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Presenter Bio: Lennart Larsson

Lennart Larsson holds a PhD in analytical chemistry and is professor in microbial metabolomics at Lund University, Sweden. During the past 25 years his research has focussed on indoor air quality especially in relation to building dampness, and in 2010 he launched a new product, the surface emissions trap (cTrap). The cTrap ( is a unique adsorption cloth that is currently being used in Europe to stop the spread of harmful microbial and chemical emissions from building materials into the indoor air. Dr Larsson is mainly known for his mass spectrometry-based research on endotoxins and mycotoxins in the indoor environment.

Presentation Description:

Creosote and pentachlorphenol (PCP) have been widely used as wood preservatives. Both pose cancer and non-cancer health risks. The negative health effects of creosote, a product derived from the distillation of tar from wood or coal, are largely due to the presence of polycyclic aromatic hydrocarbons (PAH). Buildings containing PCP-treated wood typically also contain chloroanisoles (CA) formed from moisture acting on chlorophenols. Many CA have a strong and disturbing mold-like odor. Importantly, these chemicals may be spread from building into the indoor air resulting in a variety of building related illnesses (BRI). In the present communication we describe how such spread can be prevented by using an emissions barrier. In the examples given we used the surface emissions trap (cTrap), a device developed from research at Lund University Sweden.

We studied an old cultural building where a wall had been treated with creosote as a combined impregnation agent and moisture barrier. There was a strong disturbing smell inside the building similar to that of car tires or asphalt which persisted even after the tar material had been removed; then, the indoor air concentration of PAH (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluorants, pyrene, biphenyl, and dibenzofuran) was 1726 ng/m3. The cTrap cloth was installed on about 75 percent of the wall surface (because of the uneven surface structure it was not possible to cover the entire wall), and attached and secured at the wall surface by using an adhesive tape. After the cloth had been installed there were no longer complaints regarding odor and the air concentration of PAH decreased to 139 ng/m3 thus corresponding to a reduction of 92 percent.

We studied a summer house built in 1964 with disturbing "summer cottage smell" due to prior PCP treatment. Ceilings, walls and floors in the bedroom, but not the living room, as well as the doorway between the bedroom and the living room, were covered with the cTrap cloth. Subsequently, air sampling for chlorophenols/chloranisoles was done simultaneously in both the living room and the bedroom. The air concentrations of the detected chlorophenols/chloranisoles were lowest in the bedroom. For 2,3,4,6-tetrachlorophenol the decrease was 93%. For the other substances the decrease could not be quantified because the concentrations in the bedroom were below the detection limits. The disturbing odor disappeared.

The cTrap is a flexible breathable four-layer laminate with a hydrophilic polymer layer functioning together with an adsorption layer. It is air tight while allowing moisture to pass almost without any resistance at all. Covering indoor surfaces from where the emissions are being spread (floor, ceiling, walls) with the cTrap will stop and adsorb the emissions thus preventing them from reaching the indoor air (Markowicz and Larsson 2012; 2015).

In summary, a new generation of emission barriers has been developed offering an efficient, economic, quick, and environment-friendly tool against BRI.