OSWER 9200.3-54
REVIEW OF INTERNATIONAL SOIL LEVELS FOR DIOXIN
Prepared by:
U.S. Environmental Protection Agency
Office of Superfund Remediation and Technology Innovation
Washington, D.C.
with technical assistance from:
SRC, Inc.
Denver, CO
December 28, 2009

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EXECUTIVE SUMMARY
A number of foreign nations have evaluated the toxicity of dioxin and have established
concentration values in soil that are intended to provide protection to humans who may be
exposed under residential or commercial/industrial land uses. Two types of soil levels have been
established:
•	Screening Levels are generally interpreted as concentrations below which health concern is
minimal and no further investigations or evaluations are needed.
•	Action Levels are generally interpreted as concentrations above which concern is likely to
exist and where some sort of response action is likely to be needed.
Because dioxin is a carcinogen, the method used to derive screening levels or action levels
depends on the assumed mode of action of dioxin. The World Health Organization (WHO) has
evaluated the available data for dioxin, and has determined that cancer effects of dioxin are
caused by a non-linear threshold mode of action. Consequently, human health will be protected
from both cancer and non-cancer effects if the average daily ingested dose of dioxin does not
exceed the Tolerable Daily Dose (TDI).
In 1990, the WHO estimated the TDI to be 10 pg/kg-day. In 1998, the WHO revised this
estimate and identified a range of 1-4 pg/kg-day, with 1 pg/kg-day being the goal. In 2001, this
range was re-evaluated using several new studies, and a range of 2-2.3 pg/kg-day was identified.
Nearly all foreign nations have followed the approach recommended by the WHO for evaluating
dioxin toxicity, and have selected TDI levels in the 1-10 pg/kg-day range. Each of these TDI
values or ranges is a suitable candidate for consideration in EPA's determination of soil PRG
levels, with preference for the most recent values.
The method for deriving a soil level from a TDI depends upon which soil exposure pathways are
considered (ingestion, inhalation, dermal), and on the exposure parameters for each pathway. In
some cases, other factors may also be considered. Table ES-1 lists soil screening levels and
action levels that were located for foreign nations, indicating the TDI values that were
considered, and the exposure pathways that were included. As shown, screening levels range
from 1 to 250 ppt, with most values of about 10 ppt. Residential action levels range from 10 to
1,500 ppt, with most values in the 100 to 1,000 ppt range. Commercial/industrial action levels
range from 100 to 18,000 ppt, with most values in the 1,000 to 10,000 ppt range. Unfortunately,
based on the information presently located, the detailed basis for the derivation of these soil
levels is not clear except for the Netherlands.
ES-1

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TABLE OF CONTENTS
1.0 OVERVIEW	1
2.0 BASIC STRATEGIES FOR DERIVING SOIL LEVELS	1
2.1	Linear Non-Threshold Cancer Risk Model	1
2.2	Non-Linear Threshold Cancer Risk Model	2
2.3	Exceedence of "Background"	2
3.0 SEARCH OBJECTIVES AND METHODS	3
3.1	Search Obj ectives	3
3.2	Search Methods	3
4.0 RESULTS	4
4.1	Nations that Use the Linear No-Threshold Risk Model	4
4.2	Nations that Use the Non-Linear Threshold Risk Model	6
4.2.1	TDI Values	6
4.2.2	Derivation of Soil Levels	8
4.3	Nations that Use the Exceedence of Background Approach	10
5.0 EVALUATION	10
6.0 REFERENCES	11
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LIST OF ABBREVIATIONS AND ACRONYMS
BMD
Benchmark Dose
COT
Committee on the Toxicity of Chemicals in Food
EC
European Commission
ECEH
European Centre for Environmental Health Safety
IPCS
International Programme on Chemical
JECFA
Joint FAO/WHO Expert Committee on Food Additives
LOAEL
Lowest Observed Adverse Effect Level
oSF
Oral Slope Factor
OSWER
Office of Solid Waste and Emergency Response
PBPK
Physiologically-based pharmacokinetic
PCDD
Polychlorinated dibenzodioxins
PCDF
Polychlorinated dibenzofurans
RfD
Reference Dose
SCF
Scientific Committee on Food
TCDD
2,3,7,8 -tetrachl oro-p-dib enzodi oxin
TDI
Tolerable daily intake
TEQ
TCDD Equivalents
USEPA
United States Environmental Protection Agency
WHO
World Health Organization

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REVIEW OF INTERNATIONAL SOIL LEVELS FOR DIOXIN
1.0 OVERVIEW
Regulatory agencies in many nations have sought to identify a default concentration of dioxin
(2,3,7,8-TCDD) and related polychorinated dibenzodioxins (PCDDs) and dibenzofurans
(PCDFs) in soil that does not pose an unacceptable health risk to humans. These values are
generally expressed in terms of TCDD-equivalent (TEQ) concentrations, which include the
contributions from all of the relevant PCDD and PCDF congeners.
In general, one or both of two types of soil level have been established:
•	Screening Levels are generally interpreted as concentrations below which health concern is
minimal and no further investigations or evaluations are needed.
•	Action Levels are generally interpreted as concentrations above which concern is likely to
exist and where some sort of response action is likely to be needed.
The purpose of this report is to review the methods that have been used by other countries to
derive screening levels and/or action levels for dioxin in soil, and to characterize the values that
have been established.
2.0 BASIC STRATEGIES FOR DERIVING SOIL LEVELS
Review of the approaches used by various nations for deriving soil levels for dioxin have
identified three basic strategies. These are discussed below.
2.1 Linear Non-Threshold Cancer Risk Model
Dioxin is a carcinogen. If the risk of cancer from dioxin is assumed to be linear in the low-dose
range and to have no threshold, then the basic equation for calculating the soil level that
corresponds to some specified acceptable "target cancer risk" is as follows:
_ r, y t i, , x	Target Cancer Risk
Lancer Soil Level (pg/ g) =
Soil Intake Rate (g/ kg -d)- Slope Factor {pg / kg -d)
As seen, the soil level for cancer depends on the slope factor, the intake rate of soil, and the
target cancer risk. The slope factor is usually derived by fitting the linearized multistage model
to an appropriate set of cancer exposure-response data (animal data), while intake rate is based
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on default assumptions about residential or worker exposure to soil. Target cancer risk is a risk
management choice, and is typically in the 1E-04 to 1E-06 range.
Because dioxin also causes non-cancer as well as cancer effects, it is also appropriate to calculate
a soil level that will protect against non-cancer effects, as follows:
1Von - Cancer So,I Level (pg I g) = Threshold DoX (pg ! kg - day)
Soil Intake Rate (g I kg- day)
As seen, the soil level for non-cancer effects depends only on the ratio of the threshold dose (an
intake level that does not cause any adverse effects) to the soil intake rate.
Given the cancer and non-cancer soil levels, the lower of the two is generally selected to ensure
protection against both types of effect.
2.2	Non-Linear Threshold Cancer Risk Model
If the cancer effects of dioxin are assumed to occur via a non-linear threshold mode of action,
then exposures that are below the threshold for non-cancer effects are assumed to be safe for
both cancer and non-cancer effects. In this case, the soil level is calculated using the non-cancer
equation described above:
,, , , ,, , N Threshold Dose (pg /kg - day)
Soil Level (pg I g) =	——2	—
Soil Intake Rate (g I kg- day)
The threshold dose is usually referred to as a Reference Dose (RfD) in the United States, and as a
Tolerable Daily Intake (TDI) in Europe and Asia. These two terms are conceptually equivalent
and both describe the total amount of dioxin/TEQ that may be ingested per day that will not
result in an adverse health effect.
The value of the TDI or RfD can be derived in several ways, including:
•	Direct observation of no-effect dose levels in reliable studies
•	Benchmark dose (BMD) modeling of reliable non-cancer dose-response data
•	Calculations from a tissue-based no-effect level, using an appropriate physiologically
based pharmacokinetic (PBPK) model
2.3	Exceedence of "Background"
If it is assumed that any excess exposure to dioxin is undesirable because of its high potency for
both non-cancer and cancer effects, then the soil level may be set equal to the "background"
level of dioxin in soil. This approach does not require any data on toxicity or exposure, but does
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require robust data on the distribution of concentration values in soils that are considered to be
"background". Because dioxin can be released from a variety of sources (ATSDR 1998), soil
"background" levels may vary as a function of location and setting (rural, industrial, urban,
pristine, etc.).
3.0	SEARCH OBJECTIVES AND METHODS
3.1	Search Objectives
The goal of this search effort was to identify soil action levels for dioxin that have been adopted
by various nations. In addition, the primary objective was to document the underlying basis of
these soil levels (e.g., toxicity value, derivation approach, exposure parameters) with regard to
the following criteria. The resulting objective was to identify international soil levels based on
the most recent, sound science and evaluate the levels based on the following criteria:
¦	Nature of peer review
¦	Transparency/reproducibility & public availability
¦	Scientific basis
These criteria are consistent with those recommended for Tier 3 human health toxicity value
sources indicated in USEPA Office of Solid Waste and Emergency Response (OSWER)
Directive 9285.7-53, Human Health Toxicity Values in Superfund Risk Assessments (USEPA
2003).
3.2	Search Methods
Searches for information on international soil levels for dioxin were primarily performed using
web-based search engines. These searches were initially quite broad in scope in an attempt to
locate any publicly-available information on dioxin (or TEQ) toxicity assessments and/or soil
levels. These initial searches did not target specific soil level types (e.g., residential/commercial,
screening/action level), and did not attempt to target specific nations or regions. Information on
dioxin soil levels for European nations was initially located in two key summary reports:
¦	Carlon, C. (ed.). 2007. Derivation Methods of Soil Screening Values in Europe. A
Review and Evaluation of National Procedures Towards Harmonization. European
Commission, Joint Research Centre, Ispra, EUR 22805-EN, 306 pp.
http://www.nicole.om/nevvs/dovvnloads/EUR22805-EN0 o20(3) 27 AUG.pdf
¦	AEA Technology. 1999. Summary Report: Compilation ofEUDioxin Exposure and
Health Data. Task 1 - Member State Legislation and Programmes. Produced for
European Commission DG Environment, UK Department of the Environment Transport
and the Regions. October, http://ec.europa.eu/environment/dioxin/download.htm
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When potentially relevant dioxin information was located for a particular nation, a more focused
search of specific agency websites and peer-reviewed literature was performed to identify and
gather the underlying documents providing the detailed information on the basis and derivation
of the specified soil levels.
4.0	RESULTS
4.1	Nations that Use the Linear No-Threshold Risk Model
Only one foreign nation (Germany) evaluated the cancer effects of dioxin assuming a linear no-
threshold mode of action. Based on information reported in Carlon (2007), both oral exposure
and inhalation exposure are considered, and both cancer and non-cancer effects are evaluated.
Two types of values are identified:
•	"Trigger levels" are concentrations in soil that warrant further investigation to determine
if the concentration of the contaminant in soil is hazardous.
•	"Action levels" are concentrations in soil that, as a rule, indicate that a hazard is present
that must be addressed. Further investigation is usually not necessary.
Equations for calculating "Trigger Levels" utilized by Germany are as follows:
Effect
Pathway
Equation
Cancer
Oral
TL = Dtb frc 8.75 / IR
Inhalation
TL = Dtb frc 8.75 / (IR AF)
Non-Cancer
Oral
TL = Dtb (frc - 0.8) / IR
Inhalation
TL = Dtb frc / (IR AF)
where:
TL = Trigger Level in soil (pg/g)
Dtb = Tolerable body dose (pk/kg-day)
frc = risk connecting factor
8.75 = ratio of averaging time to assumed exposure duration for cancer (70 yrs/8 yrs)
0.8 = fraction of total daily dioxin intake that is derived from the diet
IR = average daily soil intake (g/kg-day)
AF = accumulation factor of dioxin in dust
Default values employed by Germany in the computation of Trigger Levels for dioxin for
residential land use are as follows (Carlon 2007):
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Parameter
Cancer
Non-cancer
Oral
Inhal
Oral
Inhal
Dtc (pg/kg-day)
6.7E-02
6.0E-02
1.0
—
frc
5
5
3.2
—
IR (g/kg-day)
1.65E-02
4.1E-05
1.65E-02
—
AF
—
10
—
—
Note that the soil ingestion rate (16.5 mg/kg-day) used by Germany is substantially higher than
the default value used by the United States Environmental Protection Agency (USEPA) (3.81
mg/kg-day). Likewise, the soil inhalation rate used by Germany (4.1E-02 mg/kg-day) is also
higher than the USEPA default (2.3E-04 mg/kg-day), although the air pathway remains minor in
both cases. Also note that the exposure duration for cancer effects (8 years) is much shorter than
assumed by USEPA (30 years), and that for non-cancer effects, only 20% of the allowable daily
intake is allocated to soil.
For cancer effects, the oral slope factor (oSF) utilized by Germany may be calculated as follows:
oSF = Target Risk / Dtc = 1E-05 / 6.7E-02 = 1.5E-04 (pg/kg-day)"1
This is the same value utilized by the United States.
Based on the inputs provided above, the derived soil Trigger Levels for dioxin are as shown
below:
Effect
Toxicity
Target
Trigger Level (pg/g)
Value
Risk
Oral
Inhal.
Combined
Cancer
1.5E-04 (pg/kg-day)"1
1E-05
178
6400
173
Non-cancer
1.0 pg/kg-day
X
o
II
145
—
145
As seen, the Trigger Level for cancer effects (1E-05) is 173 ppt, and the Trigger Level for non-
cancer effects is 145 ppt. Presuming that the lower of the two values is selected as the final
value, the final soil Trigger Level for dioxin would be 145 ppt. However, no information was
located on the selected Trigger Level for dioxin in the literature.
As noted above, Germany utilizes an approach in which both a Trigger Level and an Action
Level are identified. The residential Action Level for dioxin selected by Germany is 1,000 ppt.
No information was located on the process used by Germany to derive the selected soil Action
Level.
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4.2 Nations that Use the Non-Linear Threshold Risk Model
4.2.1 TDI Values
Most foreign nations for which information was located follow the approach in which the cancer
effects of dioxin are believed to be mediated by a non-linear threshold mode of action. This
approach has been developed mainly by the World Health Organization (WHO) and several
other international health groups. Table 1 provides a summary of TDI values that have been
derived by WHO and others. These are discussed in greater detail below.
WHO 1990
In 1990, the World Health Organization (WHO) Regional Office for Europe organized several
expert consultations and working groups to perform a toxicological evaluation for TCDD (WHO
1991, 1992). It was concluded that TCDD was carcinogenic in animals, acting as a non-
genotoxic promoter-carcinogen. Therefore, the consultation decided to establish a TDI based on
general toxicological effects. The no-effect dose was estimated to be about 1,000 pg/kg-day in
various laboratory animals, which was adjusted to an equivalent human dose of 100 pg/kg-day
using toxicokinetic data. After applying an uncertainty factor of 10 to account for insufficient
data on reproductive effects in humans, a TDI of 10 pg/kg-day was recommended.
WHO 1998
In 1998, the WHO European Centre for Environmental Health (WHO-ECEH) and International
Programme on Chemical Safety (IPCS) performed a re-assessment of the available information
on the toxicity of dioxin (WHO 1998), and reached the following key conclusions:
•	the cancer effects of dioxin are mediated by a non-genotoxic mode of action that is
mediated via a receptor binding mechanism. Consequently, cancer risk has a threshold,
and exposures that do not cause non-cancer effects will not increase cancer risk.
•	the most sensitive non-cancer effects caused by dioxin included developmental and
reproductive effects in rats and monkeys.
•	the most reliable metric of exposure for use in risk evaluation is tissue burden rather than
ingested dose.
Based on these key conclusions, WHO (1998) estimated the TDI (pg/kg-day) for lifetime
exposure in a series of 3 steps, as follows:
Step 1: Identify the tissue burden effect level for the most sensitive (and relevant) adverse
responses. Based on studies in rats and monkeys, the WHO estimated that the lowest
observed adverse effect level (LOAEL) tissue burdens ranged from 28-73 ng/kg (28,000-
73,000 pg/kg).
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Step 2: Given the tissue burden range, calculate the TDI that would yield this tissue burden
range. The WHO computed the TDI using a simple steady-state pharmacokinetic model of
the following form:
TDI (pg/kg-d) = Tissue Burden (pg/kg) • [l-exp(-ln(2)/ti/2)] / f
where:
ti/2 = half-time of dioxin in the body (days)
f = fraction of an ingested dose that is absorbed
WHO utilized a half-time of 7.5 years (2,738 days), and an assumed fractional absorption of
0.5 (50%). Based on this, the TDI was estimated to range from 14-37 pg/kg-day.
Step 3: Adjust the TDI to account for uncertainties. A factor of 10 was applied to address
the following uncertainties: a) the use of a range of LOAELs instead of a no-effect level, b)
the possible differences in susceptibility between humans and experimental animals, c) the
potential differences in susceptibilities within the human population, and d) differences in
half-lives of elimination for the compounds of a complex TEQ mixture. After application of
the uncertainty factor, the TDI (rounded) was estimated to range from 1-4 pg/kg-day.
The WHO (1998) consultation stressed that the upper range of the TDI of 4 pg/kg-day should be
considered a maximal tolerable intake on a provisional basis and that the ultimate goal is to
reduce human intake levels to below 1 pg/kg bw-day.
EC-SCF and JECFA 2001
In 2001, the European Commission Scientific Committee on Food (EC-SCF) and the Joint
FAO/WHO Expert Committee on Food Additives (JECFA) incorporated several new studies
published since the 1998 WHO re-assessment and estimated the TDI to be 2.0-2.3 pg/kg-day,
respectively, using an approach similar to the one described above1.
Table la summarizes the TDI values recommended by these various international organizations.
TDI Values Selected by Various Nations
Table 2 provides a summary of the information that was located for nations that follow the TDI
approach for evaluating dioxin toxicity. As indicated, a majority of nations have chosen to adopt
TDI values recommended by WHO. This includes:
1 EC-SCF recommended a tolerable weekly intake (TWI) of 14 pg/kg, while JECFA recommended a tolerable
monthly intake (TMI) of 70 pg/kg. These values correspond to TDI values of 2.0 to 2.3 pg/kg-day.
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WHO (1990)
TDI =10 pg/kg-day
WHO (1998)
TDI =1-4 pg/kg-day
JECFA (2001)
TDI = 2.3 pg/kg-day
¦	Austria
¦	Italy
¦	France
¦	Germany
¦	Netherlands
¦	New Zealand2
¦	Australia
¦	Canada
However, several nations (see Table lb) have performed their own re-assessment of the
available toxicity data for dioxin to derive a TDI, rather than adopting TDI values derived by
others. Japan derived a TDI of 4 pg/kg-day, which is equivalent to the maximum TDI
established by WHO (1998). For the United Kingdom, the Government's independent advisory
Committee on the Toxicity of Chemicals in Food (COT) recommended a TDI of 2 pg/kg-day,
which is equivalent to the TDI identified by EC-SCF (2001). In August 2000, several countries
(Denmark, Finland, Sweden) considered revising the Nordic Council TDI value of 5 pg/kg-day
to a value of 4 pg/kg-day in accord with WHO (1998), but it was determined that no change was
appropriate (Johansson and Hanberg 2000).
4.2.2 Derivation of Soil Levels
As noted above, given a TDI, the soil level is computed as follows:
TDI (pg/kg-day)
Soil Level (pg / g) =
Soil Intake Rate (g/kg- day)
The soil intake rate may be computed in a number of different ways, depending on which
exposure pathways are considered (ingestion, dermal contact, inhalation of particulates, and/or
ingestion of crops or livestock that have been impacted by soil). The general form of the
equation is:
Soil Level =	—r-
where:
TDI = Tolerable daily intake
k; = Ratio of dioxin concentration in medium "i" to concentration in soil
IRi = Intake rate of medium "i"
2 New Zealand has recently adopted the WHO 1998 TDI values; however, the soil action levels identified utilize
WHO 1990 TDI values.
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For example, if only the soil ingestion pathway is considered, the basic equation is:
Soil Level {pg I kg) =
1Ks
where:
TDI = Tolerable daily intake (pg/kg-day)
IRS = Average soil intake rate (g/kg-day)
If dermal contact, inhalation exposure and intake of foods (e.g., garden vegetables) grown in
contaminated soil are considered, the equation is:
Soil Level (pg / kg) =
IR-S + IRd + ^air • IRpMXO + ^veg '
where:
IRd = Intake rate of soil from dermal exposure (g/kg-day)
kair = Concentration in air (pg/m3) divided by concentration in soil (pg/g)
IRpmio = Intake rate of air (m3/kg-day)
kveg = Concentration in vegetable (pg/g) divided by concentration in soil (pg/g)
IRgv = Intake rate of garden vegetables (g/kg-day)
Note that inhalation exposure from PM10 particles usually contributes only a small dose
compared to oral exposure (typically <1%). Consequently, whether the inhalation pathway is
included or not generally has little influence on the result.
Soil Levels Identified by Various Nations
Not all nations that utilize the TDI approach have derived soil levels. Table 2 provides the
detailed information for all soil levels located for various nations. This table includes a variety
of different soil levels and nomenclature in describing these levels. As described above, the
various soil levels reported by the nations were stratified into two broad categories - screening
levels and action levels. Screening levels are soil values below which no further investigation is
likely to be needed. Usually these screening values are not land use specific, but are applied to
all land use types. Action levels are soil values above which cleanup actions are warranted.
These values are often effects-based (i.e., derived from a TDI) and land use specific. The most
common land use types are residential and commercial/industrial, although some nations also
derive action levels for agricultural and recreational land uses.
Table 3 summarizes the screening levels and action levels for residential and commercial/
industrial soils that have been derived. Figure 1 presents these soil levels in a graphical format.
As shown, screening levels (Panel A) range from 1 to 250 ppt, with most values of about 10 ppt.
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Residential action levels (Panel B) range from 10 to 1,500 ppt, with most values in the 100 to
1,000 ppt range. Commercial/industrial action levels (Panel C) range from 100 to 18,000 ppt,
with most values in the 1,000 to 10,000 ppt range.
Figure 2 presents the soil action levels for residential (Panel A) and commercial/industrial
(Panel B) grouped by the selected TDI. As shown, there is a wide range of soil levels within
each TDI value (e.g., residential action levels range from 100 to 1,000 ppt for a TDI of 1 pg/kg-
day). This suggests that the primary reason for the differences in the derived soil levels is due to
differences in the exposure parameters utilized.
Unfortunately, the basis of these soil levels is not always clear. Carlon (2007) sought to
determine the methods that had been used by each nation to establish the soil levels, and
concluded that, in most cases, the basis of the soil levels was not well documented. Even in
cases where documentation is available, derived soil values are not always reproducible.
Therefore, it is suspected that most soil values reflect risk management decisions that are not
based solely on risk-based exposure-response models.
4.3 Nations that Use the Exceedence of Background Approach
Two nations (Canada and Czech Republic) were identified in which the soil screening level is
stated to be based on background levels of dioxin. For Canada, the soil screening level identified
as the average background level is 4 ppt, and this value is intended to apply to all land use types
(i.e., agricultural, residential, commercial, industrial). For the Czech Republic, there are two soil
screening levels identified: 1 ppt, which was identified as the 95th percentile of background, and
100 ppt, which is a value selected between background and the "limit of pollution". Most
nations, including the United States (USEPA 2007), report background concentrations within
range of 1-10 ppt.
5.0 EVALUATION
In order for the USEPA to consider a human health toxicity value (TDI, slope factor) for use in
risk calculations or in the derivation of a soil level, it must meet the criteria of a Tier 3 value
established by USEPA OSWER Directive 9285.7-53 (USEPA 2003). As noted above, these
criteria are as follows:
¦	Nature of peer review - in accord with USEPA (2003), "draft assessments are not
appropriate for use until they have been through peer review, the peer review comments
have been addressed in a revised draft, and the revised draft is publicly available".
¦	Transparencv/reproducibilitv and public availability - in accord with USEPA (2003).
values should be "available to the public, and.. .transparent about the methods and
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processes used to develop the values". In addition to being transparent, values should be
reproducible (i.e., able to be derived based on the provided information).
¦ Scientific basis - in accord with USEPA (2003), values should be "based on similar
methods and procedures" as USEPA guidance (e.g., cancer risk assessment guidelines,
soil screening guidance).
Table 4 presents a matrix of the evaluation criteria for the TDI values (top panel) and soil action
levels (bottom panel) currently utilized by various nations. In general, most of the TDI values
derived by the WHO and other international health groups have been peer reviewed, are
transparent/reproducible and publically available, and are based on science that is consistent with
current USEPA guidance procedures (assuming that a threshold mode of action is accepted).
Thus, all of these TDI values would rank as appropriate for use as Tier 3 human health toxicity
values. TDI values developed by various nations (e.g., Japan), do not meet all of the specified
criteria in full.
For the soil action levels (Table 4, lower panel), with the exception the Netherlands, no nations
provided sufficient detail to document the underlying basis of the adopted soil values and no
information was located on the peer review process associated with the adopted values. For the
Netherlands, soil levels were derived using an exposure model called CSOIL. Detailed
information on this model and the underlying exposure parameters and assumptions are
documented in the Technical Evaluation of the Intervention Values for Soil/Sediment and
Groundwater (RIVM 2001). The derived soil values are subject to review by the Netherland
Technical Soil Protection Committee and Health Council.
6.0 REFERENCES
ATSDR (Agency for Toxic Substances and Disease Registry). 1998. Toxicological Profile
for Chlorinated Dibenzo-p-dioxins (CDDs). Agency for Toxic Substances and Disease Registry.
December 1998.
Carlon, C. (Ed.) (2007). Derivation methods of soil screening values in Europe. A review and
evaluation of national procedures towards harmonization. European Commission, Joint Research
Centre, Ispra, EUR 22805-EN, 306 pp.
http://eusoils.irc.ec.europa.eu/esdb archive/eusoils docs/other/EUR22805.pdf
Johansson, N. and A Hanberg. 2000. Report from a Nordic meeting on the 1998 WHO
consultation on assessment of the health risks of dioxins; re-evaluation of the tolerable daily
intake (TDI). Organohalogen Compounds. 48:252-255.
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Kimbrough RD, Falk H, Stehr P. 1984. Health Implications of 2,3,7,8-tetrachloro-
dibenzodioxin (TCDD) Contamination of Residential Soil. J. Toxicol. Environ. Health 14:47-93.
Kociba RJ, Keyes DG, Beyer JE, et al . 1978. Results of a Two-Year Chronic Toxicity and
oncogenicity Study of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) in rats. Toxicol. Appl.
Pharmacpol. 46:279-303.
NTP (National Toxicology Program). 1982. Carcinogenesis Bioassay of 2,3,7,8-
tetrachlorodibenzo-p-dioxin (CAS No. 1746-01-6) in Osborne-Mendel rats and B6C3F1 Mice
(Gavage Study). National Toxicology Program Technical Report Series, Issue 209:195.
RIVM. 2001. Technical Evaluation of the Intervention Values for Soil/Sediment and
Groundwater: Human and ecotoxicological risk assessment and derivation of risk limits for soil,
aquatic sediment and groundwater. National Institute of Public Health and the Environment
(RIVM). RIVM report 711701 023. February 2001.
http://rivm.openrepositorv.com/rivm/bitstream/10029/9660/1/71 1701023.pdf
USEPA (U.S. Environmental Protection Agency). 1985. Health Assessment Document for
Poly chlorinated Dibenzo-p-Dioxins. U.S. Environmental Protection Agency, Office of Health
and Environmental Assessment, Environmental Criteria and Assessment Office. Cincinnati, OH.
EPA 600/8-84-014F.
USEPA. 1997. Health Effects Assessment Summary Tables (HEAST). U.S. Environmental
Protection Agency, Office of Solid Waste and Emergency Response. EPA-540-R-97-036. July
1997.
USEPA. 1998. Approach for Addressing Dioxin in Soil at CERCLA and RCRA Sites. Memo
from Timothy Fields, USEPA Acting Administrator, to Regional Directors. OSWER Directive
9200.4-26. April 13, 1998.
USEPA. 2003. Human Health Toxicity Values in Superfund Risk Assessments. OSWER
Directive 9285.7-53. U.S. Environmental Protection Agency, Office of Solid Waste and
Emergency Response, Washington, DC. December 5, 2003.
http://www.epa.gov/oswer/riskassessment/pdf/hhmemo.pdf
USEPA. 2005. Guidelines for Carcinogen Risk Assessment. U.S. Environmental Protection
Agency, Risk Assessment Forum. Washington, DC. EPA/630/P-03/001B. March 2005.
USEPA. 2007. Pilot Survey of Levels of Poly chlorinated Dibenzo-P-Dioxins (PCDDs),
Poly chlorinated Dibenzofurans (PCDFs), Poly chlorinated Biphenyls (PCB) and Mercury in
Rural Soils of the U.S. U.S. Environmental Protection Agency, Washington, DC. EPA/600/R-
05/043F. http://cfpub.epa.gov/ncea/CFM/recordisplay.cfm?deid= 150944
12

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WHO (World Health Organization). 1991. Summary Report - Consultation on Tolerable Daily
Intake from Food of PCDDs and PCDFs. Bilthoven, the Netherlands, December 1990,
EUR/ICP/PCS 030(S) 0369n, World Health Organization, Regional Office for Europe,
Copenhagen.
WHO. 1992. Tolerable daily intake of PCDDs and PCDFs. Toxic Substances Journal 12:101-
128.
WHO. 1998. Assessment of the Health Risk of Dioxins: A Re-evaluation of the Tolerable Daily
Intake (TDI), Consultation, May 1998, World Health Organization, Geneva. Available on-line
at: http://vvvvvv.vvho.int/pcs/docs/dioxin-exec-sum/exe-sum-final.html
13

-------
Figure 1. International Screening Level and Action Levels
Panel A: Screening Levels
Q_
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dioxinsoillevels-international.xls

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Figure 2. International Action Levels Stratified by Adopted TDI
Panel A: Residential Action Levels
Q.
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dioxinsoillevels-international.xls

-------
Table 1a. Tolerable Daily Intake (TDI) Values Developed by International Organizations
International
Organization
Date
TDI (RfD)
Tissue Burden Used to Dereive TDI (RfD)
Information
Source(s)
Nature of Peer Review
Transparency/
Reproducibilty-
Public Availability
Scientific Basis
Incorporation of Most
Recent Science
Notes
Value
Parameter
[see note A]
Basis
Tissue
Value
Basis
Uncertainty
Factor (UF)
Half-time in
body (t1/2)
Absorption
Fraction (f)
World Health
Organization
(WHO)
1990
10 pg/kg/d
Maximum TDI
Noncancer
effects in
humans
(based on
animal
studies)

no effect level
of 100 pg/kg/d
(equivalent
dose in
humans) for
non-cancer
effects in
various
laboratory
animals
10


Ref [27]
**More
detailed
information on
TDI derivation
may be
available in
Ref [28]
Based on consensus of many different
national and international experts.
Consultation was attended by 20
experts from 11 countries, one
representative from the Netherlands
government, 3 observers and 5 staff
from the Regional Office and WHO
headquarters.
Documents available
online
Studies of liver toxicity and reproductive and
immunotoxicology in the various laboratory animal species
identified a no-effect level of 1000 pg/kg-day.
Pharmacokinetic data indicated that this was equivalent to a
dose of 100 pg/kg-day in humans. Because of the
inadequate data based on reproductive effects in humans,
an uncertainty factor of 10 was employed by the
Consultation and therefore a TDI of 10 pg/kg-day was
recommended.
Based on available
toxicological literature and
studies available at the time
of the consultation (1990).

World Health
Organization
European
Centre for
Environmental
Health (WHO-
ECEH) &
International
Programme
on Chemical
Safety (IPCS)
May 1998
1-4 pg/kg/d
(reported as
TEQ)
4 pg/kg/d
1 pg/kg/d
Provisional TDI
for lifetime
exposure
Maximum TDI
Target TDI
Noncancer
effects in
humans
(based on
animal
studies)
28-73 ng/kg
bw (maternal
body burden)
range of
LOAELs
across multiple
studies for
developmental
and
reproductive
effects in rats
and monkeys
10
7.5 years
50%
Ref [18]
Based on consensus of many different
national and international experts.
The WHO-ECEH coordinated a
comprehensive programme in
collaboration with IPCS. Consultation
attended by 40 experts from Australia,
Belgium, Canada, Denmark, Finland,
Germany, Italy, Japan, The
Netherlands, New Zealand, Spain,
Sweden, United Kingdom, and USA
and by staff from UNEP, IARC, IPCS
and WHO-ECEH.
Document available
online
Procedure for
selection of tissue
burden and
calculation of TDI is
transparent and
reproducible
The LOAELs for the most sensitive adverse responses
(noncancer effects) reported in experimental animals were
associated with maternal body burdens of 28-73 ng/kg bw,
from which a range of estimated long-term human daily
intakes of 14-37 pg/kg/d was calculated (see Table 4). An
uncertainty factor of 10 was applied to account for: a) the
use of a range of LOAELs instead of a NOAEL, b) the
possible susceptibility differences between humans and
experimental animals, c) the potential differences in
susceptibilities within the human population, and d)
differences in half-lives of elimination for the compounds of
a complex TEQ mixture. Based on this, a final TDI,
expressed as a range of 1-4 TEQ pg/kg bw (rounded
figures) was established for dioxins and dioxin-like
compounds.
Based on available
toxicological literature and
studies available at the time
of the consultation (1998).

European
Commission
Scientific
Committee on
Food (EC-
SCF)
30-May-01
14 pg/kg/d
2 pg/kg/d
TWI
(TDI equiv.)
Noncancer
effects in
humans
(based on
animal
studies)
40 ng/kg bw
(maternal
body burden)
LOAEL for
reproductive
effects in
Wistar rats
(Faqi et al.,
1998)
9.6
7.5 years
(see notes)
50%
(see notes)
Ref [19]
The SCF took cognisance of
comments received from the Swedish
National Food Administration (2001),
the Norwegian Food Control Authority
(2001) and from some members of the
Scientific Committee on Toxicity,
Ecotoxicity and the Environment
(CSTEE) of the European Commission.
Document available
online
Procedure for
selection of tissue
burden and
calculation of TDI is
generally
transparent and
reproducible (see
notes)
An estimated human daily intake (EHDI) of 20 pg/kg bw/day
was calculated from the estimated steady state TCDD body
burden in the rat dams at the LOEL of 40 ng/kg bw.
Application of a 9.6-fold safety factor to the EHDI yielded a
TDI of 2 pg/kg bw/day. Due to the long half-lives of TCDD
and related compounds in the human body, this figure was
converted to a TWI of 14 pg/kg bw.
The EC-SCF based their
updated risk assessment on
the LOEL for reproductive
toxicity in male offspring of
pregnant rats from the study
by Faqi et al (1998), rather
than the rat and monkey
studies used by the WHO
(1998).
t1/2 & f not specified
explicitly in Ref [19],
but confirmed based
on calculation of the
TDI from the
specified tissue
burden.
Joint
FAO/WHO
Expert
Committee on
Food
Additives
(JECFA)
2002
70 pg/kg/d
2.3 pg/kg/d
Provisional
TMI
(TDI equiv.)
Noncancer
effects in
humans
(based on
animal
studies)
NOAEL:
16-22 ng/kg
bw
LOAEL:
28-42 ng/kg
bw
(range of
total body
burdens as
estimated by
two different
models)
NOAEL for
reproductive
effects in
Holzman rats
(Ohsako et al.,
2001)
LOAEL for
reproductive
effects in
Wistar rats
(Faqi et al.,
1998)
NOAEL: 3
LOAEL: 9.6
7.6 years
50%
Ref [21]
Based on consensus of many different
national and international experts.
Document available
online
Procedure for
selection of tissue
burden and
calculation of TDI is
transparent and
reproducible
JECFA derived estimated human monthly intakes (EHMIs)
of 237 and 330 pg TEF/kg bw, using the linear and nonlinear
models, respectively, from the study by Ohsako et al (2001).
The corresponding EHMI values derived from the study by
Faqi et al (1998) were 423 and 630 pg TEF/kg bw. A safety
factor of 3.2 was applied to the EHMIs associated with the
NOEL identified by Ohsako et al (2001). JECFA considered
that use of the LOEL from by Faqi et al (1998) warranted an
additional safety factor of 3, leading to an overall safety
factor of (3 x 3.2) = 9.6. The four resulting provisional
tolerable monthly intake (PTMI) values ranged from 44 to
103 pg/kg bw/month. JECFA took the mid-point of the
range (70 pg TEF/kg bw/month) as the chosen PTMI for
PCDDs, PCDFs and coplanar compounds.
JECFA chose the LOEL
established in the study of
Faqi et al (1998) and the
NOEL provided by the study
of Ohsako et al (2001). Two
different models were used
to estimate the equivalent
maternal body burden with
long-term dosing: a model
that assumed a linear
relationship between
maternal and foetal body
burden, and a nonlinear
model.

Notes:
[A] Maximum TDI - Maximum Tolerable Daily Intake; life-time exposure and occasional short-term excursions above this level would have no health consequences provided that the averaged intake over long periods is not exceeded.
Target TDI - Target Tolerable Daily Intake; the ultimate goal is to reduce human intake levels below this level.
TWI - Tolerable Weekly Intake; similar to maximum TDI, but expressed on a weekly basis. TDI equivalent is calculated as TWI / 7 days.
TMI - Tolerable Monthly Intake; similar to maximum TDI, but expressed on a monthly basis. TDI equivalent is calculated as TMI / 30 days.
TDI is equivalent to a non-cancer Reference Dose (RfD)
dioxinsoillevels-international.xls
Page 3 of 9

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Table 1b. Tolerable Daily Intake (TDI) Values Developed by Specific Nations
Nation -
Agency
Date
TDI (RfD)
Tissue Burden Used to Dereive TDI (RfD)
Information
Source(s)
Nature of Peer Review
Transparency/
Reproducibilty-
Public Availability
Scientific Basis
Incorporation of Most
Recent Science
Notes
Value
Parameter
[see note A]
Basis
Tissue
Value
Basis
Uncertainty
Factor (UF)
Half-time in
body (t1/2)
Absorption
Fraction (f)
Japan -
Environment
Agency of
Japan
June 1999
4 pg/kg/d
(reported as
TEQ,
includes
PCBs)
Lifetime TDI
Noncancer
effects in
humans
(based on
animal
studies)
86 ng/kg bw
LOAEL (lowest
body burden
value just
below or above
that at which
effects are
manifested
across multiple
studies)
10
7.5 years
50%
Ref [17]
The Environment Agency and
the Ministry of Health and
Welfare have established
expert committees (the Dioxin
Risk Assessment
Subcommittee, Environmental
Health Committee, Central
Environment Council; the
Living Environment Council;
and the Special Dioxin Health
Effects Evaluation Committee,
Food Sanitation Investigation
Council) and it was decided at
a joint consultation earlier this
year that the TDI should be re-
evaluated in Japan. On 30
March 1999, a Cabinet
Meeting adopted the "Basic
Guidelines of Japan for the
Promotion of the Measures
Against Dioxins" which
required a review of the TDI
Document available
online
Procedure for
selection of tissue
burden and
calculation of TDI is
transparent and
reproducible
TDI (meaning the daily dose of 2,3,7,8-
TCDD which is assumed to have no
adverse effects on human health if taken
constantly over a lifetime), which shall be
a guideline for measures against dioxins
taken by the national government and
local governments, shall not exceed 4
pg/kg bw. Established based upon
effects due to exposure during the fetal
period which is the most sensitive period.
Manifestation of effects such as
carcinogenicity would only occur as a
result of higher exposure than the
established TDI. TDI value is
determined by extrapolating results of
animal tests for humans, multiplied by a
factor of 0.1 for taking account of
uncertainty.
A level of approximately 86
ng/kg is the lowest body
burden value just below or
above that at which effects
are manifested and is used
as the basis for estimating
TDI. This body burden
corresponds to a human
daily intake of 43.6 pg
TEQ/kg/day, to which an an
uncertainty factor of 10 was
applied. The resulting TDI is
4 pg/kg/d (rounded).
Ref [17]: "This report
discusses the TDI of
dioxins and related
compounds by analyzing
and assessing the
discussions of the 1998
WHO Consultation and
contributing new
information."
"...this paper utilizes newly
calculated values instead of
the noted [WHO] body
burden values."
"...memorandum accepts
the conclusions of the WHO
Consultation..."
Nordic Council
2000
5 pg/kg/d
TDI
no
information
located
no information located
[Ref 23]
Recommendation of "Nordic
expert group" (details on this
group not located)
Summary document
vailable in public
journal
Available
documents do not
provide the
underlying basis for
the derivation of the
selected TDI
no information located
no information located

United
Kingdom -
Food
Standards
Agency,
Committee on
T oxicity of
Chemicals in
Food (COT)
2001
2 pg/kg/d
TDI
Noncancer
effects in
humans
(based on
animal
studies)
33 ng/kg bw
(maternal
body burden)
LOAEL for
reproductive
effects in
Wistar rats
(Faqi et al.,
1998)
9.6
7.5 years
50%
Ref [29]
No information located
Document available
online
Procedure for
selection of tissue
burden and
calculation of TDI is
transparent and
reproducible
The calculated total steady-state
maternal body burden arising from the
subcutaneous dosing protocol at the
LOAEL from Faqi et al. is approximately
30 ng/kg bw, which would be about 33
ng/kg bw after allowing for the TCDD
intake from food. The resulting tolerable
daily intake for humans is 1.7 pg/kg
bw/day (rounded to 2).
Evaluation included a review
of the risk assessments of
dioxins carried out by the
WHO, the SCF, and the
USEPA.
Because the correct
mathematical model cannot
be determined based on
goodness of fit, and because
the regressions are
determined largely by body
burdens higher than those
relevant for derivation of a
tolerable intake, we decided
to adopt a simpler method of
correction using the ratios
calculated directly from the
lowest doses in each of the
studies by Hurst et al.

TDI is equivalent to a non-cancer Reference Dose (RfD)
dioxinsoillevels-international.xls
Page 4 of 9

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Table 3. Summary of International Soil Levels for Dioxin
Nation
Agency
Screening
Level(ppt
TCDD/TEQ)
Action Level (ppt TCDD/TEQ)
Soil Action Level
Derivation
Approach
Exposure
Pathways
Considered
TDI (RfD)
(pg/kg-d)
Date
Regulatory
Status
Residential
Commercial/
Industrial
Austria
Federal Environment Agency Austria;
Contaminated Sites Department
10
100
--
[9]
n/a
1 -10
.. I2!
guideline
Canada
Canadian Council of Ministers of the
Environment (CCME)
4
--
--
[11]
n/a
n/a
Mar-05
guideline
Czech Republic
Czech Ministry of the Interior
1 -100
500
10,000
Basis is not
documented [121
n/a
-
1994?
guideline?
Finland
Ministry of the Environment,
Department for Environmental
Protection
10
100
1,500
TDI Approach [11
Ing. (soil and plant),
Inhal., Dermal
5
1994?
guideline
France
Conseil Superieur d'Hygiene Publique
of France
[8]
TDI Approach [11
Ing. (soil and plant),
Dermal
1
.. I2!
guideline?
Germany
German Federal Environmental
Agency (Umweltbundesamt) & Joint
Working Group of the Federal and
Lander Ministers of the Environment
--
1,000
10,000
TDI and oSF
Approach
Ing. (soil only),
Inhal.
1 [4]
July 1999
regulation
Italy
National Toxicology Commission
(CCTN)
--
10
100
TDI Approach [11
n/a
10
.. I2!
regulation [3]
Japan
Environment Agency of Japan
250
1,000[7]
TDI Approach [11
n/a
4
2009
guideline?
Netherlands
National Institute for Public Health and
the Environment (RIVM)
--
360
--
TDI Approach
Ing. (soil and plant),
Inhal.
1 -4
Feb-01
regulation?
New Zealand
Ministry for the Environment (MfE) and
the Ministry of Health (MoH)
--
1,500[101
18,00016101
TDI Approach
n/a
10 PI
Jun-05
draft guideline
Sweden
Swedish Environmental Protection
Agency
10-250
--
--
TDI Approach [11
n/a
5
1996
guideline
See Table 2 for detailed information on soil levels and derivation approach
[1]	Uncertain; likely based on TDI approach, but this cannot be documented
[2]	Soil levels provided in a document dated 2007.
[3]	Soil values have been criticized both scientifically and practically, because they lack flexibility and do not take sufficient account of regional and local specificities. Future regulations concerning soil pollution and soil
clean-up are in preparation.
[4]	Uses an adjusted TDI of 0.2 pg/kg/d (to account from fraction of TDI attributable to soil).
[5]	Uses an adjusted TDI of 8 pg/kg/d (to account from fraction of TDI attributable to contaminated soil). Since the derivation of these soil levels, New Zealand has adopted target TDI of 1 pg/kg-d.
[6]	Applicable to unpaved areas.
[7]	Reported action levels are applicable to all land uses.
[8]	Derived soil values are not intended to be screening values or remediation goals and should not be used outside of the simplified risk assessment scoring system.
[9]	Uncertain; identified by expert working group.
[10]	Site-specific values are used as interim soil acceptance criteria; use care when applying values to other sites.
[11]	No action levels specified; screening level is based on a background soil approach.
[12]	Screening levels are based on a background soil approach.
TDI = Tolerable Daily Intake; equivalent to a non-cancer Reference Dose (RfD)
dioxinsoillevels-international.xls

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Table 4. Evaluation of TDI Values and Soil Action Levels
TDI Values

Nature of peer
review
Transparency/
Reproducability
& Public
Availabilitv
Scientific basis
Incorporation of
new science
WHO 1990
•
•
•

WHO 1998
•
•
•

EC-SCF 2001
•
•
•

JECFA 2001
•
•
•

Japan 1999
O
•
•

Nordic Council 2000
X
X
X

UK, COT 2001
X
•
•

Soil Action Levels

Nature of peer
review
Transparency/
Reproducability
& Public
Availabilitv
Scientific basis
Incorporation of
new science
Austria
X
X
X

Czech Republic
X
X
X

Finland
X
O
O

Germany
X
o
•

Italy
X
X
X

Japan
X
X
X

Netherlands
O
•
•

New Zealand
X
X
X

Legend:
meets evaluation criteria in full
meets evaluation criteria in part
does not meet evaluation criteria or no information was located
O
dioxinsoillevels-international.xls

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Cited Table References:
[1]	Compilation of EU Dioxin Exposure and Health Data Task 1 - Review of Member State Legislation and Programmes:
http://ec.europa.eu/environment/dioxin/pdf/task1 .pdf
[2]	Canadian Soil Quality Guideline (CSoQG) for dioxin and furan:
http://www.ec.gc.ca/ceqg-rcqe/English/Pdf/GAAG_DioxinFuranSoil_e.pdf
[3]	Protocol for the Derivation of Environmental and Human Health Soil Quality Guidelines:
http://www.ccme.ca/assets/pdf/sg_protocol_1332_e.pdf
[4]	Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV):
http://www.bmu.bund.de/files/pdfs/allgemein/application/pdf/bbodschv_uk.pdf
[5]	BLAG (1992): Umweltpolitik: Bericht der Bund/Lander-Arbeitsgruppe DIOXINE. Rechtsnormen, Richtwerte, Handlungsempfehlungen,
MelZprogramme, Mellwerte und Forschungsprogramme. Bundesminister fur Umwelt, Naturschutz und Reaktorsicherheit (Hrsg.), Bonn,
Januar 1992.
TRANSLATED »> BLAG (1992): Environmental policy: Report the federation/land working group of DIOXINS. Legal rules, approximate
values, recommendations for action, measuring programs, measured values and research programs. Federal Minister for environment,
nature protection and reactor safety (Hrsg.), Bonn, January 1992
[6]	Law Concerning Special Measures against Dioxins (Law No. 105 of 1999, Article 6): http://www.env.go.jp/en/laws/chemi/dioxin.pdf
1999 Informational Brochure - Dioxins: http://www.env.go.jp/en/chemi/dioxins/brochure.pdf
2009 Informational Brochure - Dioxins: http://www.env.go.jp/en/chemi/dioxins/brochure2009.pdf
Water Environment Management in Japan, Countermeasures for Dioxin: http://www.env.go.jp/en/water/wq/pamph/index.html
Dioxin Concentrations in Residential Soil, Paritutu, New Plymouth (New Zealand):
http://www.dioxinnz.com/reportsPDF/MfE2002FullReport/Sept2002SoilRPT.html
Zorge JA, AKD Liem (1994). Dioxins and related compounds - regulatory aspects in the Netherlands. Organohalogen Compounds, 20,
577-580.
Technical evaluation of the Intervention Values for Soil/sediment and Groundwater:
http://rivm.openrepository.eom/rivm/bitstream/10029/9660/1/711701023.pdf
Soil Cone and TDIs presented in: Health and Environmental Guidelines for Selected Timber Treatment Chemicals. MfE/MoH. June 1997.
http://www.mfe.govt.nz/publications/hazardous/timber-guide-jun97/timber-guide-jun97.pdf
NTG (1992) "Pentachlorophenol Risk Assessment Pilot Study, National Task Group Study Team Report" New Zealand National Task
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ATTACHMENT 1 DERIVATION DETAILS FOR THE COMPUTATION OF GERMANY TRIGGER LEVELS
Nation
Agency
Land Use
Soil Exposure Parameters used in Trigger Level Calculation
Estimated
Trigger
Level
(PPtr
Specified
Action
Level (ppt)
Pathways
considered
Intake Rate
Body
weight
Exposure
Freq. & Dur.
RBA
Target risk
or hazard
Daily Intake Rate
(mg/kg-d)
Germany
German
Federal
Environmental
Agency
(Umweltbundes
amt) & Joint
Working Group
of the Federal
and Lander
Ministers of the
Environment
playgrounds
1.	ingestion of
soil;
2.	inhalation of
soil particles.
ing: 500 mg/d
inh: 0.625 m3/hr
10 kg
EF=240 d/yr
ET=2 hr/d
ED=8 yrs
not
specified
HQ=1
Risk=1E-05
ing: 33
inhal: 0.082
-73
100
residential
(residential: set equal to 1/2 playground daily intake rates)
ing: 16.5
inhal: 0.041
-145
1,000
parks/recreation
(parks/recreation: set equal to 1/5 playground daily intake rates)
ing: 6.6
inhal: 0.016
-364
1,000
industrial,
commercial
1. inhalation of
soil particles
not specified
not
specified
EF=225 d/yr
ET=8 hr/d
not
specified
HQ=1
Risk=1E-05
inhal: -

10,000
**only incorporates soil ingestion pathway
dioxinsoillevels-international.xls

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