Risk analysis of exposure to asbestos in demolition workers of old buildings in Tabriz city

Abstract

Introduction: In the past years, although the use and import of asbestos has been banned by many countries, including Iran, but according to statistics, due to the use of this substance over many years, this dangerous substance has been used in many buildings. It is found in abundance and the building demolition workers as well as people near the demolition site are exposed to this substance. The purpose of this study is to analyze the risk of exposure to asbestos in demolition workers of old buildings in Tabriz city. Methods: In this cross-sectional study, the presence of asbestos was investigated by inspecting old buildings and the buildings containing asbestos materials were included in the study. Sampling was done from the breathing zone of the workers of the studied buildings during the demolition of the building, and after analysis by SEM and PCM methods, the amount of exposure to asbestos during the demolition was determined. Next, carcinogenic risk assessment was performed using the method proposed by the US Environmental Protection Agency, as well as semi-quantitative risk assessment according to the method provided by the Singapore Occupational Health Department. Finally, management solutions for asbestos risk management during building demolition were presented. The collected data were analyzed using SPSS version 25 software and presented descriptively such as mean, standard deviation. Also, Pearson's correlation test was used to investigate the relationship between semi-quantitative risk assessment and carcinogenic risk. Results: Based on the obtained results, for all the sampled buildings, the average asbestos concentration based on SEM-EDS analysis, which shows the actual concentration of asbestos in the breathing air of the workers, is 0.031±0.023 fibers per milliliter. It was found that it is lower than the standard amount of exposure to asbestos (0.1 fiber per milliliter). Among the fibers in the samples, 67% were asbestos fibers, among which 12.5% were chrysotile, 25% were tremolite, 12.5% were actinolite, and 17% were amosite. Also, the results of the semi-quantitative risk assessment showed that the risk rating of exposure to asbestos in the building demolition process is medium. The results of the carcinogenic risk assessment indicated "considerable carcinogenic risk" for the building demolition workers. The results of statistical analysis showed a positive and significant correlation between semi-quantitative risk assessment and carcinogenesis; also, the asbestos risk management program was presented by reviewing and studying existing programs and articles in the field of asbestos management. Conclusion: Exposure to asbestos exists in most of the sampled buildings, and the building demolition workers are exposed to different concentrations of this substance. The risk of rat generation obtained is "considerable" and as a result, the possibility of lung cancer among the demolition workers is high; Due to the significant risk of cancer, it is necessary to avoid exposure to asbestos during building demolition. The management program presented in this study can be implemented to eliminate and reduce exposure to asbestos during the demolition of buildings that contain asbestos-containing materials.