Asbestos-Cement Products in Contact with Drinking Water: SEM Observations

摘要

In studying the health effects of asbestos fibers ingested in drinking water it is important to know whether water can corrode the surface of asbestos-cement products to facilitate the release of the fibers to the water. Also, in the case of asbestos-cement pipe, it is important to know whether chemical inhibitors can coat the surface of the pipe to curtail this release. Because of these needs, the effects of water on the surfaces of three asbestos-cement materials, namely, water pipes, cistern collecting tiles, and reservoir parapet walls, were studied using the Scanning Electron Microscope (SEM) and Energy Dispersive X-ray Analysis (EDXA). The micrographs from the SEM showed that the surfaces can be corroded, exposing and releasing fibers to the drinking water. The EDXA spectra showed that the surfaces of the asbestos cement materials can be chemically altered to cause the release of fibers. Also, these spectra showed that certain chemical inhibitors, under specific conditions, can coat the surfaces of pipe and presumably impede any fiber release.