Sustainable Design and Social Responsibility - Sustainable Design: The Science of Sustainability and Green Engineering - page 189

who operate in the quantitative domain, as most engineers and architects do.
The harm principle becomes even more complicated when not taking an action
can lead to its own negative consequences. For example, consider a community
with substandard housing with a number of abandoned structures in need of
demolition. Further, some of these structures were constructed with asbestos-
containing building materials. There are a number of critical paths that could be
followed to address the need for better housing, but all of them involve some risk
of harm to others. If we decide to demolish the structures, there is a potential for
exposure to asbestos, but if we decide not to demolish the structures, ongoing
problems associated with abandoned buildings will persist (fire hazards, crack
houses and other criminal activities, aesthetics, and disease vectors such as rats).
The Home Depot Smart Home at Duke University: Green
Materials Processing
Paperless drywall carries a lower risk of developing mold growth. Unfortu-
nately, paperless drywall often requires the use of paints with high levels of
VOCs (volatile organic compounds) for surface preparation for finishing. This
is a classic example of trade-offs between one engineering option and another.
In this case, the exposure to mold and its associated hazards must be balanced
against the exposures to coatings and their associated hazards. In addition to be-
ing unsightly, hazards from mold include reduced structural integrity of walls
and health hazards from the release into the air of toxins that are unsafe to
breathe. Complicating risk comparisons between paper and paperless drywall
is that the toxins emitted by molds include organic compounds in the vapor
phases; so molds are themselves sources of VOCs. Thus, VOCs are agents of
concern in both options.
VOC is a catch-all term for organic compounds that partition readily into
the air. Generally, these compounds have an affinity for the air under environ-
mental conditions. For example, most VOCs have vapor pressures greater than
10 − 2 kilopascal at 20 ◦ C. Some VOCs are distinguishable by their smell, but
many of the most toxic compounds are odorless. The health effects depend
on the chemical form of the compound. A number of the VOCs are carcino-
genic, although in the United States those that are suspected to cause cancer
have been removed from paints and coatings. Others have been associated
with central nervous system effects (neurotoxins) and other diseases, such as
reproductive and developmental problems. Even though consumer products
such as paint continue to be reformulated to reduce these hazards, the risks can
continue if doses (e.g., the amount inhaled) are higher than disease thresholds.
Consequently, in any building, it is wise to minimize exposure to unwanted
VOCs as well as to reduce the risk of mold formation.