Public Health Community Advisory – Welcome to another school year! As students, teachers, and school staff return to school, it is good to review some of the health hazards that are potentially present in schools. One such hazard is the quality of air inside schools. According to the Environmental Protection Agency (EPA), the levels of air contaminants indoors are about two to five times higher than they are outdoors. This difference can adversely affect nearly 55 million people who spend most of their day inside elementary and secondary schools.
The main air pollutants in schools are microbial agents, volatile organic compounds (VOCs), radon gas, and combustion products. Other air pollutants, depending on the age and construction of the school, include asbestos and polychlorinated biphenyls.
Microbial agents, such as mold, mildew, dust mites, and bacteria, are a result of moisture problems in buildings. When exposed to these agents, people commonly develop allergic illness, asthma, respiratory infections, or other health effects. Typical sources of moisture include structural leaks, plumbing leaks, flooding, and heating, ventilation, and air conditioning (HVAC)-related humidity control problems.
Sources of VOCs include paints, solvents, building materials, air fresheners, adhesives, fabrics, and many more sources. Indoor air may contain hundreds of different VOCs. The main symptoms in schools from VOC exposure are eye, nose, and throat irritation and headaches. One of the more common VOCs found indoors is formaldehyde. Formaldehyde is used widely to manufacture building materials and numerous household products.
Radon is a naturally occurring, gaseous radioactive element. Parts of Nebraska and Iowa have some of the largest radon gas levels in the country. This radioactive gas can seep into buildings from soil and rocks beneath and around the foundation of the structure. Radon gas is harmful when trapped in buildings. Radon gas exposure does not cause acute symptoms; but long-term exposure has been linked to lung cancer.
It is important for schools to ensure that their HVAC systems are functioning properly. The HVAC system should filter the air, heat or cool as necessary, and control relative humidity during the cooling season. Some systems also introduce outdoor air during this process to dilute building contaminants. High levels of carbon dioxide are usually a sign that the HVAC system is not functioning properly, and that more outdoor air is needed. Excessive levels of carbon dioxide can make students and teachers feel drowsy and lethargic.
The EPA has developed an indoor air quality (IAQ) tool kit to assist school administrators with IAQ problems.
This article was written by Chandran Achutan, PhD, assistant professor in the UNMC COPH Department of Environmental, Agricultural, and Occupational Health.