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I have mentioned this very important 2016 article (from Ceramics Monthly magazine) many times here on the forum when the subject of studio dust and cleaning and respirators comes up.  The full article is now online via the DOCTOR's personal website.  This is MUST READ stuff if you are working with clay.   Particularly in a "home studio" situation.

Yes, it is a single study, and of course that alone has its limitations on how you can extend the validity of the data accumulated.   But it was done well, and by a credible professional in the field (environmental epidemiologist and professor at McGill University and avocational potter).  Right after it came out I had conversations directly with the author, since it is my professional duty to keep up with this stuff since I teach it at the college level.  Both of us were concerned with what it appears to show.

It "blows away" a lot of assumptions about dust generation in the studio and appropriate controls.  Note the highest spike on the graph.  It is from "sculpting leatherhard clay".   An activity we all assume is not a high dust producing activity.

(This study deserves WAY more research!)

http://markgoldbergpottery.com/goldberg_studiodust-final.pdf
 

best,

..........................john

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That Slat Lake Schools article is interesting. I would have assumed that with the lack of care that teenagers would put into keeping the dust down that the air quality would have been much worse at the schools. I'm also surprised that we don't see a lot more potters with lung problems. I know some of the old school legends suffered from it, but it seems that the current batch of older potters don't. Or am I just not aware of it? Perhaps the fact that fewer people mix their own clay bodies, or that respirators are now the norm.

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2 hours ago, neilestrick said:

I know some of the old school legends suffered from it, but it seems that the current batch of older potters don't. Or am I just not aware of it? Perhaps the fact that fewer people mix their own clay bodies, or that respirators are now the norm.

It seems crazy to me too. Every now and then I will see an old video or a documentary on a famous old potter. There is always the video of them in their workshop. Some of them have insanely dirty studios. I mean like the floor is made of mud and the walls are coated with clay. 

 

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I think it's because the last generation of potters had studio practices in place by the late 80s, when the real concern hit.  The link has been known for 30 years, and the nature of the risk has been well-described for 20.

For anyone interested, here's the story from the original scholarly articles.  Most are just abstracts behind paywalls, but if you go to a university library, you can get free access via libraries there (or via your alumni account at home, if your alma mater does that sort of thing).

Dutch Ceramic worker study:

https://link.springer.com/article/10.1007/BF00409382

Italian ceramic worker study:

http://onlinelibrary.wiley.com/doi/10.1002/ajim.4700100404/abstract

More Dutch ceramic study:

http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-0274(199607)30:1<26::AID-AJIM4>3.0.CO;2-Q/full

Italian female specific study, to balance male-centred studies:

https://academic.oup.com/aje/article/156/9/851/256032/Silicosis-and-Lung-Function-Decrements-among

Follow up on Italian male study (available free if you sign up for Jstor, which you should!):

http://www.jstor.org/stable/40966476?seq=1#page_scan_tab_contents

Another more recent review:

http://europepmc.org/abstract/med/16100651

I apologize if any are duplicates from different indexing sources, I just keep these links in a folder in my browser and they're not properly organized.

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5 hours ago, Tyler Miller said:

There's been some work done in this area already.  

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3945536/#!po=23.9130

Yeah there has.  For this one, it is not the general information it is the spike from the "leatherhard clay" aspect that is potentially alarming in this study.  One of the authors and I had a good bit of conversation on this, and he was pretty certain that there were not other aberrant factors that might have caused the spike. 

As I said.... we need more research on this specific aspect.  Is this accurate.... or an outlier?

best,

..........................john

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We suggest mopping at the end of the day and always wearing an approved mask while mopping. This should be done every day or every second day; once a week is not sufficient.

I have a garage studio that I open my 2 space garage door every time I am in the studio working, even in the warmer winter months. I like the sunlight that comes in. I wonder how much air gets sucked out of my garage due to the horizontal wind that blows by the opening. In the fall leaves blow by and get stuck in the corner all the time, so I know there is a lot of airflow being pulled by.

Because of this I feel like my air is much better than air in a studio with no good ventilation. But maybe this is me being lazy and I should be more concerned. I don't make much of a mess and I wipe down surfaces before and after I work on them. But I rarely mop. I can't imagine mopping every single day. Do others mop this much? 

Edited by Joseph F

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John,

I suspect the particulates from the trimming/sculpting techniques may be something benign, but it's impossible to say without that composition data.  To me, the most significant dust producing activity suggesting hazard is D, the production of plaster molds.  The reason being that the particulate matter hung around for quite some time and didn't dissipate until the sculpting--staying at a higher level than background until then.   This is consistent with what I know about how clay/silica dust behaves in air. The large spike, I feel, could be something other than silica/clay dust because of the immediate drop in concentration seems out of keeping with how it acts in air.

The fact that the composition of the particulate matter is unknown means this study may be producing misleading information.  I would like to know if indeed it was leather hard trimming or scraping/sanding drier clay, as Goldberg's wording seem to imply.

Did your conversation with the author clarify this?

Edited by Tyler Miller

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13 minutes ago, Joseph F said:

 I can't imagine mopping every single day. Do others mop this much? 

I sweep up any clay that lands on the floor everyday, but only wet mop once or twice a year. 

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Years ago I saw someone wet their broom under the faucet, sweep with the wet broom then rinse it off as often as necessary. Sort of a cross between mopping and sweeping, I think it does stir up less dust than regular sweeping. I do this with one of those synthetic fibre brooms, (corn ones don't pick up as much).

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17 minutes ago, GEP said:

I sweep up any clay that lands on the floor everyday, but only wet mop once or twice a year. 

This is basically what I do. I pickup and clean up any clay that gets on the floor. I only mop about 3 times a year. Usually spring, summer, fall or when I look down and realize its nasty. 

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12 minutes ago, Min said:

Years ago I saw someone wet their broom under the faucet, sweep with the wet broom then rinse it off as often as necessary. Sort of a cross between mopping and sweeping, I think it does stir up less dust than regular sweeping. I do this with one of those synthetic fibre brooms, (corn ones don't pick up as much).

I like this idea. I have a long water hose. I have been contemplating just picking up all the cords off the floor and spraying the garage from the wall to the door and pushing all the dust and clay that might remain out along with it. 

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I knew a potter who would mop the studio everyone she glazed, which was one or twice a week since she was spraying the glazes. Also the had a home studio so it just made sense to keep it super clean.

The studio I go to here in Tokyo is always super clean, people use slippers or are sometimes barefoot and I like that, even though it means a lot of cleaning everyday. Better not to let anything accumulate too much.

That article is so interesting, thank you John!

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I built a detached 26 x 44 studio/workshop with it's own power supply. Poured concrete floor with rubber flashing to protect the lower 10" of the stud walls. Most all of my tables are on wheels, so that I can pressure wash the floors. I have four roof top exhaust ( total of 13,400 cfm) when all four are running. Mostly to keep heat down, but also to exhaust dust. Going to install a thru wall exhaust that is 13,000 cfm as well. I have been known to put on my respirator, turn on all the exhausts: and cut loose with a leaf blower. With all fans running, the air in the entire building turns over every 25 seconds. Joys of being a builder, you can turn your entire studio into a giant shop vac. I roll my pugger and paddle mixer outside ( on wheels too) when I am dry mixing.

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4 hours ago, Tyler Miller said:

I think it's because the last generation of potters had studio practices in place by the late 80s, when the real concern hit.  The link has been known for 30 years, and the nature of the risk has been well-described for 20.

For anyone interested, here's the story from the original scholarly articles.  Most are just abstracts behind paywalls, but if you go to a university library, you can get free access via libraries there (or via your alumni account at home, if your alma mater does that sort of thing).

Dutch Ceramic worker study:

https://link.springer.com/article/10.1007/BF00409382

Italian ceramic worker study:

http://onlinelibrary.wiley.com/doi/10.1002/ajim.4700100404/abstract

More Dutch ceramic study:

http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1097-0274(199607)30:1<26::AID-AJIM4>3.0.CO;2-Q/full

Italian female specific study, to balance male-centred studies:

https://academic.oup.com/aje/article/156/9/851/256032/Silicosis-and-Lung-Function-Decrements-among

Follow up on Italian male study (available free if you sign up for Jstor, which you should!):

http://www.jstor.org/stable/40966476?seq=1#page_scan_tab_contents

Another more recent review:

http://europepmc.org/abstract/med/16100651

I apologize if any are duplicates from different indexing sources, I just keep these links in a folder in my browser and they're not properly organized.

The dust problem  has been known for longer than 30 years. Bill Alexander wrote on chemical toxins, dust in the 70s. Alexander, William C. "Ceramic Toxicology." Studio Potter, Spring 1974. He worked in Boulder before coming to Montana. he died form problems with those dusts.  Romona Mossel was at Penn State NCECA Super Mud in 1978. Already working on spreading the word. 

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2 hours ago, Tyler Miller said:

John,

I suspect the particulates from the trimming/sculpting techniques may be something benign, but it's impossible to say without that composition data.  To me, the most significant dust producing activity suggesting hazard is D, the production of plaster molds.  The reason being that the particulate matter hung around for quite some time and didn't dissipate until the sculpting--staying at a higher level than background until then.   This is consistent with what I know about how clay/silica dust behaves in air. The large spike, I feel, could be something other than silica/clay dust because of the immediate drop in concentration seems out of keeping with how it acts in air.

The fact that the composition of the particulate matter is unknown means this study may be producing misleading information.  I would like to know if indeed it was leather hard trimming or scraping/sanding drier clay, as Goldberg's wording seem to imply.

Did your conversation with the author clarify this?

Tyler,

This study is sort of "tantalizing" in the fact that it hints at certain stuff that COULD be pretty significant... but is just a hair "off the mark" for a real "authoritative" single study.    And it IS still a single study.  So that limits the immediate adoption of it as some form of "truth".   But it is a "watch this channel" moment.

We did discuss quite a bit what ELSE may have caused the seemingly anomalous spike.  Within the bounds of the constraints of the WAY in which the study was done, which was more "casual" than I'd like, he was pretty confident that nothing else was going on in there at the time....... and that it was a single person doing that work at the time.  We also explored the proximity of the sampling unit to the various activities to see if that might have skewed the sample...... and it was not set up in such a way that this item was somehow greatly 'favored' by the sampling.   He did say to the best of his knowledge it was leatherhard.... not dry sanding.

And as you say.... that sampling unit  is picking up "mixed" dusts.... so only some of that material is likely sub-micron crystalline silica.    So the airborne peak is likely not as high as the raw number.  And Brownian movement is not keeping the stuff suspended in the air too long... so some of that is toward the larger end of the particles.

To me this result SCREAMS for some follow-up air sampling studies on the carving / trimming of leatherhard clay.  If that spike on this single test is borne out by a number of further sampling sessions,..... that is really astounding.... and of significant concern, since I'd say just about everyone would consider leatherhard clay not a dust hazard (until the trimmings dried out).

Until we have more data on this....... people should just be 'aware' that there MAY be some question about this.

best,

..............................john

 

 

 

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25 minutes ago, Marcia Selsor said:

 Romona Mossel was at Penn State NCECA Super Mud in 1978. Already working on spreading the word. 

We brought Mononna in to MassArt when I was working there so she could educate the students on this stuff I think in 1975.  She stood the place on its ear!  Lots of stuff changed right after that.

best,

...........................john

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58 minutes ago, Judith B said:

The studio I go to here in Tokyo is always super clean, people use slippers or are sometimes barefoot and I like that, even though it means a lot of cleaning everyday. Better not to let anything accumulate too much.

Most of the workshops I have worked at in Japan are VERY clean.  It is a pleasure.

And you are welcome, Judith. 

best,

.......................john

 

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@JBaymore

Here's my hypothesis, please share with Dr Goldberg if you have a chance.  It's water droplets, from human breathing.  You'll note that the article does say that the equipment used cannot distinguish between the two--and counts liquid as particulates.  Perhaps someone breathing more directly at the equipment, perhaps more people (he only said usually there was one), or perhaps an individual very nervous about trimming (like I used to be).

The mixing plaster and sanding from the mould making are known dusty activities and do provide a pattern on the equipment of particles doing the Brownian motion thing.  I was using it as a template for how dust would look on a such a test.  Because that  w i l l generate dust.  That's how it will look.

I'd happily be wrong, and I'll donate $20 to a charity of your choice if I am, but I'm willing to bet it's water droplets that would disperse more quickly than the known dusty activity of plaster mixing.

@Marcia Selsor

I apologize, I should have been more clear.  I should have said known to science.  The anecdotal evidence was there in the 1970s, but not yhe proof.  the studies I quote above started around the time you're talking about.

Edited by Tyler Miller
Removed ambiguity and glossed for clarity and removed an error.
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I have to wonder if the sculpting process (H) includes sweeping those clay bits into piles on the table, and/or scooping them into the trash or slop buckets, or it it's literally just the process of cutting clay off with a loop tool. Any sort of sweeping motion, even just brushing the carvings into a pile on a table top, would likely kick up fine particles

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I often wonder about my lifetime exposure . When I was in collage working as a tech we mixed clay and had to leave the shed due to not being able to breath in that dust (early 70s -no masks)

I took less care in the first 20 years than my last 25 years. Only in last decade and 1/2  got real serious about dust..First the micron whole shop dust filter. Now with my central vac studio system its a joy to suck up anything  every few days. The shop still has dust areas that one cannot reach.I had a lung diffusion test at 56 and had lungs of a 40 year old but scuba diving  with a few thousand dives really is that driver.I think about lung issues as I lost a good friend to that.

I think everyone is so different as to how exposure affect them .

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