Laserfiche WebLink
r <br />m- -■ <br />|%i- <br />%tr <br />-fttx <br />[■ <br />•? <br />v.f'\ ;;'^--s <br />P|I' <br />S'-‘. <br />1 <br />f. ' <br />U *• <br />'.Ar,!f.. <br />■r^'. ■ <br />r^it <br />^./ ‘ <br />92-47.OS <br />The combined ash has been treated to nake the TAP a <br />physically suitable aggregate material and an environmentally <br />safe product. The TAP, as well as natural aggregate and existing <br />roadway soils, were analyzed using standardized procedures that <br />have been approved by the following agencies and scientific <br />organizations: <br />United States Environmental Protection Agency (U.S. EPA) <br />Minnesota Pollution Control Agency 'M^CA) <br />Minnesota Department of Transportation (MN DOT) <br />American Society for Testing and Materials (ASTM) <br />American Association of State Highway Transportation <br />Officials (AASHTO) <br />Health RlsX Assessment Methodology <br />Potential health risks and environmental effects associated <br />with the three roadway materials (unpaved roadway soil, natural <br />aggregate paving, and Test Section paving) were evaluated <br />according to U.S. EPA methods and criteria (1989). <br />The human health risk assessment process is composed of four <br />components: <br />Hazard Identification <br />Dose-Response Evaluation <br />Exposure Assessment <br />Risk Characterization <br />The hazard identification (sometimes referred to as <br />contaminant identification and toxicological evaluation; and <br />dose-response evaluation collectively comprise the toxicity <br />assessment. The risk assessment process is completed by <br />integrating the results from the toxicity assessment with the <br />site-specific exposure assessment to yield a complete <br />characterization of risk. <br />Hasard Identification <br />The objective of this component is to screen the informatici^ <br />and analytical data on the contaminants in roadway materials, and <br />to identify those contaminants which present potential adverse <br />effects to the exposed populations. This identification is <br />accomplished through the review of published scientific <br />literature regarding the toxicity of each contaminant. This <br />research may reflect animal and plant toxicity or actual human <br />exposure data. Important factors to be considered in the <br />toxicity evaluation of each chemical include contaminant release, <br />potential routes of exposure, contaminant mobility, types of <br />Hr ■