Many people see the buildings around them as inert units: Structures of lifeless stone, brick, and wood which do not interact with the surrounding environment in any meaningful way. This view is, however, erroneous; buildings form part of a living, breathing human ecosystem, one which is constantly evolving as buildings are built, damaged, destroyed, and repaired. Through this complex process, the sustainability of a building affects not only the health of the planet, but also that of the building’s occupants.
Just as decaying organic matter releases gas, as our buildings age, they emit vapours. As the complexity of our structures has dramatically increased over the last two centuries, so too has the range of materials required to construct our homes and offices, leading to a manifold increase both in energy consumption and the number of chemicals commonly found in indoor environments. The International Living Future Institute’s “Material Red List”, for example, delineates over a dozen environmental contaminants frequently found in conventional building materials which have been proven to negatively impact human health:
- Chlorinated Polyethylene and Chlorosulfonated Polyethlene
- Chlorofluorocarbons [CFCs]
- Chloroprene [Neoprene]
- Formaldehyde [added]
- Halogenated Flame Retardants
- Hydrochlorofluorocarbons [HCFCs]
- Lead [added]
- Petrochemical Fertilisers and Pesticides45
- Polyvinyl Chloride [PVC]
- Wood treatments containing Creosote, and Arsenic or Pentachlorophenol
Urea formaldehyde—a known human carcinogen which has been proven to have no safe level of exposure and which is a potent eye, nose, throat and lung irritant—is perhaps the most prevalent concern. It is typically found in particleboard, and the glue that is used to construct cabinets, counter tops, stair treads, and shelving. Formaldehyde has been shown to “off gas” for years.
In addition to formaldehyde, other common sources of carcinogenic chemicals include the synthetic rubber used in carpeting, and the vinyl chloride and plasticisers found in PVC flooring materials and shower curtains. Vinyl chloride is particularly notorious for leeching out into the surrounding environment; today it is found in oceanic fish and the fat of polar bears. (David Johnston, “Indoor Air Quality as Important as Energy Efficiency”)
All of the aforementioned is especially worrying when one considers that the average citizen of the developed world spends, at a low estimate, 90 per cent of his or her time indoors, with the elderly and those who are already struggling with health issues spending even more time confined to indoor spaces.
While it is difficult to prove a direct cause-and-effect relationship between building materials and cancer rates, there is one area where indoor air pollution and human health issues have been proven to correlate: Asthma, particularly in children, has been found to increase in indoor environments where high levels of formaldehyde are present.
The Sustainability of a Building and Asthma: Disaster in the Gulf
One of the best bodies of evidence we have regarding the link between unsustainable building materials and asthma arose in the wake of Hurricane Katrina. After hurricanes Katrina and Rita struck in 2005, FEMA awarded $2.7 billion in contracts to shelter the displaced residents of the United States’ Gulf Coast region, sending them to live largely in trailers and mobile homes. FEMA’s bidding process for said mobile homes failed to take into consideration the potential health impacts of bringing the formaldehyde-rich materials found in these units into a hot and humid climate where formaldehyde would be more readily volatilised. Disaster, of course, ensued.
According to the report “Asthmagens in building materials: The Problems and Solutions” (2014), “A meta-analysis of seven studies in homes and schools from several different countries concluded that asthma risk in children increased 3-17 percent for every 10 µg/m3 [8.1 parts per billion (ppb)] increase in formaldehyde in indoor air. In these studies, formaldehyde levels varied from very low to > 80 µg/m3 (65 ppb). A U.S. Centres for Disease Control (CDC) study of Katrina FEMA trailers found formaldehyde well above these levels. The mean for the 519 tested trailers was 77 ppb. In some, air concentrations exceeded 300 ppb. The most common unit – Gulfstream – had a median concentration of 111 ppb, almost seven times the national median of 17 ppb. Using the meta-analysis’ correlation rate, children living in the Gulfstream FEMA trailers had a 35% to 200% elevated risk of having asthma. In a federal health survey of FEMA trailer residents, 31% of the participating children reported having a diagnosis of asthma, nearly three-fold higher than the prevalence of childhood asthma nationally (11% in 2010).”
Sadly, as the FEMA contracts “did not contain protections against excessive formaldehyde concentrations,” little could be done to rectify the plight of these unfortunate individuals in a timely manner.
How the Sustainability of a Building Makes a Difference: Choosing Sustainable Materials
Part of sustainable architecture is the policy of using low-impact building materials wherever feasible, including insulation made from low VOC (volatile organic compound)-emitting materials such as recycled denim or cellulose (often treated with boric acid to deter pests). As conventional insulation materials are one of the primary sources of formaldehyde and other toxic chemicals, this goes a long way toward cutting down indoor air pollution. Likewise, organic or milk-based paints are often used.
This is not to suggest, however, that all green materials are completely free of chemicals—certain substances, like arsenic, do occur organically. The investigation into how to reduce even these natural compounds in sustainable materials is ongoing, but even as it stands, emerging research (such as James J. P. Yang’s 2005 study, “Indoor and Built Environment, Emissions of Volatile Organic Compounds from Several Green and Non-Green Building Materials: A Comparison”) demonstrates that green materials routinely contain fewer VOCs and have been found to be better for both human and environmental health.