The sleek lines and open spaces found in modern homes and office buildings evoke order, efficiency, quality and cleanliness.

Their clean appearances are echoed in the green materials going into them. McGraw-Hill Construction’s 2012 study of green building trends in 62 countries found an increasing emphasis on building with recyclable and environmentally friendly materials. The same study anticipates that this year, for the first time, more than half of builders will use green construction in the majority of their work.

The study finds the driver for this increase use of green building is the need for “improved health and productivity benefits.” One important facet of that need is improved indoor air quality (IAQ). Yet, World Health Organization experts say they think up to 30 percent of new or remodeled commercial buildings have employees who register high rates of health and comfort concerns. Many of these concerns can be related to air quality issues in these structures.

According to the U.S. Environmental Protection Agency (EPA), the effect on employee health of a building with poor IAQ can be difficult to determine. Symptoms of exposure to harmful airborne substances can mimic common ailments such as colds and other viral diseases. In these circumstances, it is important to note carefully whether the symptoms in a person fade when away from a building, as this could be an indicator of IAQ problems.

The EPA warns that long-term exposure to many airborne particles can contribute to chronic afflictions such as heart disease, cancer and various respiratory ailments, reducing worker productivity and having a negative effect on a business.

Some aspects of green building construction can hamper a building’s air quality. Tightly sealing a building envelope in order to efficiently heat and condition a building can also concentrate indoor airborne toxins. Addressing these concerns requires broadening the scope of green building practices and certifications, focused now on materials, energy consumption and carbon footprints, to include air quality.

To help this effort, UL created and operates the world’s only IAQ certification program for buildings. Through a three-step process of assessing a building, staff training on IAQ and moisture management, and annual monitoring, the certification program aims to reveal IAQ problems, eliminating them and preventing their recurrence.

For UL testers, there is plenty to look for in the invisible air. The Consumer Product Safety Commission identifies nine main sources of indoor air pollution:

  • Radon from soil. Radon is a carcinogenic decay product of uranium fission and can enter houses through dirt floors or foundation cracks, where it can collect inside homes.
  • Environmental tobacco smoke. Produced from cigarettes, cigars and pipes, ETS, also known as second-hand smoke, contains more than 4,000 chemical compounds, including carcinogens.
  • Biological contaminants. This group includes viruses, bacteria, mildew and other molds, animal dander and saliva, dust mites, cockroaches and pollen. These substances can cause a wide variety of illnesses, from allergies, to pneumonia.
  • Combustion sources. Stoves, heaters, fireplaces and chimneys are sources of the toxic gases carbon monoxide, nitrogen dioxide and incompletely burned particles that can damage lung tissue.
  • Household products. Volatile organic chemicals are commonly found in household products such as paints, varnishes, waxes, disinfectants, cleaners, cosmetics, degreasers, fuels and hobby parts. They can cause a wide array of health effects depending on many factors like time and exposure concentration.
  • Formaldehyde. This chemical is used in many manufactured products: permanent press clothing, glues and adhesives, paint preservatives, and wood resins used in particleboard, plywood paneling and fiberboard. High concentrations can trigger asthma attacks and even modest levels can cause burning sensations in eyes, nose and throat, nausea and difficulty breathing.
  • Pesticides. The health effects of pesticides are similar to those from household products. The Environmental Protection Agency has banned use of some cyclodiene products in pesticides due to concerns they could cause long-term liver and central nervous system damage.
  • Asbestos. This mineral was used in a large variety of building materials for its fire-retardant properties and is still found in some older homes. Small asbestos fibers can accumulate in the lungs and cause scarring and cancer.
  • Lead. This metal can be released into the air from disturbing old paint or burning wood with lead-based paint. Lead is a health hazard for all parts or the body, causing convulsions and even death at high levels and causing nervous system, kidney and blood damage at lower levels.

The CPSC’s “The Inside Story: A Guide to Indoor Air Quality” offers three basic strategies for improving IAQ from these sources: eliminating sources of pollution or reducing their emissions, improving ventilation by bringing more fresh air inside, and using air cleaners.

Click here for a recent webinar with UL on better building performance and indoor air quality.