From the stark splendor of Stonehenge to the towering elegance of the Cathedral of Notre Dame, natural stone has always been the building material of choice when architects wish to create a lasting impression. Modern architects and builders select stone for many of the same qualities their ancient forebears did: beauty, durability and low maintenance. Few building materials stand the test of time as well as stone.

For all of its selling points, natural stone must now stand more than the test of time. Today's architects, builders and consumers are influenced by an increasing awareness of the responsible use of resources and a desire to create healthy environments in which to live and work. They are raising the bar on all building materials, including stone.

Building Momentum
Ashley Katz, a communications consultant at the U.S. Green Building Council, defines a green building as a "high performance building that is more environmentally responsible and more profitable," than an average building. A "profitable" building reduces operational and "people" costs, which translates into energy savings and increased productivity due to fewer sick days. Achieving an environmentally responsible building may include using locally sourced and/or recycled materials, selecting energy-efficient products and positioning a building to take advantage of climate.

As the green movement gains momentum, products and services touted as environmentally friendly are flooding the marketplace. Furthering the trend is the knowledge that supplier, builder and architect responsiveness to demands for green methods and products translates into another form of green: profit.

In a 2008 U.S. Construction Overview, FMI (management consultants and investment bankers to the construction industry) projected that $21.2 billion of all new nonresidential construction will employ the use of green building principles. In another report, the value of green building construction is projected to increase to $60 billion by 2010.* According to the FMI, the significant growth in green construction has gradually shifted perception among construction company owners, architects and engineers. The industry increasingly has realized that green building capabilities are essential to best practices. FMI's Overview identified three forces behind the green building movement:

• Unprecedented level of government initiatives
  
• Heightened residential demand for green construction
  
• Improvements in sustainable materials.

* Source: McGraw-Hill Construction Analytics, SmartMarket Trends Report 2008

Despite allegations to the contrary, independent studies have proven that granites such as this Golden Oak variety do not harbor bacteria or emit dangerous levels of radon.
Photo courtesy of Cold Spring Granite

Selling Stone's Sustainability
Stone's legacy as a natural building material is something the industry can bank on. "It's a material built by nature to last," says president and chief operational officer of Cold Spring Granite Company John Mattke. He serves as co-chair of the Natural Stone Council (NSC), a group of businesses and trade associations that have come together to promote the use of genuine stone in commercial and residential applications. Mattke feels that stone's longstanding reputation for durability and low maintenance is now complemented by versatility. With computer-aided equipment and other modern manufacturing techniques, stone can meet nearly any architectural need, including molding, door knobs, staircases, alcoves and even toilets. And, in some climates, the material's natural ability to moderate temperature can also contribute to building efficiency.

Some in the environmental movement say stone can never be considered sustainable because it's not renewable. Jack Geibig, a senior research associate at the Center for Clean Products and Clean Technology (CCPCT) at the University of Tennessee — Knoxville, disagrees. He worked with the NSC on an operational process impact study to develop guidelines for environmentally responsible use of stone.

"The longevity of stone, the low maintenance of stone, the relatively clean way in which it's produced compared to something like PVC siding . . . I think there's a place for stone in the green building movement. I do see it as a more sustainable material," he says.

Industry Response
The stone industry has not been idle during the upsurge in all things green. In 2005, NSC formed its own Committee on Sustainability, comprised of industry representatives charged with focusing on sustainability issues and planning and executing initiatives. Mattke serves as the committee's chair. According to Mattke, the committee and the NSC are developing programs to strengthen stone's position within the green marketplace. And they're not working alone." Sustainability is universally recognized as an important issue, and I have yet to run across anyone in our industry who has been unwilling to help," Mattke says.

The industry is also taking steps to achieve a stronger standing with the U.S. Green Building Council's (USGBC) Leadership in Energy and Environmental Design (LEED®) Green Building Rating System™. LEED, a third- party certification program, is a benchmark for the design, construction and operation of green buildings. LEED recognizes a building's performance in five areas of human and environmental health: sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality. At the present time, the only LEED credit stone is generally recognized as contributing toward is as a locally sourced material. As LEED continues to develop, many in the industry believe stone could eventually contribute to generating LEED credits for building and material reuse, low volatile organic compound (VOC) emissions, and a variety of other LEED categories.

Benchmarking Best Practices
The Natural Stone Council's first initiative was an intensive data-gathering mission to establish environmental best practices for natural stone industry operations. Environmental benchmarking helps industries evaluate the environmental, health and performance factors of operations in relation to best practices. To achieve this, NSC partnered with an independent, third-party research facility, the Center for Clean Products and Clean Technology, in 2007. The Center works to create, assess and promote cleaner products and cleaner technologies to minimize pollution and to encourage sustainability.

Jack Geibig spearheaded the project. Over the course of a year, he surveyed 1,400 U.S. quarries and operations to evaluate impacts from transportation, resource consumption, water releases and operational methods. During the survey, Geibig visited 15 quarries with different types of stone. Overall, he was pleasantly surprised "at how non-impactful the quarrying practice is — there's very little chemistry involved and on-site water doesn't accumulate."

He also noted that, because stone is at the surface, quarrying isn't as environmentally destructive as mining. Geibig concluded that the stone industry was very similar to many other industries. He explains, "There's a lot of variation — the size of the company is often key," as to how sustainable their practices are.

The Center is processing the information to create life-cycle data and comparative information allowing architects and designers to weigh the environmental impacts of using stone versus other materials. Additionally, it will develop strategic sustainability goals for the industry and a plan to improve outreach to the environmental and green building communities.

Spreading the Word
As part of its efforts, NSC developed a Web site to promote the use of natural stone: www.geuinestone.com. The site includes this description of stone's environmentally friendly attributes: "an enduring life-cycle, durability, ease of care and maintenance, recyclability and quarry and manufacturing best practices."

Communication tools will be created from the data collected by CCPCT. Information will be available late summer 2008 on www.genuinestone.com and will be distributed to design and architectural trade associations. The survey data will also be disseminated in the form of material fact sheets and case studies featuring companies employing environmentally sustainable best practices.

According to Mattke, the stone industry was intentionally cautious about jumping on the green bandwagon. "We learned early on about the dangers of 'greenwashing' — making unsubstantiated claims about how green a product is. We've been preaching patience to the industry and are careful about what claims are made until we can support them with data that the architectural and design communities will relate to," Mattke says.

From his perspective as a researcher Geibig notes, "Their mandate with us was to be thorough and to bring out the truth."

Homeowners whose kitchens boast granite surfaces need not worry about the emission of radon gasses. Shown here: Carnelian granite from Cold Spring Granite's Milbank, S.D., quarry.
Photo courtesy of Cold Spring Granite

Addressing Health Concerns
If the growth of green building presents opportunities, it has also brought challenges. Concerns over indoor air quality are fueling some of the green industry's growth and have generated considerable attention, particularly in the countertop marketplace. As a result, the granite industry is working to address two negative perceptions surrounding granite countertops — that radon emissions from granite countertops could be harmful to a person's health and that granite countertops are difficult to clean and may even harbor bacteria.

A naturally occurring gas, radon results from decaying radium found in some stone and materials such as concrete, cement and gypsum. Radon is measured in units called picocuries per liter (pCi/L) — the unit of radon concentration in the air. The U.S. Environmental Protection Agency (EPA) has established four pCi/L as the safe standard for indoor air. It advises homeowners to increase ventilation at levels above four.

The Marble Institute of America (MIA) is taking the lead to address the radon issue,-- because it is closely connected to the countertop industry. L. L. Chyi, PhD, professor of geochemistry and environmental geology at the University of Akron in Ohio, conducted MIA's most recent testing in 2008. Chyi studied 13 popular granites used throughout the United States. These granites are believed to represent approximately 85 percent of the granite countertop market in recent years.

Chyi's tests measured the amount of radon that each granite type would add to the interior of a 2,000-square-foot home with 8-foot ceilings. According to his results, granites currently found in the U.S. marketplace are insignificant contributors to radon levels in the home. Based on the test results and EPA standards, the MIA concluded that the most popular granite countertops pose no health hazard to homeowners. The test results are available on MIA's Web site: http://www.marble-institute.com/industryresources/
radontesting_u-akron2008.pdf.

If granites currently in the U.S. marketplace have been proven to be insignificant contributors to radon levels in the home, then where is all the controversy coming from? A new nonprofit organization called BuildClean has conducted a study of radon levels from a granite countertop. It claims that at least one of its test results showed higher than normal levels of radon being emitted from the countertop. BuildClean's funding by synthetic stone producers, Silestone and Cambria — direct competitors to the granite industry — makes the organization's study results suspect, according to those in the natural stone industry.

However, as a follow up to the BuildClean study, which aired on KHOU Channel 11 in Houston, William J. Llope, a Rice University physics professor, independently reviewed dozens of academic studies that considered 95 different varieties of granite. The good news for the natural stone industry and its consumers: He found that 92 of the 95 granites tested emitted little or no radon. Llope's findings may be found at: http://wj-lope.rice.edu/SaxumSubluceo/.

According to 2008 test results, granites currently found in the U.S. marketplace are insignificant contributors to radon levels in the home. Based on the test results and EPA standards, the MIA concluded that the most popular granite countertops pose no health hazard to homeowners. Shown here: Agate granite from Cold Spring Granite.
Photo courtesy of Cold Spring Granite

Carl Smith, chief executive officer of Greenguard Environmental Institute (GEI) says his company hasn't done radon testing and has no plans to. "Radon is much more difficult to look at. In-home testing is tricky; how are you controlling what might be coming out of the basement, for example? The fair thing to say is that, while there's been some suspicion around radon from granite, the presence in the small amount of granite used indoors is still controversial and not empirically clear-cut."

According to Smith, Greenguard has tested a "considerable amount of stone and granite for chemical emissions." In particular, the tests look for VOCs. "We see some of these chemicals coming off stones that have been finished, glazed or grouted. Typically it's not from the stone itself, but from things used in conjunction with stone," Smith comments. Stone's long history as a building material may provide some peace of mind.

"It's been around a long, long time. It's one of the materials we know the most about, compared to other materials," says CCPCT's Jack Geibig. In regard to radon, Geibig feels it's wise to "compare and contrast" those concerns with synthetics "that we don't have compositional information on."

"Most people in the granite industry understand the facts about radon," Mattke says, "and realize that it is very difficult to establish the specific contribution of a granite countertop to a person's radon exposure relative to the rest of the materials present in a home. But the general consumer is unlikely to understand how radon works and may not have all the facts."

For their own piece of mind, Mattke's company, Cold Spring Granite, hired Daniel J. Steck, PhD, a physics professor at Saint John's University, to measure radon in its granites back in 1989. Steck's report stated that, "Even for heavy installations of your granitic materials, the radon concentrations due to these materials are much less than from similar sized areas of other building materials." Steck went on to say, "I believe that it is reasonable to say that the materials tested pose no significant radon risk." While the information presented by Steck indicates that the granites tested emit "insignificant amounts of radon," Mattke predicts that the entire industry will be required to publish more stone test data regarding radon in the future.

Other allegations claim that granite might harbor bacteria and even encourage mold growth. The MIA contends that granite is, in fact, extremely resistant to bacteria, mold and mildew because of its low porosity. In 1999, the stainless steel industry asked O. Peter Snyder, PhD, of the Hospitality Institute of Technology and Management, to perform a bacteria study on common countertop materials. Six countertops made of different materials (granite, stainless steel, laminate, wood, tile, concrete) were inoculated with E. coli bacteria. The countertops were then "cleaned with typical household detergents after which residual bacteria counts were taken," according to Chuck Muehlbauer, technical director of MIA.

Snyder reported that natural granite demonstrated strong cleaning advantages over most other countertop surfaces. Granite's bacteria count reduction was second only to stainless steel, but it was 160 times superior to the next closest material. The report can be found at: http://www.natural-stone-interiors.com/countertop-surfaces.html.

In 2006, MIA contracted with Snyder to run another bacteria study. This time, Snyder tested four unsealed natural stones (three granites and one marble) using methods similar to his earlier test. He concluded that typical stone countertops were easily sanitized to meet FDA standards to reduce bacteria contamination. The full study may be viewed at: www.marble-institute.com/indu stryresources/bulletins.cfm.

Embracing Accountability
With concerns about rising energy costs and diminishing resources, the green building movement won't likely be a passing trend. The stone industry can pride itself on facing the issues head on.

"Whether we are dealing with questions regarding environmental responsibility and sustainability or challenges related to health and safety, it's up to the stone industry to bring the truth out and let people make their own decisions," Mattke says.