United States Office of Water EPA-822R18003
Environmental Protection Agency Office of Science and Technology June 2019
4304T
oEPA Biennial Review of
40 CFR Part 503
As Required Under the
Clean Water Act
Section 405(d)(2)(C)
Biosolids Biennial Review
Reporting Period 2016-2017
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EPA-822R18003
Biennial Review of 40 CFR Part 503
As Required Under the Clean Water Act Section
405(d)(2)(C)
Biosolids Biennial Review
Reporting Period 2016-2017
U.S. Environmental Protection Agency
Office of Water
Office of Science and Technology
Washington, D.C.
May 2019
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Biosolids Biennial Review
Reporting Period 2016-2017
NOTICE
This document has been reviewed in accordance with U.S. EPA policy and approved for
publication. The report was prepared with the support of RTI International under the direction
and review of the Office of Science and Technology.
This document is not a regulation and does not change or substitute for statutory provisions and
the EPA regulations. Thus, this document does not impose legally binding requirements on the
EPA, states, tribes, or the regulated community. While the EPA has made every effort to ensure
the accuracy of the discussion in this document, the obligations of the regulated community are
determined by statutes, regulations, or other legally binding requirements. In the event of a
conflict between the discussion in this document and any statute or regulation, this document
would not be controlling. Mention of trade names or commercial products does not constitute
endorsement or recommendation for their use
This document can be downloaded from the EPAs website at http://wvvv\ epa uo\/biosolids.
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Biosolids Biennial Review
Reporting Period 2016-2017
Definition of Biosolids
For the purposes of this Biennial Report, "biosolids" is used to mean sewage sludge, as defined
in 40 CFR503:
Sewage sludge is solid, semi-solid, or liquid residue generated during the treatment of domestic
sewage in a treatment works. Sewage sludge includes, but is not limited to, domestic septage;
scum or solids removed in primary, secondary, or advanced wastewater treatment processes; and
a material derived from sewage sludge. Sewage sludge does not include ash generated during the
firing of sewage sludge in a sewage sludge incinerator or grit and screenings generated during
preliminary treatment of domestic sewage in a treatment works 4<) CFR §503.9(w).
Terms in italics are defined as follows:
Domestic sewage is waste and wastewater from luimans or household operations that is
discharged to or otherwise enters a treatment works 40 CFR §503 '¦Hu)
Treatment works is either a federally owned, publicly owned, or privately ow ned device or
system used to treat (including recycle and reclaim) either domestic sewage or a combination of
domestic sewage and industrial waste of a liquid nature 4<) CIR §503.9(aa).
Industrial wastewater is wastewater generated in a commercial or industrial process. 40 CFR
§503.9(n).
Taken together, these definitions mean that biosolids. or sewage sludge, for the purposes of 40
CFR Part 503, are the residues from treatment of domestic sewage, whether that domestic
sewage is combined with industrial wastewater or not It does not include sludge originating
from treatment of industrial wastes in the absence of domestic sewage.
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Biosolids Biennial Review
Reporting Period 2016-2017
Executive Summary
During the 2016-2017 biennial review process, the EPA collected and reviewed publicly
available information on occurrence, fate and transport in the environment, and human health
and ecological effects for pollutants that (1) have been identified in the Targeted National
Sewage Sludge Survey (TNSSS; U.S. EPA, 2009), or in the open literature as having been found
in biosolids; and (2) have not been previously regulated or evaluated (e.g., as potentially causing
harm to humans or the environment) in biosolids.
The EPA identified 32 new articles as providing relevant data for chemical pollutants that may
occur in U.S. biosolids. After initial review, information was gleaned from 15 of the new articles.
Review of the 15 articles identified 28 new chemicals in biosolids seven polybrominated
diphenyl ethers (PBDEs); nine parabens and metaboliles. Il\ e brominated flame retardants
(BFRs); three other flame retardants; two perfluoroalkyl substances (PTASs); and two triclosan
transformation products. These articles also idenlilied new data for 3 I chemicals previously
identified in biosolids. Concentration data in biosolids were found for all 2K new chemicals and
for two chemicals identified in a previous biennial re\ iew (diclofenac and lonalide). Human
health toxicity values were found for three of the new chemicals (benzoic acid. 2.4-
dichlorophenol; and hexabromobenxene) and two |iie\ iously identified chemicals,
perfluorooctanoate (PFOA) and peilluorooclancsullbnate (J'l 'OS). ECOTOXicology
knowledgebase (ECOTOX; U.S. EPA. 2<> I Kd) records were found for 17 newly identified
chemicals and 26 pre\ iously identified chemicals Physical-chemical properties were identified
for 22 new chemicals and 2d chemicals pre\ iously identified in biosolids; and bioconcentration
or bioaccumulation factors were identified for 23 new chemicals (11 in terrestrial systems and 13
in aquatic; there was one chemical with both) and 24 previously identified chemicals.
In addition, six articles were identified as pro\ iding relevant data for microbial pollutants that
may occur in biosolids Re\ iew of these articles identified no new microbial pollutants in
biosolids Data were found for se\ en |ire\ iously identified microbial pollutants: Cryptosporidium
spp., Giardia spp . antibiotic resistance genes (ARGs)/antibiotic resistant bacteria (AR bacteria),
Salmonella, Escherichia coh. human norovirus, and human adenovirus.
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Biosolids Biennial Review
Reporting Period 2016-2017
Table of Contents
Page
1. Introduction 1
2. Approach for Biennial Reviews 1
2.1 Paper Review: Identify, Review and Select Papers 3
2.2 Chemical Review: Evaluate Data Availability for Chemicals to be Included in
the Biennial Review 6
3. Results from the Biosolids Biennial Review for the 2016-2017 Reporting Period 9
3.1 Chemicals Newly Identified in the 2016-2017 Biennial Review 10
3.2 Data Found on Chemicals Previously Identified in Biennial Reviews 15
4. Conclusions 21
5. Additional Information 21
6. References 22
Appendix A. Pollutants Identified in Biosolids
Appendix B. Reference Abstracts: Chemicals
Appendix C. Reference Abstracts: Other
Appendix D. Reference Abstracts: Microbials
List of Tables
Table 1. Chemicals Newly Idenlilied in Biosolids in the 2<)|(i -2017 Reporting Period
and Types of Data Available. . 11
Table 2. Human Health Toxicity Values I'oiind lor Chemicals Newly Identified in the
2016-201 7 Reporting IVi iod 12
Table 3. Summary of Papers I'oiind in IX'OIOX for Chemicals Newly Identified in
the 2016 2<)|7 Reporting Period 12
Table 4. Physical-Chemical Properties I 'oiind for Chemicals Newly Identified in the
2016 201 7 Reporting Period 13
Table 5 Terrestrial liioaccunuilalion I'actors I'ound for Chemicals Newly Identified in
the 2d |(i 2d I 7 Reporting Period ( All Values Unitless) 14
Table (> Aquatic liioconcenlialion I-'actors Found for Chemicals Newly Identified in
the 2<)|(i -2017 Reporting Period (All Data from EPISuite) 15
Table 7. Pre\ iously Identified Chemicals with Data Found in the 2016-2017 Reporting
Period and Types of Data Available 15
Table 8. Human I lealth Toxicity Values Found in the 2016-2017 Reporting Period for
Chemicals Pre\ iously Identified 16
Table 9. Summary of Papers Found in ECOTOX in the 2016-2017 Reporting Period
for Chemicals Previously Identified 17
Table 10. Physical-Chemical Properties Found in the 2016-2017 Reporting Period for
Chemicals Previously Identified 18
Table 11. Terrestrial Bioaccumulation Factors Found in the 2016-2017 Reporting
Period for Chemicals Previously Identified 19
List of Figures
Figure 1. Overview of the Biennial Review Approach and 2016-2017 Summary for
Chemical Pollutants 3
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Biosolids Biennial Review
Reporting Period 2016-2017
1. Introduction
Section 405(d) of the CWA requires the EPA to review biosolids regulations every two years to
identify additional pollutants that occur in biosolids and to regulate those pollutants if sufficient
scientific evidence shows that they may harm (i.e., there is risk to) human health or the
environment. The EPA considers risk to be the chance of harmful effects to human health or to
ecological systems resulting from exposure to an environmental stressor (e.g., chemical). Risk
assessment is a scientific process consistent with EPA policies and depends on three factors: 1)
how much of a chemical is present in an environmental medium (e g., biosolids); 2) how much
contact a person or ecological receptor has with the contaminated environmental medium; and 3)
the inherent toxicity of the chemical.
The biennial review process is intended to fulfill the (\VA requirement to identify additional
pollutants that occur in biosolids every two years The data gleaned from the biennial review
process will be analyzed to determine whether il is sufficient to be used lor assessing potential
risk. While not listed as a biennial review, an extensive literature search ^as conducted and
published in 2003, and 10 pollutants were identified and prioritized for risk assessment in
response to the 2002 National Research Council of the National Academies report (68 FR
75531). Subsequent biennial reviews are posted to EPAs website for 2005, 2007, 2009, 2011,
2013 and 2015: https://www.epa.gov/biosolids/biennial-re\ ieus-sewage-sludge-standards.
Once additional pollutants that occur in biosolids are identified, the EPA must assess the
pollutants to determine w hether they pose a risk to human health or the environment. The EPA is
in the process of de\ eloping a tool that will enable users to screen pollutants found in biosolids
for potential risk The screening results will be used to make informed decisions about the need
to perform more refined risk assessments, or to address data gaps or uncertainties. The EPA is
also in the process of de\ eloping a probabilistic risk assessment modeling framework to conduct
refined risk assessments on those pollutants that fail the screening process.
Addressing the uncertainty around potential risk for pollutants identified in biosolids is the top
priority for the EPAs Biosolids Program. The EPA continues to make significant progress in
building capacity to assess pollutants by developing the necessary tools and data needed. The
EPA expects to begin risk screening once public review of the screening tool has been
completed.
2. Approach for Biennial Reviews
Every two years the EPA develops biennial reviews by collecting and reviewing publicly
available information on the occurrence, human health and ecological effects, and fate and
transport in the environment of pollutants that have been found in U.S. biosolids. The three
categories of information collected and presented here are needed to conduct risk assessments.
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Biosolids Biennial Review
Reporting Period 2016-2017
Concentration Data. Both the ability to detect a given pollutant in biosolids and the
determination of the concentration at which that pollutant is present are highly dependent
on the existence of analytical methods for that pollutant in the biosolids matrix.
Toxicity to Human and Ecological Receptors. For human toxicity, this type of data
includes values such as a reference dose (RfD), reference concentration (RfC), cancer
slope factor (CSF), or inhalation unit risk (IUR). For ecological toxicity, it includes
values such as lethal dose, lethal concentration, or chronic endpoints related to survival,
growth, and reproduction.
Environmental Fate and Transport Data. These data are necessary for assessing
exposure and include various physical-chemical properties. as well as bioconcentration or
bioaccumulation factors, which describe the tendency of a chemical to move from one
medium (e.g., soil) to another (e.g., planl mallei )
The biennial review approach consists of two stages, as illustrated in Figure 1, for chemical and
microbial pollutants:
Paper Review. Tn this stage, the N\\ conducts a systematic review including a literature
search and evaluation to identity papers that pro\ ide e\ idence of the occurrence of
chemical or microbial pollutants in biosolids that ha\ e not previously been identified, or
new data that fills data gaps for pollutants pre\ iously identified in biosolids.
Chemical and Microbial Review. Using the list of chemicals identified in the Paper
Review stage, the F.PA extracts data (typically concentration, and environmental fate and
transport data) from the identified papers for newly identified chemical pollutants, the
N\\ then collects additional data on human and ecological toxicity and environmental
late and transport data, not limited to the biennial review period. These data are collected
from a set of established sources (see Section 2.2). The EPA is currently revising the
approach for microbial pollutants As a result, there is no analogous data collection step
(collection of data on human and ecological toxicity, and environmental fate and
transport) for microbial pollutants for the 2016-2017 Biennial Review. The revised
approach and results for the microbial review are expected to be reported in the 2018-
2019 Biennial Re\ iew
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Biosolids Biennial Review
Reporting Period 2016-2017
Paper Review
181 microbial
119 chemical
Literature Search
I =
587 chemical papers
203 microbial papers
±
Abstract Review
I =
164 chemical papers
22 microbial papers
±
Primary Full-text Review
45 chemical papers
8 microbial papers
*
Secondary Full-text Review
to Identify Pollutants
1
h-
32 chemical papers
6 microbial papers
Chemical Review
59 chemicals
Chemicals Identified
28 chemicals
£
31 chemicals
New Chemicals)
T
Extract Paper Data
1
Existing Chemicals
nr
Extract Paper Data
Collect
Additional Data
(Any Date)
Microbial Review
7 microbials
Microbial Pollutants Identified*
(0 new, 7 existing)
* Data extraction and further data collection on hold
pending revision of microbial approach for 2018-2019
Biennial Review.
Figure 1. Overview of the Biennial Review Approach and 2016-2017 Summary for Chemical and
Microbial Pollutants
2.1 Paper Review: Identify, Review and Select Papers
For reporting period 2016-2017, the EPA conducted a literature search from January 2016
through December 2017 for articles published in English in peer-reviewed journals to identify
data published (e-pub or print) since the previous search was performed in support of the 2015
Biennial Review (EPA-822-S18-003). The bibliographic databases searched included PubMed,
Web of Science, Toxicology Literature Online (TOXLINE), Fish, Fisheries, & Aquatic
Biodiversity Worldwide, Environment Complete, CAB Abstracts, and Science Direct.
Conference abstracts, reports, comments, letters, and editorials were excluded.
Literature searches for chemical and microbial pollutants were conducted separately. For both
chemicals and microbial pollutants, the search strategy for previous reporting periods was used
with modifications. For the chemical search, keywords applicable only to microbial pollutants
were eliminated. Likewise, keywords applicable only to chemicals were eliminated for the
microbial pollutant search. To avoid limiting potential findings, the geographical search terms
restricting the searches to studies conducted in the U.S. and Canada (the approach taken for past
biennial reviews) were not used for the 2016-2017 reporting period for either chemical or
microbial pollutants. The data in the studies found from other countries were analyzed in the
review process for appropriateness for future risk determinations.
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Biosolids Biennial Review
Reporting Period 2016-2017
For chemical pollutants, health-related keywords were combined with chemical-related
keywords, and land application keywords were dropped to broaden the search. Specifically, to be
identified as a candidate, a paper had to have at least one biosolids-related keyword and at least
one chemical- or health-related keyword:
Biosolids-related keywords: (sewage sludge OR biosolids OR treated sewage OR sludge
treatment OR sewage treatment)
AND
Chemical- and health-related keywords: (pollutant* OR toxic* [toxicant, toxicology, etc.]
OR chemical OR constituent OR contaminant* OR metal* OR dioxin* OR inorganic* OR
organic* OR flame retardant* OR pharmaceutical" OR steroid" OR hormone* OR
antibiotic* OR personal care product*) OR (effect OR c flee Is OR occurrence OR
concentration).
For microbial pollutants, health-related and microbial pollutant-related keywords were kept
separate to ensure that the chemical search was not duplicated (by requiring a microbial-related
keyword). Land-application keywords were retained, because 4<) CFRParl 5l)3 includes site
restrictions specific to land application of Class B biosolids |4<) CFR 503.32(b)(5)] to allow time
for environmental conditions to furl her reduce pathogen le\ els (IS. EPA, 1994). Specifically, to
be identified as a candidate, a paper had to have at least one hiosolids-related keyword and at
least one land application-related keyword and at least one microbial pollutant-related
keyword and at least one health-related keyword
Biosolids-related Keywords: (sewage sludge OR biosolids OR treated sewage OR sludge
treatment OR sewage treatment)
AM)
Land Application-related Keywords: (land application OR farm OR agriculture OR soil)
AM)
Microbial Pollutant-related Keywords: (pathogen* OR Salmonella OR microb*)
AND
Health-related Keywords: (occurrence OR concentration OR effect OR effects OR propert*
OR fate OR transport OR health OR health effects).
For the papers identified in both literature searches (chemical and microbial), the EPA first
screened the abstracts and then the full text (for abstracts not screened out) and excluded papers
that met the following criteria:
No abstract AND insufficient information in the title to determine whether it might be
relevant.
Endpoints not pollutant-specific (i.e., overall effects of biosolids on plant growth, crop
yield, soil microbe community, or soil nutrients).
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Biosolids Biennial Review
Reporting Period 2016-2017
Media evaluated not primarily sewage sludge, as defined in 40 CFR Part 503, including:
- Influent and effluent wastewater;
- Industrial sewage sludge (e.g., paper mill biosolids) - sewage sludge is defined in 40
CFR Part 503 to exclude sludge originating solely from industrial wastes with no
domestic sewage component;
- Activated carbon - this is derived from sewage sludge and is not biosolids;
- Activated sludge - this is the sludge from secondary treatment, not biosolids, which
typically includes primary sludge as well; 4<) CIR Pan 503 specifies that sewage
sludge does not include these intermediate sludges.
- Biochar - these are residuals from burning biosolids. u hich are also excluded by 40
CFR Part 503; or
- Biosolids compost - many of these are a mixture of human Mosolids, industrial
sludge, plant waste, and other ingredients
Describes only an analytical method or eflecli\ eness of treatment methods.
The EPA then reviewed the remai ninu papers to identily new pol lutants with evidence regarding
biosolids and pollutants that had pre\ iously been identified in either the Targeted National
Sewage Sludge Survey (TNSSS; US l-l\V or a pie\ ions biennial review for which there
were new or additional data in the papers See Appendix A for a list of new and previously
identified chemical and microbial pollutants
During full-text re\iews. papers were excluded when
Countries had treatment technologies, regulatory requirements or soil types that were not
comparable to the I S and Canada AM) reported only concentration data. Note that
studies for countries that were not comparable to the U.S. and Canada but had other types
of data (e.g., toxicity, late and transport) were not excluded.
Only spiked concentration data were reported.
No evidence of the occurrence of new pollutants in biosolids AND no new data for
chemicals pre\ iously identified were reported.
The only reported data were for metals previously regulated in biosolids.1
New classes of chemicals (e.g., nanoparticles) were found in biosolids but no data were
available.
Abstracts of the papers retained after full-text review for chemical pollutants are provided in
Appendix B (15 papers) and Appendix C (14 papers excluded because they contained data only
on metals already regulated in biosolids, and three papers that identified new classes of
1 For more information on pollutants previously regulated or evaluated in biosolids, see the Statistics Support
Documentation for the 40 CFR Part 503 - Volume 1 (https://www.epa. gov/sites/production/files/2015-
04/documents/statistics 1992 support document - biosolids vol i.pdf) and EPA's response to the National
Research Council of the National Academies report on biosolids
(https://www.epa. gov/sites/production/files/2015 -06/documents/technical background document.pdf).
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Biosolids Biennial Review
Reporting Period 2016-2017
chemicals in biosolids with no data). Abstracts of the papers retained after full-text review for
microbial pollutants are provided in Appendix D (six papers).
2.2 Chemical Review: Evaluate Data Availability for Chemicals to be Included
in the Biennial Review
For both the new and previously identified chemicals, the data presented in the papers (e.g.,
concentration, physical-chemical properties, transfer factors) were extracted.
For chemicals newly identified in biosolids, the EPA also collected additional data required for
risk assessment determinations (e.g., human and ecological toxicity, and environmental fate and
transport data) that were not limited to the biennial reporting period (2016-2017). The preferred
sources for the additional data are described in the next sub-sections
For previously identified chemicals, the EPA extracted only data that had not previously been
available. However, data were extracted for pre\ iously identified chemicals of particular interest
for which limited data are available (e g . triclosan. ti iclocai han. and perfluoroalkyl substances).
2.2.1 Human Health Toxicity Values Data Sources and Selection
To estimate the potential for adverse human health effects from land application of biosolids, the
EPA uses RfDs and RlX's to e\ aluate non-cancer risk from oral and inhalation exposures,
respectively. The EPA uses oral ( Si 's and II Rs to e\ aluale risk for carcinogens from oral and
inhalation exposures.2
The P.P. Vs Integrated Risk Information System (IRIS; U.S. EPA, 2018a) Program develops
human health risk assessments, including toxicity values, using Agency guidance and
standardized methods for hazard identification and dose response.3 IRIS human health
assessments are thoroughly peer reviewed and publicly available. The EPA's primary source of
human health toxicity values to e\ aluate the potential human health risk is IRIS. However, not
all chemicals ha\ e a toxicity value in IRIS, and some chemicals with a toxicity value in IRIS do
not necessarily ha\ e all four toxicity values (RfD, RfC, CSF, IUR). Thus, a variety of other
sources are used. To make efficient use of resources, the EPA developed a hierarchy that gives
higher priority to sources of information that:
Are developed specifically for use in human health risk assessment using methodologies
similar to those used by IRIS;
Have been peer reviewed and have a transparent basis for the values; and
Are more recent than published IRIS values.
2 For more information about these toxicity values, see https://www.epa.gov/iris/basic-information-about-
integrated-risk-information-svstem.
3 For more information about these methods, see https://www.epa.gov/iris/basic-information-about-integrated-risk-
information-svstem#guidance.
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Biosolids Biennial Review
Reporting Period 2016-2017
Note, however, that during the 2016-2017 biennial review process, only Tier 1 and Tier 2
sources of the EPA hierarchy were searched for each chemical.
Tier 1: Highest Quality EPA Sources: Sources in Tier 1 contain values developed by
the EPA specifically for human health risk assessment according to standard methods and
represent the highest quality human health toxicity values available. These toxicity values
are frequently used to support EPA risk analyses.
- Integrated Risk Information System (IRIS): IRIS is the EPA's primary repository
for human health toxicity values that have been de\ eloped specifically for human
health risk assessment using standardized methods and have been thoroughly peer
reviewed. IRIS is considered the most preferred source lor human health toxicity
values for most EPA risk assessment Tor pesticides, toxicity values are developed by
the EPA's Office of Pesticide Programs (U.S. EPA, 201 Kb)
- Human Health Benchmarks for Pesticides (HHBPs): The I -PA develops chronic
oral health benchmarks (RfDs and ( Si's) for pesticides for surface and groundwater
sources of drinking water using heallh effects data submitted during the pesticide
registration process (U S. I-I\\. 2
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Biosolids Biennial Review
Reporting Period 2016-2017
species assemblages (or communities) are assessed in soil, sediment, and surface water where
they are assumed to be exposed through direct contact with the contaminated medium. For the
ingestion pathway, species are assumed to ingest contaminated food and prey from biosolids-
treated agricultural fields and farm pond that receives runoff from a biosolids-treated field. The
ecological toxicity values are expressed in terms of media concentration (e.g., mg/L for surface
water and mg/kg for soil) for the direct contact pathway and in terms of dose (mg/kg-d) for the
ingestion pathway.
The EPA does not have a single repository for approved ecological toxicity values directly
comparable to IRIS for human toxicity values; however, the '() I'OXicology knowledgebase
{ECOTOX; U.S. EPA, 2018d) was searched for all newly identified and existing chemicals to
identify the number of papers and species, if any, that were a\ ai lahle. ECOTOX is a
comprehensive, publicly available knowledgebase providing single chemical environmental
toxicity data on aquatic life, terrestrial plants and wildlife. Studies in the database must meet the
following minimum criteria based on the ECOTOX applicability criteria.
(1) The toxic effects are related to single chemical exposure;
(2) There is a biological effect on live, whole organisms;
(3) Chemical test concentrations are reported.
(4) There is an explicit duration of exposure.
(5) Toxicology information is reported for the chemical of concern;
(6) The paper is published in the I jiglish language.
(7) The paper is a\ailaMe as a lull article (not an abstract).
(8) The paper is publicly a\ ai lahle.
(l>) The paper is the primary source of the data.
(I'M A calculated endpoint is reported or can he calculated using reported or available
information.
(11) Treatment!s) are compared to an acceptable control;
(12) The location of the study (e.g., laboratory vs. field) is reported; and
(13) The tested species is reported (with recognized nomenclature).
Studies from the open literature papers that pass the ECOTOX screen of applicability are
considered potentially rele\ ant and further evaluated for inclusion in risk assessments.
2.2.3 Environmental Fate and Transport Data
The EPA uses risk assessment models that require physical-chemical properties and transfer
factors to estimate the potential for chemical transport and uptake from agricultural lands
amended with biosolids to drinking water, produce, animal products, fish, and ecological
receptor diet items.
The EPA's preferred source for physical-chemical properties is the PHYSPROP database, which
is incorporated in the Estimation Programs Interface (EPISuite; U.S. EPA, 2017). EPISuite is
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Biosolids Biennial Review
Reporting Period 2016-2017
a suite of physical/chemical property and environmental fate estimation programs developed by
the EPA and Syracuse Research Corp. (SRC) and packaged with the PHYSPROP database. It
uses available physical-chemical inputs (either from PHYSPROP, input by the user, or a
combination of both) to estimate missing physical-chemical properties and bioconcentration or
bioaccumulation factors. Physical-chemical properties include:
Molecular weight
Solubility
Vapor pressure
Henry's law constant
Log octanol-water partition coefficients (log K0«)
Soil-water partitioning coefficients (Kd and K...)
Degradation rates in various media
Diffusivities in air and water
Bioavailability
For many organic chemicals, the plant and animal product uptake/transfer factors can be
estimated using empirical relationships between the transfer factor and log Kow. Bioaccumulation
factors are preferred if available. l-'ish Moconceniralion factors (liCFs) can be estimated using
EPISuite, if some physical-chemical property data are a\ ai lahle Transfer factors include the
following:
Air-to-plant transfer factors
Root uptake factors lor aho\ e-ground \ chelation
Root concentration factors (for root \ cuelaMes)
liioconcenlialion factors for fish
liioaccumulation factors for \ arious plants and small fauna eaten by ecological receptors
Bioconcentration factors for animal products (e.g., meat and milk)
3. Results from the Biosolids Biennial Review for the 2016-2017
Reporting Period
During the Paper Re\ iew stage of the literature review process completed for the 2016-2017
reporting period, the EPA identified 32 articles that met the eligibility criteria for chemicals.
Review of these articles identified 28 new chemicals in biosolids (see Section 3.1): seven
polybrominated diphenyl ethers (PBDEs); nine parabens and metabolites; five brominated flame
retardants (BFRs); three other flame retardants; two perfluoroalkyl substances (PFASs); and two
triclosan transformation products. These articles also provided new or additional data on 31
previously identified chemicals (see Section 3.2). Of the 32 papers, 15 identified new chemicals
or provided data on previously identified chemicals (abstracts provided in Appendix B); 14
contained data on already regulated metals (abstracts provided in Appendix C, Section C.l);
and three contained information on novel chemical groups (i.e., nanoparticles and microplastics)
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Biosolids Biennial Review
Reporting Period 2016-2017
(abstracts provided in Appendix C, Section C.2). During the Chemical Review stage, data
identified include the following:
Concentration data were identified for all 28 newly identified chemicals and two
previously identified chemicals (diclofenac and tonalide).
Human health toxicity data were identified for three newly identified chemicals (see
Section 3.1.1) and two previously identified chemicals (see Section 3.2.1),
ECOTOX records were found for 17 newly identified chemicals (see Section 3.1.2) and
26 previously identified chemicals (see Section 3.2.2)
Physical-chemical property data were identified lor 22 new ly identified chemicals (see
Section 3.1.3) and 20 previously identified chemicals (see Section 3.2.3),
Bioconcentration or bioaccumulation factors were idenlilied for 23 newly identified
chemicals (see Section 3.1.3) and 24 pre\ ionsly identified chemicals (see Section 3.2.3),
The EPA also identified six articles that met the eligibility criteria for microbial pollutants
(abstracts provided in Appendix D). Review of these articles identified no new ly identified
microbial pollutants in biosolids and provided potentially useful data on seven previously
identified microbial pollutants: Cryptosporidium spp . (Hard/a spp., antibiotic resistance genes
(ARGs)/antibiotic resistant bacteria (AR bacteria). Salmonella. I.scherichia coli., human
norovirus, and human adeno\ irus
3.1 Chemicals Newly Identified in the 2016-2017 Biennial Review
Table 1 lists the 28 new chemicals identified in the 2d IO-2017 reporting period. As stated
previously, for chemicals new ly identified in biosolids. the EPA also collected data required to
inform risk assessments from preferred sources not limited to the biennial reporting period
(201(-> 2<)| 7) (see Sections 2.2.1 and 2.2.2 in this re\ iew). Chemical concentrations in biosolids
were reported in the IS. Canada. Australia, Spain and India. The EPA will evaluate these data
to determine whether they are representative of U.S. biosolids.
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Biosolids Biennial Review
Reporting Period 2016-2017
4. Conclusions
Every two years the EPA develops biennial reviews by collecting and reviewing publicly
available information on the occurrence, human health and ecological effects, and fate and
transport in the environment of pollutants that have been found in U.S. biosolids. The kinds of
information collected and presented in the 2016-2017 Biennial Review are needed to conduct
risk assessments.
The EPA identified 32 new articles as providing relevant data for chemical pollutants that may
occur in U.S. biosolids. After initial review, information was gleaned from 15 of the new articles.
Review of the 15 articles identified 28 new chemicals in biosolids seven polybrominated
diphenyl ethers (PBDEs); nine parabens and metabolites, five bi ominated flame retardants
(BFRs); three other flame retardants; two perfluoroalkyl substances (PFASs); and two triclosan
transformation products. These articles also idenlilied new data lor 3 I chemicals previously
identified in biosolids. Concentration data in biosolids were found for all 28 new chemicals and
for two chemicals identified in a previous biennial review (diclofenac and lonalide). Human
health toxicity values were found for three of the new chemicals (benzoic acid. 2.4-
dichlorophenol; and hexabromobenzene) and two prc\ ionsly identified chemicals,
perfluorooctanoate (PFOA) and peril uoiooctanesulfonalc (PI OS). ECOTOXicology
knowledgebase (ECOTOX; U.S. EPA. 2<)l8d) records were found lor 17 newly identified
chemicals and 26 previously identified chemicals Physical-chemical properties were identified
for 22 new chemicals and 2d chemicals pre\ ionsly idenlilied in Mosolids; and bioconcentration
or bioaccumulation factors were identified lor 23 new chemicals (1 1 in terrestrial systems and 13
in aquatic; there was one chemical with both) and 24 previously identified chemicals.
In addition, although no new microbial pollutants in biosolids were identified, potentially useful
data on se\en pre\ ionsly idenlilied microbial pollutants were found: Cryptosporidium spp.,
Giardia spp . antibiotic resistance genes (ARGs), antibiotic resistant bacteria (AR bacteria),
Salmonella. Escherichia co/i. luiman norovirus, and human adenovirus.
Addressing the uncertainty around potential risk for pollutants identified in biosolids is the top
priority for the 1-IWs Biosolids Program. The EPA continues to make significant progress in
building capacity to assess pollutants by developing the necessary tools and data. The EPA
expects to begin risk screening of pollutants found in biosolids once public review of its
screening tool has been completed.
5. Additional Information
For additional information about the EPA's Biosolids Program, please visit the website at:
http://epa.gov/biosolids.
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Reporting Period 2016-2017
6. References
21 CFR Part 556. Tolerances for Residues of New Animal Drugs in Food. Available at
https://www.ecfr.gov.
40 CFR Part 503. Standards for the Use or Disposal of Sewage Sludge. Available at
https://www.ecfr.gov.
ATSDR (Agency for Toxic Substances and Disease Registry). 2016. Minimal Risk Levels
(MRLs) for Hazardous Substances. Available at http://www.atsdr.cdc.gov/mrls/index.asp.
Baars, A.J., R.M.C. Theelen, P.J.C.M. Jannsen, J.M. Hcssc. M E van Apeldoorn, M.C.M.
Meijerink, L. Verdam, M.J. Zeilmaker. 2001. Rc-cvaliiaiion of Human Toxicological
Maximum Permissible Risk Levels. RIVM (Rijksinsliuiul \ oor Volksgesondheit en
Milieu) Report 711701 025.
CalEPA (California Environmental Protection Agency) 2" I I Air I oxics Hot Spots Program
Risk Assessment Guidelines: Cancer Toiency Factors. Berkeley. (A: Office of
Environmental Health Hazard Assessment Available at
http://oehha.ca.gov/media/downloads crnr appendixa.pdf.
CalEPA (California Environmental Protection Agency) 2<)|(-. . !/'/ Toxics Hot Spots Program
Risk Assessment Guidelines: OEHHA Acute, S-hour. and ("hronic Reference Exposure
Levels (RELs). Berkeley, ( A Office of Environmental I lealth Hazard Assessment.
Available at http://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-
reference-exposure-level-rel-summary.
FAO/WHO (Food and Agriculture Organization of the United Nations/World Health
Organization) 2d 14 Evaluations of the Joint FAO/WHO Expert Committee on Food
Additives (J I XT A) Updated through the 7lMli JECFA (June 2014). Available at
http://apps^\ho int I'ood-addltives-coniaminants-iecfa-database/search.aspx.
NAS (National Academy of Sciences). 2010 Tolerable Upper Intake Levels for Vitamins and
Elements. Available at https://fnic.nal usda.uov/dietarv-guidance/dietary-reference-
i n la kes/dri -tabl es-and-appl i cati on-reports.
U.S. EPA (I-n\ironmental Protection Agency). 2018a. Integrated Risk Information System
(IRISj. Washington. DC National Center for Environmental Assessment, Office of
Researcli and Development. Available at http://www.epa.gov/iris/.
U.S. EPA (Environmental Protection Agency). 2018b. Human Health Benchmarks for
Pesticides. Available at hllPs://iaspub.epa.gov/apex/pesticides/f?p=HHBP:home:
101899119218H .
U.S. EPA (Environmental Protection Agency). 2018c. Superfund Provisional Peer-Reviewed
Toxicity Values. Available at http://hhpprtv.ornl.gov/quickview/pprtv papers.php.
U.S. EPA (Environmental Protection Agency). 2018d. ECOTOXicology knowledgebase
(ECOTOX). Available at https://cfpub.epa.gov/ecotox/.
U.S. EPA (Environmental Protection Agency). 2017. EPISuite v4.11, including PHYSPROP,
updated July 19, 2017. Software. Office of Pollution Prevention and Toxics: Washington
DC. Available at https://www.epa.gov/tsca-screening-tools/download-epi-suitetm-
estimation-program-interface-v411.
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Biosolids Biennial Review
Reporting Period 2016-2017
U.S. EPA (Environmental Protection Agency). 2016a. Health Effects Support Document for
Perfluorooctanoic Acid (PFOA). EPA 822-R-16-003. Office of Water: Washington DC.
Available at https://www.epa.gov/sites/production/files/2016-05/documents/
pfoa hesd final-plain.pdf.
U.S. EPA (Environmental Protection Agency). 2016b. Health Effects Support Document for
Perfluorooctane Sulfonate (PFOS). EPA 822-R-16-002. Office of Water: Washington
DC. Available at https://www.epa.gov/sites/production/files/2016-05/
documents/pfos hesd final 508.pdf.
U.S. EPA (Environmental Protection Agency). 2009. Targeted National Sewage Sludge Survey
Statistical Analysis Report. Office of Water, Washington, DC. EPA-822-R-08-018.
Available at http://water.epa.gov/scitech/wastetech/biosolids/tnsss-overview.cfm.
U.S. EPA (Environmental Protection Agency). 1997. Health Eflecis Assessment Summary
Tables. Available at http://cfpub.epa.gov ncca/cfin/recordispkiv.cfm?deid=2877.
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