Re: Acceptable Levels of Mould Spores

[Guest guest]

Bob:

I like the way Sharon put these two statements from Health Canada

together: " However, the large number of mould species and strains

growing in buildings and the large inter-individual variability in

human response to mould exposure preclude the derivation of exposure

limits. "

" Further, in the absence of exposure limits, results from tests for

the presence of fungi in air cannot be used to assess risks to the

health of building occupants. "

If I was asked on the stand by an attorney what Health Canada says

about microbial air sampling, I would answer that it says the above,

as one statement. One goes together with the other. Anything less

is a 'no' or 'it depends' (Phil Morey's famous, and universal,

statement).

Is there an exception to every rule? Probably. Considering that

Health Canada wrote the Annex to address mold in homes, I doubt that

there were considering pathogens in hospitals when this was

written.

Also, the Annex does not talk about ALL mold sampling. It is

specific to air sampling. Tape lifts, bulks and swabs are not

included in the statement.

It also does say, do not take air samples. It says that there are

limitations on air sampling that precludes the results from being

used to assess the health risks to the occupants, one in particular

being the lack of exposure limits. How do we know 'how high is high'

without limits? How do we know if this particular mold spore

concentration has lead to this individual becoming ill?

We all, in some way, use microbial air sampling as a tool to evaluate

a building. Other sampling methods will continue to be used as well,

to supplement the informed inspection. I hope we can all agree on

that.

Don

[Guest guest]

Don,

Glad you like that. But....lol Then you go on to say "Is there an exception to every rule?"

There is no rule established in this writing. Just a statement of scientific fact.

1.It does not reference or make any rule whether to test or not air test.

2.It does not reference or make any rule whether air sampling can be used or not used to determine building health.

3. It does not reference or make any rule whether air sampling can be indicative or not indicative of human health.

4. It does not reference or make any rule whether air sampling may be used in conjunction with or not used in conjunction with other factors as evidence or lack there of, of human illness.

All it says is moldy buildings can make people sick, but based on air tests ALONE, one cannot determine if a particular building will make or not make an individual sick.

Nowhere does it recommend or not recommend air testing.

Therefore, there is no rule to take exception to. Does that make sense?

Will repost the sentences. Look back up at my points. I think you will see they are correct as to what the document says and does not say.

"However, the large number of mould species and strains growing in buildings and the large inter-individual variability in human response to mould exposure preclude the derivation of exposure limits.""Further, in the absence of exposure limits, results from tests for the presence of fungi in air cannot be used to assess risks to the health of building occupants." (building occupants, not buildings)

And I want to add, the inability to establish true exposure limits to determine human illness, does not preclude the much needed establishment of Permissible Exposure Limit Guidelines, in my opinion.

WR,

Sharon

I like the way Sharon put these two statements from Health Canada together: "However, the large number of mould species and strains growing in buildings and the large inter-individual variability in human response to mould exposure preclude the derivation of exposure limits.""Further, in the absence of exposure limits, results from tests for the presence of fungi in air cannot be used to assess risks to the health of building occupants."If I was asked on the stand by an attorney what Health Canada says about microbial air sampling, I would answer that it says the above, as one statement. One goes together with the other. Anything less is a 'no' or 'it depends' (Phil Morey's famous, and universal, statement).

See what's free at AOL.com.

[Guest guest]

What is most alarming to me is how this particular Health Canada statement can be taken out of context and misconstrued to mean an unequivocal, absolute ("do not take air samples") and have but only one person in this industry (Bob) challenge what was being expressed as fact?

Bobbins, RN, L.Ac, QME

Bob:I like the way Sharon put these two statements from Health Canada together: "However, the large number of mould species and strains growing in buildings and the large inter-individual variability in human response to mould exposure preclude the derivation of exposure limits.""Further, in the absence of exposure limits, results from tests for the presence of fungi in air cannot be used to assess risks to the health of building occupants."If I was asked on the stand by an attorney what Health Canada says about microbial air sampling, I would answer that it says the above, as one statement. One goes together with the other. Anything less is a 'no' or 'it depends' (Phil Morey's famous, and universal, statement).Is there an exception to every rule? Probably. Considering that Health Canada wrote the Annex to address mold in homes, I doubt that there were considering pathogens in hospitals when this was written. :)Also, the Annex does not talk about ALL mold sampling. It is specific to air sampling. Tape lifts, bulks and swabs are not included in the statement.It also does say, do not take air samples. It says that there are limitations on air sampling that precludes the results from being used to assess the health risks to the occupants, one in particular being the lack of exposure limits. How do we know 'how high is high' without limits? How do we know if this particular mold spore concentration has lead to this individual becoming ill?We all, in some way, use microbial air sampling as a tool to evaluate a building. Other sampling methods will continue to be used as well, to supplement the informed inspection. I hope we can all agree on that.Don

See what's free at AOL.com.

[Guest guest]

Hi, Sharon:

That was intended as more of a rhetorical question, rather than

an 'actual' question.

I take your point about the non-non-recommendation (!) by Health

Canada of air sampling and its lack of applicablity, due to the

inability to derive exposure limits, to the assessment of building

occupants' health. Air sampling has its usefulness, and, in

particular, its applicability to the assessment of a building as a

supplemental measure to a thorough and informed building inspection.

I am a bit worried about your use of the term, 'Permissible Exposure

Limit Guidelines'. As you know, Permissible Exposure Limits (PEL's)

are what OSHA uses to regulate potential airborne exposures to

chemicals. OSHA and NIOSH conduct extensive research into the

potential for exposure to the chemical in question and the health

risks involved prior to setting a new PEL. The classic example is

the reduction in the asbestos PEL over a period approximately ten

years (1972 to 1982) due to new information about the illnesses

experienced by those exposed to asbestos fibers. I believe that

would be the same as the setting of a 'true exposure limit' for

asbestos. So I am not sure how you are differentiating between

a 'true exposure limit' and a 'Permissible Exposure Limit

Guideline'. Could you clarify, please? Thanks!

Don

[Guest guest]

Hi Don,

You wrote: "So I am not sure how you are differentiating between a 'true exposure limit' and a 'Permissible Exposure Limit Guideline'. Could you clarify, please? Thanks!"

Once again I probably am not using the correct terminology so thank you for clarifying that. That is how I learn. (Where is Steve Terms? I need him!)

What I am attempting to say is that one cannot establish a true exposure limit, when assessing a building, to determine if a human will become ill or not. There are just too many variables.

But, when assessing a buildings, there needs to be a generally accepted number as to whether there is a good chance or not someone will experience ill health, in my opinion.

Schools are a great example. You have two pros look at the same numbers. One says it's no problem, the other says it's unacceptable. It would be nice to have a little chart that they could both look at as a more definitive piece of the puzzle. Often times, its the conflicting pros' interpretations that scare parents into distrust of school boards and school boards into calling parents hysterical. Thus I use the phrase permissible exposure limit guideline...but probably not used correctly.

I know of people who are extremely sensitive and require very minimal mold exposure to elicit some pretty serious symptoms. Does that mean 99.99% of the rest of the population will? No. Does that mean it is reasonable or logical to make all buildings mold free enough for this person? No. (will attach an example at the end) I do believe, however, that the number should be set pretty low, as more and more children are getting asthma, making a growing percentage of the population susceptible.

It just seems it would be helpful, I think, if there were some guideline numbers to use when assessing buildings...not occupants, buildings.

Do you get the gist of what I am trying to say?

So below is example of one that you should not build a school, based on their reactions:

Sharon

[Guest guest]

Sharon,

I agree with your well-stated comments and interpretations regarding the Health Canada Annex. I also agree that, for many situations (or any kind of regulatory enforcement), it would be helpful to have some sort of standardized testing method with a standardized way of interpreting the results. This is what I was alluding to when I answered Tony's question about how one might go about setting a mold exposure guideline using the analogy of how the radon action level was established. BTW, the terms "action level" or "exposure guideline" might be better than other terms that imply a distinction between "safe and unsafe" or permissible or not. I agree that lower is better and higher is worse when assessing the potential for mold contaminants in the indoor environment to cause health effects. This is why I think ALARA and Prudent Avoidance principles should be applied when determining what levels should be considered acceptable. As Bob s has extensively researched and written about, many countries have already established such guidelines. They are for the general population which does not include those individuals with "special needs". Certainly, public health policy should be set to be protective of as many people as possible at a reasonable cost to society without having to guarantee that every environment has to be acceptable for every individual. That's all that public health policy can ever do. Those with severe medical conditions and special needs cannot always be accommodated in normal buildings which should be reasonably safe for normal people. In the case of schools, lower levels of contaminants are preferred for a number of reasons.

But Sharon, I disagree that you need my help here. You've interpreted the Health Canada document very well and articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants.

Considering that buildings should be kept clean and dry anyway, I don't think you are asking for too much. Maybe it is time to standardize some testing and analytical methods and just "pick a number". The number should be low, but not so low that it cannot be achieved at a reasonable cost to the building owner. I encourage everyone to take a look at Bob's book, "Worldwide Exposure Standards for Mold and Bacteria". The book makes a case for doing what you suggest and even logically proposes which numerical guidelines might be considered based upon a compilation of a wide variety of sources of data. When you look at what other countries have already done, it doesn't seem so difficult from a technical standpoint. The difficulty is mostly on the political side of the issue.

Keep up the good work,

Steve Temes

Once again I probably am not using the correct terminology so thank you for clarifying that. That is how I learn. (Where is Steve Terms? I need him!)

What I am attempting to say is that one cannot establish a true exposure limit, when assessing a building, to determine if a human will become ill or not. There are just too many variables.

But, when assessing a buildings, there needs to be a generally accepted number as to whether there is a good chance or not someone will experience ill health, in my opinion.

Schools are a great example. You have two pros look at the same numbers. One says it's no problem, the other says it's unacceptable. It would be nice to have a little chart that they could both look at as a more definitive piece of the puzzle. Often times, its the conflicting pros' interpretations that scare parents into distrust of school boards and school boards into calling parents hysterical. Thus I use the phrase permissible exposure limit guideline...but probably not used correctly.

I know of people who are extremely sensitive and require very minimal mold exposure to elicit some pretty serious symptoms. Does that mean 99.99% of the rest of the population will? No. Does that mean it is reasonable or logical to make all buildings mold free enough for this person? No. (will attach an example at the end) I do believe, however, that the number should be set pretty low, as more and more children are getting asthma, making a growing percentage of the population susceptible.

It just seems it would be helpful, I think, if there were some guideline numbers to use when assessing buildings...not occupants, buildings.

Do you get the gist of what I am trying to say?

[Guest guest]

Sharon,

I agree with your well-stated comments and interpretations regarding the Health Canada Annex. I also agree that, for many situations (or any kind of regulatory enforcement), it would be helpful to have some sort of standardized testing method with a standardized way of interpreting the results. This is what I was alluding to when I answered Tony's question about how one might go about setting a mold exposure guideline using the analogy of how the radon action level was established. BTW, the terms "action level" or "exposure guideline" might be better than other terms that imply a distinction between "safe and unsafe" or permissible or not. I agree that lower is better and higher is worse when assessing the potential for mold contaminants in the indoor environment to cause health effects. This is why I think ALARA and Prudent Avoidance principles should be applied when determining what levels should be considered acceptable. As Bob s has extensively researched and written about, many countries have already established such guidelines. They are for the general population which does not include those individuals with "special needs". Certainly, public health policy should be set to be protective of as many people as possible at a reasonable cost to society without having to guarantee that every environment has to be acceptable for every individual. That's all that public health policy can ever do. Those with severe medical conditions and special needs cannot always be accommodated in normal buildings which should be reasonably safe for normal people. In the case of schools, lower levels of contaminants are preferred for a number of reasons.

But Sharon, I disagree that you need my help here. You've interpreted the Health Canada document very well and articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants.

Considering that buildings should be kept clean and dry anyway, I don't think you are asking for too much. Maybe it is time to standardize some testing and analytical methods and just "pick a number". The number should be low, but not so low that it cannot be achieved at a reasonable cost to the building owner. I encourage everyone to take a look at Bob's book, "Worldwide Exposure Standards for Mold and Bacteria". The book makes a case for doing what you suggest and even logically proposes which numerical guidelines might be considered based upon a compilation of a wide variety of sources of data. When you look at what other countries have already done, it doesn't seem so difficult from a technical standpoint. The difficulty is mostly on the political side of the issue.

Keep up the good work,

Steve Temes

Once again I probably am not using the correct terminology so thank you for clarifying that. That is how I learn. (Where is Steve Terms? I need him!)

What I am attempting to say is that one cannot establish a true exposure limit, when assessing a building, to determine if a human will become ill or not. There are just too many variables.

But, when assessing a buildings, there needs to be a generally accepted number as to whether there is a good chance or not someone will experience ill health, in my opinion.

Schools are a great example. You have two pros look at the same numbers. One says it's no problem, the other says it's unacceptable. It would be nice to have a little chart that they could both look at as a more definitive piece of the puzzle. Often times, its the conflicting pros' interpretations that scare parents into distrust of school boards and school boards into calling parents hysterical. Thus I use the phrase permissible exposure limit guideline...but probably not used correctly.

I know of people who are extremely sensitive and require very minimal mold exposure to elicit some pretty serious symptoms. Does that mean 99.99% of the rest of the population will? No. Does that mean it is reasonable or logical to make all buildings mold free enough for this person? No. (will attach an example at the end) I do believe, however, that the number should be set pretty low, as more and more children are getting asthma, making a growing percentage of the population susceptible.

It just seems it would be helpful, I think, if there were some guideline numbers to use when assessing buildings...not occupants, buildings.

Do you get the gist of what I am trying to say?

[Guest guest]

Steve,

I knew I could count on you for correct terminology!

"BTW, the terms "action level" or "exposure guideline" might be better than other terms that imply a distinction between "safe and unsafe" or permissible or not."

And now that I know how to phrase it, it also sounds like we are on the same page regarding what is and is not science and an aspect that is needed in the equation. How about "indicated action level"?

"Maybe it is time to standardize some testing and analytical methods and just "pick a number".

I want to show you all a school that is suffering from no standardization of the matter. On the 19th the school board put out a press release saying safe based on testing. Never mind the work they have to do still and for some odd reason, then retest. My guess would be that someone told them "slightly elevated". On the 20th, they are talking about closing it, based on that it wasn't tested properly. You can almost read the parents' health fears and the board's financial fears between each word written. And you know there have already been some angry words borne from distrust and frustration on this one!

NEWS RELEASE________________________________________LAFAYETTE PARISH SCHOOL SYSTEMP.O. Drawer 2158 • Lafayette, Louisiana 70502 • Website: www.LPSSonline.com FOR IMMEDIATE RELEASE Contact: e W. Sutley, APRApril 19, 2007 E-mail: jwsutley@...Work: Fax: TEST RESULTS SHOW PLANTATION BAND ROOM SAFE, TWO CLASSROOM A/C UNITS TO BE CLEANED LAFAYETTE, LA. — Post-remediation test results show that the band room at Plantation Elementary is safe for students to occupy. The Certificate of Mold Analysis from two reports by Pro-Lab, an environmental testing company, specify that air samples taken on April 14 “do not indicate the presence of elevated indoor mold spores or colonies.†This means that remediation work conducted in the band room and adjoining band storage room was successful. Results from other tests conducted on March 31 state: “The airborne fungal results from the samples taken in rooms 28 and 49 are not amplified and do not seem to be translating into a potential airborne threat.†However, recommendations included in the report state: “Envirocon recommends all components of each room’s[rooms 28 and 49] HVAC systems be cleaned and checked for proper functionality.†As a result of this recommendation, LPSS maintenance staff will arrange with contractors to clean the A/C units in rooms 28 and 49 this weekend. In addition, maintenance staff will ask contractors to begin cleaning A/C units in other rooms in the school. After the units are cleaned, staff will perform random air sampling in the school.Next week, students will not be in school on Friday, April 27. This will provide an additional day next weekend for work crews to clean A/C units at Plantation Elementary. A representative from the Louisiana Department of Health and Hospitals (DHH) will conduct a visual inspection at Plantation Elementary on Friday, April 20, at 9 .m. Following the inspection, LPSS staff will ask for recommendations on future potential work at the school. The Daily AdvertiserArticle published Apr 20, 2007Plantation Elementary mold closure decision expectedTests confirm toxins; at least five exposed aharris@...

A decision on whether to consider closing Plantation Elementary School to test for a harmful mold could come this morning, said Lafayette Parish School Board President Carl LaCombe. On Thursday, independent test results showed unsafe levels of the mold Stachybotrys after a three-room test. Parents also confirmed on Thursday that at least five children have tested positive for exposure to a byproduct of that mold, a mycotoxin called tricothecene. "We're pulling out all the stops," LaCombe said Thursday evening after a meeting with district staff. "We're not taking any chances with this." LaCombe said the district is looking "at complete testing, cleaning and retesting." He said a timeline for the project will depend on the availability of contractors that will perform the testing. But, at least two parents who learned Thursday morning that their children tested positive to exposure to tricothecene pulled their three children from Plantation. The first child who tested positive in December after violent episodes of vomiting, headaches and blacking out has been homebound since then with a suppressed immune system and continuing symptoms. Higginbotham, who learned Thursday that her child tested positive, enrolled her student in another school April 4 because she feared for her child's safety after months of illness. Plantation Elementary School is home to a gifted and talented program that allows students not zoned for the school to attend. Those students attending by choice, like Higginbotham's daughter, have the option to go back to the school in their zone. Two parents who have children zoned for Plantation said they don't know what to do, but know that they don't want to send their children back after receiving positive test results. Questions about how to test for the toxic mold continued Thursday when the district released a statement explaining that the band room, which tested positive for Stachybotrys March 31, is safe after remediation. But, one toxicologist said the test used to determine the safety of the room is not the appropriate method. According to toxicologist Lipsey of Lipsey and Associates in Florida, air quality tests, like the one performed by the district on the band room, should not be used to determine whether a room is safe. "Proper testing is swab and bulk," Lipsey said. "Not air testing."

SharonSee what's free at AOL.com.

[Guest guest]

Steve

In your recent message to Sharon, part of your response was

"you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."

I wish that were likely possible but perhaps I could provide a little background on why it might be a while.

In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:

1 short-term air samples;

2 bedding dust samples;

3 Carpet dust samples (one from the bedroom and one from the living room);

4 Several-day-long air dust samples (one from the bedroom and one from the living room.

Each has its limitations and the young man who got his PhD analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):

1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;

2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;

3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;

4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).

There were some very good discussions of air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample?

Jim H. White SSC

[Guest guest]

Jim,

You are even older than me! That's some old technology from the early 90's. Technology has been updated. The new PCR analysis in the hands of trained investigators is quite useful. PCR should be teamed with direct visual ID for best results. Like Clairol ... expensive but worth it when sick people are involved.

Rosen, Ph.D.

www.Green-Buildings.org

RE: "Acceptable Levels of Mould Spores"

Steve

In your recent message to Sharon, part of your response was

"you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."

I wish that were likely possible but perhaps I could provide a little background on why it might be a while.

In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:

1 short-term air samples;

2 bedding dust samples;

3 Carpet dust samples (one from the bedroom and one from the living room);

4 Several-day- long air dust samples (one from the bedroom and one from the living room.

Each has its limitations and the young man who got his PhD analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):

1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;

2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;

3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;

4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).

There were some very good discussions of air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample?

Jim H. White SSC

Ahhh...imagining that irresistible "new car" smell? Check out

new cars at Yahoo! Autos.

[Guest guest]

Sharon and Steve:

I agree with the gist of these postings, and I look forward to

Steve's presentation on this matter at the Philadelphia AICHE.

Perhaps we can discuss the potential of developing 'action levels'

further as we go along. It certainly opens up interesting

possibilities for the future use of air sampling, and as well as

other types of sampling.

Don

>

> Steve,

>

> I knew I could count on you for correct terminology!

>

> " BTW, the terms " action level " or " exposure guideline " might be

better than

> other terms that imply a distinction between " safe and unsafe " or

permissible

> or not. "

>

> And now that I know how to phrase it, it also sounds like we are

on the same

> page regarding what is and is not science and an aspect that is

needed in

> the equation. How about " indicated action level " ?

>

>

> " Maybe it is time to standardize some testing and analytical

methods and

> just " pick a number " .

>

> I want to show you all a school that is suffering from no

standardization of

> the matter. On the 19th the school board put out a press release

saying safe

> based on testing. Never mind the work they have to do still and

for some odd

> reason, then retest. My guess would be that someone told

them " slightly

> elevated " . On the 20th, they are talking about closing it, based

on that it

> wasn't tested properly. You can almost read the parents' health

fears and the

> board's financial fears between each word written. And you know

there have

> already been some angry words borne from distrust and frustration

on this one!

>

> NEWS RELEASE

> ________________________________________

> LAFAYETTE PARISH SCHOOL SYSTEM

> P.O. Drawer 2158 • Lafayette, Louisiana 70502 •

> Website: www.LPSSonline.com

> FOR IMMEDIATE RELEASE Contact: e W. Sutley,

> APR

> April 19, 2007 E-mail: jwsutley@...

> Work:

> Fax:

> TEST RESULTS SHOW PLANTATION BAND ROOM SAFE, TWO CLASSROOM

> A/C UNITS TO BE CLEANED

> LAFAYETTE, LA. †" Post-remediation test results show that the

> band room at Plantation Elementary is safe for students to

> occupy. The Certificate of Mold Analysis from two reports

> by Pro-Lab, an environmental testing company, specify that

> air samples taken on April 14 “do not indicate the presence

> of elevated indoor mold spores or colonies.†This means

> that remediation work conducted in the band room and

> adjoining band storage room was successful.

> Results from other tests conducted on March 31 state: “The

> airborne fungal results from the samples taken in rooms 28

> and 49 are not amplified and do not seem to be translating

> into a potential airborne threat.†However, recommendations

> included in the report state: “Envirocon recommends all

> components of each room’s[rooms 28 and 49] HVAC systems be

> cleaned and checked for proper functionality.†As a result

> of this recommendation, LPSS maintenance staff will arrange

> with contractors to clean the A/C units in rooms 28 and 49

> this weekend. In addition, maintenance staff will ask

> contractors to begin cleaning A/C units in other rooms in

> the school. After the units are cleaned, staff will perform

> random air sampling in the school.

> Next week, students will not be in school on Friday, April

> 27. This will provide an additional day next weekend for

> work crews to clean A/C units at Plantation Elementary.

> A representative from the Louisiana Department of Health and

> Hospitals (DHH) will conduct a visual inspection at

> Plantation Elementary on Friday, April 20, at 9 .m.

> Following the inspection, LPSS staff will ask for

> recommendations on future potential work at the school.

>

> The Daily Advertiser

> Article published Apr 20, 2007

> Plantation Elementary mold closure decision expected

> Tests confirm toxins; at least five exposed

>

> aharris@...

> A decision on whether to consider closing Plantation

> Elementary School to test for a harmful mold could come

> this morning, said Lafayette Parish School Board President

> Carl LaCombe.

> On Thursday, independent test results showed unsafe levels

> of the mold Stachybotrys after a three-room test. Parents

> also confirmed on Thursday that at least five children

> have tested positive for exposure to a byproduct of that

> mold, a mycotoxin called tricothecene.

> " We're pulling out all the stops, " LaCombe said Thursday

> evening after a meeting with district staff. " We're not

> taking any chances with this. "

> LaCombe said the district is looking " at complete testing,

> cleaning and retesting. " He said a timeline for the

> project will depend on the availability of contractors

> that will perform the testing.

> But, at least two parents who learned Thursday morning

> that their children tested positive to exposure to

> tricothecene pulled their three children from Plantation.

> The first child who tested positive in December after

> violent episodes of vomiting, headaches and blacking out

> has been homebound since then with a suppressed immune

> system and continuing symptoms. Higginbotham, who

> learned Thursday that her child tested positive, enrolled

> her student in another school April 4 because she feared

> for her child's safety after months of illness.

> Plantation Elementary School is home to a gifted and

> talented program that allows students not zoned for the

> school to attend. Those students attending by choice, like

> Higginbotham's daughter, have the option to go back to the

> school in their zone.

> Two parents who have children zoned for Plantation said

> they don't know what to do, but know that they don't want

> to send their children back after receiving positive test

> results.

> Questions about how to test for the toxic mold continued

> Thursday when the district released a statement explaining

> that the band room, which tested positive for Stachybotrys

> March 31, is safe after remediation. But, one toxicologist

> said the test used to determine the safety of the room is

> not the appropriate method.

> According to toxicologist Lipsey of Lipsey and

> Associates in Florida, air quality tests, like the one

> performed by the district on the band room, should not be

> used to determine whether a room is safe.

> " Proper testing is swab and bulk, " Lipsey said. " Not air

> testing. "

>

>

> Sharon

>

>

>

> ************************************** See what's free at

http://www.aol.com.

>

[Guest guest]

NIOSH - Exposure Assessment Methods Research Needs and Priorities - DHHS (NIOSH) Pub No. 2002-126

Sometime this issue seems like one step forward, one step back!

"Exposure to microorganisms or their byproducts in the workplace is of increasing concern, but methods of assessing that exposure are not well defined. Thus, evaluated, sensitive, and specific methods are needed for assessing exposure to microbes and microbial toxins, including non-aerosolized microbes, bioaerosols, and bioaerosol mixtures. Methods should include nonculturing approaches, for example DNA amplification and comparison to methods based on culturing as needed.

Recommendation: Develop and evaluate new methods for assessing exposure to workplace microbial contamination."

As biomonitoring methods are developed, the ethical, legal, and social issues related to these advances need to be addressed. These are critical issues that need to be resolved before biomarkers can be fully used in occupational safety and health practice. The potential for unethical use of biomarkers is great, perhaps more so for susceptibility markers that may be used in discriminatory practices. A major issue is what to do with employees who have altered biomarker results in the absence of disease [Ashford et al. 1990].

Recommendation: Perform research and engender dialogue to help resolve the ethical, legal, and social issues of biomonitoring.

SharonSee what's free at AOL.com.

[Guest guest]

Sharon ...

You quote a Niosh article about the need for new technology for assessment.

The EPA has spent millions developing just the new technology asked for. It is called PCR. Why consultant's don't use this fantastic technology to help diagnose sick homes is a mystery.

They keep using old technology that either does not work or does not work well. And yet consultants want to make it a law that clients must use consultants to do post remedition verfication with the techniques that are considered at best marginally useful!

Yet a mold remediation contractor that takes a sample of carpet dust and/or a piece of the HVAC duct lining to make sure that the house is left safe for even the most sensitive people ... well there is something wrong with.

Our firm uses PCR extensively not just in court cases but when sick people are involved. I have NEVER met any consultants in this area that have used PCR even once.

Yes it is expensive. But when sick people are involved I feel it is unethical to cut costs at the expense of people's health.

Rosen, Ph.D.

www.Mold-Books.com

Re: Re: "Acceptable" Levels of Mould Spores

NIOSH - Exposure Assessment Methods Research Needs and Priorities - DHHS (NIOSH) Pub No. 2002-126

Sometime this issue seems like one step forward, one step back!

"Exposure to microorganisms or their byproducts in the workplace is of increasing concern, but methods of assessing that exposure are not well defined. Thus, evaluated, sensitive, and specific methods are needed for assessing exposure to microbes and microbial toxins, including non-aerosolized microbes, bioaerosols, and bioaerosol mixtures. Methods should include nonculturing approaches, for example DNA amplification and comparison to methods based on culturing as needed.

Recommendation: Develop and evaluate new methods for assessing exposure to workplace microbial contamination. "

As biomonitoring methods are developed, the ethical, legal, and social issues related to these advances need to be addressed. These are critical issues that need to be resolved before biomarkers can be fully used in occupational safety and health practice. The potential for unethical use of biomarkers is great, perhaps more so for susceptibility markers that may be used in discriminatory practices. A major issue is what to do with employees who have altered biomarker results in the absence of disease [Ashford et al. 1990].

Recommendation: Perform research and engender dialogue to help resolve the ethical, legal, and social issues of biomonitoring.

Sharon

See what's free at AOL.com.

Ahhh...imagining that irresistible "new car" smell? Check out

new cars at Yahoo! Autos.

[Guest guest]

Wallemia sebi can be found growing in materials in indoor environment other than food. PCR is a good tool for a specific microorganism. For example, if someone is infected by Aspergillus fumigatus, you can use PCR to analzye air and source samples to find it. It's always recommended to confirm it by other method (culture). However, detecting 36 species out of hundreds of species that you can find in indoor environment is only a SCREENING. It's necessary to analyze the total fungi using microscopic direct examination on the very same sample. Wei Tang QLab"Jim H. White" wrote: Interestingly-enough some of the first use of the PCR testing was in Canada and by people like . I was trying to point out the facts that: a) airborne levels vary widely so air testing has to be more than one grab sample; testing methods often change the sample and we do not know enough about these effects. Wei has stated the limitations of just PCR as it is at the moment. I though that is

arguments were very good indeed and that they, in some ways, reinforce my concerns. If this problem is properly-addressed and large-scale research is done we will likely get useful results. PCR is not good enough at the moment. It is just too limited In the Wallaceburg study we found that a few percent of the homes had Wallemia sebi in them and we were told that we were foolish to test for it because it was only found on salt fish. Wallemia sebi can make you sick and you don't find it unless you are looking for highly-xerophillic molds. Remember that, in this area as well as others, we do not know how little

we know! Jim H. White SSC RE: "Acceptable Levels of Mould Spores" Steve In your recent message to Sharon, part of your response was "you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast

majority of occupants." I wish that were likely possible but perhaps I could provide a little background on why it might be a while. In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were: 1 short-term air samples; 2 bedding dust samples; 3 Carpet dust samples (one from the bedroom and one from the living room); 4 Several-day- long air dust samples (one from the bedroom and one from the living room. Each has its limitations and the young man who got his PhD analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many): 1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so; 2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover; 3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has

been cleaned with toxic chemical post-treatment; 4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea). There were some very good discussions of air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample? Jim H. White SSC Ahhh...imagining

that irresistible "new car" smell?Check out new cars at Yahoo! Autos. Wei Tang, Ph.D. Lab Director QLab5 DriveCherry Hill, NJ 08003www.QLabUSA.com

[Guest guest]

:

This is what Wei Tang said:

'PCR is a good tool for a specific microorganism. For example, if

someone is infected by Aspergillus fumigatus, you can use PCR to

analzye air and source samples to find it. It's always recommended to

confirm it by other method (culture). However, detecting 36 species

out of hundreds of species that you can find in indoor environment is

only a SCREENING. It's necessary to analyze the total fungi using

microscopic direct examination on the very same sample.'

Please note the emphasis on 'screening'. PCR is one more tool in the

arsenal. It is not a replacement for other types of sampling,

including microscopic direct exam. It is a supplemental measuring

device, and it should be used judiciously.

Don

Don

>

> Jim,

>

> I use PCR quite extensively. I am quite sure that Wei certainly did

not mean to give the impression that there is anything wrong with

PCR. Simply that it should be considered part of a complete

investigation procedure that includes inspection along with a visual

ID under a microscope of total spore count.

>

> Rosen, Ph.D.

> www.mold-books.com

>

>

>

>

> RE: " Acceptable Levels of Mould Spores "

>

>

> Steve

>

> In your recent message to Sharon, part of your response was

> " you . . articulated a very cogent argument for some sort of

objective way of using testing to determine whether the building is

likely to cause problems for the vast majority of occupants. "

>

> I wish that were likely possible but perhaps I could provide a

little background on why it might be a while.

>

> In the Wallaceburg study in the early 90's we used a number of mold

sampling methods and compared results. The methods were:

> 1 short-term air samples;

> 2 bedding dust samples;

> 3 Carpet dust samples (one from the bedroom and one from the

living room);

> 4 Several-day- long air dust samples (one from the bedroom and

one from the living room.

>

> Each has its limitations and the young man who got his PhD

analysing them, , along with J. , would be

better able to judge the limitations of each, but here goes my

attempt at defining the top ones (of many):

>

> 1 short-term samples are very non-reproducible; sometimes counts

and species ratios vary by even decimal orders of magnitude over a

week or so;

> 2 depending on the length of time between washing of the

bedding, and mattress cover, if any, sample dust mass can be adequate

or way too small, especially if the bed has a plastic mattress cover;

> 3 carpet dust is often only partly organic and may have very low

levels of culturable spores if it has not been cleaned for a while;

or has been cleaned with toxic chemical post-treatment;

> 4 the sampling protocol seems to desiccate some of the spores so

that viability is impaired (both viable and total counts seem a good

idea).

>

> There were some very good discussions of air flow patterns and

where to air sample within containment. All of these points are valid

here to some extent, as well. On many spaces the air patterns are

complex and mixing is not all that good, especially in homes. If so,

where do we sample?

> Jim H. White SSC

>

>

>

>

>

>

>

> Ahhh...imagining that irresistible " new car " smell?

> Check out new cars at Yahoo! Autos.

>

>

> __________________________________________________

>

[Guest guest]

Don,

That is my feeling as well. A good tool that needs to be supplemented by direct microscopic exam. When there are sick people ... you OFTEN have negative on the direct microscopic exam but positive on PCR due to the presence of mold fragments that cause illness but are not detectable under a microscope.

I have a theory about air duct cleaning making mold senstivev people sick. Many air duct cleaners spray biocide into ducts and plenums (even though the EPA says this may not be done unless what is sprayed is metal ... no fiberglass or flex duct.) The biocide kills any live mold and then the dead mold decomposes and the fragments are blown into the air space for the residents to breath making them sick.

PCR finds sub-micron fragments but direct microscopic exam does not as they are too small to see.

Rosen, Ph.D.

www.Mold-Books.com

RE: "Acceptable Levels of Mould Spores"> > > Steve> > In your recent message to Sharon, part of your response was > "you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."> > I wish that were likely possible but perhaps I could provide a little background on why it might be a while.> > In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:> 1 short-term air samples;> 2 bedding dust samples;> 3 Carpet dust samples (one from the bedroom and one from the living room);> 4 Several-day- long air dust samples (one from the bedroom and one from the living room.> > Each has its limitations and the young man who got his PhD

analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):> > 1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;> 2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;> 3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;> 4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).> > There were some very good discussions of

air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample?> Jim H. White SSC> > > > > > > > Ahhh...imagining that irresistible "new car" smell?> Check out new cars at Yahoo! Autos. > > > ____________ _________ _________ _________ _________ __>

[Guest guest]

(and Group), PCR is a powerful tool. There is certainly nothing wrong with using it at all. Like you said, it's part of a complete investigation. As any other powerful tools, they can be misused. I am sure that you don't do that, , but many other people do. I am glad that you can use it to help with your investigation on top of your other sampling and building inspection. However, we need to let people know its limitations. (1) Data Interpretation ERMI, which interpret PCR data in a complete new way, still needs more evaluation. It's not a magic bullet. It doesn't replace a good consultant's knowledge and skills. Use the index as a reference only. Look at all 36 species (including Group 2) and do not skip other sampling and investigations. It's only one carpet dust sample. Many fungal biomass (spores/hyphae) in carpet dust can simply be carried in by shoes

and pets from outdoor soil. (2) 36 species vs. hundreds of species And, as I keep saying to people (not you, I got you covered), always, always do direct exam for the same sample submitted for PCR. Wei Tang QLab Weekes wrote: :This is what Wei Tang said:'PCR is a good tool for a specific microorganism. For example, if someone is infected by Aspergillus fumigatus, you can

use PCR to analzye air and source samples to find it. It's always recommended to confirm it by other method (culture). However, detecting 36 species out of hundreds of species that you can find in indoor environment is only a SCREENING. It's necessary to analyze the total fungi using microscopic direct examination on the very same sample.'Please note the emphasis on 'screening'. PCR is one more tool in the arsenal. It is not a replacement for other types of sampling, including microscopic direct exam. It is a supplemental measuring device, and it should be used judiciously.DonDon >> Jim,> > I use PCR quite extensively. I am quite sure that Wei certainly did not mean to give the impression that there is anything wrong with PCR. Simply

that it should be considered part of a complete investigation procedure that includes inspection along with a visual ID under a microscope of total spore count.> > Rosen, Ph.D.> www.mold-books.com> > > > > RE: "Acceptable Levels of Mould Spores"> > > Steve> > In your recent message to Sharon, part of your response was > "you . . articulated a very cogent

argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."> > I wish that were likely possible but perhaps I could provide a little background on why it might be a while.> > In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:> 1 short-term air samples;> 2 bedding dust samples;> 3 Carpet dust samples (one from the bedroom and one from the living room);> 4 Several-day- long air dust samples (one from the bedroom and one from the living room.> > Each has its limitations and the young man who got his PhD analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):> > 1 short-term

samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;> 2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;> 3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;> 4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).> > There were some very good discussions of air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good,

especially in homes. If so, where do we sample?> Jim H. White SSC> > > > > > > > Ahhh...imagining that irresistible "new car" smell?> Check out new cars at Yahoo! Autos. > > > __________________________________________________>

[Guest guest]

Steve:

I am sorry, it is Tony Havics who is presenting at the AICHE on this

issue. I apologize to both Steve and Tony.

I also agree with Steve that a 'building assessment' numerical

guideline for microbial air sampling would be useful, as an indicator

as to whether or not further investigation is necessary of the

building. It would not be useful for health risk assessment, but as

a tool for building assessment. I am sure that this could be

developed.

I will note that the other countrys' numerical guidelines are being

used as a measure of occupant health, for the most part. It would

have to be made clear that this is not the intention of the 'building

assessment' numerical guideline, so that there is no confusion that a

building is 'safe'.

Don

> > >

> > >Steve,

> > >

> > >I knew I could count on you for correct terminology!

> > >

> > > " BTW, the terms " action level " or " exposure guideline " might be

> > better than

> > >other terms that imply a distinction between " safe and unsafe "

or

> > permissible

> > >or not. "

> >

> >

> >

>

[Guest guest]

Correct me if I am wrong, but don't you need to know the fungal species before you look for it with PCR. I also thought most labs that do PCR will typically look for about only 30 species out of the thousands out there. - do you tell the lab what species to look for and if nothing turns up, do you tell them to look for additional species. Just curious. Sherry, CMCgary rosen wrote: Don, That is my feeling as well. A good tool that needs to be supplemented by direct microscopic exam. When there are sick people ... you OFTEN have negative on the direct microscopic exam but positive on PCR due to the presence of mold fragments that cause illness but are not detectable under a microscope. I have a theory about air duct cleaning making mold senstivev people sick. Many air duct cleaners spray biocide into ducts and plenums (even though the EPA says this may not be done unless what is sprayed is metal ... no fiberglass or flex

duct.) The biocide kills any live mold and then the dead mold decomposes and the fragments are blown into the air space for the residents to breath making them sick. PCR finds sub-micron fragments but direct microscopic exam does not as they are too small to see. Rosen, Ph.D. www.Mold-Books.com RE: "Acceptable Levels of Mould Spores"> > > Steve> > In your recent message to Sharon, part of your response was > "you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."> > I wish that were likely possible but perhaps I could provide a little background on why it might be a while.> > In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:> 1 short-term

air samples;> 2 bedding dust samples;> 3 Carpet dust samples (one from the bedroom and one from the living room);> 4 Several-day- long air dust samples (one from the bedroom and one from the living room.> > Each has its limitations and the young man who got his PhD analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):> > 1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;> 2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;> 3 carpet dust is often only partly organic and may have very low levels of culturable spores if it

has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;> 4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).> > There were some very good discussions of air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample?> Jim H. White SSC> > > > > > > > Ahhh...imagining that irresistible "new car" smell?> Check out new cars at Yahoo! Autos. > > > ____________ _________ _________ _________ _________ __>

[Guest guest]

No.

You order a Fungal Panel. Depending on how much you want to spend. Level 1, II of Level III. Level III has about 30+ species. This level includes almost all of the water damage indicator species so it is is quite good for determining if a house is a sick house asa a result of water damage. The EPA has used this panel very effectively in correlating sick houses with sick people.

One does not really care to know all mold species in a house. Just if the house fits the general profile of sick house due to water damage indicators.

Rosen, Ph.D.

www.Mold-Books.com

RE: "Acceptable Levels of Mould Spores"> > > Steve> > In your recent message to Sharon, part of your response was > "you . . articulated a very cogent argument for some sort of objective way of using testing to determine whether the building is likely to cause problems for the vast majority of occupants."> > I wish that were likely possible but perhaps I could provide a little background on why it might be a while.> > In the Wallaceburg study in the early 90's we used a number of mold sampling methods and compared results. The methods were:> 1 short-term air samples;> 2 bedding dust samples;> 3 Carpet dust samples (one from the bedroom and one from the living room);> 4 Several-day- long air dust samples (one from the bedroom and one from the living room.> > Each has its limitations and the young man who got his PhD

analysing them, , along with J. , would be better able to judge the limitations of each, but here goes my attempt at defining the top ones (of many):> > 1 short-term samples are very non-reproducible; sometimes counts and species ratios vary by even decimal orders of magnitude over a week or so;> 2 depending on the length of time between washing of the bedding, and mattress cover, if any, sample dust mass can be adequate or way too small, especially if the bed has a plastic mattress cover;> 3 carpet dust is often only partly organic and may have very low levels of culturable spores if it has not been cleaned for a while; or has been cleaned with toxic chemical post-treatment;> 4 the sampling protocol seems to desiccate some of the spores so that viability is impaired (both viable and total counts seem a good idea).> > There were some very good discussions of

air flow patterns and where to air sample within containment. All of these points are valid here to some extent, as well. On many spaces the air patterns are complex and mixing is not all that good, especially in homes. If so, where do we sample?> Jim H. White SSC> > > > > > > > Ahhh...imagining that irresistible "new car" smell?> Check out new cars at Yahoo! Autos. > > > ____________ _________ _________ _________ _________ __>

[Guest guest]

,

That is the difference between a sampler

(as chuck calls them) and an IAQ professional. The professional does an

inspection, builds a hypothesis, and than moves to prove and/or disprove it and

sampling may be a tool of choice although not necessarily the only tool. A

sampler just takes samples and than looks at results not realizing that he

he/she missed was the greater importance due to not having a purpose for

sampling other than to sample.

EnviroBob

From: iequality [mailto:iequality ] On Behalf Of gary rosen

Sent: Monday, April 23, 2007 9:50

PM

To: iequality

Subject: Re: Re:

" Acceptable Levels of Mould Spores "

No.

You order a Fungal Panel. Depending on how much you want

to spend. Level 1, II of Level III. Level III has about 30+ species.

This level includes almost all of the water damage indicator species so it is

is quite good for determining if a house is a sick house asa a result of water

damage. The EPA has used this panel very effectively in correlating sick

houses with sick people.

One does not really care to know all mold species

in a house. Just if the house fits the general profile of sick house

due to water damage indicators.

Rosen, Ph.D.

www.Mold-Books.com

RE: " Acceptable Levels of Mould Spores "

>

>

> Steve

>

> In your recent message to Sharon,

part of your response was

> " you . . articulated a very cogent argument for some sort of

objective way of using testing to determine whether the building is

likely to cause problems for the vast majority of occupants. "

>

> I wish that were likely possible but perhaps I could provide a

little background on why it might be a while.

>

> In the Wallaceburg study in the early 90's we used a number of mold

sampling methods and compared results. The methods were:

> 1 short-term air samples;

> 2 bedding dust samples;

> 3 Carpet dust samples (one from the bedroom and one from the

living room);

> 4 Several-day- long air dust samples (one from the bedroom and

one from the living room.

>

> Each has its limitations and the young man who got his PhD

analysing them, , along with J. , would be

better able to judge the limitations of each, but here goes my

attempt at defining the top ones (of many):

>

> 1 short-term samples are very non-reproducible; sometimes counts

and species ratios vary by even decimal orders of magnitude over a

week or so;

> 2 depending on the length of time between washing of the

bedding, and mattress cover, if any, sample dust mass can be adequate

or way too small, especially if the bed has a plastic mattress cover;

> 3 carpet dust is often only partly organic and may have very low

levels of culturable spores if it has not been cleaned for a while;

or has been cleaned with toxic chemical post-treatment;

> 4 the sampling protocol seems to desiccate some of the spores so

that viability is impaired (both viable and total counts seem a good

idea).

>

> There were some very good discussions of air flow patterns and

where to air sample within containment. All of these points are valid

here to some extent, as well. On many spaces the air patterns are

complex and mixing is not all that good, especially in homes. If so,

where do we sample?

> Jim H. White SSC

>

>

>

>

>

>

>

> Ahhh...imagining that irresistible " new car " smell?

> Check out new cars at Yahoo! Autos.

>

>

> ____________ _________ _________ _________ _________ __

>