Risk assessment of asbestos cement roofs in Chekka : a pilot study

Abstract

This study assessed the risk of asbestos fibers presence in Eternit corrugated sheets in the urban-industrial city of Chekka, North Lebanon. Corrugated asbestos-cement sheets (total of 963m2 ) were examined using different methods to assess their friability and the exposure potential of the nearby population. Two quick assessment algorithms previously used in Italy and the standardized pull-up test were used. Crocidolite fibers were visually identified in most of the studied roofs. The algorithm results showed that most of the roofs should be removed, whereas the pull-up scores indicated a relatively lower hazard. The pull-up test showed that microclimatic conditions might be standing behind the segregation of the results between the roofs. Depending on the location of the studied roof, the reasons for high surface release was possibly related to erosion, abrasion, water leaching and moss development. Vulnerability and hazard criteria were used to determine the associated risk for each roof. The risk map showed a total of 738m2 roof surface classified as "high risk". This risk analysis proved to be a better choice compared to the use of the algorithms or the pull-up test alone for decision making. The results of this study suggest the removal of the high-risk asbestos surfaces. Additional recommendations such as raising awareness were proposed at municipal and ministerial levels to highlight the importance of professional removal activities versus the current chaotic removal.