Not exactly what I was asking! Is there a level of exposure below which there is no risk of developing any of the above afflictions?
Regulations:
Asbestos can be present as bulk, suspended in air or in water. When it is bulk (let say in Vermiculite) The safe-unsafe threshold in Ontario is set at 0.5%. For industrial air - 0.1 fiber per cc. Not sure how little is OK for water. There is no regulation, which would tell how little is safe for residential houses.
**Common sense **
There is no safe or unsafe concentration for carcinogenic chemicals and minerals like asbestos. Higher exposure leads to higher chance to develop a lung disease or even cancer.
Will one asbestos fiber of the right (wrong) type and size kill you?
No, it will not. I just did some calculations. On an average day we all inhale 0.1-1000 fibers even if we are on fishing trip. :twisted:
In 1952 I worked as apprentice electrician on airport runway .
We put in Many miles asbestos Transite pipe , my job for many months was to put the taper on the end of the pipes . 10 hours a day for many months I was covered and inhaled this dust .
Being a none smoker I have zero lung problems and still able to do most things ,Climb the roofs and do the crawl spaces.
Roy,you are fortunate,many were not.
In your worst conditions/estimate, a person would inhale 365,000 fibers per year!
I have done 2 calculations…one from an outdoor IAQ study about 10 years ago and another from an older study…both included Montreal and here are the conditions for someone at rest there:
Respiration… 12-20 breaths/minute (16 average)
Volume of air… 0.5 liters per breath
of fibers inhaled per year… 750,000 to 1,500,000 (newer study); up to 3,780,000 (older study)
From most information I have read there usually is a reason for concerns one is being a smoker on top of working with asbestos.
Harry I after that worked on Boilers that where all covered with Asbestos for years .
So I do not think I am lucky just smarter.
Harry and we as Home Inspectors are far from experts .
There is usually more information required and I will listen to the experts before I take as facts from a know it all .
I love it when I read from an self apointed expert Home Inspector who knows every thing about every thing .
He gets a bit of knowledge and comes into our NACHI home and tells us how smart he is and how we at NACHI have no ideas on how to do things .
There is a lot more to this Indusry then some smart aleck who has all the answers .
Telling us NACHI has no idea how to run an association .
He loves to state how great he is and how all other NACHI home Inspectors are not.
Not needed not wanted ,He comes into our home and thinks he is the **greatest **gift to our industry.
A neat post from Brian A MacNeish on another string sort of fits .
("I am quite sure that Darwin’s Theory of Evolution was wrong. The smarter/stronger/faster are not the majority surviving…more of the others are!..it’s called devolution! In about another 200-300 years, another Neanderthal man may be seen. ")
I wonder is the Neanderthal man here now visiting the NACHI site
Up and at it real early this morning, Roy!!..more “Roy and the Brian Stalk”!!
BTW, Roy, you again don’t seem to remember!! From fall/90 until spring/92, I had been hired by an engineering firm in New Brunswick to set up and manage a subsidsiary carrying out IAQ investigations/testing and commercial/industrial air balancing so…I obviously know NOTHING about this stuff…you wish!!
Another BTW…the "Will one asbestos fiber of the right (wrong) type and size kill you?" question above has a story to go with it!!!
I am sure your calculation is more accurate. I estimated my number based on the info I have seen that fiber level in ambient air can be anywhere from 0.0000001 to 0.0001 fibers/cc
PS. Brian, could you please send me a link on the Montreal study you used for the above calculation. Thank you
http://www.inspq.qc.ca/pdf/publications/342-AsbestosIndoorOutdoorAir.pdf
Found the 5 year old thread from Fine Homebuilding forum where I quote a number from Toronto and Montreal…(my moniker is “experienced”):
Later in this thread, I predict what happened in Edmonton (for simple removal of exterior asbestos-cement shingles)!!
I had a very learned person say if possible as a home inspector try to avoid taking any samples, pass it on to some one else .
He also said samples should be taken form the bottom as the asbestos dust is very fine and the higher concentrations are on the top of the ceiling .
He also said amount of samples varies as to the thicknes of the vermiculite 5 inches should have more samples taken then one inch .
Please all be very guarded we have many out there who love to hang NACHI home Inspectors .
They know more then you do just listen they will tell you so.
It was the siding that was removed.
I was not referring to roof shingles,…VERN! In our area, I have never seen asbestos-cement roof shingles; every one here called the individual panels used as siding…guess what… “shingles”. And from your post, I knew it was asbestos-cement siding…picky…picky…picky…take a pill or two…Stop talking to Roy! The asbestos-cement “product” was on the exterior of the home…that was the main issue!!!
BTW, am I allowed to use “shingles” when cedar shingles, which may be used as roof shingles also, are applied as siding…or do I have to call it “cedar siding”?
Anyways, the whole house was covered in at a big cost when the danger was in the extremely low range for workers (if properly masked and using water to suppress fibers) and the public…if the work was done with care! I’ve removed 1,000’s of these “shingles” when I had the insulation company…and I ain’t dead yet!
SO if some one with an older house in Edmonton wants to get insulation blown into their house walls with asbestos-cement shingle siding, do they have to have the house exterior closed in, hire a certified asbestos abatement team at a cost of 4-5 times the cost of the insulation job?
SAD!!
I suggest you follow this protocol
I just heard two horror stories with asbestos siding , One was removal cost’s of about $20,000.00 and the other was the home burned down and all the remains where removed as contaminated asbestos refuse.
I have been told some insurance companies are no longer insuring asbestos siding .
Treat it all as if it’s the worst case, such as friable asbestos-based fire protective insulation in a school, and the costs will be up there!!
Again, IMHO, the siding should be treated differently (it’s less of a personal hazard than the above mentioned) but still have a protocol that is less constraining and not necessarily needing workers in space suits!!
Rodney , why would you have problems getting Ins. for sampling Insulation ? It’s the labs that decide whether or not there is asbestos present .
[quote=“Brian_A.MacNeish, post:35, topic:54353”]
I was not referring to roof shingles,…VERN! In our area, I have never seen asbestos-cement roof shingles; every one here called the individual panels used as siding…guess what… “shingles”. And from your post, I knew it was asbestos-cement siding…picky…picky…picky…take a pill or two…Stop talking to Roy! The asbestos-cement “product” was on the exterior of the home…that was the main issue!!!
BTW, am I allowed to use “shingles” when cedar shingles, which may be used as roof shingles also, are applied as siding…or do I have to call it “cedar siding”?
[quote]
Cedar shingles are cedar shingles and cedar siding is cedar siding.
Asbestos siding is asbestos siding and asbestos shingles are asbestos shingles.
Architectural Graphic Standards shows the difference.
According to Architectural Graphic Standards there are shingles and there is siding.
Just for you I’ve uploaded the drawings that show Asbestos cement siding and asbestos cement shingles from the fifth edition of the Architectural Graphic Standards.
Page 4.pdf (182 KB)
Page 2.pdf (113 KB)
Because you never seen it does not mean it does not exist.
BTW Roy has forgotten more then you will ever know.