1、DRAFT FOR DEVELOPMENTDD ISO/TS 17924:2007Soil quality Assessment of human exposure from ingestion of soil and soil material Guidance on the application and selection of physiologically based extraction methods for the estimation of the human bioaccessibility/ bioavailability of metals in soilICS 13.
2、080.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD ISO/TS 17924:2007This Draft for Development was published under the authority of the Standa
3、rds Policy and Strategy Committee on 29 February 2008 BSI 2008ISBN 978 0 580 53132 3National forewordThis Draft for Development is the UK implementation of ISO/TS 17924:2007.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publica
4、tions and is of a provisional nature. It should be applied on this provisional basis, so that information and experience of its practical application can be obtained.Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international o
5、rganization responsible for its conversion to an international standard. A review of this publication will be initiated not later than three years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period wil
6、l be made in an announcement in the appropriate issue of Update Standards.According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification o
7、r to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical Committee at British Standards House, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to Technical Committee EH/4, Soil quality.A list of organizations represented
8、on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Amendments/corrigenda issued since publicationDate CommentsReference numberISO/TS 17924:2007(E)TECH
9、NICAL SPECIFICATION ISO/TS17924First edition2007-12-15Soil quality Assessment of human exposure from ingestion of soil and soil material Guidance on the application and selection of physiologically based extraction methods for the estimation of the human bioaccessibility/bioavailability of metals in
10、 soil Qualit du sol valuation de lexposition humaine par ingestion de sol et de matriaux du sol Lignes directrices pour lapplication et la slection de mthodes dextraction fondes sur le point de vue physiologique pour lestimation de la bioaccessibilit/biodisponibilit pour ltre humain de mtaux dans le
11、 sol DD ISO/TS 17924:2007ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Bioaccessibility/bioavailability as a concept in assessment of soils and sites with respect to human exposure. 3 5 Description of the mechanisms of human contam
12、inant uptake 5 6 Description of metal-binding mechanisms (speciation of metals) in soil 8 7 Concept for a method to test the bioavailability through human exposure. 8 7.1 General. 8 7.2 Choosing an appropriate test 9 7.3 Description of applicable test methods 11 7.4 Recommendations 12 7.5 Use and in
13、terpretation of in vitro tests for risk assessment 13 8 Data handling, quality control and presentation of results 14 Annex A (informative) Human bioaccessibility testing 15 DD ISO/TS 17924:2007iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national
14、 standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internationa
15、l organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules
16、given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at lea
17、st 75 % of the member bodies casting a vote. In other circumstances, particularly when there is an urgent market requirement for such documents, a technical committee may decide to publish other types of document: an ISO Publicly Available Specification (ISO/PAS) represents an agreement between tech
18、nical experts in an ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the parent committee casting a vote; an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical committee and is accepted for publicatio
19、n if it is approved by 2/3 of the members of the committee casting a vote. An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is confirmed, i
20、t is reviewed again after a further three years, at which time it must either be transformed into an International Standard or be withdrawn. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for ide
21、ntifying any or all such patent rights. ISO/TS 17924 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 7, Soil and site assessment. DD ISO/TS 17924:2007vIntroduction When assessing soils contaminated with, for example, metals, soil ingestion, especially by children, is of
22、ten considered to be the most important exposure pathway. Currently, this assessment is often carried out on the basis of the total content of the metals in question in the soil. However, several studies suggest that the availability of the metals in the gastrointestinal tract is dependent on the fo
23、rm of the metals present and the site-specific soil chemistry. Test methods based on in vivo tests with, for example, juvenile swine or mini-pigs are time consuming and expensive, and not very compatible with the decision processes connected with the assessment and clean-up of contaminated sites. At
24、 present, test methods are being developed and validated, which involve in vitro laboratory tests aimed at simulating in vivo results. This will reduce the cost and practicalities related to the use of such testing on contaminated land. Due to the large expenditure necessary for both private landown
25、ers and public funds set aside for the remediation of contaminated land, International Standards on the assessment of contaminated soil, especially with regard to human health, are in great demand. International Standards in this complex field will support a common scientific basis for the exchange
26、of data, development of knowledge and sound evaluation. Furthermore, International Standards will facilitate international recommendations and regulations. The aim of this Technical Specification is to describe the elements of such an in vitro test system, and give advice on the appropriate combinat
27、ion and use of these elements in the specific situation. In human health-risk assessment, “bioavailability” is specifically used in reference to absorption into systemic circulation, consistent with the toxicological use of the term. This encompasses bioaccessibility, which again is a combined measu
28、re of the processes determining the interaction between the metal associated with the soil and the liquid in the human digestion system. Bioavailability furthermore includes the absorption of the contaminant through a physiological membrane and the metabolism in the liver. The bioavailable fraction
29、is thus the fraction left after release into the human digestive liquid, transport across the intestinal epithelium and metabolism in the liver. A further description of these processes is given in Clause 4. When considering bioavailability as the fraction of the chemical that is absorbed into syste
30、mic circulation, two operational definitions are important, absolute and relative bioavailability. Absolute bioavailability is the fraction of the applied dose that is absorbed and reaches the systemic circulation (and can never be greater than 100 %). Relative bioavailability represents a compariso
31、n of absorption under two different sets of conditions, for example, from a soil sample vs. food or another matrix used in a toxicity study, and can be greater than or less than 1. This factor can be used in exposure assessments for exposure by direct ingestion of soil, for instance, if the absolute
32、 bioavailability of the metal in the specific soil is suspected to differ significantly from the absolute bioavailability implicit in the toxicity value/quality criteria used. DD ISO/TS 17924:2007blank1Soil quality Assessment of human exposure from ingestion of soil and soil material Guidance on the
33、 application and selection of physiologically based extraction methods for the estimation of the human bioaccessibility/bioavailability of metals in soil 1 Scope This Technical Specification deals with the assessment of human exposure from ingestion of soil and soil material. This Technical Specific
34、ation gives guidelines to be used when choosing a physiologically based test procedure for the estimation of the human bioaccessibility/bioavailability of metals from contaminated soil in connection with the evaluation of the exposure related to human oral uptake. Suggestions are made for the use of
35、 as many generic-method elements as possible, but it is important that the choice of method be based on the needs of the specific investigation. Methods that are validated for specific metals and/or contexts are highlighted. 2 Normative references The following referenced documents are indispensable
36、 for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 11074, Soil quality Vocabulary 3 Terms and definitions For the purposes of this document, the ter
37、ms and definitions given in ISO 11074 and the following apply. 3.1 absorption process by which a body takes in substance and makes it a part of itself 3.2 bioaccessible fraction fraction of a substance in soil or soil material that is liberated in (human) gastrointestinal juices and is thus availabl
38、e for absorption 3.3 bioavailable fraction fraction of a substance present in ingested soil or soil material that reaches the systemic circulation (bloodstream) DD ISO/TS 17924:20072 3.4 contaminant substance or agent present in the soil as a result of human activity NOTE 1 There is no assumption in
39、 this definition that harm results from the presence of the contaminant. NOTE 2 Adapted from ISO 11074:2005. 3.5 dermal contact contact with (touching) the skin 3.6 exposure dose of a chemical that reaches the human body 3.7 exposure pathway route a substance takes from its source to a receptor 3.8
40、ingestion act of taking substances (e.g. soil and soil material) into the body by mouth 3.9 in vitro bioaccessibility test designation for bioaccessibility test carried out outside a living organism 3.10 no observed adverse-effect level NOAEL dose at which no adverse effect on a receptor can be obse
41、rved 3.11 pica eating habit where usually strange and unpalatable materials are consumed, e.g. soil material, stones NOTE The term “pica” stems from the Latin name Pica pica for the raven bird magpie which randomly picks up any kind of material for nest construction. 3.12 provisionally tolerable wee
42、kly intake PTWI designation of the provisional weekly tolerable amount of a substance which can be taken in by a human body in its lifetime through the food chain without affecting human health 3.13 receptor potentially exposed person or part of ecosystem ISO 11074:2005 3.14 relative absorption frac
43、tion RAF ratio between the amount of a contaminant reaching systemic circulation when ingested with, for example, soil and the same amount obtained when ingested in the toxicity experiment underlying the criteria DD ISO/TS 17924:200733.15 species different forms of a substance always arising with ea
44、ch other in a reaction equilibrium 3.16 tolerable daily intake value TDI designation of the tolerable daily amount of a substance which can be taken in by a human body in its lifetime through the food chain without affecting human health 4 Bioaccessibility/bioavailability as a concept in assessment
45、of soils and sites with respect to human exposure The characterisation of bioaccessibility/bioavailability is usually performed as a part of a risk and/or exposure assessment. A risk assessment comprises the following elements: a hazard identification; a dose-response assessment; an exposure assessm
46、ent; and, based on the above, a risk characterisation. An exposure assessment is the process wherein the intensity, frequency, and duration of human exposure of a contaminant are estimated, and it comprises the following: source identification and characterisation; identification of exposure routes;
47、 identification of relevant receptors/target groups; and, based on this, the actual exposure assessment. For the assessment of possible effects on human health, an analysis of the exposure routes is a prerequisite. Where receptors are not directly exposed to a contaminant, exposure assessment needs
48、to consider the various ways by which indirect exposure might occur and the significance of them. Human exposure from soil contamination may occur through different media. Directly from the soil, the following exposure routes exist. Soil ingestion, both dietary and through adherence to hands and unw
49、ashed vegetables, etc. Dermal contact. Ingestion of house dust that predominantly consists of soil material. Airborne exposure comprises the following: inhalation and ingestion of fugitive dust; inhalation of elevated outdoor concentrations; inhalation of vapours that have intruded into buildings. DD ISO/TS 17924:20074 Exposure through the food chain comprises the following: consumption of plants including crops, plants, wild plants and fungi; consumption of animals and animal products, including wild animals; consumptio
