Asbestos Portions of El Dorado County are known to contain natural asbestos formations near the surface. The USGS studied amphiboles in rock and soil in the area in response to an EPA sampling study and subsequent criticism of the EPA study. The study found that many amphibole particles in the area meet the counting rule criteria used by the EPA for chemical and morphological limits, but do not meet morphological requirements for commercial-grade-asbestos. The executive summary pointed out that even particles that do not meet requirements for commercial-grade-asbestos may be a health threat and suggested a collaborative research effort to assess health risks associated with naturally occurring asbestos.
asbEstoS POrtions Of eL dorado COunTy are knoWn tO cOntain natUraL AsbEStos formAtIOnS Near ThE suRFacE. The usgs stUdIed AMphiboLeS in ROCk anD soil iN the arEa In respOnse to aN epa sampliNG sTudy aNd subSEquEnt criTicIsm Of THE epa StUdy. thE sTUdy found ThaT many AmPHiBoLE pArTIcLes in thE area mEeT tHe cOUntiNg rule cRiTEria useD by The epa For chEMical and MoRpHOlOgical LimitS, but dO noT meet MoRpHoloGicaL Requirements foR commERcIal-gradE-asBeStos. the exEcutive SUmma.Ry poiNtEd out thAt EVen pARticleS thAt do nOt MEEt Requirements for coMMErCiAl-gradE-ASbesTos mAy be a hEALTh threAT And sugGestEd A collaBOratIVE rESeaRCh efFOrT To asSeSS heALth risks aSsOCiated wIth nAtUrallY OccuRriNg AsbeStoS