ASTM E2020-99a pdf free.Standard Guide for Data and lnformation Options for Conducting an EcologicalRisk Assessment at Contaminated Sites.
Consider the environmental fate and transport of thechemicals,including degradation products.Consider the bioavailability of constituents， for ex-ample，dissolved metal concentrations in water for exposureevaluation of aquatic species.Consider seasonal influences on exposure, in termsof biotic responses，for example.increased sensitivity duringreproductive season,diet cormposition changes.types of spe-cies present, for example, species that migrate or hibernate, andmedia fluctuations，for examplc，groundwater discharges tosurface water during different seasons.For media in which constituent concentrations areexpected to increase or decrease in the future，estimate thefuture exposure levels, if relevant and feasible.Ensure that analytical detection limits are below toxi-cological thresholds, if practicable.Apply appropriate statistical approaches for the calcu-lation of exposure concentrations.
Characterization.In addition to the data and information options listed inSection 10, the following may be considered for a complexERA exposure characterization.Obtain information on potential nonchemical stressors,and identify any expected seasonal changes in these stressors.Modes of Exposure:Describe “direct exposures for chemical andnonchemical stressors,including factors as follows. Some of the data and information options in effectscharacterization are applicable to both screening and complexERAs and are outlined below.Additional data and informationtypically found only in complex ERAs are listed in Section 13.12.2 Toxicological Benchmarks:Obtain relevant federal，state，and other applicablecriteria and guideline values that may be used as toxicologicalbenchmarks，such as the following:National/state ambient water quality criteria(USA);National/provincial sediment and water qualityguidelines (Canada);Guidelines published in peer-revicwed journals, forexample,Rcf (8);or, National/state soil standards.Describe the method used to develop toxicity bench-marks that are not criteria or guidelines as described previ-ously,for example,weight of evidence, see Ref.(2), or fromliterature data，Refs. ( 9-14).Consider development of toxicological profile for eachconstitucnt of concern and cndpoint species.Consider dose-response information,including bothno-effect and low-effect levels,when available.Consider lethal and sublethal toxicity endpoints.12.3.3 Consider information on bioaccumulation in end-point species and their food.Consider information,such as persistence, degrada-tion half-life，octanol-water partition coefficient(Kow)，andother relevant chemical information. Consider information on any known interactionsbetween the constituent of concern and any other constituentsat the site.Consider the scasonality of potential effects，forexample,life stage or physiological state.Consider structure activity relationship information.ASTM E2020 pdf download.