December 1998
Indoor Air Quality Basics for Schools
- Many IAQ problems can be prevented by school staff and students
- When IAQ problems happen, 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 solve problems after they develop
Why IAQ is Important to Your School
Most people are aware that outdoor air pollution can damage their health, but many do not
know that indoor air pollution can also cause harm. 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 are 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 four environmental risks to the public.
Failure to prevent indoor air problems, or failure to act promptly, can have consequences such as:
- increasing the chances for long-term and short-term health problems for students and staff
- impacting the student learning environment, comfort, and attendance
- reducing productivity of teachers and staff due to discomfort, sickness, or absenteeism
- faster deterioration and reduced efficiency of the school physical plant and equipment
- increasing the chance that schools will have to be closed, or occupants temporarily moved
- 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 are 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 includes safety and good management of our investment in the students, staff, and facilities.
Good indoor air quality contributes to a favorable learning environment for students, productivity for teachers and staff, and a sense of comfort, health, and well-being for school occupants. These combine to assist a school in its core mission -- educating children.
Understanding IAQ Problems and Solutions
Over the past forty or fifty years, exposure to indoor air pollutants has increased due to
a variety of factors, including the 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 decisions, such as delaying maintenance to
"save" money, can lead to problems from sources and ventilation. Four basic
factors affect IAQ: sources of indoor air pollutants, the heating, ventilation, and
air-conditioning (HVAC) system, pollutant pathways, and occupants.
Sources of Indoor Air Pollutants
Indoor air contaminants can begin within the building or be drawn in from outdoors. If
pollutant sources are not controlled, IAQ problems can occur, even if the HVAC system is
working properly. Air pollutants consist of numerous particles, fibers, mists, molds,
bacteria, 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, indoor air pollutant levels can vary within the school building, or
even a single classroom. Pollutants can also vary with time, such as only once each week
when floor stripping is done, or continuously such as when fungi is growing in the HVAC
system.
Typical Sources of Indoor Air Pollutants |
|||
Outside Sources |
Building Equipment |
Component/Furnishings |
Other Indoor Sources |
Polluted Outdoor Air
Nearby Sources
Underground Sources
|
HVAC Equipment
Non-HVAC Equipment
|
Components
Furnishings
|
|
HVAC System Design and 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 do all of these things. Some buildings rely only on natural ventilation. Others lack cooling, and many have little or no humidity control.
Pollutant Pathways and Driving Forces
Airflow patterns in buildings are caused by mechanical ventilation systems,
human activity, and natural effects such as wind. 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.
Building Occupants and Health All of these symptoms, however, may also be caused by other factors, and are not
necessarily due to air quality problems. Environmental stressors such as improper
lighting, noise, vibration, overcrowding, 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 people are different, one individual may react to a particular IAQ problem
while surrounding occupants have no noticeable 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. Some groups that may
be particularly susceptible to effects of indoor air contaminants include:
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 vague symptoms rather than clearly defined illnesses. Symptoms commonly attributed
to IAQ problems include:
headache, fatigue, and shortness of breath
Six Basic Control Strategies
There are six basic methods for lowering concentrations of indoor air pollutants. Specific
applications of these methods are noted in the Indoor Air Quality Tools for Schools Kit
(go to "How to Order the Kit").
--Source Management includes source removal, source substitution, and source
encapsulation. Source management is the most effective control method when it can be
practically applied. The best prevention method is never to bring unnecessary pollutants
into the school building. Examples of source removal include not allowing buses to idle
near outdoor air intakes, not placing garbage in rooms where HVAC equipment is located,
and banning smoking within the school. Source substitution includes actions such as
selecting 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.
--Local Exhaust is very effective in removing sources of pollutants before they can be dispersed into the indoor air, exhausting the contaminated air outside. Well known examples include restrooms, kitchens, and science lab fume hoods. Other examples of pollutants that originate at specific points and that can be easily exhausted include science lab and housekeeping storage rooms, printing and duplicating rooms, and vocational/industrial areas such as welding booths.
--Ventilation uses cleaner (i.e., outdoor) air to dilute the contaminated (i.e., indoor) air that people are breathing. Generally, local building codes specify the amount 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 fumes in the air.
--Exposure Control includes the principles of 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 release gases over the weekend, reducing the level of odors or contaminants in the air when the school is occupied. An example of location of use involves 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 usually this type of system should be engineered on a case-by-case basis.
--Education of the school occupants is critical. If school staff 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 can act to reduce their personal exposure.
How Do I Know if There is an IAQ Problem
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, however, that can serve as indicators of potential indoor air problems:
- the symptoms are widespread within a class or within the school, potentially indicating a ventilation problem
- the symptoms disappear when the students or staff leave the school building for the day
- the onset is sudden after some change at school, such as painting or pesticide application
- persons with allergies, asthma, or chemical sensitivities have reactions indoors but not outdoors
- a doctor has diagnosed a student or staff member as having an indoor air-related illness
However, a lack of symptoms does not mean that the quality of the air within the school is acceptable. Symptoms from long-term health effects (such as lung cancer due to radon) often do not become evident for many years. For this reason, schools should establish a preventive indoor air program to minimize exposure of students and staff to indoor air pollutants.
.What Should I Do if I Think a School has an IAQ Problem
If your child, or someone else you know, is experiencing symptoms that you believe may be
related to their school environment, contact a school official immediately, such as the
school IAQ Coordinator, or the health and safety coordinator. Whether or not the school
has a known problem, encourage the school to obtain and use the Indoor Air Quality
Tools for Schools Kit. This easy-to-use Kit shows schools how to carry out a practical
plan of action at little or no cost, using in-house staff.
The Kit includes simple checklists for all school employees, a flexible step-by-step guide for using the checklists, an Indoor Air Quality Problem Solving Wheel, a fact sheet on indoor air pollution sources and solutions, sample memos to help school personnel respond to inquiries, and sample policies.
The kit is co-sponsored by the National PTA, National Education Association, Council for American Private Education, Association of School Business Officials, American Federation of Teachers, and the American Lung Association.The Federal government, as well as most state and local governments, do not have enforcement capabilities regarding indoor air quality in schools. In Washington State, assistance is available by contacting your local health department.
How to Order the Kit
The Indoor Air Quality Tools for Schools Kit, item number
055-000-00503-6, can be purchased for $22 from the U.S. Government Printing Office.
MasterCard and Visa are accepted. For telephone orders, call 202-512-1800. Or send a check
or money order to:
Superintendent of Documents
PO Box 371954
Pittsburgh, PA 15250.
While supplies last, school districts and schools may receive a free copy of the IAQ Tools for Schools Kit by having a school administrator mail or fax a request on official school letterhead to:
EPA Kit
PO Box 37133
Washington, DC 20013-7133
Fax: 202-484-1510
Resources
- Advocacy Topic Chair: Ann Bisgard
- Advocacy Topic Committee Member: Elizabeth Koch for information on selecting materials for use in schools
- Other information on IAQ: EPA Region 10 Office, Seattle: Brook Madrone, Indoor Air Program, (206) 553-2589; e-mail <madrone.brook@epamail.epa.gov>. (Call Ann Bisgard for additional program names and numbers.)
- Washington Toxics Coalition: Elizabeth Loudon, Pesticide Reform Project, (206) 632-1545 ext. 18; e-mail <eloudon@watoxics.org>
- For questions or help in devising a strategey on how to proceed:
- Government Relations Director, Barbara Casey (staff position); e-mail <bcasey@wastatepta.org>; Washington State PTA Office: (800) 562-3804 (9:00 AM –1:00 PM )or (253) 565-2153.
- Legislative Director, Marilyn Enright (elected volunteer).
- Conference: Indoor Air Quality at School and at Home — 2/4/99, 8:00 AM – 5:00
PM at the Center for Urban Horticulture, University of Washington, 3501 NE 41st Street
(off Sand Point Way). Registration: $60 before 1/21/99, $95 after. For information call
(206) 543-1069, or e-mail ce@u.washington.edu
Reprinted with permission, U.S. Environmental Protection Agency
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