Risks of Designing Buildings with Poor Indoor Air Quality

On average, Americans spend over 21 hours per day inside of buildings. The most vul­ner­a­ble, infants and elderly, spend even more time indoors. For most Americans, exposure to toxic air pol­lu­tants is dominated by what we breathe indoors, rather than what we are exposed to outdoors. These health risks dwarf all other envi­ron­men­tal exposures the typical person will be subjected to.

For that reason, rea­son­able changes in building design and operation must be made in order to improve indoor envi­ron­men­tal quality. The social cost due to poor health is con­sid­er­able. The economic cost in terms of worker pro­duc­tiv­i­ty in the United States alone is estimated to be on the order of tens of billions of dollars annually. In fact, studies have shown that improved indoor air quality can raise worker pro­duc­tiv­i­ty and even raise the test scores of school children.

A Shift to Indoor Air Quality Research

Despite knowing the impor­tance of indoor air quality, the majority of research and funding today continues to be focused on outdoor air quality issues. There are more laws and reg­u­la­tions of products and processes that effect outdoor air quality than there are for indoor air quality. Research into the impacts of building materials, furniture, chemicals, and other products on human health are still rel­a­tive­ly new but gaining serious attention in academic circles.

The Building Energy and Envi­ron­ments Program at the Uni­ver­si­ty of Texas in Austin is leading the way in indoor air quality research and is making sig­nif­i­cant and sometimes unex­pect­ed dis­cov­er­ies year in and year out. Led by Dr. Richard Corsi, the program and the University’s Indoor Air Quality Lab are paving the way to under­stand­ing what is in the indoor air we breathe and the impacts on our health and wellbeing.

Earlier this summer, we were treated by Dr. Corsi to a tour of the IAQ Lab on the J. J. Pickle Research Campus in Austin, Texas, where faculty and students conduct micro (small test chamber) and macro (full size home) lab­o­ra­to­ry testing of indoor air. The lab tour and pre­sen­ta­tion was one of the high­lights of the 2017 Austin Sus­tain­able Building Material Forum, a gathering of thought leaders in the man­u­fac­ture, spec­i­fi­ca­tion, and instal­la­tion of building materials. What we learned on this brief tour was nothing short of surprising.

Are We Doing More Harm Than Good?

As the con­struc­tion industry continues to push for the greenest and most sus­tain­able building materials, indoor air quality has become sig­nif­i­cant­ly more important. The industry has suc­cess­ful­ly reduced or eliminate VOC’s (volatile organic compounds) from indoor materials and finishes in response to the known effects of these pol­lu­tants on human health. While the push to rid our building of VOC’s has been positive, there have been some unin­tend­ed results.

When policies mandate change, we often don’t imme­di­ate­ly recognize or realize the impacts. What the researchers at the IAQ Lab have dis­cov­ered is that man­u­fac­tur­ers of the glues and paints used in buildings have sig­nif­i­cant­ly reduced VOC’s, but are now using SVOC’s (semi-volatile organic compounds) in order to maintain the material’s effec­tive­ness. While man­u­fac­tures are able to claim 0% VOC content for their new sus­tain­able” products, SVOCs may not be any better in the long-run.

Semi-volatile organic compounds are a subgroup of VOC’s that tend to have a higher molecular weight and higher boiling point tem­per­a­ture than VOC’s. SVOC’s are of concern because of their abundance in the indoor envi­ron­ment and their potential for negative health effects on humans. SVOC’s are found in carpets, textiles, furniture, mat­tress­es, paints, aerosols, personal hygiene products, cleaning products, and flame-retar­dants to name a few. The health effects from exposure to SVOC’s vary depending on the par­tic­u­lar SVOC, the length of exposure, and personal sen­si­tiv­i­ty. SVOC’s have been asso­ci­at­ed with allergies, asthma, endocrine and thyroid dis­rup­tion, repro­duc­tive toxicity, and fetal and child devel­op­ment delays.

How Heat and Humidity Makes Things Worse

Another inter­est­ing research topic being studied at the IAQ Lab is the effects of relative humidity (RH) and tem­per­a­ture on chemicals stored in the surfaces of materials inside buildings. Chemicals we bring indoors with us, cleaning products and household items we use every day, and building materials like carpet glue, paint, and numerous other products are all sources of poten­tial­ly toxic pol­lu­tants. The lab dis­cov­ered that as indoor humidity increased in a building, the water molecules in the air are adsorbed (adhesion of molecules of gas, liquid, or dissolved solids to a surface) onto the various materials in the building, thereby dis­plac­ing chemicals already adsorbed to the material and releasing them into the air. They also found that as the tem­per­a­ture in a building rose, there was an increased rate of release of chemicals into the air.

The tour was eye opening and led to many questions for Dr. Corsi and the researchers at the IAQ Lab. As buildings are being bombarded with higher heat and humidity in the summer what is being released into the indoor air we breathe? As the archi­tec­ture and con­struc­tion indus­tries continue to push for more sus­tain­able building practices, we need to be more knowl­edge­able of the drivers of indoor air quality for the buildings we are designing and constructing.

Improving Indoor Air Quality

For starters, designers should be spec­i­fy­ing materials with no VOC’s and no SVOC’s. Using fewer adsorp­tive materials will help reduce the trapping and storage of poten­tial­ly dangerous chemicals and pol­lu­tants that can con­tribute to long term health effects. A thermally efficient wall system with a high per­form­ing air barrier and well-designed HVAC system can also help by keeping the humidity and tem­per­a­ture well-regulated, keeping outdoor pol­lu­tants out, and effec­tive­ly filtering indoor pol­lu­tants before they cause problems.

Buildings need to be built better with a specific focus on the indoor air quality for the occupants. The Bautex Wall System™ gives archi­tects a thermally efficient and air tight building envelope option for com­mer­cial and res­i­den­tial con­struc­tion. Bautex Interior Wall Finish (IWF) is a direct-applied abuse-resistant plaster that can be applied to the Bautex Wall System as well as con­ven­tion­al­ly framed interior walls. The IWF finish provides a 0%VOC and 0%SVOC hardened surface that provides a healthier, stronger, and easier to maintain finish compared to con­ven­tion­al drywall and paint.

For more infor­ma­tion about indoor air quality and the Bautex Wall System, visit bau​texsys​tems​.com