• WORD ON THE STREET
• Resistant to Growth
• Using the Outdoor Aerosol as a Background Control Presence
• Drying Contractor Finds a New Customer: ABC’s Extreme Makeover Show
• The Deadly Consequences of Poor Kitchen Exhaust Maintenance
• Sampling … Where, What, When and How Much?
• Do Radon Mitigation Systems Reduce Moisture in Homes?

KEEP THE BRUNSWICKS, DITCH THE SMOKES
Big John’s Billiards fought the law, but the law won: The Nebraska Supreme Court has ruled that the Omaha pool hall has to comply with the state’s new ban on smoking in public accommodations.
Big John’s had argued that the law placed an unreasonable financial burden on its business, and asked for a “grandfather clause” that would allow it to not comply with the ban. But the state high court found that evidence of a financial burden was not sufficient to allow a business to evade the ban.

Pool hall owner Will Prout said that after a local smoking ban was passed in Lincoln, the revenue for his Lincoln establishment was cut in half, dropping from $600,000 per year to $300,000 per year. He estimated that 90 percent of his customers in Omaha smoke while shooting pool.

“Although Big John’s argued that undue financial burden should be a consideration in granting a waiver, the district court noted that Nebraska law does not mention financial burden as a basis for a waiver,” the high court ruled. The court stated that the legislative history of the smoking ban “suggests financial consideration was not intended as a factor because the Legislature stated that the health, welfare, and comfort of the citizens far outweighed the economic effects as a result of the Act.”

The court’s opinion can be found at http://www.supremecourt.ne.gov/opinions/2008/february/feb22/s06-764.pdf
 
OSHA FIGHTS THE DUST
Edwin Foulke, assistant secretary of occupational safety and health, testified on Capitol Hill to discuss the Occupational Safety and Health Administration’s (OSHA) efforts to protect workers from combustible dust hazards and investigate the cause of the Feb. 7 explosion at Imperial Sugar Refinery in Savannah, Ga. The explosion was believed to be due to a failure to follow safety rules.
“OSHA is intensifying its ongoing enforcement, education and outreach programs to ensure that employers and workers are doing everything they are supposed to be doing to protect against combustible dust,” Foulke told the House Education and Labor Committee.

Foulke also announced several initiatives that OSHA has undertaken to improve its enforcement and outreach. Employers and employees are urged to review a new Occupational Safety and Health Administration fact sheet titled Hazard Alert: Combustible Dust Explosions, which is available online at www.osha.gov/OshDoc/data_General_Facts/OSHAcombustibledust.pdf.

The fact sheet provides a descriptive overview of combustible dust hazards and offers suggestions for eliminating these hazards.

Foulke has ordered OSHA to refi ne and expand the combustible dust National Emphasis Program that was announced in October 2007 to focus on facilities most likely to experience catastrophic dust explosions. That directive is available online

at www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=DIRECTIVES&p_id=3830.
 
ROOFS COOL ENOUGH FOR THE FONZ
If your roof needs repairs, taking the extra step to create a cool roof could signifi cantly impact energy cost savings — as much as $.20 per square foot of roof area, according to industry experts, in a report in Building Operating Management.

The idea of cool roofs has been around for decades, but many are still unconvinced that they make sense in all locations.

While there are many factors to consider before installing a cool roof, research shows a cool roof can make sense in almost any climate. Also, advancements in cool colors and databases which rate the coolness of certain materials make finding the right cool roof that much easier.
Cool roofing materials include membranes, metal roofs, tile and even asphalt shingles.

Above a certain point of reflectance and emittance, a roof is deemed “cool.” Where that line is, however, is not universally agreed upon. Ideally, the roof needs to have the highest solar reflectance and highest solar emittance possible, said Hashem Akbari, group leader of the Heat Island Group and senior scientist at the Lawrence Berkeley National Lab. These properties are rated on a scale of zero to one, with one being 100 percent reflective or emissive.

The U.S. Department of Energy has more details on “cool roofs” at http://www.ornl.gov/sci/roofs+walls/facts/CoolCalcEnergy.htm
 
AND THAT INCLUDES PEACE PIPES, TOO
Connecticut Attorney General Richard Blumenthal, in a legal opinion issued March 11, said that the state’s proposed smoking ban would apply to casinos run by Indian tribes, despite the tribes’ argument that their status as sovereign entities made them exempt from the ban.

But to avoid protracted litigation over the issue, Blumenthal also encouraged the state legislature to open negotiations with the Mashantucket Pequot Tribe, which owns Foxwoods Casino, and the Mohegan Tribe on the issue of smoking.

“In the end, on so profoundly signifi cant a public health issue as smoking, we should seek common ground and avoid conflict in the courts,” Blumenthal said.

According to Blumenthal’s opinion, even though Foxwoods and Mohegan Sun are on sovereign tribal land, the agreements between the tribes and the state require the tribes to adopt health standards at the casinos that are “no less rigorous” than state public health standards. A smoking ban would fall under that requirement, the attorney general said.

The opinion was requested by state legislators following the introduction of a bill that would ban smoking in the casinos and other areas of Foxwoods and Mohegan Sun. The bill is currently before the legislature’s public health committee.

Legislators exempted the casinos in a 2003 state law banning smoking at restaurants and bars in Connecticut.

Dealers have said smoking by casino patrons is a health hazard. The tribes, however, defend the air quality at the casinos and have said their business would decline if a smoking ban were put in place. The Mashantucket Pequots and Mohegans said a state ban cannot be applied to the casinos because of tribal sovereignty.

I think it is fair to state that all of us interested in the quality of our indoor environments want to do everything possible to assure that growth of microorganisms (especially bacteria and fungi) are minimized inside buildings. Rapid and extensive growth (also known as amplification) leading to contamination (or Condition 3, as defined in the IICRC S520 standard) in inconsistent with an acceptable quality of indoor air and environment.

I think most will agree that the first priority in limiting or controlling growth is to eliminate sources of unplanned moisture in the indoor environment. By unplanned moisture, I include four examples in building environments:

1. Water features such as ponds, fountains, streams and falls that are not well-maintained and kept free of bacterial amplification.


2. Other water that remains outside the building plumbing system for more than a few hours due to leaks or spills.
3. Water that enters the building through breaks or unintended voids in the building envelope.
4. Moisture content of air high enough to reach dew point and remain at that level for more than brief periods. Although air at relative humidity of 65 percent or greater is generally held to be the level of concern, virtually any RH level can lead to accumulation of unplanned moisture under the right conditions, especially when a surface at or below dew point is present.

Although elimination of unplanned water in the indoor environment is an important (and proper) goal, it is a difficult goal to realize in each and every building at all times. For that reason, our buildings are always at risk for amplification of micro-organisms leading to contamination and eventual indoor-environmental problems. For that reason, building owners and those who serve and advise them are well-advised to seek and utilize additional ways of preventing, or at least minimizing, growth.

Not surprisingly, many manufacturers advertise that use of their products will improve the ability of a building (or building system) to resist microbial growth (often headlined as “Toxic Black Mold Growth”). In the past, I have advised that, for antimicrobial products and other chemicals that claim to control growth, one important criterion is registration of the product with the U.S. Environmental Protection Agency. Although EPA registration does not guarantee that use of a given product will lead to total satisfaction, it does indicate that the manufacturer of that product has data to back up claims and the product has been reviewed and accepted by an independent third party. Achieving EPA registration requires that a manufacturer develop and submit a sizable array of data. This data is analyzed by agency scientists who make an impartial judgment as to whether the data supports the claims of safety and effectiveness for the given product. Products not registered may or may not be bad – they are either in violation of the law or have found some way to exempt themselves from it. People who decide to use those products must utilize some other criteria than independent evaluation of data, which is their right ... along with the accompanying risks.

However, there are a raft of substances, products and building materials not regulated by the EPA and it is thus not even possible for manufacturers of those products to seek registration. Should there be a way for those who want to make claims about the growth-resistant properties of those products to achieve independent recognition? That question was raised by two recent announcements that were brought to my attention.
 
Is Copper Proper?
The first announcement contained the following in the lead paragraph: “Congressionally appropriated funds to continue clinical trials determining the antimicrobial effectiveness of copper, brass and bronze have been awarded to the Copper Development Association ...” That made my blood boil from several standpoints:

• As a taxpayer, I do not like Congress giving money to a manufacturer (or association representing several manufacturers) to establish new markets for their products. I know it happens all the time – that does not make me like it.
• Has anyone thought through the practicality of what they are suggesting (using copper on touch surfaces in health care)? There are more than a few issues with substituting copper where stainless steel or plastics are now normally used.
• We do not need a massive federally funded study to discover that copper resists growth. We already know that copper and silver and zinc and lime and a whole bunch of other substances are good natural antimicrobials. That does not mean it makes sense to use them.

It is the last point that especially hit home for me. Some years ago, a friend called me and asked me to test a new “wonder” product he had developed. It was a concentrated suspension of copper ions he claimed would do away with the need to use chemicals in my swimming pool. I told him it sounded great and I would take a look at it. Soon, a package arrived with a test kit for copper concentration and detailed instructions on how I could move to a chemical-free pool. All I had to do was introduce the suspension into my water until I reached the proper concentration. The instructions included a caution that the pH of the water was critical (aren’t the acid and base buffers needed to maintain pH chemicals?).

I proceeded and soon achieved the proper concentration according to the test kit and stopped my use of chlorine. Sure enough, the water was beautiful and remained that way for some time. I also tested the pH frequently and kept it adjusted ... for a while. I travel frequently and at best am casual about the condition of my pool from time to time. Upon returning from an extended trip, I observed huge blue-green stains all over the bottom of the pool. Obviously, my pH had gotten out of whack and all those wonderful copper ions became copper salt and settled out of the water, making a huge mess that, years later, the remains of which I can still see in places. The wonder product was good, but not perfect (or, at least, I was not).

This is the case with many materials and products. They have positive aspects, but also limitations. I suspect that is what the current study will ultimately discover about copper. In my experience, it has limitations as a growth preventative. I have taken apart cooling coils that were heavily involved with microbial growth and observed that the copper tubing appeared as covered as the aluminum fins. Is that because the copper did not resist the growth? Probably not ... there was probably some particulate matter clinging to the copper that kept the spores from contacting the copper and thus allowed them to grow. From this experience, I conclude that the cleanliness of the surface is more important than the composition of the surface.
 
Independent Certification
The second announcement brought to my attention was titled, “Easy-to-Use Rating System Provides Tool for Selecting Mold Resistant Building Materials.” It was released by Air Quality Sciences and says “[the] rating system is derived from comprehensive product evaluation study by Air Quality Sciences, Inc. (AQS), and is being used by the GREENGUARD Environmental Institute (GEI) to establish certification criteria for the microbial resistance of building products.”

The person who shared the announcement with me made sure I understood that AQS and GEI have almost the same address in Marietta, Ga. and that AQS CEO Marilyn Black is highly visible in the management of GEI. It seemed I might be expected to be outraged about the possibility that the relationship between AQS and GEI was overly cozy possibly self-serving. I am not outraged. In contrast, I admire Dr. Black and commend her for the expense, effort and sacrifice that she must have put into creating and nurturing a non-profit entity like GEI.

I spent some time on the GEI Web site and observed that the advisory board and consensus bodies maintained by the organization reflect a great deal of diversity and independence. I also noticed that GEI qualified received American National Standards Institute recognition of its standards projects in 2004, which, I believe, is the gold standard in the United States for standards development. Further, over a dozen PINS for ANSI projects are listed on the GEI web site. This is a significant achievement for an organization with an ANSI affiliation dating only back to 2004.

Does AQS utilize GEI standards and criteria in conducting its for-profit business? Sure – why not, if they are good standards and criteria? A more appropriate question is, “If Bob Baker organized an RGB Laboratory, could he have equal access as AQS to GEI work products for his lab?” Although I did not call Dr. Black to ask the question, I am sure the answer would have been yes – ANSI affiliation assures equal access for all. I am not offended by any possibility of self-serving. I am more offended (although not much) by the self-serving represented by a Nobel Prize recipient or former American president flying around the globe and accepting fees in the tens to hundreds of thousands of dollars for appearing at a conference or dinner and giving a short speech.

Again, at the risk of being redundant, I commend Dr. Black for her reputation as a dedicated scientist, the vision she has provided and her contributions to our understanding of the indoor environment. I am sure she would gladly give up whatever control she has over GEI the minute someone showed willing to devote the energy, time and other resources she has. I know I am not a candidate. Are you?

There is, however, an interesting question that occurred to me as I looked at GREENGUARD and the services AQS offers: Is this needed? I see two possible arguments here:

1. Determining if a given substance, device, piece of furniture, etc. is supportive of microbiological growth or actually resists it is far from a simple undertaking. An organization that provides an independent, science-based assessment of a given item’s ability to resist growth is providing a useful service to both manufacturers and the general public since few laymen know how to tell the difference. The information developed is both valuable and cost-effective as it can lead to a real impact on health and well-being.
   
2. Even if you know a given item is resistant to growth, that is not really useful or valuable information. Whether a given piece of building material or a piece of furniture is growth-resistant is less important than how it is used and the environmental conditions that surround it. A given brand of wall board may be very resistant to growth on its surface; however, if it is installed with mastic that supports growth or covered with a coating supportive of growth, it might still become quite contaminated. Also, use conditions can lead to growth opportunity despite the level of resistance. For example, if the wall board remains saturated with water for a long period of time, the resistance may be overcome; if allowed to become heavily coated with soil, the soil may provide a growth medium for organisms and insulate them from any antimicrobial properties of the underlying surface. The usefulness of the information just does not justify the expense involved. Costs of such tests only serve to increase the price without any accompanying benefit to the purchaser or anyone else.

Which of these arguments is most valid? I will leave that up to you. I must admit, however, that this situation reminds me of a favorite story from my youth. I think it was named, “The Emperor’s New Clothes.” The climax of the story came when the emperor was walking down the street nude in front of his admiring subjects and a small boy called out, “He doesn’t have any clothes on.” I suspect the emperor would have paid quite well for an independent opinion of his appearance prior to walking out on the street. On the other hand, think about air-conditioning cooling coils. Do you really think the highly growth-resistant copper really makes that much of a difference?

Robert Baker is president of the RGB Group, which provides consulting services related to improving building-maintenance practices in a cost-effective manner. He studies antimicrobial products and their uses as part of his interest in using these formulations in the indoor environment as part of a comprehensive maintenance strategy. Bob serves as chair of the ASHRAE committee responsible for the HVAC System Maintenance Standard (180), published in March, 2008. He is also a member of the IE Connections editorial advisory board and immediate past president of the Indoor Air Quality Association. He can be reached at (813) 774-4161 or rgb@rgbgp.com.
 
From 2096 to 2013

Outdoor air almost always contains some fungal spores. These spores penetrate indoor environments in various ways and to various degrees, and once indoors may or may not grow on indoor materials. The outdoor fungal aerosol is a complex mixture of many different kinds of spores with sources of variability different for each kind. Most spores in outdoor air are derived from plant-borne fungi. These fungi may be obligate pathogens, depending on the distribution of the host plant (e.g., rust spores) or saprobes that can grow on almost any dead organic material (e.g., some species of Cladosporium). They may produce spores seasonally or throughout the year. They may be dispersed by wind or other dry mechanical disturbance, or they may require raindrops or abrupt changes in humidity for dispersal. These and other variables contribute to both rapid and slow changes in the outdoor spore aerosol and make the use of outdoor spore samples problematic.

In order to determine whether the indoor spore aerosol is different from that outdoors, one must understand these variability factors and how the outdoor aerosol actually penetrates indoor environments. For example, suppose you are sampling in a home with open windows. In this case, the indoor aerosol is going to be strongly influenced by that outdoors and you will need to take multiple samples both indoors and out to document this relationship if you hope to find indoor sources using air sampling. Even if the windows are currently closed, you need to know when and for how long they were last opened. Even in a permanently closed environment in which ventilation air enters through filters, there will always be components of the outdoor aerosol in the space. The spores enter as people enter, both with the air surrounding them and on their clothes, hair and skin surfaces.

So, given all these problems, how can we use outdoor aerosols as controls for indoor sampling events?

For large studies, in which money is available for many samples, you can make your own small database of what the outdoor aerosol looks like throughout the indoor-sampling period. I would start outdoors, then collect an outdoor sample for every hour that sampling is ongoing indoors. Also, if the weather changes during sampling (i.e., if it begins to rain, the wind changes direction, etc.), additional samples should be taken.

If you are going to look at many different houses (hundreds), single indoor and outdoor samples can be collected and compared. These kinds of studies do not seek to say whether a specific home has mold problems, but rather on average how many homes have mold concentrations above those outdoors. The fact that a single sample is not very representative of outdoor conditions for a single house is compensated for somewhat by the large number of samples.

This is really the only way single outdoor samples can be effectively used to estimate the chances of an indoor sample representing contamination. Ideally, the samples for the database were collected at a nearby location and at a similar time of the year. Also, weather conditions should be taken into consideration. Unfortunately, most of us don’t have this kind of data available. You can create your own database by carefully compiling all the outdoor samples you collect for a specific geographic area, keeping track of weather conditions. The easiest way to use these data is to enter them into a spreadsheet and plot the data over time. This will give you an idea of the variability in the outdoor aerosol for the area and time. You can then compare individual samples you collect with your graphs. The MoldRange is a large database compiled from outdoor data collected by EMLAB and EMlab P&K clients. It can be used in the same way as data you might collect yourself, but we have done the data analysis work for you. On the other hand, your own data may be more relevant.

Because of the enormous potential for variability in the outdoor aerosol, the errors involved in comparing indoor and outdoor samples are enormous. This makes it essential that outdoor samples be collected as close as possible to the entry point of the specific indoor environment and as close as possible in time. It is possible that several outdoor samples within a large apartment complex could be compared with dozens of indoor samples from different apartments. For single residences, however, samples not collected close to the residence and close in time (within an hour or less) to the indoor samples are not useful.

Finally, it is important to evaluate indoor/outdoor relationships by individual spore types rather than totals. The reasons for this should be obvious: Seven hundred Cladosporium spores does not equal 700 Penicillium spores. The EMLab MoldScore compares indoor and outdoor sampling data both qualitatively and quantitatively. It is also extremely important to rely on your professional judgment and to make decisions based on all the data you collect in an investigation, including information from occupants and visual inspection.

A New Jersey-based drying contractor has found an unusual forum for its message about the importance of fighting building dampness early – ABC Television’s popular Extreme Makeover: Home Edition show.

What makes the construction projects on Extreme Makeover unique is their speed. Each show begins with host Ty Pennington surprising a family with the news they have been selected to receive a new home and then sends them on a vacation, while the Extreme Makeover team completely changes their home. 

The Extreme Makeover team is joined by builders, roofers, electricians, plumbers, carpenters, painters, dry wall installers, designers, landscapers and countless other volunteers to completely renovate the home, sometimes even knock it down and start over again, in just seven days.  These are projects that would often take as many as four months to complete. All of the materials and services are donated.

“In a typical project like this, you would wait for the drywall to dry,” Kelly Cressy, director of marketing at Water Out, told IE Connections. “But Extreme Makeover doesn’t have that option. That’s where our process comes in.”  

The Water Out drying system, which is typically used in emergency drying situations, uses heat to dry.  Once the drywall is installed in the home the trailers are used to accelerate drying the mud and any other construction materials and reduce the amount of time between drywall installation and painting.  The trailers have been used on several projects to dry frames which got wet due to weather and even for temporary heating.   

“We’ve done about 20 projects for the show. “It’s pretty exciting,” Cressy said. The program is currently on a production break.

“The benefit to builders is to get the drying done during the building,” Cressy said. “It keeps the paint from peeling, and prevents drywall cracking.”

The process is also useful for reducing the risk of mold, bacteria and mildew growing inside the walls during a construction effort, Cressy asserted.

“It’s good for us on a national level, and also in the local markets,” Cressy said. She noted that hundreds of people show up at the builds, which is good for making contacts for future business. The show’s policy is that donations of $50,000 or more entitle a business to being mentioned on the show, and the value of Water Out’s services typically doesn’t reach that level. “But we get mentioned on their Website, can mention it on our site, and can send out a press release after the job is done.”

Water Out contractors across the country have been volunteering their drying services for Extreme Makeover: Home Edition projects throughout season five of the show, including Oklahoma, New Hampshire, Maine, Maryland, Washington, Kentucky, West Virginia and Virginia.  The company will also be involved in the coming season, with projects already completed in Nevada and several more scheduled over the next few weeks.  

For example, during a February project in Mobile, Alabama, Frank Leff of Water Out of Atlanta, Georgia and Steve Smith of Water Out of Flagler County, Florida donated their time and services to assist Extreme Makeover with a project by sending two Water Out trailers to dry stem walls, the foundation, block walls and construction materials to help keep the builders on their tight construction schedule.

Steve Smith sent a recap of the project: “We arrived, the night before we were needed, to find the home without the roof. At 6:00 A.M. the next morning on our arrival the home was under roof, shingled and all the windows were installed. The project was well organized and the builder had his own crew taking photos, which can be viewed on his website www.heritagebuildersfamily.com. The family was well deserving of this project and I'm sure they were surprised and pleased to go from 1000 sq. ft. to 3400 sq. ft. The fourth day was when we were needed to help dry concrete, structural wood framing and the entire drywall-mud process.”

Smith added: “We all need to give to those who need our help, whether on a nationally known event or in our local communities. Whether it is considered advertising, making contacts or sharing your heart for a good cause, remember it’s always for the best to help another who's not as fortunate as us.”

Cressy seconded this view. “The reward on both a personal and professional level is enormous,” she said.

An internal investigation into the deaths of two Boston firefighters during a response to a restaurant’s kitchen fire on Aug. 29, 2007 has divided the public, driven wedges between the firefighters’ union, the fire commissioner and city government, and led to accusations of cover-up and finger-pointing. All sides involved, though, agree that the blaze reached its deadly apogee because of a faulty kitchen-ventilation system.

The union’s board of inquiry released on Feb. 22 its final report, in which it stated “the substandard construction, installation and maintenance of the kitchen hood, duct and exhaust system, along with the degradation of the ductwork were the underlying factors involved in this fatal fire incident.”

But those factors – poor construction, improper maintenance and degraded materials – are not unique to Boston’s tragedy. Two days before the union’s report was released, a Hardee’s restaurant in Hampton, Va. was evacuated because, as reported in the Virginian-Pilot, “firefighters ... found that the fire was confined to the ventilation system lead to the roof from the kitchen.” Fire Marshal Anne-Marie Loughran said, “There was a lot of grease up in there that caught fire.” On the same day, a Wal-Mart in Muhlenberg Township, Pa. was evacuated, according to WFMZ-TV News, “because of a fire in the ventilation system.”

Fires of this sort are “incredibly problematic,” according to Tim Shaw, executive director of the International Kitchen Exhaust Cleaning Association. The fire in Boston, he noted, was directly caused by “improper cleaning ... compounded by a separation in the ductwork that had never been properly repaired or noted on the service report.”

“The general public,” Shaw said, “are at great risk in many cases and local jurisdictions are burdened with an overwhelming number of [facilities] to inspect and too little staff and funding to do so. ... No one who eats a meal in a restaurant is aware that the restaurant could catch fire at any time.”

“To many restaurateurs and facility managers, getting the exhaust cleaned is at the bottom of their priority list and budget. They often contract the lowest bidder ... to clean a substantial system. The contractor cleans what the manager can see and cashes the check, leaving the grease building up in the ductwork and into the [system’s] fan assembly. ... Grease travels the length of the system, reacting with all the particulates in the exhaust, and becomes a match head sitting on a striker.”
 
Boston
Such was the case in Boston on Aug. 29, when firefighters Warren J. Payne and Paul J. Cahill died “in an inferno after a kitchen grease fire exploded into a 2,000-degree fireball” inside Tai Ho Mandarin and Cantonese Restaurant, as reported by the Boston Globe.

By the Globe’s account, Cahill was killed when a “massive plume of carbon monoxide enveloped him as he fought the fire inside the restaurant’s kitchen.” Payne was “killed by a massive fireball created when pent-up flammable gases found an ignition source and detonated, engulfing him in flames that incinerated him in second.” The fire, according to the union’s report, “had ignited and burned for an extended period of time prior to fire companies being dispatched and arriving on scene. This extended burn time allowed the fire to ‘feed’ and increase in size within the restaurant’s exhaust hood and ducts and ceiling areas directly in and over the cooking area …

Accumulations of grease along with the ceiling support framing and roof structure were ignited.”
The union’s report noted “considerable grease buildup and a separation in the ductwork that was made obvious by the observance of rust and severe degradation of the duct-to-hood connection in the plenum chamber. This separation in the dust was approximately 12 [inches] long and 1 [inch] wide.” After the grease caught fire and smoldered, a sudden release of gas from a broken feed and created space within the ceiling, caused by a sudden drop of the HVAC unit thanks to weakened “structural members,” led to the explosion.

“This incident is a cause-given fire, a failure to clean, with the severe grease buildup and the separation in the ductwork contributing to the rapid spread of the fire.”

Poor venting of grease and the failure to adequately clean it were ongoing problems recognized by restaurant staff, at least tangentially. “The grease buildup in the ventilation system above the ceiling of the restaurant kitchen was so extensive,” reported the Globe, “that workers had covered a stove with foil to catch falling grease and installed a pan to collect dripping grease in another part of the kitchen.”

As IKECA president Bernard Besal said in a letter to IE Connections, “The exhaust duct that was concealed in the sub-ceiling was fabricated of non-welded, light gauge sheet metal” and did not meet modern model building codes, an occurrence which “is greatest in older structures in large cities … Unfortunately, the older structures are where combustible building material is most tender.”

“When kitchen exhaust ductwork does not meet these requirements,” Besal wrote, “several challenges exist. Non-welded exhaust ductwork likely will not be cleanable by any process involving steam cleaning or pressure washing due to leakage; manual scraping will be the only alternative to wash processes. In a fire condition, fuel load in horizontal non-welded exhaust ducts liquefies, leaks and ignites the ceiling areas.”
 
A Broader Problem
“Most of the kitchen hoods in the restaurants inspected did not meet the recommended flow rates specified,” reads the conclusion of the article “Kitchen Hood Performance in Food Service Operations” by Charles B. Keil, Hailu Kassa and Kenny Fent, which appeared in the Dec., 2004 issue of the Journal for Environmental Health. “Inadequate hood flow can create food safety and fire hazards by allowing grease fumes to spread throughout the facility and deposit on surfaces. In addition, these fumes pose a health risk to workers exposed at elevated concentrations.”

In response to the article’s opening questions, “Are hoods meeting quantitative operating guidelines [and do] qualitative inspections identify hoods that are not meeting guidelines,” the answers were “no.”

The article cited the environmental quality risks inherent to poor kitchen-exhaust function, but noted in particular, by citing a 1997 report by the National Fire Protection Association, that “properly operating kitchen hoods can capture fumes and prevent widespread grease contamination, reducing fire risks. Grease accumulation in hood systems can still present localized risk of fire, and proper maintenance and cleaning of these systems is need to keep fire risks low. If a fire does occur, a properly operating ventilation system can slow the spread of flames outside of the hood.”

But after assessing data on various hood types and their in-restaurant operations compared to product guidelines based on standards set by the American Conference of Industrial Hygienists and the American Society of Heating, Ventilating and Air-Conditioning Engineers, the research team’s conclusions did not express optimism.

“Restaurant operators need to be more diligent about the operation of their kitchen ventilation units. … Restaurants should be sure that contractors installing or working on ventilation systems are familiar with the published guidelines. … [Units] should be periodically re-evaluated to detect any change in performance.”
 
Finding Solutions
Besal wrote, “The first line of defense in prevention of deadly kitchen-exhaust fires is hiring a ‘properly trained, qualified and certified cleaning contractor’ as required by NFPA-96 [the National Fire Protection Association’s Standard for Ventilation Control and Fire Protection].
Secondly, “qualitative routine compliance inspections that are normally provided by a local authority,” can ensure proper exhaust operation.

But prevention goes beyond cleaning and inspection. “From the standpoint of serviceability, maintenance for kitchen exhaust systems begins with proper design and installation. The onus on the design architect and the mechanical engineer should be to eliminate any possible excuse for exhaust cleaning contractors to not clean any portions of exhaust systems,” Besal noted.
Governments, Shaw stated, tend to react to tragedies by making law “rather than taking obvious and often simple steps to prevent the incident altogether.” Those steps, according to Shaw, would begin with standardizing fire codes across jurisdictional boundaries. “In Boston, the local fire codes do not follow the same standards as those in the state,” which is “common everywhere in the U.S.” And while in some states, “local jurisdictions are beginning to require that exhaust cleaners be permitted in some fashion,” the lack of set standards results in “inexperienced and uncertified fly-by-night cleaners who have saturated the market and provide a low cost and high-risk alternative to a proper exhaust cleaning.”

In addition to urging code unification, Shaw suggested adopting standards based on NFPA-96. “In Canada, there is a national standard based on NFPA-96.” However, he noted that “because of bureaucracy, they base their codes on the 2001 edition, even though there have been two revisions released since.”

“NFPA-96 requires areas of exhaust systems that are inaccessible or not cleaned be provided to the owner of the system on a written report,” Besal noted. “I do not believe this ever happened in [the Boston] case.”

Because “even legitimate cleaners [frequently] cannot properly clean and service the entire system” due to design, Shaw noted that a regular, proper maintenance regimen is key to the integrity of an exhaust system. He also suggested hiring exhaust cleaners who adhere to standards like NFPA-96 “as well as similar standards from the International Fire and International Mechanical Codes,” as do IKECA members.

Besal agreed. “Building codes must be taken as a united whole inclusive of construction and maintenance,” he noted. “Proper exhaust system cleaning must be a continuous program to operate with the level of safety intended by model codes.”

“The company that cleaned the exhaust system in Boston did not follow any of those codes,” Shaw said, noting that the company in question is not an IKECA member.

All sources agreed that proper kitchen-exhaust cleaning and maintenance are key to preventing tragedies. As Besal put it, “If the fuel is properly removed [from the ductwork] on a regular basis, there is no fire event.”

The Boston firefighters’ union made recommendations of its own in the board of inquiry’s report. Among its 60 points for preventing further incidents such as the one that took the lives of Cahill and Payne, the report calls for “legislation required to govern the installation/maintenance/cleaning/inspection of commercial cooking ducts/hoods/vent systems and affiliated equipment by licensed and insured contractors,” including the adoption of NFPA-96.

When fungal contamination of a building is suspected, four questions emerge immediately: Are fungi really present? If so, where are they? Which fungi are present? How significant or extensive is the contamination, and is it recent, ongoing and active?

Science is largely about numbers – quantification – especially as those numbers relate to other numbers like constants or known ranges. We measure ambient outdoor temperature at a specific time and can then compare it to expected values or ranges, both in order to make judgments about the current weather and to add information to our database, and improve the accuracy of future forecasts. So when we attempt to quantify fungi in a building, we do a modicum of sampling, perhaps using more than one technique, and derive lots of numbers in an attempt to be precise.

Unfortunately, our sampling techniques are inevitably partial or short-term. We have no way of counting all the fungi in a building. If the distribution of fungi was even or random, that might not be too bad, since we could apply corrective statistical procedures to our partial data. But that is almost never the case. The occurrence of fungi is almost always patchy and the number of propagules in the air can rise and fall precipitously under the influence of various kinds of disturbances or environmental conditions, as repeated measurements will probably show. So we do the best we can, making approximations and extrapolations on the limited evidence at hand. If that is understood, then we can explain how we proceed in making our estimates and drawing our conclusions.

How does the suspicion of fungal contamination arise? There may be olfactory clues. There may be health issues, such as respiratory allergies. There may be visual evidence. I'll deal with them in turn.

Olfactory Clues
Sometimes, a musty or moldy odor is present. To a scientist, this suggests the presence of volatile organic compounds produced by the putative fungi. These may be detectable by the human olfactory organs at very low levels, levels not measurable even by very expensive analytical instruments. So it may be difficult and costly to confirm or deny the presence of mold in this way. I have eaten apples that were partly colonized by spoilage fungi, such as Penicillium italicum, and found that the apparently sound parts of the apple already had a very distinct off-flavor. It was obvious to me that a level of contamination detectable to my sense of taste (which also has elements of smell) was present, even though there was no visible fungal presence in the apparently healthy tissue. In other words, a musty odor may be diagnostic, but frequently will not yield much specific information about the nature or extent of the contamination.

Health Issues
If occupants complain of health problems, often respiratory allergies or headaches, the causes of those conditions may or may not be fungi. There are obviously many other possibilities. If health problems exist and are blamed on molds, fungal elements must be present in the air (not just on the wall or in the basement) before they can be labelled as major suspects. Once this has been established, the next step may be to call in an allergist to determine whether the individuals are in fact allergic to molds – many people are not.

The best and quickest way to test for the presence of fungal elements in the air is to use spore traps. I should point out that this is an inherently expensive and time-consuming approach. A typical sampler uses a fan to draw defined quantities of air through a narrow slit, beneath which the air impacts on a glass surface covered with a sticky substance to which the fungal elements (spores, conidiophores, hyphal fragments) adhere. A typical sampling time is 10 minutes at a flow rate of 15 litres per minute. The trapped structures, usually spores or hyphal fragments, can then be painstakingly counted and identified under the microscope, though identification in the absence of other diagnostic parts of the organism, such as the structures that produced the spores, can be difficult or impossible.

A major deficiency of this technique lies in the requirement that the fungi must become airborne. Some fungi have evolved to release their spores during the night, others in the middle of the day. Many fungi will shoot their spores into the air after it has rained. Remember: Most spores inside a building usually originate outside.

Many fungi, including the notorious black mold, Stachybotrys, produce their spores in droplets of mucilage, and those spores simply do not become airborne in the short term. Eventually, if conditions change, the spore droplets may dry out and physical disturbances can then inject the spores into the atmosphere. We must understand, however, that this is not the initial or intended route of travel for the spores of many fungi, which have evolved mechanisms of dispersal involving either the migratory movements of invertebrate animals or splashing or flowing water.

As you can probably tell, I am not an advocate of extensive air sampling unless other manifestations of fungi have already been found. I would also point out that air sampling must be done both inside and outside the building, since most spores inside a building usually come from outside. Samples taken outside buildings very frequently contain higher numbers of spores than samples taken inside – such quantitative differences are to be expected. It is only when indoor and outdoor samples differ qualitatively – specific fungi that do not show up in external samples being found inside the building – that we suspect an internal source. I should also mention that air samples do not pinpoint the source or extent of the fungal contamination, which must be sought in other ways.
 
Visual Evidence
In most cases, then, the presence of the fungus (or fungi) must be demonstrated in more tangible ways, which involve finding where it is or has been growing. We must always keep in mind that there may be, and often are, multiple sources. This possibility dictates an extremely careful and detailed examination of the premises that may even involve invasive observations of wall cavities.

There are two principal approaches. The first and more obvious of these is by straightforward visual inspection. If a white fluffy growth is seen on wood, or a black stain on wallboard, it is easy to follow up by taking bulk samples. These must then be subjected to microscopic inspection by a trained analyst. Attempts to isolate the organism(s) on standard culture media may also be made. I must admit that if I cannot find any visual trace of fungi, I become rather sceptical of the claims being made by the supposedly injured parties. It is also my experience that many stains or discolorations, when subjected to microscopic examination, will be found not to involve fungi at all. In many cases, they will be accumulations of fine dust or soot; in others, they will be dried-out water or other stains or substances dissolved in moisture and subsequently recrystallized.
The second approach may involve two other ways of detecting molds. In the first, dust samples can be collected and analysed microscopically or by culturing. A major problem with this approach is that dust represents a historical record of precipitated atmospheric contaminants, sometimes ranging back over many years. Most of the contaminants will not be fungi and these other elements will seriously interfere with visual efforts to quantify and identify the fungal component.

We must view any fungi detected in dust with a certain amount of scepticism because they may have been produced long before the current problems surfaced. In addition, attempts to culture the fungi must keep in mind two salient facts: Many of the spores in the air are dead; and many airborne taxa of fungi will not grow on standard culture media. Those media apparently lack growth substances required by some fungi, particularly by fungi that enter into mycorrhizal relationships with plants. This is why I generally do not recommend what are called “viable” tests, which depend on the viability and culturability of the fungi.

The second way of detecting and identifying molds is to use tape lifts. Here, a strip of transparent adhesive tape is pressed against a surface either obviously supporting fungal growth or suspected of doing so. The tape is then pressed, sample/adhesive side downward, onto a clean microscope slide for transport to the lab. There, a drop of lactic acid can be placed between the tape and the slide and the tape can be examined microscopically. This technique is not particularly quantitative, but it can give a good idea of local concentrations and populations. It also has the advantage that if the fungus is growing and sporulating, the essential parts of the organism will often be picked up by the tape and retained in a more-or-less natural configuration. This can be a tremendous help in identifying the fungi.

For example, I often see the highly diagnostic conidiophores of Aspergillus or Penicillium on tape lifts. This removes the kind of uncertainty so common in air samples in which quite frequently only the conidia are seen and it is basically impossible to tell whether the contaminant is an Aspergillus or Penicillium, which is why these two names are lumped together on reports from air sampling.
 
Sampling Methods
The tape-lift sampling method and the counting of spores trapped from the air are often called “non-viable” analyses. I have already listed some disadvantages of spore traps and I prefer to call the tape-lift technique a form of “total” analysis because all fungal structures present at the sampled site can be examined and often, though not invariably, identified.

It is not difficult to take a series of tape lifts from wherever fungal traces are found or even suspected, and the microscopic analysis of these tapes is much quicker than the slow business of counting taxa in spore-trap samples. There is also no waiting around while colonies grow to identifiable sizes on culture plates. I have found recording the presence on tapes of such things as invertebrate frass (excreta) and carcasses as useful. Observations of the general condition of the fungus, which may include how actively it is sporulating, whether the fungal structures look old, whether chlamydospores are being produced rather than conidia, etc., give valuable insights into the history of the situation and allows worthwhile forensic commentary to be added to the analysis. If I find invertebrate excreta, this suggests there was time after the growth of the fungus for the mycophagous (fungus-eating) animals to find the sporulation and have a good meal or two. If chlamydospores predominate or sporulation is scanty, this suggests to me that the fungus was growing in less-than-optimal conditions.

One problem is that tape-lifts by themselves do not give a quantitative assessment of the total amount or degree of fungal contamination. It might be suggested that spore counts from air samples are truly quantitative, involving as they do numbers of spores detected per cubic metre. And so, in one way, they are. But if we take air samples from different rooms, from different heights or locations within a room, at different times of day or before and after various kinds of physical disturbance, such as foot traffic or vacuum cleaning, cooking or showering, these quantitative results will often be revealed as little more than snapshots taken during an ongoing and sometimes cyclic process of variation.

Tape lifts by themselves cannot quantify fungal contamination, but, in concert with detailed visual assessments, they can form part of an overall report that specifies all the information necessary to make decisions about what further steps – remediation that may involve repair or replacement of the building envelope; cleaning or replacing various internal surfaces or structures – may be required.

Bryce Kendrick has studied fungi for 50 years and has authored over 300 mycological publications, including several books. Among other honors, he received the Distinguished Mycologist award of the Mycological Society of America in 1995 and was elected a Centenary Fellow of the British Mycological Society in 1996. In May, 2001, he was the invited keynote speaker at the Mycological Society of Japan’s annual meeting in Tokyo and in June, 2001, received the Lawson Medal of the Canadian Botanical Association for lifetime contributions.
Kendrick current serves as the technical advisor for Aerobiology Laboratory Associates Inc. in Dulles, Va. He can be reached at bryce@mycolog.com.

Over the years, several mitigation contractors have passed on reports from their clients indicating that, in addition to the radon in their homes being reduced after an active soil depressurization system has been installed, they also sense that their basements feel drier. As a result of these growing anecdotal stories, several mitigation contractors have listed moisture reduction as an added benefit for having a mitigation system installed. The potential that ASD systems reduce mold-promoting moisture has also found its way into Environmental Protection Agency literature as a potential side benefit for radon-resistant new construction.

It is also logical to believe a system that draws air from beneath a structure and exhausts it above the roof would also draw out water vapor from the underlying soil. Couple this with a reversal in air flow that used to come into the basement from the soil, which now flows from inside the basement to beneath the slab when the ASD system is activated, and it is very logical to think moisture loads from the underlying soil would be reduced.

Perhaps the most visible indication of the potential for ASD systems to mine moisture is the amount of ice formed in the discharge of ASD systems or the need to not trap-vent piping to prevent the accumulation of condensed moisture in the piping systems.

However, even with logic and anecdotal reports from clients, the hard data to prove that these systems reduce moisture has not been authoritatively assembled. So the question has remained for several years as to whether radon-mitigation systems can reduce moisture in homes and it was the answer to this question that an EPA-funded 18-month study that began in 2005 set out to answer.
 
The Answer is a Very Qualified “Yes ...
But Only in the Non-Summer Months
The recently released contractor’s report to EPA (available for download at http://www.epa.gov/radon/pubs/index.html) provides details on the study of three Pennsylvania basement homes, each having active radon-mitigation systems. Researchers, led by principal investigators Brad Turk of Environmental Building Sciences Inc. and Jack Hughes of the Southern Regional Radon Training Center, performed exhaustive measurements of basement relative humidity and moisture levels of slab and block walls at different depths as well as in the soil beneath or behind them. This data was logged over an 18-month period with different intervals of having the ASD systems both on and off.

In essence, the data indicated that, in all three homes, the relative percent humidity in the basement air was reduced when the ASD systems were operating, but only in the non-summer months. In other words, when moisture control may be the most needed during the summer, the ASD systems did not perform as well in reducing moisture (even though radon reductions remained excellent), as the radon industry would have preferred. Much to the credit of the researchers involved, they were not satisfied with a simple quantitative conclusion, but rather went further to determine what the mechanism for moisture reduction during the winter months was in order to better understand the phenomena that has been reported anecdotally by mitigation contractor clients.
 
How Do ASD Systems Reduce Moisture?
Although many have thought the major mechanism for reducing moisture is the ASD system’s ability to extract vapor-laden soil gases from the underlying soil, researchers discovered in the homes they studied the mechanism is actually quite different and is accomplished by altering the airflow patterns in the home.

What the researchers found is that as an ASD system draws air from the soil beneath a basement slab, air interior to the basement is drawn down. This extraction of basement air causes air from upper floors to be drawn into the basement. As a result of upper-floor air being drawn into the basement, additional air from outdoors is in turn drawn into the building. As this occurs, if the outdoor air is drier than the indoor air, the overall effect is to bring drier air into the home and hence reduce the relative percent humidity in the lower level of the home.

In addition to performing tests to determine air flows within the test homes, data tracking the ASD system’s ability to reduce interior air moisture closely followed outdoor humidity levels (the figure below from the report illustrates this concept). So, in essence, the ASD system functions as a building exhaust fan that causes an increased infiltration of outside air, the effect of which, if the outside air is dry, as it would be in the winter time, is to reduce RH. However, in the summer, when the outdoor air can be more humid than indoor air, the benefit is reduced and could even increase moisture loading if the air is allowed into the home without the benefit of passing over dehumidification coils, as in the case of a home having an air conditioner.
 
  
Active soil depressurization systems can reduce moisture by drawing air down from upper floors that in-turn increases infiltration of outdoor ambient air, and if the ambient air is dry, the effect is to reduce moisture content in the basement.  Figure from Exploratory Study of Basement Moisture During Operation of ASD Radon Control Systems, December, 2007.
 
So Where Does all the Water Come From in an ASD System?
During the study, researchers measured ASD discharges for both flow rate and moisture content. In one home, they also operated a dehumidifier to allow them to compare the relative RH-reducing effectiveness of an ASD system to a dehumidifier. Interestingly enough, even though the dehumidifier was able to reduce the RH of the basement air more effectively than the ASD system, the dehumidifier in one test was only able to wring 13.4 liters of moisture from the air per day, whereas the ASD system collected 52.2 liters of water a day, or essentially four times as much.
So if the ASD system was collecting four times as much water than from a dehumidifier, where was the extra water coming from? Presumably, the ASD system was collecting water from other sources than the indoor air, which would likely be from the soil under and surrounding the test homes. Actually, this could be a good thing, especially in areas where expansive soils exist and the reduction of soil moisture can reduce the damaging pressures that expansive clays can exert on a foundation, provided the shrinkage is not so large that unsupported slabs could crack.
 
Effect on Wall Spaces or Other Foundation Types
The three homes studied had basement foundations. Furthermore, they did not have any furred-out walls, as would be the case if the basements had been finished. Two did have block walls and it was noted by researchers that the moisture content within the block walls was more effectively reduced by the ASD systems than would occur with a room dehumidifier. This observation is very intriguing in that it would suggest, as Brad Turk relayed to me in a phone conversation, that air leakage down a slab floor to wall joints located behind a finished wall could have the effect of drying out the micro-climates of spaces behind finished walls or other cavities on the shell of a basement.

Although not studied, the drying action observed within block-wall cavities affected by an ASD system would have a similar effect of drawing moisture-laden soil gas from between the plastic sheeting and surface of an earthen crawlspace in the case of a sub-membrane depressurization system.

However, I would not like to make too many extrapolations so as to prevent the kind of surprise this study has presented in altering our thinking as to the mechanism by which ASD systems reduce interior moisture. As Gene Fisher of the EPA relayed to me in a discussion in February of this year, “We need to repeat this study on different foundation types and in different climates.”
One would totally agree with Dr. Fisher’s caution in interpreting the study’s results, especially when one considers the potential that if one assumes ASD systems increase the infiltration of outdoor air, it could also increase moisture infiltration  in a humid climate like the Southeast or a tropical area like Guam, provided a mechanical dehumidification system is not in place, as suggested by ASHRAE Standard 62.2.
 
Other Interesting Revelations
I encourage anyone serious about understanding radon entry and the effects of ASD systems to read this study. There was a tremendous amount of data collected that may have some impact on the way we think about ASD systems. For example, test data suggests that as much as 72 percent of air exhausted by ASD systems came from within the basement, which is a lot of lost interior air.

The data collected also indicated that radon soil-gas measurements in two of the homes were in the single digits, which, when mixed with the large amount of indoor air, could result in very low system-discharge concentrations. It would be interesting to see measurements of radon levels in system-discharge gases in the future studies recommended by Dr. Fisher.

Although the question has not been answered definitively, the researchers should be applauded for both their method and their objectivity. A lot has been learned from this study and hopefully the EPA will continue to the next step and repeat this in other climates and with other foundation types. Kudos, gentlemen!

As always who says there is nothing new in radon?