The Office of Toxic Substances of the Environmental Protection Agency has sponsored a nationwide survey to determine the impact of point and non-point sources on levels of waterborne asbestos. Part I of the final report presented the results of analyses of water from the ten Regional cities. Part II of the final report, contained herein, presents the results of the analyses of water from natural sources and from point sources manufacturing asbestos products. The results described indicate that waterborne levels of asbestos originating from natural sources may be as high as 10 to the 8th power fibers per liter and is subject to seasonal variation. Where asbestos was found, fibers were usually below 5 micrometers in length. Levels of asbestos originating from asbestos product manufacture may range from below the detection limits of electron microscopy to values in excess of 10 to the 12th power fibers per liter. Levels of asbestos fibers above 5 micrometers in length were found in excess of 10 to the 11th power fibers per liter. The major impact on the environment due to such sources would be expected from asbestos paper plants which combine a high fiber content with a large effluent flow.

"Final report part II." "October 1976." "EPA Project Officer Robert J. Carton." "EPA Contract No. 68-01-2690." "EPA-560/6-76-020." "Office of Toxic Substances."