Anybody using Pro-Labs out of Florida?

Originally Posted By: bkelly2
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Excellent Ray, you win the prize



“I used to be disgusted, Now I try to Be amused”-Elvis Costello

Originally Posted By: rwand
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Of course if wood is completely submerged that is a different story. I know there are companies salvaging old growth timbers from bottoms of lakes in Canada that sunk during harvesting when they would float the trees on rivers and lakes to the saw mills. The lumber is sought after because of its age and size. Cold deep water has less oxygen, thus preserving same, no deterioration on wood that sunk over 100 years ago. You can’t get the same with salt water. That is why old sailing ships and schooners sunk in the Great Lakes are in very good shape even though they are very, very old wood.


But I digress.... ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif)

Raymond Wand
Alton, ON


--
The value of experience is not in seeing much,
but in seeing wisely. - Sir William Osler 1905

http://www.raymondwand.ca
NACHI Member
Registered Home Inspector (R.H.I.)

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Gents ?


OK here?s the scoop- There are a number of ways this could pan out where a lab result of 5,000 CFU/g indicates a lower mould concentration than 1,000 CFUs/g. But, I?m only going to select two scenarios (long-windedness notwithstanding). Importantly, I would like to repeat something I said on May 2, on this board ( http://www.nachi.org/bbsystem/viewtopic.php?t=10216 ) regarding data quality objectives (DQOs) which was: ?Without DQOs, you don?t have data, you have numbers or names on a lab report that possibly CANNOT be interpreted by anyone, since ?data? has no intrinsic meaning outside of a priori decision criteria.? Such is the case here.

The units of expression, a CFU/g is a unit that is used for the convenience of the lab, not necessarily for that of the consultant or, in this case even meaningful, since the unit is missing tons of information not included in the report (possibly not even provided to the lab, known by the lab, or even known by the ?mould inspector.?)

Here is how this pans out; two carpets were sampled in exactly the same manner with exactly the same proper sampling and collection equipment, and submitted to a reputable lab for analysis.

Carpet #1 is in a brand new model house, in which no family has ever lived, and with brand new carpets, and no history of water damage and no mould problem. Sampling parameters: Sample area = 12 inches by 12 inches, sample result =5,000 CFUs/g. The lab, in order to report the value, must weigh the material collected in the sample, thus providing the denominator of the unit. In this case, the cassette contained 0.01 grams of vacuumed material (which is about right for a brand new carpet).

Carpet #2 is from a ten year old family home with dogs, cats, kids spilling food and real people living real lives. Sampling parameters: Sample area = 12 inches by 12 inches, sample result =1,000 CFUs/g. In this case, the cassette contained 0.35 grams of vacuumed material, which is about right since Dad didn?t have time to run the vacuum cleaner last Saturday.

We look at our DQOs and determine what is the question that is being asked? Which is ?Which carpet is most heavily contaminated with mould?? But the answer being given by the lab is to the question ?Which amount of removable debris contains the most mould?? That is a different question and does not meet one of our DQOs.

So our first step is to convert the reported lab units into a number that will speak to our question; that number is CFU density in the carpet, which is expressed as ?CFU/g/area of carpet (in square centimeters, cm2)? which algebraically becomes CFU/cm2 and which expresses the amount of mould in the carpet per gram of material removed per unit of area sampled.

In this example, Carpet #1 with 5,000 CFUs/g = 0.05 CFU/cm2; and Carpet #2 with 1,000 CFUs/g is equal to 0.38 CFU/cm2. NOW we have two sample results which can be compared with each other. As you can see 0.38 is much greater than 0.05 even though it came from a sample that had a lower result reported by the lab. Now we take our numbers and determine the final answer to our question.

Both of the carpets measure 12 feet by 20 feet. Carpet #1 (5,000 CFUs/g) contains an estimated total fungal loading of only 12,000 viable spores; while Carpet #2 (1,000 CFUs/g) contains an estimated total fungal loading of 84,000 viable spores; seven times more contaminated than the carpet that contained 5,000 CFUs/g.

Now, which sample result indicates more contamination? Answer 1,000 CFU/g ? OBVIOUSLY! (The poor home inspector buries face in hands and weeps gently in the back of the court room, as the two million dollar law suit against him inches just a little closer to reality?)

Here is the second scenario:

The lab tells you, the HI, that you need at least half a gram of material for them to analyze the sample. So in Carpet #1, being a brand new carpet, in order to get the requisite 0.5 grams, you have to sample a carpet area of 60 inches by 120 inches (It?s a pig! Trust me, I?ve had to do it!) But in the Smith residence, (you know, dogs, cats, kids), you only need to sample an area of 14 inches by 15 inches to get the half a gram of debris needed by the lab.

Now, in each case, you have the same amount of vacuum debris, 0.5 grams, but in one case you had to sample 50 square feet (the nice new clean carpet) to get it, and in the other case you only had to sample 1.5 square feet to get the sample. But now there is a disparity in areas, so, again, we convert the units into density, and we see that the results still come out the same, and the nice clean never walked on carpet contains 5,000 CFUs/g, and the dirty mould infested carpet contains 1,000 CFUs/g.

A person, like myself, who makes a living out of collecting samples, and interpreting lab data, and then defending that data in court, won?t get tripped up or fooled into thinking that 5,000 is greater contamination than 1,000 because we use our DQOs to guide us, and the intermediate numbers are not the answer to the question; often they aren?t the answer to ANY question? they're just numbers! However, other consultants who think interpreting a lab result is as easy as assuming the higher value means more and the lower value means less ? meets me in court, and looses their shirt (and their reputation) and possibly some finances along the way.

By the way ? these are just two examples of why 5,000 is less than 1,000 ? there are others even when one has accounted for debris and area. This is just the tip of the industrial hygiene ice burg that will sink a ?certified mould inspector? or other untrained mould "expert" every time. These aren?t tricks, these are the realities of the expertise of sampling (for anything).

By the way these same concepts just came up in a case that had nothing to do with mould - a bunch of engineers, who had no competency in sampling tried to interpret chemical concentrations in air based on the lab report. Unfortunately, they lacked the technical expertise to understand the conversion of a nanogram per liter of air into a part per million- it is likely that their firm is going to have to part with several hundreds of thousands of dollars in damages, based on my report, all because they were engineers pretending to be industrial hygienists investigating indoor air quality issues.

I hope this sheds some light on issue. By the way, I didn?t even touch on sampling error, (which is one of my fortes), and could even sink a PhD CIH ? and which did, in a real life trial, because even being a CIH is no axiomatic badge to competency in microbial issues (and the PhD didn't help her one bit).

Again ? my bottom line ? if one didn?t know all this before, and one can?t anticipate the other scenarios to which I alluded, its my humble opinion that one should not be out pretending they are performing mould sampling and/or mould assessments, and they shouldn?t be pretending they are interpreting data.

Enlightenment before agreement.

Cheers!
Caoimh?n P. Connell
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: kjones
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Quote:
I to took the three day course with CMHC.
I also took another course with a private organization .
One scientist said one thing .
Another scientist said a different thing .
I decided I did not have near the knowledge to get involved with disagreeing with either one .
If I was on the other side in court I would be the looser .
No way do I want to be involved with a court case .
I write Hard talk soft and recommend they get immediate further evaluation by qualified personal.
I could care less if they do or don't ,I just make sure I Cover myself.
I am a generalist in many things but I am not an expert in any thing .
I report what I see tell what I feel and make most clients very happy.
In most cases I do not have to recommend further evaluation but if I am not sure I DO!.


This doen't tell me if you offer sampleing for mold, lead, Radon etc. Do you or don't you?


Originally Posted By: bkelly2
This post was automatically imported from our archived forum.



Caoimh?n P. Connell wrote:
Gents ?

In this example, Carpet #1 with 5,000 CFUs/g = 0.05 CFU/cm2; and Carpet #2 with 1,000 CFUs/g is equal to 0.38 CFU/cm2. NOW we have two sample results which can be compared with each other. As you can see 0.38 is much greater than 0.05 even though it came from a sample that had a lower result reported by the lab. Now we take our numbers and determine the final answer to our question.

Both of the carpets measure 12 feet by 20 feet. Carpet #1 (5,000 CFUs/g) contains an estimated total fungal loading of only 12,000 viable spores; while Carpet #2 (1,000 CFUs/g) contains an estimated total fungal loading of 84,000 viable spores; seven times more contaminated than the carpet that contained 5,000 CFUs/g.


]


This where you lost me. Same area of sample so area cancels out?
Same units of measure or in this case CFU's/g (Colony forming units per gram) so they cancel out?
So how did you get to .38 and .05?


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: rwand
This post was automatically imported from our archived forum.



It apparently would take a minimum of 8 sweeps with a beater bar vacuum to remove dirt from carpeting. Carpeting is a no no for environmentally sensitive people. Again why would you test carpeting when it is a proven fact it is a breeding ground, and entrapement pad for dirt, dander, odours?


If you have client who is seeking guidance and advice regarding IAQ the best advice you could offer is for them to get rid of the carpeting and install ceramic or hardwood. Carpeting also off gases.

No homeowner will be able to put all these test procedures and results in perspective. However they can comprehend that materials in houses can and will most certainly affect their health. It would most certainly seem that liability is less offering practical solutions and dealing with the source than offering laboratory testing that by all appearances is very complicated in understanding and explaining.

![icon_idea.gif](upload://6VKizmOm2U7YYmfXNtFW4XTwFVy.gif) You can charge the same price for IAQ testing under CMHC guidelines as you can for testing and reporting and have more satisfactory results and have a lot less liability if any. Something to think about.

Would anyone care for me to post an IAQ report carried out under CMHC guidelines? If so I can post a link here?

Cheers,
Raymond Wand
Alton, ON


--
The value of experience is not in seeing much,
but in seeing wisely. - Sir William Osler 1905

http://www.raymondwand.ca
NACHI Member
Registered Home Inspector (R.H.I.)

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Mr. Jones: I disagree with most of what you said, but it?s off-topic. Perhaps you could start a new thread.


Mr. Kelly ?

No, the areas don?t ?cancel out? I just used the same sized carpets and the same sized sample areas to make the thinking process a little easier. And the units of measurement don?t ?cancel out? either?

Look, here?s the math for the first scenario which is normalized for area:

Carpet #1:
1) Area sampled: 12?X12? (929 cm2)
2) Weight of removed debris: 0.01g
3) Lab Result: 5,000 CFU/g
4) Absolute CFUs in sample: (5,000 CFU/g X 0.01g= 50 CFUs)
5) CFUs/area (Absolute CFUs/sampled area cm2): 50 CFUs/929 cm2= 0.053 CFU/cm2
6) Total area of carpet:12 feet X 20 feet = 240 ft2 = 222967 cm2
7) Total CFUs in carpet = 0.053 CFU/cm2*222967 cm2= 12,000 CFU

Carpet #2:
1) Area sampled: 12?X12? (929 cm2)
2) Weight of removed debris: 0.35g
3) Lab Result: 1,000 CFU/g
4) Absolute CFUs in sample: (1,000 CFU/g X 0.35g= 350 CFUs)
5) CFUs/area (Absolute CFUs/sampled area cm2): 350 CFUs/929 cm2= 0.377 CFU/cm2
6) Total area of carpet:12 feet X 20 feet = 240 ft2 = 222967 cm2
7) Total CFUs in carpet = 0.377 CFU/cm2*222967 cm2= 84,000 CFU

The math for the second scenario, which is normalized for weight, is similar, but the result is the same:

Carpet #1:
1) Area sampled: 60?X120? (46452 cm2)
2) Weight of removed debris: 0.5g
3) Lab Result: 5,000 CFU/g
4) Absolute CFUs in sample: (5,000 CFU/g X 0.5g= 2,500 CFUs)
5) CFUs/area (Absolute CFUs/sampled area cm2): 2,500 CFUs/46452 cm2= 0.053 CFU/cm2
6) Total area of carpet:12 feet X 20 feet = 240 ft2 = 222967 cm2
7) Total CFUs in carpet = 0.053 CFU/cm2*222967 cm2= 12,000 CFU

Carpet #2:
1) Area sampled: approx. 14?X15? (1327 cm2)
2) Weight of removed debris: 0.5g
3) Lab Result: 1,000 CFU/g
4) Absolute CFUs in sample: (1,000 CFU/g X 0.5g= 500 CFUs)
5) CFUs/area (Absolute CFUs/sampled area cm2): 500 CFUs/1327 cm2= 0.377 CFU/cm2
6) Total area of carpet:12 feet X 20 feet = 240 ft2 = 222967 cm2
7) Total CFUs in carpet = 0.377 CFU/cm2*222967 cm2= 84,000 CFU

Ergo: Carpet with 1,000 CFU/g has more mould than carpet with 5,000 CFU/g (Industrial Hygiene 101). I hope that clarifies.

Cheers, on this beautiful Saturday morning , as I get ready for work.

Caoimh?n P. Connell
Forensic Industrial Hygienist
www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: rcooke
This post was automatically imported from our archived forum.



kjones wrote:
Quote:
I to took the three day course with CMHC.
I also took another course with a private organization .
One scientist said one thing .
Another scientist said a different thing .
I decided I did not have near the knowledge to get involved with disagreeing with either one .
If I was on the other side in court I would be the looser .
No way do I want to be involved with a court case .
I write Hard talk soft and recommend they get immediate further evaluation by qualified personal.
I could care less if they do or don't ,I just make sure I Cover myself.
I am a generalist in many things but I am not an expert in any thing .
I report what I see tell what I feel and make most clients very happy.
In most cases I do not have to recommend further evaluation but if I am not sure I DO!.


This doen't tell me if you offer sampleing for mold, lead, Radon etc. Do you or don't you?


I do not do either.


--
Roy Cooke Sr.

http://Royshomeinspection.com

Originally Posted By: bkelly2
This post was automatically imported from our archived forum.



that the cfu/g measurement told the story, I did not think that that I would have to factor out the weight of the sample and the size of the sample area, I just assumed that was done in the sampleing plan/procedure. Once again shame on me.


It is interesting that the cfu number from the lab is not broken down further, why is that?


--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: kmcmahon
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It would then make sense to have a standardized test area of say 12"x12" or so the results can be more easily interpreted. Apples to apples instead of apples to oranges.


That's what ASTM does.


--
Wisconsin Home Inspection, ABC Home Inspection LLC

Search the directory for a Wisconsin Home Inspector

Originally Posted By: bkelly2
This post was automatically imported from our archived forum.



Quote:
Monty Python-Holy Grail



--
"I used to be disgusted, Now I try to Be amused"-Elvis Costello

Originally Posted By: jeubank
This post was automatically imported from our archived forum.



This has been an interesting thread to follow on the Message Board. The discussion has moved into more technical and legal aspects, but I have some different questions about labs and testing. So I’m starting up a related discussion at http://www.nachi.org/bbsystem/viewtopic.php?p=162829#162829. It’s some basic questions about how you offer environmental testing.



Inspected once, inspected right throughout southern Colorado


www.eubankinspections.com

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello Messrs Kelly and McMahon:


I?m glad you enjoyed the info.

Mr. McMahon, you say:

It would then make sense to have a standardized test area of say 12"x12" or so the results can be more easily interpreted. Apples to apples instead of apples to oranges. Unfortunately, that's not not correct. In my first example, the sample areas ARE the same size, and yet the samples cannot be compared with each other. Read further, it gets worse.

Mr. Kelly, you ask:

It is interesting that the cfu number from the lab is not broken down further, why is that?

Many labs will break down the report further into genus and even species level. However, this is almost NEVER required. In the thousand or so samples I have collected, I can think of perhaps three projects when knowing the genus had probative value (for mould projects). For the most part, when ?mould inspectors? spend extra money to determine genus and species, they are throwing away their client?s resources.

Having said that, (peeling yet another layer from the ever-souring onion), one CFU from one sample does NOT equal one CFU from another sample (even if the same areas and the same weights are collected and the same lab analyzes the report and regardless of the denominator used). Let me repeat that 1 CFU does not equal 1 CFU. One CFU from one sample may equal 12 or 29 or 0.12 or 12,259 CFUs from another sample.

Virtually all home inspectors, ?certified mould inspectors,? and sadly, even an handful of Industrial Hygienists quite wrongly think that a CFU is a unit of quantification ? that is why they use it to quantify (report) the mould concentration. However, that is not correct, and even for two identical samples each from an area of one square foot and each containing, say, 0.5g, and both reporting 10,000 CFUs/cm2 (or CFUs/g, or CFUs/anything), one cannot, from that report say with confidence that the two samples actually contain roughly the same amount of mould. The term CFU is not a unit that can be used to quantify mould, rather it is a value used to qualify data. And so even if an HI, or ?certified mould whatzit? has kept all of the sampling parameters the same ? they may still get torpedoed out of the water by a qualified Industrial Hygienist or microbiologist who will demonstrate that the interpretation of the data was made in a vacuum and without regard for proper sampling theory since CFUs of any kind can?t be compared with each other in a quantitative manner ? they can ONLY ONLY ONLY be compared with each other within the context of the consultant?s a priori DQOs (there?s those damnable DQOs again); which is why it is imperative to establish DQOs before collecting a single sample- or you will (or at least should) loose the data in court. If you do not have DQOs - you don't have data, and your results will lack intrinsic meaning.

Anyway ? that?s yet another topic for a long-winded discussion and my brain hurts.

Cheers,
Caoimh?n P. Connell

Remembering my Brothers in Sisters in Blue.

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG



Originally Posted By: jferry
This post was automatically imported from our archived forum.



Raymond Wand wrote:


Quote:
Hi firstly I am not sure how you pronounce your first name, no disrepect but could you spell it phonetically for us Caoimh?n?


Raymond -

Caoimh?n is pronounced exactly as it is spelled - "Kevin".

This service is brought to you by your dual national General Counsel whose two sons are named Se?n and Tadhg.

Joe


Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Thanks for the ribbing, Joe ? I didn?t see Raymond Wand?s question. Raymond, by name, as Joe points out is pronounced exactly as it is spelled ? however, there are only 19 letters in the Irish alphabet (or at least there were when I was a schoolboy, the Irish government has added a few extra here and there since then). However, there is no ?Q? and there is no letter ?V.? And, yet, my name is actually pronounced ?QWEE-veen;? as Joe said, exactly like it?s spelled!


Now everyone (except Joe) wanna take a stab at my middle name? : P?dra?g

Cheers,
Caoimh?n


Originally Posted By: jnosworthy
This post was automatically imported from our archived forum.



Kevin,


that would be Patrick of course


Originally Posted By: jnosworthy
This post was automatically imported from our archived forum.



or perhaps Paddy to a close friend


Originally Posted By: jferry
This post was automatically imported from our archived forum.



My Uncle Patrick we called “Packy”.


Originally Posted By: lkage
This post was automatically imported from our archived forum.



Wow! Some very interesting reading…but I’m glad I finished.


I don't think I could take any more tonight...my eyes and brain hurt. ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif)


--
"I have never met a man so ignorant that I couldn't learn something from him."
Galileo Galilei

Originally Posted By: Caoimh?n P. Connell
This post was automatically imported from our archived forum.



Hello All -


With a name like ?Caoimh?n? naturally I picked up a lot of nick-names in the US (some repeatable, some not?) but fortunately, I never picked up the nick-name ?Kevin.? With all due respect to all the wonderful ?Kevins? out there in cyberland, it just seems that name disproportionately comes with ready-made warrants attached to it. Whenever I pull over a driver named ?Kevin,? I can?t help but think ?Somebody?s going to jail, today??

P?dra?g ? Depending on where in Ireland the poor Paddy lives, the pronunciation changes, but ?POUR-ick? is how it?s pronounced where I lived.

Cheers!
Caoimh?n
p.s. Not "Irish-American," just good ol' AMERICAN, and proud of it.