Serpentine and amphibole minerals can be found in the bedrock of about forty percent (40%) of the United States. With the proper geological conditions, these minerals may form into long, thin fibers that could have (at one time) commercial value and would be classified as "asbestos". In California, specifically in the western foothills of the Sierra Nevada mountains and the Coast Range mountains, the bedrock contains these minerals. Within this bedrock, where the rock has undergone significant shearing or faulting, these minerals may occur as asbestos.
The El Dorado Hills region, located in the western foothills of the Sierra Nevada mountains, has experienced significant population growth over the last 40 years, resulting in extensive building development. Parts of these developments have occurred over the regions of bedrock that may contain asbestiform amphibole and chrysotile minerals, raising the residents' concerns over possible exposure to the minerals. Prior testing and evaluations of the soils have been conducted by local and state authorities and verified that amphibole and serpentine minerals are in the local soils.
At the request of a citizen, the U.S. Environmental Protection Agency (EPA) assessed the possible exposure to airborne asbestos fibers in several locations in and around El Dorado Hills in the parks and school areas. This assessment, conducted in October 2004, comprised of conducting a series of activities typical of the areas being investigated, collecting the generated airborne particles, and analyzing these particles for asbestos concentrations. In May 2005, an interim final report [1] of these assessments was issued. Figure 1-1 shows the locations of the test areas in El Dorado Hills, CA.
RJ Lee Group obtained the produced laboratory data for this assessment and has evaluated the data to determine the reliability of these analyses. RJ Lee Group also received several split samples of soil taken from the areas where activity-based air samples were collected. This report details the evaluation of these data from the testing in El Dorado Hills as well as summarizes the results of the soils testing.
[ 1] Ecology and Environment, Inc. (2005). "El Dorado Hills Naturally Occurring Asbestos Multimedia Exposure Assessment El Dorado Hills, California Preliminary Assessment and Site Inspection Report Interim Final", Contract No. 68-W-01-012; TDD No.: 09-04-01-0011; Job No.: 001275.0440.01CP.
1.1 Background on RJ Lee Group
RJ Lee Group, Inc., ("RJ Lee Group") has its principal office in Monroeville, Pennsylvania, and laboratories in San Leandro, California; and Manassas, Virginia. RJ Lee Group provides research, analytical and consulting services relating to materials characterization [2].
RJ Lee Group has a long history of scientific consulting and service for government agencies, including the U.S. Environmental Protection Agency (EPA). RJ Lee Group’s laboratory has served as a quality assurance and referee laboratory on a number of EPA programs and performed the analyses for the EPA’s major study on airborne levels of asbestos in public buildings. RJ Lee Group has participated in the development by the EPA and American Society for Testing and Materials (ASTM) of analytical methods and procedures for asbestos analyses. The EPA requested that Dr. Richard Lee (President of RJ Lee Group) personally participate in several projects, including the drafting of the analytical portions 3 of the EPA Asbestos Hazard Emergency Reduction Act (AHERA) regulations governing air sample analysis following an asbestos abatement. Dr. Lee was also a member of the literature review panel for the Health Effects Institute – Asbestos Research (HEI-AR) program that summarized the existing literature of asbestos up to 1990.
RJ Lee Group also performs analyses for the United States Navy, the United States Army and the United States General Services Administration. RJ Lee Group has developed a program to determine the cause of failure in components of the guidance system in the Trident missile for the Department of the Navy. RJ Lee Group’s laboratory has also performed microscopic analyses for the State of California Air Resources Board when that agency performed testing of the air in major cities in the State of California to determine the presence of asbestos.
[2] Materials characterization of bulk building materials, also referred to as "constituent analysis", involves analyzing a sample of material using various techniques to identify and quantify the components of that material. 3 The TEM analytical method can be found at 40 CFR, Part 763, Appendix A to Subpart E.
Summary -- Intro -- Data Source -- Analysis of El Dorado Hills Air Samples -- Analysis of El Dorado Hills Soil Samples
