Indoor air pollution has been found by the EPA to be among the top five envi­ronmental risks to public health. Good IAQ is an important component of a healthy indoor environment, and is nec­essary to help schools reach their primary goal of educating children.

Failure to prevent or respond promptly to IAQ problems can increase long- and short-term health problems for students and staff and aggravate asthma and other respiratory illnesses. Nearly one in 13 children of school age has asthma, the leading cause of school absenteeism due to chronic illness.

The EPA says in its IAQ Tools for Schools Kit, there are six basic control methods that can lower concentrations of indoor air pollutants. Often, only a slight shift in emphasis or action using these control methods is needed to control IAQ more effectively.

1. Source Management — Managing pollutant sources, the most effective con­trol strategy, includes:
Source removal — Eliminating or not allowing pollutant sources to enter the school. Examples include not allowing buses to idle, especially not near outdoor air intakes, not placing garbage in rooms with HVAC equipment, and replacing moldy materials.

Source reduction — Improving technol­ogy and/or materials
to reduce emissions. Examples include re­placing two-stroke lawn and garden equipment with lower emitting options (e.g., manual or electrically powered or 4­stroke); switching to low emissions portable gasoline containers; and imple­menting technology upgrades to reduce emissions from school buses.
Source substitution — Replacing pol­lutant sources. Examples include, select­ing less- or non-toxic art materials or interior paints.

Source encapsulation — Placing a barrier around the source so that it releases fewer pollutants into the indoor air. Ex­amples include covering pressed wood cabinetry with sealed or laminated sur­faces or using plastic sheeting when reno­vating to contain contaminants.

                 2. Local Exhaust — Removing (ex­hausting fume hoods and local exhaust fans to the outside) point sources of in­door pollutants before they disperse. Ex­amples include exhaust systems for restrooms and kitchens, science labs, storage rooms, printing and duplicating rooms, and vocational/industrial areas (such as welding booths and firing kilns).

                3. Ventilation — Lowering pollutant concentrations by diluting polluted (in­door) air with cleaner (outdoor) air. Lo­cal building codes likely specify the quantity (and sometimes quality) of out­door air that must be continuously sup­plied in your school. Temporarily increasing ventilation as well as properly using the exhaust system while painting or applying pesticides, for example, can be useful in diluting the concentration of noxious fumes in the air.

     4. Exposure Control — Adjusting the time and location of pollutant exposure. Location control involves moving the pol­lutant source away from occupants or even relocating susceptible occupants.
 Time of use — Avoid use of pollutant sources when the school is occupied. For example, strip and wax floors (with the ventilation system functioning) on Friday after school is dismissed. This allows the floor products to off-gas over the week­end, reducing the level of pollutants in the air when the school is reoccupied on Monday. Another example is to mow around the building and near play fields only before or after school hours.
Amount of use — Use air-polluting sources as little as possible to minimize  contamination of the indoor air. Location of use — Move polluting sources as far away as possible from occu­pants or relocating susceptible occupants.

                   5. Air Cleaning — Filtering particles and gaseous contaminants as air passes through ventilation equipment. This type of system should be engineered on a case-by-case basis.

                 6. Education — Teaching and training school occupants about IAQ issues. Peo­ple in the school can reduce their expo­sure to many pollutants by understanding basic information about their environment and knowing how to prevent, remove or control pollutants.  

Some solutions, such as major ventila­tion changes, may not be practical to im­plement due to lack of resources or the need for long periods of non-occupancy to ensure the safety of the students and staff. Use temporary measures to ensure good IAQ in the meantime. Other solu­tions, such as anti-idling programs, offer low-cost options that can be easily and quickly implemented.

Specific lighting deficiencies or local­ized sources of noise or vibration may be easily identified. Remedial action may be fairly straightforward, such as having more or fewer lights, making adjustments for glare, and relocating, replacing, or acoustically insulating a noise or vibration source.

In other cases, where problems may be more subtle or solutions more complex, such as psychogenic illnesses (originating in the mind), enlist the services of a qualified professional.

Remedial actions for lighting and noise problems can range from modifications of equipment or furnishings to renovation of the building. Reducing stress for school staff may involve new manage­ment practices, job redesign, or resolu­tion of underlying labor-management problems.

Evaluating Solutions
To help ensure a successful solution, evaluate mitigation efforts at the planning stage by considering the following criteria:
.                       • Permanence;
.                       • Durability;
.                       • Operating principle;
.                       • Installation and operating cost;
.                       • Control capacity;
.                       • Ability to institutionalize the solution; and
.                       • Conformity with codes.

Permanence
Mitigation efforts that create perma­nent solutions to indoor air problems are clearly superior to those that provide temporary solutions, unless the problems are also temporary. Opening windows or running air handlers on full outdoor air may be suitable mitigation strategies for a temporary problem, such as off-gassing of volatile compounds from new furnishings, but they are not acceptable permanent solutions because of in­creased costs for energy and mainte­nance. A permanent solution to microbiological contamination involves cleaning and disinfection as well as moisture control to prevent regrowth.  

Durability
IAQ solutions that are durable are more attractive than approaches that require fre­quent maintenance or specialized skills. New items of equipment should be quiet, energy-efficient and durable.  

Operating Principle
The operating principle of the IAQ solution needs to make sense and be suited to the problem. If a specific point source of contaminants is identified, treatment at the source by removal, seal­ing, or local exhaust is a more appropri­ate correction strategy than diluting the contaminant with increased ventilation. If the IAQ problem is caused by outdoor air containing contaminants, then in­creasing the outdoor air supply will only worsen the situation, unless the supply of outdoor air is cleaned.  

Installation and Operating Costs
The approach with the lowest initial cost may not be the least expensive over the long run. Long-term economic con­siderations include energy costs for equip­ment operation, increased staff time for maintenance, differential cost of alterna­tive materials and supplies, and higher hourly rates. Strong consideration should be given to purchasing ENERGY STAR qualified products.

 Control Capacity
It is important to select a solution that fits the size and scope of the problem. If odors from a special use area such as a kitchen entering nearby classrooms, increasing the ventilation rate in the classrooms may not be successful. If mechanical equipment is needed to cor­rect the IAQ problem, it must be pow­erful enough to accomplish the task. For example, a local exhaust system should be strong enough and close enough to the source so that none of the contami­nant moves into other portions of the building.  

Ability to Institutionalize the Solution
A solution will be most successful if it is integrated into normal building operations. To ensure success, solutions should not re­quire exotic equipment, unfamiliar con­cepts, or delicately maintained systems. If maintenance, housekeeping procedures, or supplies must change as part of the solu­tion, it may be necessary to provide addi­tional training, new inspection checklists, or modified purchasing guidelines. Operat­ing and maintenance schedules for heat­ing, cooling, and ventilation equipment may also need modification.

Conformity with Codes
Any modification to building compo­nents or mechanical systems should be designed and installed in conformance with applicable fire, electrical and other building codes.

Two kinds of indicators can be used to evaluate the success of correcting an indoor air problem:
.                       • Reduced complaints; and
.                       • Measurement of the properties of the indoor air. A solution will be most successful if it is integrated into normal building operations.  
Although reduction or elimination of complaints appears to be a clear indica­tion of success, it may not necessarily be the case. Occupants who feel their con­cerns are being heard may temporarily stop reporting discomfort or health symptoms, even if the actual cause of their complaints has not been corrected.

On the other hand, lingering com­plaints may continue after successful mitigation if people are upset over the handling of the problem. A smaller number of ongoing complaints may in­dicate that multiple IAQ problems exist and have not been resolved.

Measurements of airflows, ventilation rates, and air distribution patterns can be used to assess the results of control efforts. Airflow measurements taken during the building investigation can identify areas with poor ventilation; later they can be used to evaluate at­tempts to improve the ventilation rate, distribution, or direction of flow.

Studying air distribution patterns will show whether a mitigation strat­egy has successfully prevented the transportation of a pollutant by airflow. While in some cases measuring pollu­tant levels can help determine whether IAQ has improved, in many cases this may be difficult and/or cost prohibi­tive. Concentrations of indoor air pol­lutants typically vary greatly over time, and the specific contaminant measured may not be causing the problem. Mea­suring a specific pollutant by a professional is appropriate if the problem can be limited to that pollutant.  

Persistent Problems
Ongoing complaints may indicate that multiple IAQ problems have not been resolved.
Sometimes even the best-planned in­vestigations and mitigation actions will not resolve the problem. You may have carefully investigated the problem, iden­tified one or more causes, and imple­mented a control system. Nonetheless, your efforts may not have noticeably re­duced the concentration of the contami­nant or improved ventilation rates or efficiency. Worse, the problem may continue to persist.

If your efforts to control a problem are unsuccessful, consider seeking out­side assistance. The problem could be fairly complex, occur only intermit­tently, or extend beyond traditional fields of knowledge. It is possible that poor IAQ is not the actual cause of the complaints. FSM

Source: Environmental Protection Agency