Joint Sealants: An Overlooked Diffuse Source of Polychlorinated Biphenyls in Buildings

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• 作者：Martin Kohler ; Josef Tremp ; Markus Zennegg ; Cornelia Seiler ; Salome Minder-Kohler ; Marcel Beck ; Peter Lienemann ; Lukas Wegmann ; and Peter Schmid
• 刊名：Environmental Science & Technology
• 出版年：2005
• 出版时间：April 1, 2005
• 年：2005
• 卷：39
• 期：7
• 页码：1967 - 1973
• 全文大小：123K
• 年卷期：v.39,no.7(April 1, 2005)
• ISSN：1520-5851

文摘

In October 2000, joint sealants containing polychlorinatedbiphenyls (PCB) were discovered in various publicbuildings in Switzerland. Triggered by this event, anationwide comprehensive study was initiated by theSwiss Agency for the Environment, Forests, and Landscape,and 1348 samples of joint sealants as well as 160 indoorair samples from concrete buildings erected between 1950and 1980 were analyzed. Out of 1348 samples, 646 (48%)contained PCB. In 279 (21%) samples, PCB concentrationsof 10 g/kg and more were detected, and concentrationsof 100 g/kg of PCB or more were found in 129 (9.6%) samples.These data indicate that PCB were widely used asplasticizers in joint sealants in Switzerland. In buildingsconstructed between 1966 and 1971, one-third of all jointsealants investigated contained more than 10 g/kg of PCB.PCB concentrations exceeding the limit of 0.050 g/kgabove which material is required to be treated as PCBbulk product waste were reached by 568 samples (42%).PCB with a chlorine content between 45 and 55%,corresponding to mixtures such as Clophen A50, Aroclor1248, and Aroclor 1254, were encountered in 316 samples(70%). In 42 cases (26%) where joint sealants containingPCB were present, clearly elevated PCB indoor airconcentrations above 1 ges/entities/mgr.gif">g/m³ were encountered. In eightcases (5%), levels were higher than 3 ges/entities/mgr.gif">g/m³. The Swisstentative guideline value of 6 ges/entities/mgr.gif">g/m³ (based on a daily exposureof 8 h) for PCB in indoor air was exceeded in one case(0.6%). On the basis of this work, representing the first large-scale nationwide analysis of the issue of PCB-contaminatedjoint sealants, we estimate that there are still 50-150 t ofPCB present in these materials, acting as diffuse sources.They are distributed over many hundreds of buildings all overthe country and represent a significant but frequentlyoverlooked inventory of PCB. In light of the StockholmConvention on persistent organic pollutants that enteredinto force last year, reduction of the release of PCB fromthese widely used materials is an important issue to beaddressed.