Half of U.S. Schools Suffer From Poor Indoor Air Quality

The typical elementary-aged child in America will spend 940 hours in school this year, thus the indoor environment of the school can have a major impact. Although it is commonly known that poor indoor air quality can cause major health issues such as asthma and lung cancer, it is a less known fact that it can degrade productivity, the ability to concentrate, energy levels and even mood.

In fact, mental confusion, reduced mental performance, anxiety and coughing are all common responses to indoor air pollution. Longer exposure can lead to personality changes, impaired memory and slower motor responses -– which can all impact a child’s educational experience and achievement.

There are numerous workplace studies related to indoor air quality. The National Institutes of Health found the impact of poor indoor air quality on work performance to be as high as 6 to 9 percent in resulting loss of productivity. A series of studies by the Lawrence Berkeley Laboratory found that the presence of carpeting and less ventilation lowered typing speed, typing accuracy and proofreading accuracy by 4 percent for each variable.

Indoor air quality characteristics include humidity, temperature, level of pollutants and other factors. A number of maintenance issues can cause or exacerbate poor indoor air quality, such as a leaky roof, inadequate ventilation and excessive use of cleaning chemicals.

Because their bodies are still developing, children are especially vulnerable to the impact of poor indoor air quality. Teachers are also affected, eroding productivity and boosting absenteeism. Schools in particular present unique air-quality challenges, as they tend to have high occupant densities and are sometimes overcrowded. Many schools also have tight budgets, making it difficult to properly address this important issue.

Roughly half of the schools in the United States reported issues related to indoor air quality during a survey by the National Center for Educations Statistics. According to the U.S. Environmental Protection Agency, levels of indoor pollutants are commonly two to five times greater than outdoor levels, and occasionally as much as a 100 times greater. Addressing this important classroom issue can boost both achievement and overall health for children.

Ventilation strategies

The supply of healthy indoor air is paramount for a healthy classroom environment for children. Ventilation dilutes the concentration of pollutants and is one of the most effective strategies in promoting indoor air quality. There is also a connection between a lack of ventilation and the amount of bacteria and viruses in indoor air, which can boost absenteeism.

“Increases in classroom ventilation rates up to approximately 20 [cubic feet per minute (cfm)] per student are associated with improvements in student performance of a few to several percent, with the magnitude of improvement depending on the initial ventilation rate,” reads the Lawrence Berkeley National Laboratory website. “Increases of ventilation rates up to approximately 15 cfm per student are associated with a higher proportion of students passing standardized reading and math tests.”

Schools need controlled and strategic introduction of outdoor air into the conditioned space to ensure suitable indoor air quality. Balanced ventilation systems both supply and remove stale air, without pressurizing or depressurizing spaces.

Zehnder heat recovery ventilation systems (HRVs) or energy recovery ventilation systems (ERVs) have been used in many schools and are effective in promoting both indoor air quality and energy efficiency. These systems supply a constant stream of clean, filtered air throughout the school -- diluting or removing indoor contaminants. Intake air is filtered before entering the school. Fine filters can even be used to remove many common allergens and asthma triggers, such as pollen, mold and dust.

Zehnder HRVs preheat incoming winter air or pre-cool incoming summer air by transferring heat from the warmer airstream to the cooler airstream. ERVs also transfer moisture from the humid airstream to the drier airstream, reducing the need for dehumidification in summer and preserving interior humidity during cold, dry winter. As a result, energy costs are reduced.

Reduce the prevalence of toxins

Chemical pollutants are a major source of indoor air pollution, with studies finding that a typical classroom has between 50 and 300 volatile organic compounds (VOCs) in the air. Common sources include furnishing, finishes, cleaning products and building products.

Using products and materials that release fewer contaminants into the air can boost indoor air quality. Greenguard Gold Certified-products are screened for emissions of more than 10,000 VOCs and meet rigorous product emissions standards.

Image credit: Flickr/Elizabeth Albert