NATURALLY OCCURRING ASBESTOS: AN ALTERNATE ANALYSIS

As a known carcinogen and inducer of fibrotic lung disease, asbestos has been a serious concern for occupational and public health and safety for over three decades. The asbestos issues familiar to the scientific and medical communities are the exposure consequences from ore-grade asbestos mining, milling, manufacturing and removal activities. Recently, the issue of naturally occurring (non-commercial) asbestos (NOA) deposits has gained the regulatory and public spotlight. There is debate regarding the mineral identification and morphology of this purported asbestos. The lack of supporting epidemiological evidence pointing to increased public health risk with respect to NOA further complicates the matter. As populations sprawl, mineral dust exposure resulting from the disturbance of local rock and soil has become a contentious issue. The experience in El Dorado Hills, CA is illustrative of the dissension within the scientific community regarding the actual nature of the mineral species involved.

This presentation will specifically address the analysis of mixed mineral dust generated from sampling in El Dorado Hills. RJ Lee Group employed both standard and alternative methodologies to analyze this dust for mineral constituents. The resulting data indicate that the minerals in question deserve much greater scrutiny than standard analytical techniques provide in order for the minerals to be positively identified and therefore regulated as asbestos.

Current federal regulatory language and published laboratory analytical methods are oriented toward addressing exposure to ore-grade asbestos present in manufactured materials. Standard requirements for all appropriate inquiry and analytical practices do not sufficiently address non ore-grade deposits. The State of California has begun to develop policy with the specific aim of curtailing exposure to NOA. Non-commercial potentially asbestos containing rock deposits present a number of difficulties with respect to comparison with the body of evidence and practice derived from industrial exposure. It is in the national interest that appropriate revisions to current analytical and risk assessment techniques be implemented before the El Dorado experience is repeated.