Issue link: https://hi.iaq.net/i/664324
EMISSIONS FROM BUILDING MATERIALS INTO THE INDOOR AIR. SOURCES AND CONTROL Lennart Larsson 1 and Johan Mattsson 2 1 Department of Laboratory Medicine, Lund University, Sölvegatan 23, 22362 Lund, Sweden 2 cTrap Ltd, Scheelevägen 15, 223 70 Lund, Sweden * Corresponding email: lennart.larsson@med.lu.se Introduction Unsatisfactory indoor air quality (IAQ) may result from volatile organic compounds (VOCs) and/or particles contaminating the air. Both long- and short-term exposure to VOCs can result in eye, nose, and throat irritation, allergic reactions, headache, fatigue etc (Fiedler et al. 2005). Particles that may carry e.g. microbial compounds such as mycotoxins and endotoxins are also of health concern. Contaminants may leak in from outdoor air, e.g. from industry or traffic. Items brought indoors (furniture, clothes, tools, toys, cleaning agents etc) may contain irritating or harmful chemicals; examples that are particularly worrying are plasticisers (acting as hormone disruptors) and brominated flame retardants. Such substances may adhere to dust particles and contaminate the indoor air. Human activity indoors may also contribute to air contamination (e.g. stirring up dust by walking, cooking, smoking etc); petkeeping leads to more of microbes indoors. Finally, emissions may also spread to the indoor air from the building itself. Such emissions may result from the effect of water on a particular material. Examples are 2-ethylhexanol and n-butanol formed from alkaline hydrolysis of components of PVC flooring and glue applied on a moist concrete floor (Björk et al. 2003). Some of these emissions may be relatively easy to control, i.e. by using adequate ventilation, not bringing items loaded with chemicals indoors, or modifying occupancy behavior. Emissions from the building itself are harder to control. Here we describe ways to handle the latter type of emissions and, in particular, a new tool for emissions control that has been developed at Lund University, Sweden - the surface emissions trap. What is healthy indoor air? According to the so-called "hygiene hypothesis" exposure to a balanced mix of bacteria early in life facilitates a sound development of the immune system leading to allergy protection. Endotoxin, a family of potent proinflammatory agents present in all gram-negative bacteria, has long been in focus in this context; the results have however been confusing. A study from 1996 reported that high levels of endotoxin in home environments related to the severity of asthmatics´ symptoms (Michel et al. 1996). Another study found that endotoxin levels in home environments correlated with the prevalence of wheeze in infants (Milton et al. 2001); almost simultaneously, Braun-Fahrländer et al. reported that endotoxin levels in dust from childrens´ mattresses correlated inversely with occurrance of hayfever and atopic asthma (Braun-Fahrländer et al. 2002). Thus, endotoxin was found to be a negative health factor in two of these studies while the opposite was found in the third study. Later it was suggested, from chemical analyses of endotoxin-specific components in house dust samples, that some endotoxins are health-promoting whereas other endotoxins are associated with negative health effects (Norbäck et al. 2014, Zhao et al. 2008, Zhang et al. 2011). On the basis of these IAQA 19th Annual Meeting The views and opinions herein are those of the volunteer authors and may not reflect the views and opinions of IAQA. The information is offered in good faith and believed to be reliable but it is provided without warranty, expressed or implied, as to the merchantability, fitness for a particular purpose or any other matter. IAQA 19th Annual Meeting, Orlando, FL, January 24 – 27, 2016