Trenchless Technology Center, College of Engineering and Science, Louisiana Tech University, Ruston, LA 71272, USA.
Engineering Research and Development Center, United States Army Corps of Engineers, Vicksburg, MS 39180, USA.
Int J Environ Res Public Health. 2022 Oct 24;19(21):13800. doi: 10.3390/ijerph192113800.
Cured-in-place pipe (CIPP) is one of the most popular in situ rehabilitation techniques to repair sewer and water pipes. While there are multiple approaches to curing CIPP, steam-curing of styrene-based resins has been found to be associated with air-borne chemical emissions. Health officials, utilities and industry representatives have recognized the need to know more about these emissions, especially styrene. Such concern has led to multiple studies investigating the concentrations of volatile organic compounds on CIPP installation sites. This study expands upon previous effort by modeling worst-case, steam-cured CIPP emissions over a 5-year weather record. The effort also includes calibration of the model to emissions averages over the work day rather than instantaneous field measurements. Dispersion modelling software, AERMOD, was utilized to model the styrene component of CIPP emissions on two CIPP installation sites in the US. Based on the analysis results, it was found that the styrene emitted from stacks dissipates rapidly with styrene concentrations only exceeding minimum health and safety threshold levels at distances close to the stack (2 m or less). The values predicted by the model analysis are comparable with the field measured styrene concentrations from other studies. Current safety guidelines in the US recommend a 4.6-m (15-ft) safety perimeter for stack emission points. The results of this study indicate that significant and lasting health impacts are unlikely outside recommended safety perimeter. The results also validate the importance of enforcing recommended safety guidance on steam-cured CIPP sites.
原位固化管道（CIPP）是修复污水和供水管的最受欢迎的原位修复技术之一。虽然有多种方法可以固化 CIPP，但已发现蒸汽固化苯乙烯基树脂与空气传播的化学排放物有关。卫生官员、公用事业和行业代表已经认识到需要更多地了解这些排放物，尤其是苯乙烯。这种关注导致了多项研究调查 CIPP 安装现场挥发性有机化合物的浓度。本研究通过对过去 5 年的天气记录进行最坏情况蒸汽固化 CIPP 排放建模，扩展了以前的研究。该研究还包括将模型校准到工作日的排放平均值，而不是瞬时现场测量。利用扩散建模软件 AERMOD 对美国两个 CIPP 安装现场的 CIPP 排放的苯乙烯成分进行建模。根据分析结果，发现从烟囱排放的苯乙烯会迅速消散，只有在靠近烟囱的距离（2 米或更短）处，苯乙烯浓度才会超过最低健康和安全阈值。模型分析预测的值与其他研究中从现场测量的苯乙烯浓度相当。目前美国的安全指南建议对烟囱排放点设置 4.6 米（15 英尺）的安全半径。本研究的结果表明，在推荐的安全半径之外，不太可能产生重大和持久的健康影响。结果还验证了在蒸汽固化 CIPP 现场执行推荐安全指南的重要性。
