose but I’ll talk about it in more detail. We also have a section for high-resolution CT scans, and this is more for diagnostic purposes as opposed to screening purpose.

There is a lot of talk about chest x-rays and low-dose CT scan in relation to silicosis. The cost is one of the factors that employers are reluctant to proceed with a chest CT. A chest x-ray typically costs about $150 and a low-dose CT between $350-$400 so it’s almost doubles the cost. And the $400 is at the lower end. Some places we are aware of charge up to $600.

The other issue is in relation to availability. In regional areas, this could potentially be an issue for us because not all CT scans can provide the technology for a low-dose CT. When we talk about low-dose CT, we’re talking about CT scans that delivers a radiation dose of 1 millisievert or less. Historically, the high-resolution chest CT can deliver up to 3-5 millisieverts and a typical chest x-ray is under .1 millisievert. That’s the comparison. I’ll talk about radiation in relation to environmental exposure later on, as well.

The low-dose CT scan or chest CT has a higher specificity and sensitivity for picking up silicosis. Chest x-ray is good as a screening tool but what we found in silicosis is that there is proteinaceous material that does not show up on chest x-rays but may show up on the CT scan. And we’ll touch on the legislative requirement as well. Under current legislation, we only require a chest x-ray but it’s currently under review and being put through as a proposal to amend that to include chest CT as part of screening for silicosis.

This is a comparison between a chest x-ray and a low-dose CT. This is a chest x-ray and low-dose CT of a 42-year-old man with 20 years of exposure. The chest x-ray which is on the left of the screen was completed in August last year and it looks completely normal. Whereas the CT scan, which is on the right of the screen, you can see the fluffiness at the bottom. That presents with what we call nodules and it indicates the presence of silicosis, of simple silicosis.

If you look in the centre – so the black bits are the lungs – and in the centre of that is what we call the hila and we look at the lymph nodes and that looks that there are lymph nodes that are enlarged in that area. This next slide compares a normal CT scan on the left to the CT scan that you saw in the previous screen on the right and you can see that difference now in that fluffiness and that enlargement or the fullness in the centre of the chest.

This is a radiation dose comparison table that I obtained by courtesy of Perth Radiological Clinic which is one of the radiological providers that completed the silica Recall Project with us. The annual dose of radiation for any person living in Perth is approximately 3 millisieverts. It depends on whether you’re coastal or on the hills. The low-dose CT scan should be below 1 millisievert. This was one of the protocols in our project, that it had to be under 1 millisievert.

The chest x-rays as you can see, is depending on the weight of the patient, and is usually under .1 millisievert. In this situation, they’ve shown a dose of .02. There are some radiological providers out there that have completed CT scans that are up to a radiation dose of 10 millisieverts and we do not want that type of radiation dose as a screening tool. Hence, why we define this as a low-dose HR CT and the definition of under 1 millisievert dose delivery.

The equipment of the Recall Project, as I said, we had an occupational medicine registrar who then contacted the individuals via telephone. We also contacted the employer to notify them that this was offered to their employees. And then, an email confirmation on how to organise the low-dose CT scan. We had two radiological providers and if you’ve been to Perth, there is this north and south of the river thing so we thought we’d just draw a line north of the river, south of the river and anyone that worked north of the river went to one radiological provider and anyone that worked south, went to another radiological provider.

It actually evened out quite well. We offered 103 low-dose HR CT scans. 90 of the employees accepted it and 13 declined. There were concerns when we called them about who was funding it, which was quite simple as WorkSafe was funding it but also, people started expressing concern about their workplace exposure and workplace controls, because when they go to the AMP, some of the information was not as clear on the health surveillance forms. There were also concerns raised about radiation exposure and our registrar was able to address that because we knew that we were delivering an as low as possible dose for a CT scan in our project.

As a result of completing the scans, what we found was that things were not that clear cut. It wasn’t whether you had silicosis or things were normal. We found that there were changes in between those that were exposed. We decided to develop a multi-disciplinary team meeting which consists of respiratory physicians, the radiologist and the occupational physicians.

What we found was that there were changes that were not specific of silicosis itself but there may have been intermediaries of exposure with inflammation of the airways and large lymph nodes with no other findings seen on the CT scan. We were seeing that in some quite young individuals. The other thing I forgot to mention is that as part of this Recall Project, we only did it on people with high levels of exposure, typically above 5 years of dry cutting. We weren’t doing it on people who had recently been exposed to the stone benchtop industry.

During the multi-disciplinary team meeting, we would have a discussion about the history of exposure, the symptoms, the results of the office spirometry which was completed as part of the health surveillance, the radiological findings, the previous chest x-ray compared to the CT scan that we had completed and then, come up with a consensus about recommendations with the respiratory physicians, radiologists and the occupational physicians.

This was also quite useful to discuss whether the individual is fit to return back into the industry and continue exposure in view of the findings in the CT scans. As a result of the Recall Project, we detected 6 clear silicosis cases. These were individuals aged between the age of 41 and 55 with between 8 to 30 years of exposure in the artificial stone benchtop industry.

There were 16 cases that were probable or possible silicosis. They had potential other exposures, a confounding practise such as the possibility of sarcoidosis which can make it unclear so further history and information will be required, and these individuals would need to see a respiratory physician as well. This group of individuals aged between 24 and 59 with between 7 to 30 years of exposure. 68 cases had either clearly no silicosis or had changes on their CT scan that were not consistent with silicosis.

The Recall Project wasn’t just to look at the CT scans and to pick up silicosis but also, tied back to what the inspectors at WorkSafe does, which is visiting the workplaces, ensuring that the controls that are meant to be in place are truly in place. It ties back to what Eve was talking about some of the proactive steps that the inspectors had undertaken. If we then saw a workplace with multiple cases of silicosis or probably silicosis, we refer it back to our inspectors and they go out and check their controls and work processes. They also ensure that the workers that are meant to be removed from silica exposure have been removed from silica exposure as per the recommendations from the specialists.

An example of this was just this week, the registrar and I went out with one of the inspectors to visit a workplace that had two cases of silicosis and we make sure – and one of them is the owner of the business – and we make sure that they had processes in place and controls in place. This workplace we visited did not have the best controls, but you would not be able to tell that just looking at a piece of paper. A visit is often helpful so that remediation can be undertaken.

The second project that we’ve started undertaking is the WA Silicosis Screening Project. This project has just commenced and it’s in collaboration with the Institute of Respiratory Health in Western Australia. This project defers from the Recall Project in the sense that it is focusing on workers who have not had a silica health surveillance previously. The other difference between that and the Recall Project is that they do undergo a chest x-ray and also, an ultra-low-dose HR CT.

When we talk about ultra-low-dose HR CT, that is less that 0.2 millisieverts and it will be done on 100 at-risk workers which is workers that work in the artificial stone benchtop industries. As part of this project, instead of having office barometry, they will undergo a laboratory pulmonary function test and this is all reviewed by an AMP that has been selected by WorkSafe in conjunction with ourselves, the occupational physician and as I said, collaborates with the Institute of Respiratory Health which is run by a respiratory physician for follow-ups.

This may also inform further guidance on legislation with regards to requirements for silica health surveillance, not only in the sense of imaging but also, pulmonary function test requirements.

And we’re now opening up for questions.

Andrew:

Terrific. Thank you for that presentation. That was really interesting and obviously an issue that’s affecting across almost all jurisdictions there. There are a few questions that have come through around exposure monitoring being compulsory. Is exposure monitoring compulsory?

Eve:

Exposure monitoring for silica, I take it, in engineered stone – it’s not compulsory here in WA. I know some States and jurisdictions have instigated legislation to make sure that it is compulsory or a mandatory requirement. What we do however, is when we go out on site as an inspector, we ask if monitoring has been done. Some of the larger companies have done it. What’s again unique to WA and it sounds like I’m flying our banner – I don’t mean to – but one of the things in WA is the majority of businesses are small businesses.

We have 200,000 small businesses in WA and in the silica space, it’s quite evident that you’ll have a workplace with less than 20 employees. And very often, it’s a family-run business with a brother and an apprentice, for example. Those small businesses are always lacking funds to conduct that. If we think it’s necessary, we’ll take enforcement action to make it happen but very often, our focus is about controlling exposure.

Andrew:

Terrific. And somebody has made a mention here about the ratio of notices to visit seems very high.

Eve:

Yes, it is quite high. What we were finding when we went out there was there were sufficient inadequacy of controls and systems at work to prevent exposure to RCS. We were really firm with that. Like I said, health surveillance was one of them. We were writing a lot of notices on specific controls across the board. Clean-up as well, so no dry sweeping. Information and training specifically to RCS, the use of respiratory protective equipment as well as maintenance and storage, and I could go on there but yes, I agree. In a way, I think it’s evident that the industry needed to improve its systems.

Andrew:

And somebody’s asked around the number of occupational physicians WorkSafe WA has got.

Eve:

I’ll leave that to June.

Dr Sim:

Yes. There is myself and Dr Evelyn Lee. There are two of us that job shares but we do not job share full time. We job share one day a week position.

Eve:

They are very busy, as I mentioned. We have about 6000 health surveillance notifications that come in. I think it’s something that’s been developed over the years. It’s worked really well having in-house occupational physicians that help us drive our business in order to prevent health effects from exposure.

Dr Sim:

And the silicosis project is just an example. We do that for all hazardous substances, so it could be lead, mercury, anything.

Andrew:

That’s impressive. Some impressive numbers getting through that. There is a question around technology that supports detection. Breathalyser style of devices, is there any technology that supports that?

Eve:

Not that I’m aware of.

Dr Sim:

For diagnostic of silicosis, no. Often, what we’re seeing is that young people are affected by this. They have excellent lung function tests and we’re not even picking up on the spirometry necessarily, unless they’re already quite symptomatic. What we are finding is that people can have completely normal lung function tests but in terms of breathalyser devices, that won’t pick it up because it’s something that lodges in the lungs and changes the architecture of the lungs over time. So, not for diagnostic purposes, for sure.

Andrew:

It looks like that’s all the questions that we’ve got there. Thank you so much Eve and Dr Sim. That was a wonderful presentation. Eve, I have to say that’s a very impressive mug that you’ve got there. Any chance we can have another look at that mug?