In the wake of the energy crisis of the 1970s, building codes meant to increase energy effi- ciency were enforced throughout
the United States. The consequences of tighter envelopes on
commercial buildings included
reduced energy consumption—
and poor ventilation. “Sick
buildings,” as they were called,
led to sick people. Eventually,
building codes were changed to
require adequate ventilation in
commercial buildings. Most
codes now stipulate at least one
air change per hour (ACH) in
office buildings.
Unfortunately, proper ventilation in
residential homes was overlooked. But
that’s beginning to change.
In recent years, concerns about energy conservation measures have
prompted industrial hygienists to bring
their skills into residential environments.
Since 2000, new homes have been made
increasingly airtight to save energy, and
outdoor air ventilation rates have decreased to low levels—some as low as 0.1
ACH. Energy-conserving “green building” practices, which save energy in part
by reducing air infiltration through airtight building envelope construction, can
have the unintended consequence of
substantially increasing indoor exposures for many chemicals.
Buildings are for people, of course,
and health must trump energy conservation. Buildings and residences need to be
designed and built to provide a healthy
indoor environment, while striving for
energy efficiency and sustainability. Recent investigations of green homes in
California show how the unintended
consequences of energy conservation
practices and the habits of homeowners
can lead to high exposures to dangerous
chemicals.
Unintended Consequences: Formaldehyde in Green Homes | FEATURE
California IAQ Study
Silicon Valley Homes
EPA indicates that 100 ppb formaldehyde will cause respiratory irritation in
most adults. However, more damaging
symptoms appear below 100 ppb. Studies
reported by California’s Office of Environmental Health Hazard Assessment
(OEHHA) found that children exposed to
30 ppb had decreased lung function.
Children exposed to 60 ppb to 120 ppb
formaldehyde were more likely to have
asthma or chronic bronchitis.
OEHHA has set an acute Reference
Exposure Level (REL) of 45 ppb to protect against sensory and eye irritation.
The OEHHA 8-hour and chronic RELs are
both 7. 3 ppb, protecting against respiratory system effects. People chronically
exposed to formaldehyde also experience
asthma, chronic bronchitis, severe
headaches, sleep disorders, chronic fatigue, and nausea.
In early 2009, Linda Kincaid, CIH,
learned about a family in Silicon Valley
who had experienced respiratory problems since moving into a new rental
house the previous summer. The family
was convinced that their house was
making them ill. The property owner
contested their claims. Rather than cover
the costs of testing and remediation
themselves, the family moved to an
older home. Their health issues resolved
within days of moving.
Kincaid asked builders and real estate
agents for their cooperation in collecting
data on chemical exposures in new
homes. “There is no way you are getting
into any of our homes” was one of the
kinder responses. The builders’ and
agents’ hostility made the issue all the
more intriguing.
Suspecting formaldehyde was a likely
culprit, Kincaid used a real-time
formaldehyde meter (an Interscan 4160)
to estimate the formaldehyde concentrations in open houses on weekends.
(Since this real-time formaldehyde meter
has positive and negative interferences
from other chemicals, the measured concentrations are estimates.) To accurately
measure formaldehyde concentrations,
Kincaid used UMEx formaldehyde
badges, which have been validated
against the ASTM active sampling
method (ASTM Standard D5197-03).
After spending a few weekends measuring formaldehyde, Kincaid became
convinced that an unidentified factor
was at play. Although many new homes
had formaldehyde at levels of concern,
exposures were considerably higher in
homes located in Los Altos, where concentrations ranged from 60 ppb to 120
