United States
Environmental Protection
Agency
Office of Water
Regulations and Standards
Washington, DC 20460
Water
June, 1985
Environmental Profiles
and Hazard Indices
for Constituents
of Municipal Sludge:
Benzidine
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PREFACE
This document is one of a series of preliminary assessments dealing
with chemicals of potential concern in municipal sewage sludge. The
purpose of these documents is to: (a) summarize the available data for
the constituents of potential concern, (b) identify the key environ-
mental pathways for each constituent related to a reuse and disposal
option (based on hazard indices), and (c) evaluate the conditions under
which such a pollutant may pose a hazard. Each document provides a sci-
entific basis for making an initial determination of whether a pollu-
tant, at levels currently observed in sludges, poses a likely hazard to
human health or the environment when sludge is disposed of by any of
several methods. These methods include landspreading on food chain or
nonfood chain crops, distribution and marketing programs, landfilling,
incineration antl ocean disposal.
These documents are intended to serve as a rapid screening tool to
narrow an initial list of pollutants to those of concern. If a signifi-
cant hazard is indicated by this preliminary analysis, a more detailed
assessment will be undertaken to better quantify the risk from this
chemical and to derive criteria if' warranted. If a hazard is shown to
be unlikely, no further assessment will be conducted at this time; how-
ever, a reassessment will be conducted after initial regulations are
finalized. In no case, however, will criteria be derived solely on the
basis of information presented in this document.
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TABLE OF CONTENTS
Page
1. INTRODUCTION 1-1
2. PRELIMINARY CONCLUSIONS FOR BENZIDINE IN MUNICIPAL SEWAGE
SLUDGE 2-1
Landspreading and Distribution-and-Marketing 2-1
Landfilling 2-1
Incineration 2-1
Ocean Disposal 2-1
3. PRELIMINARY HAZARD INDICES FOR BENZIDINE IN MUNICIPAL SEWAGE
SLUDGE 3-1
Landspreading and Distribution-and-Marketing 3-1
Landf illing 3-1
Incineration 3-1
Ocean Disposal 3-1
Index of seawater concentration resulting
from initial mixing of sludge (Index 1) 3-1
Index of seawater concentration representing
a 24-hour dumping cycle (Index 2) 3-5
Index of toxicity to aquatic life (Index 3) 3-6
Index of human cancer risk resulting
from seafood consumption (Index 4) 3-8
4. PRELIMINARY DATA PROFILE FOR BENZIDINE IN MUNICIPAL SEWAGE
SLUDGE ; 4-1
Occurrence 4-1
Sludge 4-1
Soil - Unpolluted 4-1
Water - Unpolluted 4-1
Air 4-2
Food 4-2
Human Effects 4-2
Ingestion 4-2
Inhalation 4-2
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TABLE OF CONTENTS
(Continued)
Page
Plant Effects 4-3
Domestic Animal and Wildlife Effects 4-3
Toxicity 4-3
Uptake 4-4
Aquatic Life Effects 4-4
Toxicity (water concentration causing) 4-4
Uptake 4-4
Soil Biota Effects 4-4
Physicochemical Data for Estimating Fate and Transport 4-5
5. REFERENCES 5-1
APPENDIX. PRELIMINARY .HAZARD INDEX CALCULATIONS FOR
BENZIDINE IN MUNICIPAL SEWAGE SLUDGE A-l
111
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SECTION 1
INTRODUCTION
This preliminary data profile is one of a series of profiles
dealing with chemical pollutants potentially of concern in municipal
sewage sludges. Benzidine was initially identified as being of
potential concern when sludge is ocean disposed."' This profile is a
compilation of information that may be useful in determining whether
benzidine poses an actual hazard to human health or the environment when
sludge is disposed of by these methods.
The focus of this document is the calculation of "preliminary
hazard indices" for selected potential exposure pathways, as shown in
Section 3. Each index illustrates the hazard that could result from
movement of a -pollutant by a given pathway to cause a given effect
(e.g., sludge •* seawater •* marine organisms •* human toxicity). The
values and assumptions employed in these calculations tend to represent
a reasonable "worst case"; analysis- of error or uncertainty has been
conducted to a limited degree. The resulting value in most cases is
indexed to unity; i.e., values >1 may indicate a potential hazard,
depending upon the assumptions of the calculation.
The data used for index calculation have been selected or estimated
based on information presented in the "preliminary data profile",
Section 4. Information in the profile is based on a compilation of the
recent literature. An attempt has been made to fill out the profile
outline to the greatest extent possible. However, since this is a pre-
liminary analysis, the literature has not been exhaustively perused.
The "preliminary conclusions" drawn from each index in Section 3
are summarized in Section 2. The preliminary hazard indices will be
used as a screening "tool to determine which pollutants and pathways may
pose a hazard. Where a potential hazard is indicated by interpretation
of these indices, further analysis will include a more detailed exami-
nation of potential risks as well as an examination of site-specific
factors. These more rigorous evaluations may change the preliminary
conclusions presented in Section 2, which are based on a reasonable
"worst case" analysis.
The preliminary hazard indices for selected exposure routes
pertinent to ocean disposal practices are included in this profile. The
calculation formulae for these indices are shown in the Appendix. The
indices are rounded to two significant figures.
* Listings were determined by a series of expert workshops convened
during March-May, 1984 by the Office of Water Regulations and
Standards (OWRS) to discuss landspreading, landfilling, incineration,
and ocean disposal, respectively, of municipal sewage sludge.
1-1
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SECTION 2
PRELIMINARY CONCLUSIONS FOR BENZIDINE IN MUNICIPAL SEWAGE SLUDGE
The following preliminary conclusions have been derived from the
calculation of "preliminary hazard indices", which represent
conservative or "worst case" analyses of hazard. The indices and
their basis and interpretation are explained in Section 3. Their
calculation formulae are shown in the Appendix.
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being- conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
II. LANDFILLING
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
III. INCINERATION
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
IV. OCEAN DISPOSAL
Increases in seawater concentration of benzidine occur when worst
concentration sludges are dumped at typical or worst sites (see
Index 1).
Slight increases of seawater benzidine concentrations occur after a
24-hour dumping cycle (see Index 2).
No toxic conditions to aquatic life occur due to the dumping of
benzidine-containing sludge (see Index 3).
A potential exists for significant human health risk for the case
of worst seafood consumption from organisms exposed to the worst
benzidine concnetrations dumped at the worst and typical disposal
sites (see Index 4).
2-1
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SECTION 3
PRELIMINARY HAZARD INDICES FOR BENZIDINE
IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTE ON-AND-MARKETING
Based on Che recommendations of Che experts at the OWES meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
II. LANDFILLING
Based on the recommendations of the experCs at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
III. INCINERATION
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessmenC of chis reuse/disposal opcion is
noC being conducted at this time. EPA reserves the right to
conduct such an assessment for this option in the future.
IV. OCEAN DISPOSAL
For the purpose of evaluating pollutant effects upon and/or
subsequent uptake by marine life as a result of sludge disposal,
two types of mixing were modeled. The initial mixing or dilution
shortly after dumping of a single load of sludge represents a high,
pulse concentration to •which organisms may be exposed for short
time periods but which could be repeated frequently; i.e., every
time a recently dumped plume is encountered. A subsequent addi-
tional degree of mixing can be expressed by a further dilution.
This is defined as the average dilution occurring when a day's
worth of sludge is dispersed by 24 hours of current movement and
represents the time-weighted average exposure concentration for
organisms in the disposal area. This dilution accounts for 8 to 12
hours of the high pulse concentration encountered by the organisms
during 'daylight disposal operations and 12 to 16 hours of recovery
(ambient water concentration) during the night when disposal
operations are suspended.
A.. Index of Seawater Concentration Resulting
from Initial Mixing of Sludge (Index 1)
1. Explanation - Calculates increased concentrations in Ug/L
of pollutant in seawater around an ocean disposal site
assuming initial mixing.
3-1
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2. Assumptions/Limitations - Assumes that the background
seawater concentration of pollutant is unknown or zero.
The index also assumes that disposal is by tanker and
that the daily amount of sludge disposed is uniformly
distributed along a path transversing the site and
perpendicular to the current vector. The initial
dilution volume is assumed to be determined by path
length, depth to the pycnocline (a layer separating
surface and deeper water masses), and an initial plume
width defined as the width of the plume 4 hours after
dumping. The seasonal disappearance of the pycnocline is
not considered.
3. Data Used and Rationale
a. Disposal conditions
Sludge Sludge Mass Length
Disposal Dumped by a of Tanker
Rate (SS) Single Tanker (ST) Path (L)
Typical 825 mt DW/day 1600 mt WW 8000 m
Worst 1650 mt DW/day 3400 mt WW 4000 m
The typical value for the sludge disposal rate assumes
that 7.5 x 10^ mt WW/year are available for dumping
from a metropolitan coastal area. The conversion to
dry weight assumes 4 percent solids by weight. The
worst-case value is an arbitrary doubling- of the
typical value to allow for potential future increase.
The assumed disposal practice to be followed at the
model site representative of the typical case is a
modification of that proposed for sludge disposal at
the formally designated 12-mile site in the New York
Bight Apex (City of New York, 1983). Sludge barges
with capacities of .3400 mt WW would be required to
discharge a load in no less than 53 minutes travel-
ing at a minimum speed of 5 nautical miles (9260 m)
per hour. Under these conditions, the barge would
enter the site, discharge the sludge over 8180 m and
exit the site. Sludge barges with capacities of
1600 mt WW would be required to discharge a load in
no less than 32 minutes traveling at a minimum speed
of 8 nautical miles (14,816 m) per hour. Under
these conditions, the barge would enter the site,
discharge the sludge over 7902 m and exit the site.
The mean path length for the large and small tankers
is 8041 m or approximately 8000 m. Path length is
assumed to lie perpendicular to the direction of
prevailing current flow. For the typical disposal
rate (SS) of 825 mt DW/day, it is assumed that this
would be accomplished by a mixture of four 3400 mt
3-2
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WW and four 1600 me WW capacity barges. The overall
daily disposal operation would last from 8 to 12
hours. For the worst-case disposal rate (SS) of
1650 mt DW/day, eight 3400 mt WW and eight 1600 mt
WW capacity barges would be utilized. The overall
daily disposal operation would last from 8 to 12
hours. For both disposal rate scenarios, there
would be a 12 to 16 hour period at night in which no
sludge would be dumped. It is assumed that under
the above described disposal operation, sludge
dumping would occur every day of the year.
The assumed disposal practice at the model site
representative of the worst case is as stated for
the typical site, except that barges would dump half
their load along a track, then turn around and
dispose of the balance along the same track in order
to prevent a barge from dumping outside of the site.
This practice would effectively halve the path
length compared to the typical site.
b. Sludge concentration of pollutant (SC)
Worst 12.7 mg/kg DW
Benzidine was detected in only 1 percent of the 256
publicly-owned treatment works (POTWs) surveyed
throughout the United States. The maximum
concentration detected, 12.7 mg/kg DW, is chosen as
the worst case; no typical case is available.
c. Disposal site characteristics
Average
current
Depth to velocity
pycnocline (D) at site (V)
Typical 20 m 9500 m/day
Worst 5 m 4-320 m/day
Typical site values are representative of a large,
deep-water site with an area of about 1500 km^
located beyond the continental shelf in the New York
Bight. The pycnocline value of 20 m chosen is the
average of the 10 to 30 m pycnocline depth range
occurring in the summer and fall; the winter and
spring disappearance of the pycnocline is not consi-
dered and so represents a conservative approach in
evaluating annual or long-term impact. The current
velocity of 11 cm/sec (9500 m/day) chosen is based
on the average current velocity in this area (CDM,
1984b).
3-3
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Worst-case values are representative of a near-shore
New York Bight site with an area of about 20 km^.
The pycnocline value of 5 m chosen is the minimum
value of the 5 to 23 m depth range of the surface
mixed layer and is therefore a worst-case value.
Current velocities in this area vary from 0 to
30 cm/sec. A value of 5 cm/sec (4320 m/day) is
arbitrarily chosen to represent a worst-case value
(COM, 1984c).
Factors Considered in Initial Mixing
When a load of sludge is dumped from a moving tanker, an
immediate mixing occurs in the turbulent wake of the
vessel, followed by more gradual spreading of the plume.
.The entire plume, which initially constitutes a narrow
band the length of the tanker path, moves more-or-less as
a unit with • the prevailing surface current and, under
calm conditions, is not further dispersed by the current
itself. However, the current acts to separate successive
tanker loads, moving each out of .the immediate disposal
path before the next load is dumped.
Immediate mixing volume after barge disposal is
approximately equal to the length of the dumping track
with a cross-sectional area about four times' that defined
by the draft and width of the discharging vessel
(Csanady, 1981, as cited in NOAA, 1983). The resulting
plume is initially 10 m deep by 40 m wide (O'Connor and
Park, 1982, as cited in NOAA, 1983). Subsequent
spreading of plume band width occurs at an average rate
of approximately 1 cm/sec (Csanady et al., 1979, as cited
in NOAA, 1983). Vertical mixing is limited by the depth
of the pycnocline or ocean floor, whichever is shallower.
Four hours after disposal, therefore, average plume width
(W) may be computed as follows:
*
W = 40 m + 1 cm/sec x 4 hours x 3600 sec/hour x 0.01 m/cm
= 184 m = approximately 200 m
Thus the volume of initial mixing is defined by the
tanker path, a 200 m width, and a depth appropriate to
the site. For the typical (deep water) site, this depth
is chosen as the pycnocline value of 20 m. For the worst
(shallow water) site, a value of 10 m was chosen. At
times the pycnocline may be as shallow as 5 m, but since
the barge wake causes initial mixing to at least 10 m,
the greater value was used. >
3-4
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5. Index 1 Values (ug/L)
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical
Worst
Worst
Worst
0.0
0.0
0.025
0.22
0.025
0.22
6. Value Interpretation - Value equals the expected increase
in benzidine concentration in seawater around a disposal
site as a result of sludge disposal after initial mixing.
6. Preliminary Conclusion -
Increases in seawater concentration of benzidine occur
when worst concentration sludges are dumped at the
typical or worst sites.
B. Index of Seawater Concentration Representing a 24-Hour Dumping
Cycle (Index 2)
1. Explanation - Calculates increased concentrations in Ug/L
of pollutant in seawater around an .ocean disposal site
utilizing a time weighted average (TWA) concentration.
The TWA concentration is that which would be experienced
by an organism remaining stationary (with respect to the
ocean floor) or moving randomly within the disposal
vicinity. The dilution volume is determined by the
tanker path length and depth to pycnocline or for the
shallow water-site, the 10 m effective mixing depth, as
before, but the effective width is now determined by cur-
rent movement perpendicular to the tanker path over 24
hours.
2. As sumptions /Limitations - Incorporates all of the assump-
tions used to calculate. Index 1. In addition, it is
assumed that organisms would experience high-pulsed
sludge concentrations for 8 to 12 hours per day and then
experience recovery (no exposure to sludge) for 12 to 16
hours per day. This situation can be expressed by the
use of a TWA concentration of sludge constituent.
3. Data Used and Rationale
See Section 3, pp. 3-2 to 3-4.
3-5
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4. Factors Considered in Determining Subsequent Additional
Degree of Mixing (Determination of TWA Concentrations)
See Section 3, p. 3-5.
5. Index 2 Values (ug/L)
Disposal Sludge Disposal
Conditions and Rate (rot DW/day)
Site Charac- Sludge
teristics Concentration 0 825 1650
Typical
Worst
Worst
Worst
0.0
0.0
0.0069
0.061
0.014
0.12
6. Value interpretation - Value equals the effective
increase in benzidine concentration expressed as a TWA
concentration in seawater around a disposal site
experienced by an organism over a 24-hour period.
7. Preliminary Conclusion - Slight increases of seawater
benzidine concentrations occur after a 24-hour dumping
cycle.
C. Index of Toxicity to Aquatic Life (Index 3)
Explanation - Compares the effective increased concentra-
tion of pollutant in seawater around the disposal site
resulting from Che initial mixing of sludge (Index 1)
with the marine ambient water quality criterion of the
pollutant, or with another value judged protective of
marine aquatic life. For benzidine, this value is the
criterion that will protect marine aquatic organisms from
both acute and chronic toxic effects.
Wherever a short-term, "pulse" exposure may occur as it
would from initial mixing, it is usually evaluated using
the "maximum" criteria values of EPA's ambient water
quality criteria methodology. However, under this
scenario, because the pulse is repeated several times
daily on a long-term basis, potentially resulting in an
accumulation of injury, it seems more appropriate to use
values designed to be protective against chronic
toxicity. Therefore, to evaluate the potential for
adverse effects on marine life resulting from initial
mixing concentrations, as quantified by Index 1, the
chronically derived criteria values are used.
3-6
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2. Assumptions/Limitations - In addition to the assumptions
stated for Indices 1 and 2, assumes that all of the
released pollutant is available in the water column to
move through predicted pathways (i.e., sludge to seawater
to aquatic, organism to man). The possibility of effects.
arising from accumulation in the sediments is neglected
since the U.S. EPA presently lacks a satisfactory method
for deriving sediment criteria.
3. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 1)
See Section 3, p. 3-5.
b. Ambient water quality criterion (AWQC) = 2,500 pg/L
Water quality criteria for •the toxic pollutants
listed under Section 307(a)(l) of the Clean Water
Act of 1977 were developed by the U.S. EPA under
Section 30A(a)(l) of the Act. These criteria were
derived by utilization of data reflecting the
resultant environmental impacts and human ^health
effects of these pollutants if present in any body
of water. The criteria values presented in this
assessment are excerpted from the .ambient water
quality criteria document for benzidine.
Toxicity to freshwater fish and invertebrates occurs
at the above concentration of benzidine and would
occur at lower concentrations among organisms more
sensitive than those tested (U.S. EPA, 1980). As
not data are available on marine organisms, it is
assumed for the purpose of this study that values
are similar for both freshwater and marine aquatic
life.
4. Index 3 Values
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge
teristics
Typical
Worst
Concentration
Worst
Worst
0
0
0
.0
.0
0
0
825
.000010
.000086
0
0
1650
.000010
.000086
3-7
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5. Value Interpretation - Value equals Che factor by which
the expected seawater concentration increase in benzidine
exceeds the protective value. A value > 1 indicates that
acute or chronic toxic conditions may exist for organisms
at the site.
6. Preliminary Conclusion - No toxic conditions occur due to
the dumping of benzidine-containing sludge.
D. Index of Human Cancer Risk Resulting from Seafood Consumption
(Index 4)
1. Explanation - Estimates the expected increase in human
pollutant intake associated with the consumption of
seafood, a fraction of which originates from the disposal
site vicinity, and compares the total expected pollutant
intake with the cancer risk-specific intake (RSI) of the
pollutant.
2. Assumptions/Limitations - In addition to the assumptions
listed for Indices 1 and 2, assumes that the seafood
tissue concentration increase can be estimated from the
increased water concentration (Index 2) by a
bioconcentration factor. It also assumes that, over the
long term, the seafood catch from the disposal site
vicinity will be diluted to some extent by the catch from
uncontaminated areas.
3. Data Used and Rationale
a. Concentration of pollutant in seawater around a
disposal site (Index 2)
See Section 3, p. 3-6.
Since biconcentration is a dynamic and reversible
process, it is expected that uptake of sludge
pollutants by marine organisms at the disposal site
will reflect TWA concentrations, as quantified by
Index 2, rather than pulse concentrations.
b. Dietary consumption of seafood (QF)
Typical .14.3 g WW/day
Worst 41.7 g WW/day
Typical and worst-case values are the mean and the
95th percentile, respectively, for all seafood
consumption in the United States (Stanford Research
Institute (SRI) International, 1980).
3-8
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Fraction of consumed seafood originating from the
disposal site (PS)
For a typical harvesting scenario, it was assumed
that the total catch over a wide region is mixed by
harvesting, marketing and consumption practices, and
that exposure is thereby diluted. Coastal areas
have been divided by the National Marine Fishery
Service (NMFS) into reporting areas for reporting on
data on seafood landings. Therefore it was
convenient to express the total area affected by
sludge disposal as a fraction of an NMFS reporting
area- The area used to represent the disposal
impact area should be an approximation of the total
ocean area over which the average concentration
defined by Index 2 is roughly applicable. The
average rate of plume spreading of 1 cm/sec referred
to earlier amounts to approximately 0.9 km/day.
Therefore, the "combined plume of all sludge dumped
during one working day will gradually spread, both
parallel to and perpendicular to current direction,
as it proceeds down-current. Since the
concentration has been averaged over the direction
of current flow, spreading in this, dimension will
not further reduce average concentration; only
spreading in the perpendicular dimension will reduce
the average. If stable conditions are assumed over
a period of days, at least 9 days would be required
to reduce the average concentration by one-half. At
that time, the original plume length of
approximately 8 km (8000 m) will have doubled to
approximately 16 km due to spreading.
It is probably unnecessary to follow the plume
further since storms, which would result in much
more rapid dispersion of pollutants to background
concentrations are expected on at least a 10-day
frequency (NOAA, 1983). Therefore, the area
impacted by sludge disposal (AI, in km2) at each
disposal site will be considered to be defined by
the tanker path length (L) times the distance of
current movement (V) during 10 days, and is computed
as follows:
AI = 10 x L x V x 10~6 km2/m2 . (1)
To be consistent with a conservative approach, plume
dilution due to spreading in the perpendicular
direction to current flow is disregarded. More
likely, organisms exposed to the plume in the area
defined by equation 1 would experience a TWA. concen-
tration lower than the concentration expressed by
Index 2.
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Next, the value of AI must be expressed as a
fraction of an NMFS reporting area. In the New York
Bight, which includes NMFS areas 612-616 and 621-
623, deep-water area 623 has an area of
approximately 7200 km2 and constitutes approximately
0.02 percent of the total seafood landings for the
Bight (CDM, 1984a).' Near-shore area 612 has an area
of approximately 4300 km2 and constitutes
approximately 24 percent of the total seafood
landings (CDM, 1984b). Therefore the fraction of
all seafood landings (FSt) from the Bight which
could originate from the area of impact of either
the typical (deep-water) or worst (near-shore) site
can be calculated for this typical harvesting
scenario as follows:
For the typical (deep water) site:
= AI x 0.02% = (2)
t 7200 km^
[10 x 8000 m x 9500 m x 10"6 km2/m2] x 0.0002 5
A ~~ ^ • X X J. U
7200 km2 . .
For the worst (near shore) site:
FSt = ^-J
4300 km2
[10 x 4000 m x 4320 m. x 10"6 km2/m2] x 0.24 _ 3
2— y • u x i u
T^VW ~»
To construct a worst-case harvesting scenario, it
was assumed that the total seafood consumption for
an individual could originate from an area more
limited than the entire New York Bight. For
example, a particular fisherman providing the entire
seafood diet for himself or others could fish
habitually within a single NMFS reporting area. Or,
an individual could have a preference for a
particular species which is taken only over a more
limited area, here assumed arbitrarily to equal an
NMFS reporting area. The fraction of consumed
seafood (FSW) that could originate from the area of
impact under this worst-case scenario is calculated
as follows:
For the typical (deep water) site:
FSW = AI 0 = 0.11 (4)
7200 km2
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For the worst (near shore) -site:
- ^— -
4300 km2
FSW = - — - = O.OAO (5)
d. Bioconcentration factor of pollutant (BCF) =
87.5 L/kg
The value chosen is the weighted average BCF of
benzidine for the edible portion of all freshwater
and estuarine aquatic organisms consumed by U.S.
citizens (U.S. EPA, 1980). The weighted averate BCF
is derived as part of the water quality criteria
developed by the U.S. EPA to protect human health
from the potential carcinogenic effects of benzidine
induced by ingestion of contaminated water and
aquatic organisms. The weighted average BCF is
calculated by adjusting the mean normalized BCF
(steady-state BCF corrected to 1 percent lipid
content) to the 3 percent lipid content of consumed
fish and shellfish. It should be noted that lipids
of marine species differ in both structure and
quantity from those of freshwater species. Although
a BCF value calculated entirely from marine data
would be more appropriate for this assessment, no
such data are presently available.
e. Average daily human dietary intake of pollutant (DI)
= 0 ug/day
Although no data are immediately available on DI , a
value of 0 ug/day is assumed so that index values
can be calculated*
f. Cancer potency = 234 (mg/kg/day)~^
The cancer potency value is derived by U.S. EPA
(1980) based on studies of bladder cancer in humans.
g. Cancer risk— specific intake (RSI) =
2.99 x 10~4 Ug/day
The RSI is the pollutant intake value which results
in an increase in cancer risk of 10~° (1 per
1,000,000). The RSI is calculated from the cancer
potency using the following formula:
_ IP"6 x 70 kg x 103 Ug/mg
Cancer potency
3-11
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4. Index 4 Values
Disposal Sludge Disposal
Conditions and Rate (mt DW/day)
Site Charac- Sludge Seafood
teristics Concentration3 Intakea»b 0 825 1650
Typical Worst Typical 0.0 0.00061 0.0012
Worst 0.0 9.3 18
Worst Worst Typical 0.0 2.4 4.9
Worst 0.0 30.0 59
a All possible combinations of these values are not
presented. Additional combinations may be calculated
using the formulae in the Appendix.
0 Refers to both the dietary consumption of seafood (QF)
and the fraction of consumed seafood originating from
the disposal site (FS). "Typical" indicates the use of
the typical-case values for both of these parameters;
"worst" indicates the use of the worst-case values for
both.
Value Interpretation - Value > 1 indicates a potential
increase in -cancer risk of > 10~6 (1 per 1,000,000).
Comparison with the null index value at 0 mt/day
indicates the degree to which any hazard is due to sludge
disposal, as opposed to pre-existing dietary sources.
Preliminary Conclusion - A potential exists for
significant human health risk for the case of worst
seafood consumption from organisms exposed to the worst
benzidine concentrations dumped at the worst and typical
sites.
3-12
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SECTION 4
PRELIMINARY DATA PROFILE FOR BENZIDINE IN MUNICIPAL SEWAGE SLUDGE
I. OCCURRENCE
Benzidine and its congeners are used in the industry primarily for
the synthesis of azo dyes. U.S. production, and importation of
benzidine and benzidine compounds may exceed 3.5 million kilograms
per year. Benzidine and its derivatives are not naturally
occurring compounds and are not thought to be generally dispersed
in the environment.
A. Sludge
1. Frequency of Detection
Benzidine not detected in influent,
effluent, or sludges from 50 POTWs
Benzidine detected in 1 percent of
256 POTWs studied
2. Concentration
Maximum value 12.7 yg/g DW in
256 POTWs studied
B. Soil - Unpolluted
"No data were found concerning the
distribution of benzidine compounds in
soil. Benzidine has been shown to be
absorbed to some clays and, because of
its physical properties, is probably
immobilized rapidly in soils and sediments."
C. Water - Unpolluted
In the United States, benzidine and its
derivatives have been observed in
dye manufacturing factory wastes, but
not in the drainage areas into which these
wastes feed; however, few attempts at
actual measurements have been made.
Benzidine has not been found to occur in
the aquatic environment in the U.S.
U.S. EPA, 1982a
(p. 36-50)
COM, 1984c
(p. 8)
CDM, 1984c
(p. 8)
U.S. EPA, 1978
(p. 4)
U.S. EPA, 1978
(p. 4)
U.S. EPA, 1978
(p. 79)
4-1
-------
A field survey of the Buffalo and Niagara U.S. EPA, 1980
River using the chloraraine-T method (p. C-27)
(method is suspect) detected as no benzidine
positive samples (Detection Limit = 0.2 ug/L).
D. Air
No measurements for benzidine in ambient U.S. EPA, 1979
air have been reported. (p. 10)
E. Pood
Ingestion is not generally an important U.S. EPA, 1980
source of exposure to benzidine. (p. C-l)
No data on benzidine in food were found.
II. HUMAN EFFECTS
A. Ingestion
1. Carcinogenicity
a. Qualitative Assessment
Data not immediately available.
b. Potency
Cancer potency = 234 U.S. EPA, 1980
(mg/kg/dayr1 ' (p. C-54)
c. Effects
Data not immediately available.
2. Chronic Toxicity
Data not immediately available.
B. Inhalation
1. Carcinogenicity
a. Qualitative Assessment
Data show that benzidine is a human U.S. EPA, 1980
carcinogen.
b. Potency
Cancer potency = 234 U.S. EPA, 1980
(mg/kg/dayr1 . - (p. C-54)
4-2
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c. Effects
Benzidine and its derivatives have U.S. EPA, 1980
' been shown to produce bladder (p. C-15)
cancer after a long period of
latency.
2. Chronic Toxicity
Data not immediately available.
III. PLANT EFFECTS
No data are available on benzidine metabolism U.S. EPA, 1978
or effects from benzidine exposure in higher (p. 6)
plants. Benzidine has not received much
attention in this area since it is not a natural
environmental constituent and is not believed
to be widely dispersed from industrial sources.
IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS
A. Toxicity
Rats fed N,N'-diacetylbenzidine and U.S. EPA, 1978
N, N, N1,N'-tetramethylbenzidine at (p. 101)
equal molar levels of 0.25% and 0.27%
respectively, developed, lipemia and
glomerular lesions consisting of fat-
filled spaces in the glomerular tuft
2 to 4.5 months after beginning of
treatment.
Mice fed 0.01%-0.08% benzidine U.S. EPA, 1978
dihydrochloride exhi-bited various toxic (p. 101)
symptoms: lost weight in proportion to
the dose of benzidine received, decreased
weight of liver and kidney with increased
dosage, increased thymus weight with
increased dosage.
Subcutaneous injection of benzidine has U.S. EPA, 1978
produced cancer in mice and rats. (p. 102)
Rats fed 0.043% N,N'-diacetylbenzidine U.S. EPA, 1980
developed glomerulonephritis and (p. C-12)
nephrotic syndrome.
Orally administered benzidine did not U.S. EPA, 1980
produce urinary bladder cancer in dogs. (p. C-17)
No tumors were found in female beagle dogs
fed 1 rag/kg, 5 days per week for 3 years.
4-3
-------
In hamsters fed benzidine in 0.1% of their U.S. EPA, 1980
diet throughout their life span, extensive (p. C-17)
bile duct proliferations and cysts appeared
along with cholangiofibrosis, hepatomas, and
liver cell carcinoma.
It is the metabolites of benzidine that U.S. EPA, 1980
are considered to be the proximate (p. C-17)
carcinogens.
Benzidine and its salts, without question, U.S. EPA, 1979
are carcinogenic to humans, with the site (p. 11)
of tumor induction being the bladder.
B. Uptake
Benzidine does not appear to be stored or From data
concentrated in animal tissue, but is presented in
metabolized, with metabolites and free U.S. EPA, 1980
benzidine eliminated in urine (primarily) (p. C-4 to
and feces. C-ll)
V. AQUATIC LIFE EFFECTS
A. Toxicity (Water concentration causing)
1. Freshwater
Acute toxicity occurs at concen- U.S. EPA, 1980
trations as low as 2500 Ug/L. _. (p. B-2)
Based on tests of one invertebrate
and five fish species.
2. Saltwater
Data not immediately available.
B. Uptake
Bioconcentration factor = 87.5 L/kg
Based on the edible portion of all U.S. EPA, 1980
freshwater and estuarine aquatic (p. C-3)
organisms consumed by U.S. citizens.
VI. SOIL BIOTA EFFECTS
Benzidine inhibited biooxidation in activated U.S. EPA, 1978
sludges at 500 mg/L, caused some inhibition (p. 74)
at 1 to 5 mg/L, and was thought to be oxidized
at 0.1 mg/L or less.
4-4
-------
VII. PHYSICOCHEMICAL DATA FOR ESTIMATING FATE AND TRANSPORT
Molecular weight: 184.23
Density: 1.250
Melting point: 115° to 120°C (slow heating)
128°C (fast heating)
Boiling point: 400°C
Soluble in alcohol and ether
Slightly soluble in water: 400 mg/L (12°C)
Under experimental water waste treatment U.S. EPA, 1978
conditions, air oxidation of benzidine (p. 5)
proceeded readily, and there was also some
evidence of biological oxidation.
Chemical f-ormula:
Benzidine is apparently not easily degraded . U.S."EPA, 1980
by the microorganisms in sewage plant sludge (p. A-2)
Benzidine half life in water is estimated at U.S. EPA, 1980
100 days (p. C-27)
4-5
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SECTION 5
REFERENCES
Camp Dresser and McKee, Inc. 1984a. Technical Review of the 106-Mile
Ocean Disposal Site. Prepared for U.S. EPA under Contract No. 68-
01-6403. Annandale, VA. January.
Camp Dresser and McKee, Inc. 1984b. Technical Review of the 12-Mile
Sewage Sludge Disposal Site. Prepared for U.S. EPA under Contract
No. 68-01-6403. Annandale, VA. May.
Camp Dresser and McKee, Inc. 1984c. A Comparison of Studies of Toxic
Substances in POTW Sludges. .Prepared for U.S. EPA under Contract
No. 68-01-6403. Annandale, VA. August.
City of New York Department of Environmental Protection. 1983. A
Special Permit Application for the Disposal of Sewage Sludge from
Twelve New York. City Pollution Control Plants at 'the 12-Mile Site.
New York, NY. December.
NOAA Technical Memorandum NMFS-F NEC-26. 1983. Northeast Monitoring
Program 106-Mile Site Characterization Update. U.S. Department of
Commerce National Oceanic and Atmospheric Administration. August.
Stanford Research Institute International. 1980. Seafood Consumption
Data Analysis. Final Report, Task 11. Prepared for U.S. EPA under
Contract No. 68-01-3887. Menlo Park, California, September.
U.S. Environmental Protection Agency. 1978. Reviews of the
Environmental Effects of Pollutants. II. Benzidine. EPA-600/1-
78-024. Cincinnati, Ohio.
U.S. Environmental Protection Agency. 1979. Status Assessment of Toxic
Chemicals. Benzidine. EPA-600/2-79-210e. Cincinnati, Ohio.
U.S. Environmental Protection Agency. 1980. Ambient Water Quality
Criteria for Benzidine. EPA 440/5-80-023. Washington, D.C.
U.S. Environmental Protection Agency. 1982a. Fate of Priority
Pollutants in Publicly-Owned Treatment Works. Volume 1. EPA
440/1-82/303. Washington, D.C.
U.S. Environmental Protection Agency. 1982b. Test Methods for
Evaluating Solid Waste. SW-846. Washington, D.C. ^
5-1
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APPENDIX
PRELIMINARY HAZARD INDEX CALCULATIONS FOR
BENZIDINE IN MUNICIPAL SEWAGE SLUDGE
I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such as assessment for this option in the future.
II. LANDFILLING
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such as assessment for this option in the future.
III. INCINERATION
Based on the recommendations of the experts at the OWRS meetings
(April-May, 1984), an assessment of this reuse/disposal option is
not being conducted at this time. EPA reserves the right to
conduct such as assessment for this option in the future.
IV. OCEAN DISPOSAL
A. Index of Seawater Concentration Resulting from Initial Mixing
of Sludge (Index 1)
1. Formula
SC x ST x PS
Index 1 =
W x D x L
where:
SC = Sludge concentration of pollutant (mg/kg DW)
ST = Sludge mass dumped by a single tanker (kg WW)
PS = Percent solids in sludge (kg DW/kg WW)
W = Width of initial plume dilution (m)
D = Depth to pycnocline or effective depth of
mixing for shallow water site (m)
L = Length of tanker path (m)
2. Sample Calculation
12.7 mg/kgDW x 1600000 kg WW x 0.04 kg DW/kg WW x 103 ug/mg
- — - - - — * -a
n
0. ,
200 m x 20 m x 8000 m x 103 L/m3
A-l
-------
B. Index of Seawater Concentration Representing a 24-hour Dumping
Cycle. (Index 2)
1. Formula
SS x SC
Index 2 =
V x D x L
where:
SS = Daily sludge disposal rate (kg DW/day)
SC = Sludge concentration of pollutant (mg/kg DW)
V = Average current velocity at site (m/day)
D = Depth to pycnocline or effective depth of
mixing for shallow water site (m)
L = Length of tanker path (m)
2. Sample Calculation
,, /T - 825000 kg DW/day x 12.7 mg/kg DW x 103 Ug/mg
ug/L - -> '-*
9500 m/day x 20 m x 8000 m x 10->
C. Index of Toxicity to Aquatic Life (Index 3)
1. Formula
IndeX 3 = ATJQC"
where:
I± = Index 1 = Index of seawater concentration
resulting from initial mixing after sludge
disposal (ug/L)
AWQC = Criterion or other value expressed as an average
concentration to protect marine organisms from
acute and chronic toxic effects (ug/L)
2. Sample Calculation
O.OOOOiO
D. Index of Human Cancer Risk Resulting from Seafood Consumption
(Index 4)
1. Formula
_ , . (I2 x BCF x 10~3 kg/g x FS x QP) + PI
Index 4 = - RSI
A-2
-------
where:
12 = Index 2 = Index of seawater concentration
representing a 24-hour dumping cycle (ug/L)
QF = Dietary consumption of seafood (g WW/day)
FS = Fraction of consumed seafood originating from the
disposal site (unitless)
BCF = Bioconcentration factor of pollutant (L/kg)
DI = Average daily human dietary intake of pollutant
(Ug/day)
RSI = Cancer risk-specific intake (ug/day)
2. Sample Calculation
0.00061 =
(0.0069ug/L x 87.5L/kg x 10~3kg/g x O.OQ0021 x 14.3gWW/day) * Oug/dav
2.99 x 10"* Ug/day
A-3
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