ISO 8259

Soil quality — Bioaccessibility of organic and inorganic pollutants from contaminated soil and soil-like materials

This document specifies a method for testing the availability for absorption or bioaccessibility of substances from contaminated soils and soil-like materials. Only those substances can be investigated that have a sufficiently low vapour pressure and for which larger losses cannot occur under the test conditions in accordance with this standard. Furthermore, suitable analysis methods shall be used for extraction and detection of substances and/or elements from complex digestion assays. In the test system presented here, the mobilisation of organic and inorganic pollutants from contaminated particles is tested in a physiologically close-to-realistic manner under standardised conditions with the aid of artificial digestive juices (gastric juice and intestinal juice). In terms of their main components, their composition corresponds approximately to the average composition of natural digestive juices of humans in the case of stimulated secretion, as occurs during the intake of foodstuffs. The treatment duration of the samples with gastric juice of 2 h corresponds to the average residence times of foodstuffs in the stomach. In contrast, the treatment duration with intestinal juice of 3 h is based on the residence time of foodstuff components in the upper section of the small intestine, which is the main site of absorption.

Qualité du sol — Bioaccessibilité des polluants organiques et inorganiques provenant d’un sol ou de matériaux de type sol pollués

General Information

• Status: Not Published
• ICS: 13.080.30 - Biological properties of soils
• Technical Committee: ISO/TC 190/SC 7 - Impact assessment
• Drafting Committee: ISO/TC 190/SC 7 - Impact assessment
• Current Stage: 6000 - International Standard under publication
• Completion Date: 03-Jul-2024

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 8259
ISO/TC 190/SC 7
Soil quality — Bioaccessibility of
Secretariat: DIN
organic and inorganic pollutants
Voting begins on:
from contaminated soil and soil-like
2024-05-07
materials
Voting terminates on:
2024-07-02
Qualité du sol — Bioaccessibilité des polluants organiques et
inorganiques provenant d’un sol ou d’un matériau de type sol
pollué
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 8259:2024(en) © ISO 2024

FINAL DRAFT
ISO/FDIS 8259:2024(en)
International
Standard
ISO/FDIS 8259
ISO/TC 190/SC 7
Soil quality — Bioaccessibility of
Secretariat: DIN
organic and inorganic pollutants
Voting begins on:
from contaminated soil and soil-like
materials
Voting terminates on:
Qualité du sol — Bioaccessibilité des polluants organiques et
inorganiques provenant d’un sol ou d’un matériau de type sol pollué
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 8259:2024(en) © ISO 2024

ii
ISO/FDIS 8259:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle of the test . 2
4.1 Human digestion .2
4.2 General test description .3
4.3 Applicability .4
4.4 Substances and elements .5
4.5 Contaminated soil and soil-like materials .6
5 Sampling and pre-treatment of soil and soil-like materials . 6
6 Reagents and apparatus . 6
6.1 Reagents .6
6.2 Enzymes and digestive aids .7
6.3 Apparatus .7
7 Test system . 7
7.1 Set-up of apparatus .7
7.2 Artificial digestive juices .8
8 Preparation and analysis of the sample. 9
8.1 Sample preparation .9
8.2 Test procedure .10
8.3 Separation of dissolved contaminants from particle-bound contaminants .10
8.4 Quantification . . .11
8.4.1 General .11
8.4.2 Analysis of inorganic substances . .11
8.4.3 Analysis of organic substances . .11
9 Calculation of bioaccessibility .12
10 Quality assurance .13
10.1 General . 13
10.2 Quantification of the bioaccessible content . 13
10.3 Mass balance and overall recovery . 13
10.4 Additional control measurements .14
11 Test report . 14
Annex A (informative) Enzymes and digestive aids.16
Annex B (informative) Method performance characteristics for selected bioaccessible
inorganic and organic substance fractions . 17
Annex C (informative) Example of an assay with artificial digestive juices, adjusting the
pH value and resulting volumes .21
Annex D (informative) Example of the extraction of polycyclic aromatic hydrocarbons (PAHs)
from the gastrointestinal phase solution .22
Bibliography .26

iii
ISO/FDIS 8259:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national 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. International 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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 7, Impact
assessment.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO/FDIS 8259:2024(en)
Introduction
The concept of bioavailability is used during risk assessment of contaminants and contaminated land. It
is used during human health risk assessment by application of in vitro methods designed to assess the
bioaccessible fraction of a chemical such as the one described in this document.
ISO 17402 provides a general overview of the definitions and concept of bioavailability and of available
methods to assess the bioavailability for several exposure pathways. ISO 15800 provides guidance on the
soil and site characterization necessary for the evaluation of human exposure to substances present in
soil including bioaccessibility and bioavailability. ISO 17924 describes a method to assess the bioaccessible
fraction of metals in a contaminated soil after soil ingestion. This document describes a test procedure
for the estimation of human bioaccessibility after oral uptake of both metals and non-volatile organic
contaminants from soil.
To evaluate the health effects of the oral ingestion of contaminated soil or soil-like materials by humans, it
is necessary to consider the total concentration of a contaminant in soil, the quantity of soil ingested, the
dissolution of the contaminants from soil in the gastrointestinal tract as well as their absorption through
membranes. Si
...

2024-02-28
ISO/DIS FDIS 8259:2024(E)
ISO/TC 190/SC 7
Secretariat: DIN
Date: 2024-04-23
Soil quality — Bioaccessibility of organic and inorganic pollutants
from contaminated soil and soil-like materials
Qualité du sol — Bioaccessibilité des polluants organiques et inorganiques des sols contaminésprovenant d’un
sol ou d’un matériau de type sol pollué
FDIS stage
ISO/FDIS 8259:2024(Een)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH--1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO/FDIS 8259:2024(Een)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle of the test . 2
4.1 Human digestion . 2
4.2 General test description . 3
4.3 Applicability . 5
4.4 Substances and elements . 6
4.5 Contaminated soil and soil-like materials . 7
5 Sampling and pre-treatment of soil and soil-like materials . 7
6 Reagents and apparatus . 7
6.1 Reagents . 7
6.2 Enzymes and digestive aids . 8
6.3 Apparatus . 8
7 Test system . 8
7.1 Set-up of apparatus . 8
7.2 Artificial digestive juices . 9
8 Preparation and analysis of the sample . 10
8.1 Sample preparation . 10
8.2 Test procedure . 11
8.3 Separation of dissolved contaminants from particle-bound contaminants . 11
8.4 Quantification. 12
8.4.1 General . 12
8.4.2 Analysis of inorganic substances . 12
8.4.3 Analysis of organic substances . 12
9 Calculation of bioaccessibility . 13
10 Quality assurance . 14
10.1 General . 14
10.2 Quantification of the bioaccessible content . 14
10.3 Mass balance and overall recovery . 15
10.4 Additional control measurements . 15
11 Test report . 15
Annex A (informative) Enzymes and digestive aids . 17
Annex B (informative) Method performance characteristics for selected bioaccessible inorganic
and organic substance fractions . 18
Annex C (informative) Example of an assay with artificial digestive juices, adjusting the
pH value and resulting volumes . 22
Annex D (informative) Example of the extraction of polycyclic aromatic hydrocarbons (PAHs)
from the gastrointestinal phase solution . 23
Bibliography . 27

iii
ISO/FDIS 8259:2024(Een)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national 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. International 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.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO documentdocuments should be noted. This document was drafted in accordance with the editorial rules
of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 7, Impact
assessment.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO/FDIS 8259:2024(Een)
Introduction
The concept of bioavailability (the fraction of a substance present in ingested soil that reaches the systemic
circulation (blood stream) [ISO DIS 11074, 2.48]) is used during risk assessment of contaminants and
contaminated land. It is used during human health risk assessment by application of in vitro methods designed
to assess the bioaccessible fraction of a chemical (fraction of a substance in soil or soil material that is
liberated in (human) gastrointestinal juices and thus available for absorption) such as the one described in
this document.
ISO 17402 provides a general overview of the definitions and concept of bioavailability and of available
methods to assess the bioavailability for several exposure pathways. ISO 15800 provides guidance on the soil
and site characterisationcharacterization necessary for the evaluation of human exposure to substances
present in soil including bioaccessibility and bioavailability. ISO 17924 describes a method to assess the
bioaccessible fraction of metals in a contaminated soil after soil ingestion. This document describes a test
procedure for the estimation of human bioaccessibility after oral uptake of both metals and non-volatile
organic contaminants from soil.
To evaluate the health effects of the oral ingestion of contaminated soil or soil-like materials by humans, it is
necessary to consider the totalconcentrationtotal concentration of a contaminant in soil, the quantity of soil
ingested, the dissolution of the contaminants from soil in the gastrointestinal tract as well as their absorption
through membranes. Simulation of human absorption and bioavailability of contaminants can be determined
in animal tests. For ethical reasons, as welland to reduce the amount of work and time needed, in vitro
methods have been developed determining the quantity of contaminants that can be dissolved from the
contaminated soil and soil-like materials by the digestive juices in the digestive tract.
Contaminants bound to soil and soil-like materials are generally only dissolved to a partial extent by the
digestive juices in the digestive tract. The degree of dissolution depends on the type of contaminant, the
characteristics of the soil and soil-like materials and the components of the digestive juices in the digestive
tract. The dissolved contaminants can be absorbed into the organism in the gastrointestinal tract.
Contaminants that remain bound are largely excreted in an unchanged state. The quantity actually resorbed
is always less than or, at most, equal to the dissolved quantity.
Digestive juices are complex mixtures of electrolytes, enzymes and digestive aids. The composition of the
digestive juices varies depending on their type, characteristics and quantity, and depends on exogenous and
endogenous factors. The type of food consumed is a significant exogenous factor in this regard.
The presence of food has an impact on the dissolution process of contaminants from soil particles ingested by
humans to their gastrointestinal juices. Therefore, it is relevant to add a food surrogate in an in vitro test, to
mimic the true situation in vivo. Food surrogates like milk powder are acting as emulsifiers because the
absorption of lipophilic substances depends significantly on the presence of lipids, for example from food,
which causes the secretion of bile salts, as well as the formation of micelles resulting in higher
[56,61 ]
bioaccessibilities for hydrophobic organic contaminants. [56, 61]. In addition, they maycan also have an
impact on inorganic contaminants. The use of food additives in in vitro testing simulates dissolution in
children after a standard meal (e.g. baby food) to achieve “realistic worst case” estimates for risk assessment
[34 ]
especially for organic contaminants [34]. .
This document standardizes a test system to assess the bioaccessible fraction of pollutants in contaminated
soils and soil-like materials with the aid of artificial digestive juices. The composition of the used artificial
digestive juices corresponds approximately to the average composition of natural digestive juices of humans
in the case of stimulated secretion, as occurs during the intake of foodstuffs. The treatment duration of the
samples with gastric juice is 2 h and corresponds to the average residence times of foodstuffs in the stomach.
In contrast, the treatment duration with intestinal juice is 3 h and based on the residence time of foodstuff
[61 ]
components in the upper section of the small intestine, which is the main site of absorption. [61]. To
simulate food consumption and, hence,
...