In vitro toxicity assessment of emitted materials collected during the manufacture of water pipe plastic linings

Abstract

U.S. water infrastructure is in need of widespread repair due to age-related deterioration. Currently, the cured-in-place (CIPP) procedure is the most common method for water pipe repair. This method involves the on-site manufacture of a new polymer composite plastic liner within the damaged pipe. The CIPP process can release materials resulting in occupational and public health concerns. To understand hazards associated with CIPP-related emission exposures, an in vitro toxicity assessment was performed utilizing mouse alveolar epithelial and alveolar macrophage cell lines and condensates collected at 3 worksites utilizing styrene-based resins. All samples were normalized based on the major emission component, styrene. Further, a styrene-only exposure group was used as a control to determine mixture related toxicity. Cytotoxicity differences were observed between worksite samples, with the CIPP worksite 4 sample inducing the most cell death. A proteomic evaluation was performed, which demonstrated styrene-, worksite-, and cellspecific alterations. This examination of protein expression changes determined potential biomarkers of exposure including transglutaminase 2, advillin, collagen type 1, perlipin-2 and others. Pathway analysis of exposure-induced proteomic alterations identified MYC and p53 to be regulators of cellular responses. Protein changes were also related to pathways involved in cell damage, immune response, and cancer. Together these findings demonstrate potential risks associated with the CIPP procedure as well as variations between worksites regarding emissions and toxicity. Our evaluation identified biological pathways that require future evaluation and also demonstrates that exposure assessment of CIPP worksites should examine multiple chemical components beyond styrene, as many cellular responses were styrene-independent.

Regulatory Significance of Plastic Manufacturing Air Pollution Discharged into Terrestrial Environments and Real-Time Sensing Challenges

“…These nonstyrene components of the emission mixture have shown to be responsible for toxicological effects ( S9 ). 51 PID sensors should not be used to estimate air pollution magnitude, gas-phase styrene concentrations, and the capabilities of these sensing technologies, and their limitations require scrutiny ( S9 ). 52…”

Evaluation of exposures to styrene during cured-in-place pipe liner preparation and during pipe repairs using hot water and steam.

“…Recent research on CIPP emissions have determined that styrene, benzaldehyde, phenol, and many other substances are often present in the air during the curing process [Teimouri Sendesi et al 2017]. Samples of these emissions have been shown to be harmful to lung cells, potentially predisposing exposed workers to the development or worsening of conditions such as fibrosis, obstructive pulmonary disease, and cancer [Kobos et al 2019].…”

Contaminant Release from Storm Water Culvert Rehabilitation Technologies: Understanding Implications to the Environment and Long-Term Material Integrity

“… 2019: In the U.S., an inhalation toxicology study of materials emitted from four steam CIPP manufacturing sites indicated potential health risks as well as variations between worksites regarding emissions and toxicity. The evaluation identified biological pathways that require future evaluation and also demonstrated that exposure assessment of CIPP worksites should examine multiple chemical components beyond styrene, as many cellular responses were styrene-independent (Kobos et al 2019).…”