The potential environmental benefits of nanomaterials may be significantly offset by the intensive demands of their manufacturing processes, according to research recently published in the

Journal of Industrial Ecology.

Nanotechnology has attracted attention within the green building industry (see

EBN

Vol. 17, No. 3) for creating building products that are higher performing than conventional materials while being less material-intensive. However, health and safety concerns have focused on the question of whether the same properties that make nanomaterials more useful than their conventional counterparts might also make them more harmful. In a “cradle to gate” study of carbon nanofiber production, scientists at Ohio State University concluded that some nanomaterials may have a life-cycle footprint of up to 100 times greater per unit of weight than that of many conventional materials. At the University of Illinois–Chicago, scientists identified aspects of nanotechnology manufacturing that may be to blame, including strict purity requirements, lower tolerances for defects, and lower yields per production process.

Responding to growing international requirements for suppliers to document that their wood comes from legal sources, the American Hardwood Export Council (AHEC) released a report claiming to validate the legality of North American hardwood sources as a whole. While a trade association promoting hardwood exports might not be the most objective source on this question, the team of scientists behind the report lends it credibility.

The two major certification programs operating in Europe, the Forest Stewardship Council and the Programme for the Endorsement of Forest Certification, both have protocols for identifying regions that are low-risk for illegal supply (see

EBN

Vol. 16, No. 2). By establishing the U.S. as a low-risk region, AHEC aims to exempt American suppliers from having to prove the legality of their wood. Two potential problem areas—timber theft and wood that is imported from other countries and then re-exported by U.S. suppliers—were deemed to represent less than one percent of the trade.

The 250-page report, “Assessment of Lawful Harvesting & Sustainability of US Hardwood Exports,” is available online at www.ahec-europe.org.

Can the presence of porches and stoops affect people’s health? Numerous designers, researchers, and authors have explored the connection; Jane Jacobs famously wrote about the benefits of “eyes on the street” and the architectural features that support them. A team led by Scott Brown of the Miami Miller School of Medicine recently published research in

Environmental Health Perspectives that quantitatively examined the relationship between selected neighborhood features and physical health.

The team mapped seven features in the Little Havana neighborhood of Miami, then correlated those features with a two-year health assessment of 237 elderly residents. The researchers found that porches, stoops, and above-grade buildings are associated with better physical functioning because they promote walking, stair-climbing, and social interaction.

Window area, low-sill-height windows, and ground-floor parking were found to correlate negatively with physical functioning. Ground-floor parking blocks visual and physical connection between dwellings and the street. Larger window area and low sill height are negative factors, the researchers speculated, because they may drive residents to isolate themselves from public intrusion.

A recent review in Environmental Health Perspectives of 41 scientific papers found sparse but suggestive evidence for a connection between phthalate exposure and asthma and allergies. The reviewers examined evidence that phthalates, commonly used as plasticizers in polyvinyl chloride (PVC) products, increase the risk of asthma and allergies and that common ambient phthalate levels are sufficient to cause harm.

Experiments with mice have shown that phthalates can exacerbate allergic responses, and epidemiological studies of children have shown a correlation between exposure to PVC indoors and the incidence of asthma and allergies. There is also evidence that occupational exposure to heated phthalates increases the risk of asthma. But one human experiment found no bronchial reactivity to PVC.

Most people are exposed to phthalates through dietary sources; other sources of exposure are consumer goods, medical procedures, household dust, and, more rarely, fumes from heated or burned PVC. Understanding of phthalate emissions from PVC interior surfaces, such as floor tiles, is weak, but heating or exposure to moisture increases the migration of phthalates into air and dust, and there is some evidence linking such interior surfaces to respiratory problems.

 

 

Recent research published in the journal

Psychological Science gives a boost to the

biophilia hypothesis, which suggests that humans have an innate affinity for nature and that we benefit from exposure to nature—even through images (see

EBN

Vol. 15, No. 7).

Subjects in a University of Michigan study were given a task that required deliberate focus before and after walking about three miles either in a park or in a busy urban area. Both mood and performance improved after subjects walked in the park but did not improve after the urban walk. In a second experiment, subjects were shown photographs of either natural or urban environments. They were given a task structured to engage and tire three distinct mental functions: alertness, orientation, and attention. Attention improved following exposure to the nature imagery.

The researchers suggest that while urban environments make powerful demands on attention, natural environments allow the faculty of directed attention to rest and recover.

 

In signing a voluntary agreement with the U.S. Environmental Protection Agency (EPA), real estate development firm Cushman & Wakefield has pledged to cut energy use in its U.S. buildings by 30% by 2012. The commercial real estate services firm holds more than 3,200 properties in the U.S. that amount to over 265 million square feet.

Cushman & Wakefield will participate in several new voluntary EPA programs to reduce not only energy use but also water use and solid waste. The firm will report its results to EPA every six months, and EPA will compile the results and compare them with other projects, such as the New York Mets’ Citi Field stadium. EPA hopes to sign more such agreements and expand environmental performance reporting.

U.S. Green Building Council (USGBC) co-founder David Gottfried has, not surprisingly, built a very green house. The 1,460 ft² (136 m²) house in Oakland, California, has earned 106.5 points out of a possible 136 in USGBC’s LEED for Homes rating system, making it the highest-scoring project to date.

To achieve the rating, Gottfried renovated a 1915 bungalow, knocking out walls to make the space feel bigger and work better, reusing existing materials, and installing everything from locally built cabinets to a solar hot water system. He also added a prefabricated off-the-grid home office in the backyard, a LifePod from Envision Solar.

More information is available at www.gottfriedhome.com.

In a recent ruling, the U.S. Department of Energy (DOE) updated the energy code used by states in crafting their own codes for commercial buildings. All states now must have codes equal to or more stringent than ASHRAE/IESNA Standard 90.1-2004 or apply for an exemption; the previous requirement referenced the 1999 version of the standard. The change represents a 12% increase in site energy savings, according to DOE.

Fewer than half the states currently meet this requirement, and several have no statewide codes at all (see

EBN

Vol. 17, No. 4).

 

The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) has proposed six addenda to Standard 90.1-2007 that would expand its scope and change how lighting efficiencies are calculated.

One addendum would add operations and maintenance as well as renewable energy to the scope of the standard, which currently covers only the design and construction of buildings. Other addenda would add calculations for exterior lighting power limits and would expand the applicability of lighting-efficiency standards.

The addenda were released for public comment late in 2008, and, if passed, would become effective sometime in 2009. More information is available at www.ashrae.org.

One of a handful of laws in the U.S. requiring private buildings to meet LEED standards, legislation passed in 2006 in Washington, D.C., may be unenforceable as currently written. According to the Washington Business Journal, the D.C. Department of Environment is working to address a complaint from the surety industry, which issues bonds that guarantee the completion of construction projects.

The law mandates specific LEED standards for new construction in the city, starting with LEED Silver public buildings in 2008 and ending with LEED Certified large commercial buildings in 2012 (see EBN Vol. 15, No. 12). Developers must provide “performance bonds” for up to four percent of the construction cost, up to a maximum of $3 million. If the building fails to achieve LEED certification, the bond is paid into a green building fund held by the City.

One of a handful of laws in the U.S. requiring private buildings to meet LEED standards, legislation passed in 2006 in Washington, D.C., may be unenforceable as currently written. According to the Washington Business Journal, the D.C. Department of Environment is working to address a complaint from the surety industry, which issues bonds that guarantee the completion of construction projects.

The law mandates specific LEED standards for new construction in the city, starting with LEED Silver public buildings in 2008 and ending with LEED Certified large commercial buildings in 2012 (see EBN Vol. 15, No. 12). Developers must provide “performance bonds” for up to four percent of the construction cost, up to a maximum of $3 million. If the building fails to achieve LEED certification, the bond is paid into a green building fund held by the City.

The National Association of Surety Bond Producers (NASBP) and the Surety and Fidelity Association of America (SFAA) complained to D.C. officials in 2007 that the way the bonds are defined is not consistent with industry practice. Performance bonds are often issued by a third party (the surety) to ensure, for example, that a contractor meets its obligations. The performance bond in this case, however, does not serve to bring the building into compliance (developers are not required to change their buildings, just pay the fee) and may represent a conflict of interest, since the bond is paid to the same agency that enforces the law. The two groups also expressed concern that the legislation does not specify which party in a project team would be responsible for paying the bond to the City. That lack of clarity could lead the surety industry to avoid issuing the bonds, requiring owners to acquire lines of credit or put bond money in escrow, which could be more expensive for them.

The Department of Environment has created an interagency working group that hopes to have revised regulation ready in spring of 2009.

– Allyson Wendt

For more information:

D.C. Department of Environment

Washington, D.C.

202-535-2600

http://ddoe.dc.gov