School of Health Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, Indiana, USA.
Lyles School of Civil Engineering, Purdue University, West Lafayette, Indiana, USA.
Toxicol Sci. 2023 May 12;193(1):62-79. doi: 10.1093/toxsci/kfad029.
Cured-in-place pipe (CIPP) technology is increasingly being utilized to repair aging and damaged pipes, however, there are concerns associated with the public health hazards of emissions. CIPP installation involves the manufacture of a new plastic composite pipe at the worksite and includes multiple variable components including resin material, curing methods, and operational conditions. We hypothesize styrene-based composite manufacturing emissions (CMEs) will induce greater pulmonary inflammatory responses and oxidative stress, as well as neurological toxicity compared with nonstyrene CMEs. Further, these CME-toxicological responses will be sex- and time-dependent. To test the hypothesis, representative CMEs were generated using a laboratory curing chamber and characterized using thermal desorption-gas chromatography-mass spectrometry and photoionization detector. Styrene was released during staying, isothermal curing, and cooling phases of the process and peaked during the cooling phase. Male and female C57BL6/J mice were utilized to examine alterations in pulmonary responses and neurotoxicity 1 day and 7 days following exposure to air (controls), nonstyrene-CMEs, or styrene-CMEs. Serum styrene metabolites were increased in mice exposed to styrene-CMEs. Metabolic and lipid profiling revealed alterations related to CIPP emissions that were resin-, time-, and sex-dependent. Exposure to styrene-CMEs resulted in an influx of lymphocytes in both sexes. Expression of inflammatory and oxidative stress markers, including Tnfα, Vcam1, Ccl2, Cxcl2, Il6, Cxcl1, Tgfβ1, Tgmt2, and Hmox1, displayed alterations following exposure to emissions. These changes in pulmonary and neurological markers of toxicity were dependent on resin type, sex, and time. Overall, this study demonstrates resin-specific differences in representative CMEs and alterations in toxicity endpoints, which can potentially inform safer utilization of composite manufacturing processes.
原位固化管道（CIPP）技术越来越多地被用于修复老化和损坏的管道，但人们对排放物对公共健康的危害仍存在担忧。CIPP 的安装涉及在现场制造新的塑料复合管，并包括多个可变组件，包括树脂材料、固化方法和操作条件。我们假设基于苯乙烯的复合材料制造排放物（CME）将比非苯乙烯 CME 引起更大的肺部炎症反应和氧化应激，以及神经毒性。此外，这些 CME 毒性反应将具有性别和时间依赖性。为了验证假设，使用实验室固化室生成了代表性的 CME，并使用热解吸-气相色谱-质谱和光离子化检测器进行了表征。苯乙烯在过程的停留、等温固化和冷却阶段释放，并在冷却阶段达到峰值。雄性和雌性 C57BL6/J 小鼠被用于研究暴露于空气（对照）、非苯乙烯 CME 或苯乙烯 CME 后 1 天和 7 天肺部反应和神经毒性的变化。暴露于苯乙烯 CME 的小鼠血清中苯乙烯代谢物增加。代谢和脂质分析揭示了与 CIPP 排放物相关的变化，这些变化与树脂、时间和性别有关。暴露于苯乙烯 CME 导致两性淋巴细胞流入。炎症和氧化应激标志物的表达，包括 Tnfα、Vcam1、Ccl2、Cxcl2、Il6、Cxcl1、Tgfβ1、Tgmt2 和 Hmox1，在暴露于排放物后发生改变。这些毒性终点的肺部和神经变化取决于树脂类型、性别和时间。总的来说，这项研究表明，代表性 CME 存在树脂特异性差异，以及毒性终点的改变，这可能为更安全地利用复合材料制造过程提供信息。
