With increased airtightness believed to cause serious health problems, architects need to consider the harmful emissions coming from some building materials, argues Tom Woolley
The unintended consequences of increased air tightness in buildings have been recognised (Airtightness blamed for health risks in homes), but these are often interpreted as problems concerning ventilation. While it is essential to ensure that ventilation is effective and adequate, what is often overlooked is the source of hazardous materials that, without adequate ventilation, can lead to ill health.
There is considerable evidence of health problems resulting from increased air tightness, and this is because pollutants are trapped inside buildings for far longer. Even good ventilation will not always remove toxic and hazardous chemicals that are bound into the building fabric. Furthermore, dampness and mould, which are also being found in new airtight homes, are aggravated by modern construction materials that cannot deal with moisture and increased humidity.
Many ailments can be directly attributed to chemical emissions in buildings
The World Health Organisation (WHO) and the EU have identified bad indoor air quality as a significant contributor to poor health. One report, from the Royal College of Physicians and the Royal College of Paediatrics and Child Health, suggests it causes 99,000 deaths annually in Europe.
Data linking bad air quality and health problems is patchy, as until recently this had been overlooked in medical research. However, asthma, other respiratory illnesses, allergies and many other ailments can be directly attributed to chemical emissions in buildings. Even more serious are problems of reproduction and child development linked with ‘endocrine’-disrupting chemicals such as flame retardants. There is also significant research that suggests environmental causes of cancer need to be taken much more seriously.
The UK government, though its Committee on the Medical Effects of Pollutants (COMEAP), has decided to ignore indoor air quality and concentrate on external pollution from traffic. But external pollutants get into houses and become trapped in fabrics and materials, and the WHO says indoor air pollution can be 10 times worse than external.
The government has undoubtedly been lobbied by the manufacturers of synthetic insulation materials, plastic membranes, adhesives, composite timber products, glues, sealants and flooring materials, encouraging it to turn a blind eye to the hazardous emissions from such products.
There are a wide range of construction materials and methods that do not contain hazardous chemicals
It is possible to avoid many of the problems of airtight and unhealthy buildings through good design and specification, by adopting the precautionary principle. There are a wide range of construction materials and methods (some certified by natureplus) that do not contain toxic carcinogenic or hazardous chemicals, and they are frequently breathable and hygroscopic, helping to reduce moisture and damp problems. Materials such as wood fibre insulation, hempcrete, sheep’s wool, linoleum flooring and so on are readily available.
Indoor air emissions standards can be specified as part of a contract; and are now incorporated into BREEAM standards. Minimisation of volatile chemical emission standards is already included in the Building Regulations, but seldom enforced. Relatively inexpensive indoor air sampling methods are now available and are simple to carry out.
This is a vast and complex subject and much of the evidence of health problems related to hazardous building materials remains convincing but circumstantial. I have set out much of the evidence and conflicting views in my new book, Building Materials, Health and Indoor Air Quality, (Routledge, £34.99). A number of organisations such as the UKIEG, ASBP, Natureplus and ISIAQ are available to give advice.
Contact me at firstname.lastname@example.org for more information