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My daughter is
“housed” in a wooden portable building at her school, which I would say
is over 5 years old. She, along with about five other children, has
been complaining about headaches. Water lies stagnant underneath the
portable all the time. Could the headaches be caused by
mold/mildew?-Tami ,Florida
The headaches could be related to mold
exposures, inadequate ventilation, and/or exposures to elevated levels
of formaldehyde. Headaches among building occupants have been
associated with all three of these factors.
Because of rapid population growth in
Florida, Texas, California, and many suburban areas throughout the
country, school systems are increasingly choosing to meet space needs
particularly at the elementary level by contracting with manufactured
housing companies to construct, deliver and set up portable or modular
classroom buildings or in many cases lease them.
On its website (http://www.epa.gov/iaq/schooldesign/portables.html)
USEPA initially states that “The effects of poor indoor air quality in
portable classrooms are no different from those in permanent classrooms.
All school buildings use similar construction and furnishing materials,
so that the type of chemicals present in indoor air are not likely to be
different for portable versus permanent classrooms”. It then goes onto
say in somewhat of a contradiction that because of the use of pressed
wood products in new portable schools , airborne chemicals may be higher
especially if ventilation is reduced.
The construction and siting, and
climate control of portable classrooms is in fact very different from
permanent classroom spaces. For example, floors in portables are made
from wood materials such as oriented-strand board, CDX plywood, and
likely in some cases particleboard. This differs considerably from the
concrete floors that are typical of permanent classrooms. Wood
materials bonded with adhesives are more likely to emit volatile organic
compounds than concrete flooring. In some cases that may mean exposures
to significant levels of formaldehyde.
Wood-based floors can serve as an
excellent growth media for mold when subject to water spills or
excessive water vapor levels associated with portables located on very
wet sites (not unlike the building you describe).
Portable classrooms because they are
constructed by manufactured building makers use relatively large
quantities of formaldehyde-emitting cabinetry materials. Resultant
formaldehyde levels may be sufficient to cause mucous membrane symptoms
and general symptoms such as headaches and fatigue. In the recently
published California portable school study (http://www.epa.gov/iaq/schooldesign/portables.html)
formaldehyde levels in portable schools were significantly elevated
above more permanent classroom spaces. On the whole such formaldehyde
levels were considerably lower than what was common in many residential
environments two decades ago. Based on the scientific literature
concentrations of 40-100 ppbv reported for a number of portable schools
in California are excessive and pose a health risk to school occupants,
particularly very young children, whose exposure is greater because of
their relatively small body mass.
The subject of portable
schools and indoor air quality will be continued in future postings.
September 26, 2003
Indoor
Environmental Quality (2000), Thad Godish Ph.D., C.I.H
Direct E-mail
00tjgodish@bsu.edu
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