IAQ Backgrounder
                                          Indoor Air Quality
      goal of the Checklist is to provide
clear and easily applied activities that you
can use to help prevent indoor air quality
problems and resolve any problems
promptly if they dp arise. Once you
understand the basic principles and factors
that influence indoor air quality  in your
school, you will note that the specific
activities involve two major actions - the
management of pollutant sources, and the
use of ventilation for pollutant control. This
guidance is based on the following
»  Many IAQ problems can be prevented by
  school staff and students.

•  When IAQ problems do arise, they can
  often be resolved using the skills of
  school staff.

•  The expense and effort required to
  prevent most IAQ problems is much less
  than the expense and effort required to
  resolve problems after they develop.

Why IAQ is Important to Your

Most people are aware that outdoor air
 pollution can damage their health, but many
 do not know that indoor air pollution can
 also have significant harmful effects. U.S.
 Environmental Protection Agency (EPA)
 studies of human exposure to air pollutants
 indicate that indoor levels of pollutants may
 be 2-5 times, and occasionally more than
 100 times, higher than outdoor levels.
 These levels of indoor air pollutants may be
 of particular concern because it is estimated
 that most people spend about 90% of their
 time indoors. Comparative risk studies
 performed by EPA and its Science Advisory
 Board have consistently ranked indoor air
 pollution among the top five environmental
 health risks to the public.

 Failure to prevent indoor air problems, or
 failure to respond promptly, can have
consequences such as:

• increasing the potential for long term
  and short term health problems for
  students and staff

• impacting the student learning
  environment, comfort, and attendance

• reducing performance of teachers and
  staff due to discomfort, sickness, or

• accelerating deterioration and
  reducing efficiency of the school
  physical plant and equipment

• increasing the potential that schools
  will have to be closed, or occupants
  temporarily relocated

•  straining relationships among school
  administration and parents and staff

•  creating negative publicity that could
  damage a school's or administration's
  image and effectiveness

•  creating potential liability problems

Indoor air problems can be subtle and
do not always produce easily recognized
 impacts on health, well-being, or the
 physical plant Children may be
 especially susceptible to air pollution.
 For this and the reasons noted above, air
 quality in schools is of particular
 concern - proper maintenance of indoor
 air is more than a "quality" issue, it
 encompasses safety and stewardship of
 our investment in the students, staff, and


 Over the past several decades, exposure
 to indoor air pollutants has increased
 due to a variety of factors, including the
Tools for Schools

   Good indoor air
 quality contributes

    to a favorable

teaming environment

    for students,
   performance of

 teachers and staff,
   and a  sense  of
 comfort, health and
   well-being for all

  school occupants.

  These combine to
  assist a school in
   its core mission •
  educating children.

                              construction of more tightly sealed
                              buildings, reduced ventilation rates to
                              save energy, the use of synthetic
                              building materials and furnishings, and
                              the use of chemically-formulated
                              personal care products, pesticides, and
                              housekeeping supplies. In addition, our
                              activities and our decisions, such as
                              deferring maintenance to "save" money,
                              lead to problems from sources and
                              Four basic factors affect IAQ: sources of
                              indoor air pollutants, heating,
                              ventilation, and air-conditioning
                              (HVAC) system, pollutant pathways,
                              and occupants.
                              Soucesof Moor Ar Mutants
                              Indoor air contaminants can originate
                              within the building or be drawn in from
                              outdoors. If pollutant sources are not
                              controlled, IAQ problems can arise,
                              even if the HVAC system is properly
                                             operating. Air pollutants consist of
                                             numerous particulatcs, fibers, mists,
                                             bioaerosols, and gases. It may be helpful
                                             to think of air pollutant sources as fitting
                                             into one of the categories in the table
                                             shown below.
                                             In addition to the number of potential
                                             pollutants, another complicating factor
                                             is (hat indoor air pollulanl concentration
                                             levels can vary by time and location
                                             within the school building, or even a
                                             single classroom. Pollutants can be
                                             emitted from point sources, such as
                                             from science store rooms, or from area
                                             sources, such as newly painted surfaces,
                                             and pollutants can vary with time, such
                                             as only once each week when floor
                                             stripping is done, or continuously such
                                             as fungi growing in the HVAC system.
Typical Sorces of Moor ArPMutants
 Outjkfe Scutes
 Fbfahd Outdoor As-

 • Pollen, dust, fungal
 • Industrial emissions
 • Vehicle emissions
 • Loading docks

 • Odors from dumpsters

 • Unsanitary debris or
   building exhausts near
   outdoor air intakes

 •  Radon

 •  Pesticides

   Leakage from
   underground storage
•  Microbiological growth in
  drip pans, ductwork, coils,
  and humidifiers

•  Improper venting of
  combustion products

•  Dust or debris in ductwork
  Emissions from office
  equipment (volatile
  organic compounds,

  Emissions from shops,
  labs, cleaning processes
   Microbiological growth
  on soiled or water-
  damaged materials

   Dry traps that allow the
  passage of sewer gas

   Materials containing
  volatile organic
  compounds, inorganic
  compounds, or damaged

  Materials that produce
  particles (dust)


  Emissions from new
  furnishings and floorings

  Microbiological  growth
  on or in soiled or water-
  damaged furnishings

 •  Science laboratories
 •  Vocational arts areas
 •  Copy/print areas
 •  Food prep areas
 •  Smoking lounges
 •  Cleaning materials
 •  Emissions from trash
 •  Pesticides
 •  Odors and volatile
  organic compounds from
  paint, chalk, adhesives
 •  Occupants with
  communicable diseases
•  Dry-erase markers and
  similar pens
•  Insects and other pests
•  Personal care products

i .
                                                              Optional Location for
                                                              Unit Ventilator
                                     Cr<:                     !^_      ?$§
                                                        Exhaust Air Through
                                                     Central       Room
                                                     Vent    <*   Vent

                                                                               Outdoor Air
           HVAC System Demand Operation

           The heating^ ventilation, and air-
           conditioning (HVAC) system includes
           all heating, cooling, and ventilating
           equipment serving a school. A properly
           designed and functioning HVAC system:
           •  controls temperature and humidity to
             provide thermal comfort

           •  distributes adequate amounts of
             outdoor air to meet ventilation needs
             of school occupants

           •  isolates and removes odors and
             pollutants through pressure control,
             filtration, and exhaust fans

           Not all HVAC systems are designed to
           accomplish all of these functions. Some
           buildings rely only on natural
           ventilation. Others lack mechanical
           cooling equipment, and many function
           with little or no humidity control. The
           two most common HVAC designs used
           in schools are unit ventilators and
           central air handling systems. Both can
           perform the same HVAC functions, but
           the central air handling unit serves
           multiple rooms while the unit ventilator
           serves a single room.
The three building figures in this
Backgrounder show typical methods for how
outdoor air enters a room, and how exhaust
air exits through a vent If exhaust airflow
through door or wall grilles into corridors is
sealed due to fire  codes, ensure that air has
another path to reach the central exhaust
 Airflow patterns in buildings result from the
 combined forces of mechanical ventilation
 systems, human activity, and natural effects.
 Air pressure differences created by these
 forces move airborne pollutants from areas
 of higher pressure to areas of lower pressure
 through any available openings in building
. walls, ceilings, floors, doors, windows, and
 HVAC system. An inflated balloon is an
 example of this driving force. As long as the
 opening to the balloon is kept shut, no air
 will flow, but when open, air will move from
 inside (area of higher pressure) to  the
 outside (area of lower pressure).
 Even if the opening is small, air will move
 until the pressures inside and outside are
 equal.            '
                                            How outdoor air is
                                            supplied through a unit
                                                                                               Typical supply vents and
                                                                                               return/exhaust grilles.
                                             •tooted only on callings, not wall*


                              Building occupants in schools include
                              the staff, students, and other people who
                              spend extended periods of time in the
                              school. The effects of IAQ problems on
                              occupants are often non-specific
                              symptoms rather than clearly defined
                              illnesses. Symptoms commonly
                              attributed to IAQ problems include:
                              • headache, fatigue, and shortness of

                              • sinus congestion, cough, and
                              • eye, nose, throat, and skin irritation

                              • dizziness and nausea

                              All of these symptoms, however, may
                              also be caused by other factors, and are
                              not necessarily due to air quality
                              deficiencies. Environmental stressors
                              such as improper lighting, noise,
                              vibration, overcrowding, poor
                              ergonomics, and psychosocial problems
                              (such as job or home stress) can produce
symptoms that are similar to those
associated with poor air quality, but
require different solutions.
Because of varying sensitivity among
people, one individual may react to a
particular IAQ problem while
surrounding occupants do not display ill
effects. In other cases, complaints may
be widespread In addition to different
degrees of reaction, an indoor air
pollutant or problem can trigger
different types of reactions in different
people. Groups that may be particularly
susceptible to effects of indoor air
contaminants include, but are not limited
•  allergic or asthmatic individuals, or
  people with sensitivity to chemicals

•  people with respiratory disease

•  people whose immune systems are
  suppressed due to radiation,
  chemotherapy, or disease

•  contact lens wearers
Hew outdoor air is
supplied in a central air
handling system.
                                                                      Centra Air HonoDng Unfi


There are six basic control methods for
lowering concentrations of indoor air
pollutants. Specific applications of these
basic control strategies are noted in your
Checklists.   .    .
Source Management includes
source removal, source substitution, and
source encapsulation. Source
management is the most effective
control method when it can be
practically applied. Source removal is
very effective. However, policies and
actions that keep potential pollutants
from entering the school are even better
at preventing IAQ problems. Examples
of source removal include not allowing
buses to idle near outdoor air intakes,
not placing garbage in rooms with
HVAC equipment, and banning smoking
within the school. Source substitution
includes actions such as selecting a less
toxic art material or interior paint than
the products which are currently in use.
Source encapsulation involves placing a
barrier around the source so that it
releases fewer pollutants into the indoor
air (e.g., asbestos abatement, pressed
 wood cabinetry with sealed or laminated
• surfaces).

 Local Exhaust is very effective in
 removing point sources of pollutants
 before they can disperse into the indoor
 air by exhausting the contaminated air
 outside. Well known examples include
 restrooms and kitchens where local?
 exhaust is used. Other examples of
 pollutants that originate at specific
 points and mat can be easily exhausted:
 include science lab and housekeeping
 storage rooms, printing and duplicating.
 rooms, and vocational/ industrial areas
 such as welding booths.

 Ventilation through use of cleaner
 (outdoor) air to dilute the polluted
 (indoor) air that people are breathing.
 Generally, local building codes specify
                                               Outdoor Air

the quantity (and sometimes quality) of
outdoor air that must be continuously
supplied to an occupied area. For
situations such as painting, pesticide
application, or chemical spills,
temporarily increasing the ventilation
can be useful in diluting the
concentration of noxious fumes in the

Exposure Control includes adjusting
the time of use and location of use. An
example of time of use would be to strip
and wax floors on Friday after school is
dismissed, so that the floor products
have a chance to off-gas over the
weekend, reducing the level of odors or
contaminants in the air when the school
is occupied. Location of use deals with
moving the contaminating source as far
as possible from occupants, or
relocating susceptible occupants.

Air Cleaning primarily involves the
filtration of particles from the air as the
air passes through the ventilation
equipment Gaseous contaminants can
also be removed, but in most cases this
type of system should be engineered on
a case-by-case basis.
How outdoor air is
supplied in an exhaust-
only system.


• Teacher's

• Administrative Staff

• Health Officer's

• Ventilation

• Building Maintenance

• FoodService

• Waste Management

• Renovation and Repairs

• Walkthrough
 Education of the school occupants
 regarding IAQ is critical. If people are
 provided information about the sources
 and effects of contaminants under their
 control, and about the proper operation
 of the ventilation system, they will better
. understand their indoor environment, and
 am act to reduce their personal


 As one of the people in your school,   .
 your activities and decisions have>an
 impact on the quality of the indoor air in
 your school. You can participate by
 applying the activities noted in your
 Checklist, and by continuing to apply
 these principles on a daily basis.
 Someone from your school or district
 has taken the role of IAQ Coordinator,
 and serves as a focal point for collecting
 IAQ information and handling IAQ

 How Do You Know if You Have an

 Diagnosing symptoms that relate to IAQ
 can be tricky. Acute (short-term)
 symptoms of IAQ problems typically
 are similar to those from colds, allergies,
 fatigue, or the flu. There are clues that
 can serve as an indicator of a potential  •
 indoor air problem:
 •  the symptoms are widespread within
   a class or within the school

 •  the symptoms disappear when the
   students or staff leave the school
   building for a day

 •  the onset is sudden after some change
   at school, such as painting or pesticide

 •  persons with allergies, asthma, or
   chemical sensitivities have reactions
   indoors but not outdoors
• a doctor has found that a student or
  staff member has an indoor air-related

However, a lack of symptoms does not
ensure that IAQ is acceptable.
Symptoms from long-term health effects
(such as lung cancer due to radon) often
do not become evident for many years.

What if Yo« Think You Have an
If you receive complaints that seem to
indicate a potential IAQ problem and the
problem is self-evident, then attempt to
correct the problem. If the problem
cannot be corrected, or if the complaint
seems to indicate a potentially severe
IAQ problem, contact the IAQ
Coordinator immediately. The IAQ
Coordinator may ask you questions to
try to identify whether you have
overlooked potential causes of the
problem (such as, "Has anything
changed since the last time you
completed your Checklist?^, and then
may call in other help from within or
outside the school to investigate further.
                                                                       . Because indoor air problems can
                                                                        jeopardize the health of students and •
                                                                        .staff, parents and the public may react
                                                                        strongly to reports of bad indoor air
                                                                        quality in your school. With this in
                                                                        mind, it is recommended that you follow
                                                                        the communications guidelines
                                                                        established by the IAQ Coordinator.
                                                                        Usually, this will involve referring
                                                                        questions from the public and media to
                                                                        one central source, the IAQ Coordinator
                                                                        for your school. In this way, students,
                                                                        parents,  staff, and the public will not
                                                                        become  alarmed by conflicting or wrong
                                                                        information, and will have a consistent
                                                                        and complete source of information
                                                                        regarding the quality of the indoor air in
                                                                        your school.