Nationwide and globally there is a growing need for repair of sanitary sewer, storm sewer, and drinking water pipes. The cured-in-place pipe (CIPP) method has become the most popular method to repair deteriorated water pipes. This process involves the onsite chemical fabrication of a polymer composite plastic pipe within the damaged pipe. Recent evidence has indicated public health incidences related to chemical air contamination emitted from CIPP sites. These incidents span 29 states and have prompted evacuations of office buildings, homes, and schools. Our recent evaluations of CIPP worksites have identified emissions containing numerous hazardous air pollutants, carcinogens, endocrine disrupting compounds, and others that are being released into the environment. Further, our preliminary in vitro examination of emission-related toxicity demonstrated site- specific responses suggesting the impact of CIPP operational procedures. Specifically, the differential toxicity was determined via alterations in cytotoxicity, as well as gene and protein expression changes in markers of inflammation and oxidative stress. The multitude of resins, curing approaches, and environmental conditions along with the transient nature of worksites, impacts the ability to perform systematic evaluation of emissions and toxicity. Therefore, we have produced a novel curing chamber to characterize CIPP-related emissions and examine adverse biological responses. The central objective of this proposal is to investigate CIPP operational procedures that influence emissions and toxicity. Our hypothesis is that commonly utilized resin materials (styrene or non-styrene based) produce distinct emissions during the curing process that result in differential toxicity following inhalation. To address our hypothesis, we propose the following specific Aims: 1. Evaluation of differential CIPP-related emission profiles due to resin materials, and 2. Assessment of adverse health effects following inhalation exposure to CIPP-emissions.
In Aim 1, tubing impregnated with either styrene or non-styrene based resin will be thermally cured within the curing chamber and emissions will be characterized via photoionization detectors and gas chromatography-mass spectrometry.
In Aim 2, male and female mice will be exposed to filtered air (controls), CIPP emissions, or styrene-only and examined for pulmonary and liver toxicity (inflammation and oxidative stress) as well as alterations in serum metabolites. At the completion of this project, it is our expectation that we will have begun to elucidate the relationship between CIPP resin materials, emission profiles, and toxicity. Ultimately, the long-term impact of this research will be the potential to regulate risk, related to CIPP emission exposures by the general public through defining safe operational procedures.
The cured-in-place pipe procedure is increasingly being utilized to repair the U.S. water infrastructure, however results in the release of toxic emissions into the air. There exists a gap within our current knowledge regarding the risks associated with cured-in-place pipe emission exposures and the impact of common variations in operational procedures. This project will utilize a novel curing and exposure chamber system to examine modifications in emissions resulting from the use of styrene and non-styrene based resin materials as well as their impact on toxicity outcomes, thereby producing new knowledge necessary to protect public health.
