• The Problem Defined
• Government Standards
• Improving Indoor Air Quality
• Ventilation Problems In Closed Schools
• Ventilation Problems in Schools With Windows
• Temperature and Relative Humidity
• Copying Equipment
• Pesticides
• Vocational and Art Classes
• Science Rooms and Laboratories
• Air Quality During Renovation Work
• Coal-Fueled Boilers
• Pollution From Outside Sources
• Resolving Indoor Air Quality Problems

The Problem Defined

Is indoor air pollution widespread? Can it have a significant impact on health?

The answer to both questions is “yes.” Scientists have discovered that the levels of a dozen common pollutants are generally two to five times higher inside buildings than they are outdoors. The potential impact of these pollutants on human health is magnified because most people spend about 90 percent of their time indoors.

The U.S. Occupational Safety and Health Administration (OSHA) estimates that 30 percent of the Americans who work in non-industrial buildings such as offices, schools and hospitals are exposed to poor indoor air quality in their workplaces — without taking into account exposure to tobacco smoke. (Since city law now bans smoking in public buildings, secondhand smoke is no longer a factor in city schools.

Are some people more vulnerable to indoor air pollution than others?

Yes. Children are more vulnerable because they breathe in a greater volume of air (including pollutants) relative to their body weight. Other susceptible groups include the elderly and people with asthma and other respiratory problems.

In addition, some people have become very sensitive to certain chemicals as a result of past exposure. They can suffer a wide range of health effects — such as rashes, severe headaches, nausea, dizziness and fatigue — whenever they are exposed to even very low levels of those substances. This condition is often called multiple chemical sensitivity.

What are the most common sources of indoor air pollution?

The table on the following page identifies some common indoor air pollutants and their sources.

What is “sick building syndrome”?

Sick building syndrome is the name given to a group of symptoms that appear to be triggered by exposure to poor indoor air quality but neither fit the pattern of any particular illness nor can be traced to any specific exposure source. The symptoms often include headaches, fatigue, nausea, difficulty in concentrating and irritation of the eyes, nose, throat and skin. Usually, those affected feel better soon after they leave the building.

Generally, sick building syndrome strikes people who work in buildings where there are problems with the design, operation and maintenance of the ventilation system, the supply of outside air, preventive maintenance and/or housekeeping.

What does the term “building-related illness” mean?

n contrast to sick building syndrome, building related illness is the term used when symptoms of a diagnosable illness can be identified and attributed directly to contaminants in a building’s air. The classic example is legionellosis, popularly known as Legionnaire’s disease). This bacterial infection — caused by the legionella pneumophila bacteria — got its name when many people attending an American Legion convention in a Philadelphia hotel became sick. The hotel stopped recurrences by cleaning and improving the water system where the bacteria had grown.

Legionella pneumophila grows in poorly maintained warm or tepid water systems including cooling towers, hot water pipes and tanks, or humidifiers. Persons may become infected when highly contaminated water droplets become airborne and are inhaled. Some people have contracted Legionnaire’s as a result of a short-duration exposure, but the risk of infection increases if the contaminated droplets are breathed in over extended time periods. Proper cleaning and sanitizing of building water systems prevent the growth of legionella.

Another building-related illness is hypersensitivity pneumonitis, which is associated with exposure either to “bioaerosols” that flourish in moist areas or to pests such as rodents and cockroaches and/or their excreta. Bioaerosols are airborne biological contaminants that are, were or came from living organisms like bacteria, viruses, fungi, molds, pollen and animal dander and insect waste. Those could possibly pose problems in a school among sensitive persons.

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