^6DSr^ Addendum to the 2002
Lindane Reregistration
Eligibility Decision (RED)
July 2006
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United States Prevention, Pesticides EPA 738-R-06-028
^•^^•^V^^H Environmental Protection and Toxic Substances July 2006
%^^l J^ Agency (7508P)
Addendum to the
2002 Lindane
Reregistration
Eligibility Decision
(RED)
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Addendum to the
2002 Lindane Reregistration
Eligibility Decision (RED)
Case No. 315
Approved by:
Debra Edwards, Ph.D.
Director, Special Review and
Reregistration Division
Date
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I. Introduction
This document serves as an addendum to the July 2002 Lindane Reregistration
Eligibility Decision document (2002 RED). This document addresses whether pesticide
products containing the active ingredient lindane are eligible for reregistration under the
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and whether existing
tolerances for residues of lindane in food and feed are safe under the provisions of the
Federal Food, Drug and Cosmetic Act (FFDCA).
This RED Addendum reflects the Agency's conclusions on the remaining lindane
seed treatment uses in light of the information gathered since the 2002 RED. The seed
treatment use is a source of human exposure to lindane, and it will add to the reservoir of
lindane already present in the environment. EPA believes that dietary exposure to
lindane from the seed treatment use may pose a risk to nursing infants who consume
breast milk contaminated with lindane. EPA, however, is not able to quantify that risk at
this time or determine whether current exposures result in any harm. Lindane's persistent
and bioaccumulative nature is also of concern to the Agency. In addition, the Agency's
updated analysis of the seed treatment use indicates very minor benefits to growers. In
light of these factors, EPA now concludes that the six lindane seed treatment uses are
ineligible for reregistration.
As of July 27, 2006, the Agency had received requests from all lindane technical
and end-use product registrants to voluntarily cancel all lindane product registrations.
Once the cancellation process is complete, EPA will propose to revoke the existing
lindane fat tolerances pursuant to section 408(1)(2) of the Food Quality Protection Act
(FQPA).
II. Background
In July 2002, EPA issued a RED for lindane that captured the Agency's then-
current analysis of the registered uses of lindane as well as the existing tolerances. The
2002 RED concluded in part that existing tolerances for lindane were no longer needed as
the uses associated with those tolerances had all been cancelled, or voluntary cancellation
had been requested. The 2002 RED also concluded that the current uses of lindane for
seed treatment would be eligible for reregistration under FIFRA provided several
conditions were met. First, EPA determined that a number of changes to the terms and
conditions of registration of the seed treatment products were necessary to prevent
"unreasonable adverse effects on the environment." These changes are specified in the
2002 RED. Second, EPA determined that the use of lindane for seed treatment was likely
to result in residues in raw agricultural commodities derived from plants grown from
seeds treated with lindane. Therefore, new tolerances for the existing seed treatment uses
were needed. Third, EPA identified additional data that were needed to characterize
lindane metabolites in order to establish appropriate tolerances for lindane. In summary,
EPA determined that the currently registered lindane seed treatment products would be
eligible for reregistration if: 1) the registrants amended product labels to reflect the terms
and conditions specified in the 2002 RED; 2) the registrants provided the metabolism
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data set forth in the 2002 RED; and 3) EPA was able to establish all required tolerances
for residues of lindane in food.
Following the 2002 RED, the registrants submitted revised labels for all end-use
products reflecting the risk mitigation measures specified in the 2002 RED. The Agency
has reviewed and approved these labels. The registrants also submitted the required
product and residue chemistry data, and the Agency reviewed these data and found them
to be acceptable. To satisfy generic data requirements, Crompton (now Chemtura)
submitted a required seed leaching study; a nature of the residue study, also known as a
plant metabolism study, originally required in the 1985 Lindane Registration Standard
Data Call-In (DCI); and an anaerobic aquatic metabolism study to satisfy an anaerobic
soil metabolism data requirement also originally required under the 1985 Lindane
Reregistration Standard DCI.
The Agency has taken a number of actions with respect to lindane since the 2002
RED. EPA received and reviewed a number of comments on the 2002 RED. EPA also
revoked all current tolerances of lindane, except for fat tolerances, because the associated
uses had been cancelled (70 FR 55282, Sept. 21, 2005). EPA did not revoke the fat
tolerances because residue data suggested that livestock that were fed lindane-treated
seeds would bear residues of lindane in meat commodities (i.e., fat). In February 2006,
EPA prepared and released for public comment a document titled "Assessment of
Lindane and Other Hexachlorocyclohexane Isomers" (2006 Assessment). This
assessment provided information on potential health effects of lindane as well as its
associated isomers.
III. Lindane's toxicity
The Agency's conclusions regarding effects of lindane in humans are largely
based on studies in animals. Lindane primarily affects the nervous system. In acute,
subchronic, and developmental neurotoxicity studies and chronic toxicity/oncogenicity
studies, lindane was found to cause neurotoxic effects. Lindane also appears to cause
renal and hepatic toxicity. In addition, there is evidence that lindane may act as an
endocrine disrupter. Moreover, infants and children are expected to be more susceptible
to the potential adverse effects of lindane than adults. In both a developmental
neurotoxicity study and a 2-generation reproduction study, offspring demonstrated
increased susceptibility to lindane's adverse effects. The 2002 RED and its supporting
documents provide a detailed summary of lindane's toxicity.
IV. Sources of Lindane Exposure
A. Seed Treatment Use
The seed treatment use is a source of human exposure to lindane. There are
several possible routes by which this exposure may occur. First, individuals may be
exposed to lindane residues when eating plants grown from treated seeds. Residue data
demonstrate that the aerial portion of a growing crop will uptake lindane residues present
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on treated seed (2002 RED, pp. 44-45). Second, consumption of meat is a potential
source of lindane exposure. It is possible that livestock feed may be derived from grain
grown from lindane-treated seed. EPA expects that livestock fed lindane-treated seed
will bear residues of lindane in meat commodities (i.e., fat). USDA annual pesticide
monitoring data show one detection of lindane residues in milk in 1998, one detection in
the fat of poultry in 2000, and three detections (one from imported cows) in the fat of
livestock (e.g., cows) in 2001 and 2002 (USDA Pesticide Data Program). In addition, the
USDA's Food Safety and Inspection Service (FSIS) detected lindane in the fat of
domestic and imported meat products in 1998, 1999 and 2000. For example, in 2000,
four imported samples (three calf and one pig) and 16 domestic samples (cow, sheep,
turkey, goat, veal) contained lindane. EPA acknowledges these detections cannot be
attributed solely to treated seeds.
Third, treated seeds are a potential source of lindane in drinking water. Modeling
also shows that lindane concentrations in both surface water and groundwater may reach
environmentally significant levels (greater than the Maximum Contaminant Level [MCL]
of 0.2 ppb), even when lindane is restricted to seed-treatment uses only. Even
considering lindane's very low use rate for seed treatment, lindane may be expected to
reach water resources at environmentally significant levels because of its mobility and
high persistence. Based on a screening-level assessment, lindane from seed treatment
may reach water resources at levels above the MCL of 0.02 ppb (U.S. EPA 2002 EFED
RED Chapter at p. 3). This conclusion is based solely on lindane's use as a seed
treatment and does not consider past uses of lindane (U.S. EPA 2002 EFED RED
Chapter). Water monitoring data, to be discussed in Section IV.B.i. of this addendum,
show that residues of lindane are present in surface water in the United States.
Exposure to lindane may also occur through volatilization from treated seeds.
Field studies from Canada report an increase in lindane in the atmosphere in areas where
lindane-treated seeds are used (2006 Assessment at p. 20). Due to lindane's persistence
and mobility, these lindane releases may contribute to human exposure via any route.
B. Other Sources of Exposure
In addition to the seed treatment use, U.S. populations may be currently exposed
to lindane from several other sources.
i. Past/historical uses
Lindane was first registered in the U.S. in the 1940s. Since that time, lindane has
been registered for use on a wide variety of fruit and vegetable crops (including seed
treatment), ornamental plants, tobacco, greenhouse vegetables and ornamentals, forests,
Christmas tree plantations, log dips, livestock dips, household sprays, domestic outdoor
and indoor use by homeowners (including dog dips, household sprays, and shelf paper),
commercial food or feed storage areas and containers, wood or wooden structures sites,
and human skin/clothing (a military use). In 1977, EPA initiated a Rebuttable
Presumption Against Registration (RP AR) review of lindane, now called a Special
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Review, that resulted in the cancellation of lindane uses in smoke fumigation devices for
indoor domestic use. Following the RPAR, EPA issued a Registration Standard for
Lindane in September 1985 that included a requirement for the submission of additional
data to support lindane registration and to address exposure concerns. Between 1993 and
1998, long-range transport and environmental concerns about lindane increased; in
response to these concerns, lindane registrants voluntarily cancelled all registered uses of
lindane in 1998 and 1999, except for seed treatment uses on 19 agricultural crops and a
dog mange treatment. The dog mange use was voluntarily cancelled in December 2001.
Finally, in 2001 and 2002, the registrants voluntarily cancelled all but the following six
lindane seed treatment uses: barley, corn, oats, rye, sorghum, and wheat. As of 2002, the
only remaining agricultural uses for lindane were the six seed treatment uses that are
being addressed in this document.
Any of these past uses potentially result in continued exposures to lindane today
due to its persistent, bioaccumulative nature and potential for long-range transport.
Indeed, as shown below, lindane has been detected in a variety of foods as well as surface
waters. EPA cannot link these residue detections with particular uses of lindane.
The Food and Drug Administration's Center for Food Safety and Applied
Nutrition (CFSAN)'s Total Diet Study summary of residues from 1991 to 2001 indicates
that many food items contain residues of lindane
(http://www.cfsan.fda.gov/~acrobat/tdslbyps.pdf). The summary shows almost 50 types
of food items in which lindane has been detected at least once between 1991 and 2001.
The food items with the most detects were plain milk chocolate candy bars, yellow
mustard, and commercial chocolate chip cookies. In addition, FDA's pesticide residue
monitoring program indicates that, between 1993 and 2003, lindane is consistently
detected in 2% to 3% of foods tested (http://www.cfsan.fda.gov/~dms/pesrpts.html).
The United States Geological Survey (USGS) National Water Quality Assessment
program (NAWQA) database includes 373 surface-water samples in which lindane was
detected. Four of these samples had lindane concentrations of 0.1 ppb or greater, with a
maximum concentration of 0.219 ppb detected in a sample from the agricultural "Harding
Drain" in Stanislaus County, California in February 2000. The samples were collected
between 1992 and 2004, with 199 of the samples with detections collected in 1999 or
later. The USGS classified 115 of the samples with detections as having come from
water bodies in areas of agricultural land use, 101 from water bodies in mixed land-use
areas, and 49 from water bodies in urban land-use areas. Eight samples were classified as
having been collected from areas classified as "other."
ii. Imported meats
Lindane may currently be used in other countries to directly treat livestock against
external parasites. Because U.S. tolerances currently exist for lindane in livestock fat,
livestock or meat products that have been treated with lindane and containing lindane
residues can be legally imported into the United States. Approximately 8 percent of red
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meat and 5 percent of animal fat consumed by the U.S. population is imported, and red
meat is among the fastest growing U.S. imports (Jerardo 2003).
iii. Subsistence diets
Indigenous populations are exposed to lindane via consumption of subsistence
diets. As noted in the 2006 Assessment, indigenous populations rely heavily on animal
fats and protein in their subsistence diets. For example, EPA reported high harvest
amounts of walrus, seal and whale for Alaska communities. Residues of lindane and
other HCH isomers are present in these animals even though they are not in areas where
lindane is manufactured or used. As explained in Section V of this addendum, lindane
and other HCH isomers are mobile once released into the environment and can be
transported long distances. Lindane and other HCH isomers tend to accumulate in colder
climates, such as the arctic, and concentrate in the food chain. Thus any manufacture or
use of lindane, or other HCH isomers, is a potential source of exposure to indigenous
populations (2006 Assessment at pp. 26, 44-45).
iv. Pharmaceutical use
Lindane is also used as a treatment for lice and scabies. Individuals who use
lindane pharmaceutical products will be exposed to lindane in amounts that will exceed
exposure from the seed treatment use. The pharmaceutical use, though, is also a source
of exposure to the general population. EPA believes that lindane from the
pharmaceutical use may reach drinking water via "down the drain" release; that is,
lindane enters drinking water when individuals using the pharmaceutical products wash
off their hands/bodies. Based on information from Los Angeles County, California, EPA
estimated average effluent concentrations of lindane discharged from publicly owned
treatment works to be 0.03 ppb (2002 RED at p. 23). In fact, California banned the
pharmaceutical uses of lindane due to concerns about water contamination and acute
neurotoxicity concerns from direct application. Although FDA has recommended that
lindane be prescribed as a second line treatment since 1995, these products remain a
source of exposure.
v. Use in foreign countries
As far as EPA is aware, lindane is still being used in a few other countries. For
example, EPA believes that lindane is still used in India. In addition, lindane is registered
for use in Bolivia, Burkina Faso, Cameroon, Cape Verde, Chad, Kenya, Malaysia, Mali,
Mauritania, Mexico,1 Papua New Guinea, Syria, Tanzania, Togo, and Zimbabwe
(Lindane NARAP Annex B). Because of lindane's persistence and potential for long
range transport, EPA believes that releases of lindane in these other countries could result
in exposures in the United States. Bailey et al. (2000) demonstrated that organochlorine
pesticides including lindane can travel from eastern Asia to North America in as little as
five days.
1 Mexico, however, has stated that it intends to phase out all uses of lindane.
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V. Environmental Fate
Lindane is a persistent organochlorine compound that is widely distributed in the
environment with a long half-life in various environmental compartments. The presence
of lindane and other HCH isomers (namely a- and P-HCH) in the environment and
human and wildlife tissues, as well as the environmental fate and exposure routes of
lindane, have been documented in detail in scientific literature as well as in the Agency's
2002 RED and 2006 Assessment. The fate characteristics of lindane, including
persistence, bioaccumulative potential, and potential for long-range transport, are the key
elements to understanding the extent and scope of exposures associated with the use of
lindane. Lindane's toxicity in association with these fate characteristics results in risks of
concern for the Agency. Below is a summary of these concerns.
Based on the submitted environmental fate data, physical and chemical properties,
lindane is a persistent, moderately mobile, and relatively volatile compound. Selected
physical-chemical properties of lindane are summarized in Table 1. Lindane can migrate
over a long distance through various environmental media such as air, water and
sediment. Due to the persistent nature and long-range transport, lindane has been
detected in air, surface water, groundwater, sediment, soil, ice, snowpack, fish, wildlife
and humans. The source of these lindane detections is unclear; but it may be the result of
a combination of past widespread use in the U.S. and other countries, lindane's extreme
persistence, current seed treatment use, current use in foreign countries, and use as a
pharmaceutical.
Table 1. Fate and Physical-Chemical Properties of Lindane
Parameter
Molecular Weight
Solubility (25 °C)
Vapor Pressure (25 °C)
Henry's Law Constant (atm-m3/mol)
Hydrolysis Half-life (pH 5, 7, 9; 25 °C)
Aqueous Photolysis Half-lives (pH 5)
Soil Photolysis Half-life
Aerobic Soil Metabolism Half-lives
Organic Carbon Partition Coefficients (Koc)
Octanol - Water Partition Coefficient (log Kow)
Bioconcentration Factors (BCF)
Value
290.82
7mg/L
9.4x 10-6torr
3.5xlO'6@25°C
Stable, stable, 43-53 days
Stable
Stable
980 days
1368 mL/g (mean of 4 soils)
3.78
In fish bluegill sunfish, 780 (fillet),
2500 (viscera), 1400 (whole fish
tissues)
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A. Persistence
Once released into the environment, the primary process by which lindane
dissipates is volatilization into the air, although abiotic and biotic degradation as well as
uptake by crops can also occur. However, lindane is resistant to abiotic processes like
photolysis and hydrolysis (except at high pH), and degrades very slowly by microbial
actions. The hydrolysis half-lives of lindane were reported to be stable at pH 5 and pH 7,
and > 43 days at pH 9 (U.S. EPA 2002 EFED RED Chapter). Since lindane does not
contain chromophores that absorb light >290 nm, direct photolysis is not expected to
occur. In an aerobic soil metabolism study, lindane degraded very slowly, with a
calculated half-life of 980 days (U.S. EPA 2002 EFED RED Chapter). Since most
degradation pathways occur slowly, the presence of degradates is generally low. Possible
lindane degradates could include pentachlorocyclohexene, 1,2,4,-trichlorobenzene, and
1,2,3-trichlorobenzene (U.S. EPA 2002 EFED RED Chapter).
Additional evidence of its persistence is the fact that lindane has been found at
numerous hazardous waste sites which have been abandoned. Of the 1,662 current or
former industrial sites on the National Priorities List, lindane was found in 189 (ATSDR
1997 at p. 1).
B. Bioaccumulation and Bioconcentration
Lindane can bio-accumulate easily in the food chain due to its high lipid solubility
and can bioconcentrate rapidly in microorganisms, invertebrates, fish, birds and
mammals (WHO 1991). The octanol-water partition coefficient (log Kow = 3.78, Table
1) for lindane indicates that it has the potential to bioaccumulate. Lindane has potential
to enrich in lipid-containing biological compartments. However, lindane is a multimedia
chemical, existing and exchanging among different compartments of the environment
such as the atmosphere, surface water, soil and sediment. In addition, temperature,
humidity, and other environmental properties may have significant influence on
environmental degradation rates. These properties likely affect the presence of lindane in
the environment as well as the variability in the bioaccumulation, bioconcentration and
biomagnification in the various biological compartments. Differences in accumulation
are also likely due to different modes of uptake, metabolism and sources of
contamination.
The estimated bio-concentration factors (BCF) of lindane were 780x in fillet,
2500x in viscera and 1400x in whole fish (U.S. EPA 2002 EFED RED Chapter).
Although lindane may bioconcentrate rapidly, most data suggest that bio-transformation,
depuration and elimination are relatively rapid once exposure is eliminated. After 14
days of depuration, lindane levels were reduced by 96% in fillet, 95% in viscera, and
85% in whole fish.
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C. Transport and Mobility
Lindane has often been detected in ambient air, precipitation, and surface water
throughout North America, and it has also been detected in areas of non-use (e.g., the
Arctic), indicating long-range transport of lindane occurs. The source of these lindane
detections is unclear, but may be the result of a combination of manufacture (i.e., release
during manufacture, disposal of HCH isomers), past widespread use in the U.S. and other
countries, its extreme persistence, current seed treatment use, current use in foreign
countries, and the pharmaceutical use of lindane. Once released into the environment,
lindane can partition into various environmental media. Lindane present in soil can leach
to groundwater, sorb to soil particulates and transport to surface water via runoff, or
volatilize to the atmosphere. However, the Henry's law constant (Table 1) of lindane
suggests that volatilization is the most important route of dissipation from water and
moist soils followed by aerial long-range transport. Adsorption of HCH isomers to soil
and sediments is generally a preferential partitioning process after volatilization.
Leaching of HCH isomers through soil is governed by their water solubility and their
propensity to bind to soil. The calculated Koc of lindane ranges from 942 to 1798 mL/g,
with a mean of 1368 mL/g for four soils tested (U.S. EPA 2002 EFED RED Chapter).
These data suggest that lindane has low leaching potential. Data also indicate that
lindane is expected to adsorb to suspended solids and sediment in water. Based on the
results of a number of laboratory soil column leaching studies that used soils of both high
and low organic carbon content as well as municipal refuse, lindane has low subsurface
mobility in soils (Melancon et al. 1986, Reinhart et al. 1991).
D. Volatility and Long-Range Transport
The behavior of lindane in the environment is complex because it is a multimedia
chemical, existing and exchanging among different compartments of the environment
such as the atmosphere, surface water, soil and sediment. Volatilization from soil and
surface waters is a major dissipation route for lindane. The Henry's law constant for
lindane suggests that it will volatilize from moist soil and surface water into the air,
although microbial and chemical degradation and uptake by crops can also occur (Walker
et al. 1999). Lindane can also enter the air as adsorbed phase onto suspended particulate
matter, but this process does not appear to be a major contributor like volatilization
(Walker et al. 1999 and Bidleman 2004). Brubaker and Kites (1998) measured the gas
phase kinetics of the hydroxyl radical with lindane, and reported that it has long
atmospheric half-lives in air and, therefore, can be transported long distance.
Once airborne, lindane may move into the upper troposphere for more widespread
regional and possibly transcontinental distribution as a result of large-scale vertical
perturbations that facilitate air mass movement out of the near surface. Also, it may
reversibly deposit on terrestrial surfaces close to the source and still be transported over
large distances, even global scales, through successive cycles of deposition and re-
emission as result of ambient temperature and latitude differences known as "global
distillation or fractionation" (Wania and Mackay 1996 as cited in U.S. EPA 2002 EFED
RED Chapter at pp 9-10). Recently, soil and air samples were collected for
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organochlorine pesticides in northwest Alabama to estimate soil-to-air fluxes and their
contribution to the atmospheric concentration (Harner et al. 2001). The researchers
concluded that the atmospheric concentration of lindane in northwest Alabama may be
due to atmospheric advections or regional sources rather than the studied soils. A field
study conducted by Waite et al. (2001) in Saskatchewan, Canada demonstrated
volatilization of lindane from fields planted with lindane-treated canola seed. Waite
reported that significant quantities (12-30%) of applied lindane volatilize from treated
canola seed to the atmosphere during the growing seasons and have direct implications
on regional atmospheric concentrations of lindane. The study also estimated that a range
of 66.4 to 188.8 tons of atmospheric load of lindane occurred during 1997 and 1998,
following the planting of canola in the region of the Canadian-prairies. Poissant and
Koprivnjak (1996) reported that 90% of elevated lindane concentration in the atmosphere
at Villeroy, Quebec in 1992 was from secondary emissions of applied lindane-treated
corn, while the rest was from the volatilization of residual lindane from the previous year
seed treatment (U.S. EPA 2002 EFED RED Chapter at pp. 8-9).
Recently, seasonal air concentrations of lindane and other HCH isomers were
monitored using Passive Air Samplers (PAS) along an urban to rural transect in Toronto,
Canada (Motelay-Massei et al. 2005). The air concentrations of lindane were 159 pg/M3
to 1020 pg/M3 in the rural sites during the spring-summer monitoring period. A similar
trend of air concentrations of lindane was also observed by Hoff et al. (1992) in Ontario,
Canada. Both studies concluded that the continuing use of lindane during spring is likely
associated with higher concentration of lindane in the air samples. Analysis of 1990 to
2001 data from the Integrated Atmospheric Deposition Network (IADN) also confirmed
that annual agricultural application was a key variable in explaining the annual cycle of
atmospheric lindane concentrations (Buehler et al. 2004). Jianmin et al. (2003) modeled
lindane transport and deposition to the Great Lakes from usage areas in the Canada
prairies and corn-belt regions of southern Ontario and Quebec. Results showed that
lindane transport to the Great Lakes during spring-summer came mainly from application
sites in the prairies, with minor contribution from the corn-belt. They compared the
modeled concentration with the monitoring data of the IADN sites, which were within
50-134% of those measured during summer, 16-51% in fall and 3-20% in winter.
E. Surface Water, Sediments and Groundwater
Lindane is moderately mobile and can migrate over a long distance through
various environmental media like water and sediment. Adsorption of lindane to soil and
sediments is generally a preferential partitioning process after volatilization. The
calculated Koc of lindane ranges from 942 to 1798 mL/g, with a mean of 1368 mL/g for
four soils tested (U.S. EPA 2002 EFED RED Chapter). These data suggest that lindane
has low leaching potential. Data also indicate that lindane is expected to adsorb to
suspended solids and sediment in water. Lindane reaches water resources via surface
runoff and through rain and snow deposition (ATSDR 1997 at p. 190 citing Tanabe et al.
1982; Wheatley and Hardman 1965). "For example, Lake Ontario received <2 kg/year of
y-HCH because of suspended sediment loading from the Niagara River between 1979 and
1981" (ATSDR 1997 at p. 190 citing Kuntz and Warry 1983). Studies also show that the
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Great Lakes received 3.7 to 15.9 metric tons/year of lindane through atmospheric
deposition (ATSDR 1997 at p. 190 citing Eisenreich et al. 1981). Lindane has also been
detected in stormwater runoff in Denver, Colorado and Washington, D.C. (0.052-0.1
ug/L) (ATSDR 1997 at p. 190 citing Cole et al. 1984).
VI. Dietary Risk
A. Presence of Lindane in Breast Milk
Although there currently are no programs in the United States for monitoring
lindane levels in human breast milk, EPA believes that lindane is present in the breast
milk of at least some nursing mothers in the United States. In general, lindane is very
persistent and highly soluble in fat or fatty tissue. Therefore, it has the potential to bio-
accumulate in the food chain and bioconcentrate in microorganisms, invertebrates, fish,
birds, and mammals. In practical terms, this means that when women are exposed to
lindane through food, water, or the atmosphere, they will accumulate lindane residues in
their fatty tissue, including breast milk and breast milk fat, and that these lindane residues
will remain there for an undetermined amount of time.2 Thus, to the extent women in
the United States are exposed to lindane, EPA believes that that lindane likely will
accumulate in their breast milk or breast milk fat.
Moreover, in the 1970s and 1980s, lindane was detected in breast milk in women
in Binghamton, New York; Saint Louis, Missouri; several places in Mississippi, and in
Philadelphia, Pennsylvania. Lindane also has been detected in breast milk of women in
Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the former Czechoslovakia,
Denmark, the former Federal Republic of Germany (FRG), Greece, Finland, France,
Hungary, India, Iran, Iraq, Ireland, Israel, Italy, Japan, Luxembourg, Mexico,
Netherlands, Nigeria, Norway, Poland, Rwanda, Spain, Sweden, Switzerland, Taiwan,
Thailand, Tunisia, Turkey, the United Kingdom, Vietnam, Yugoslavia, and Zaire (Jensen
1991). Several of these countries, like Canada, have had production and use patterns
similar to those in the United States. Given the U.S. and world-wide presence of lindane
in breast milk, EPA expects that, if U.S. monitoring programs existed, lindane would be
detected in breast milk in other U.S. locales as well.
B. Lindane from Treated Seed Could Contribute to Breast Milk Contamination
EPA believes that lindane from the treated seed use could contribute to levels of
lindane in breast milk. As discussed earlier, there are several routes by which women in
the United States could be exposed to lindane from treated seed. These include: (1)
eating food grown from treated seed; (2) eating the meat of animals fed with feed grown
2 Several studies suggest, however, that once exposure stops, certain species may be able to eliminate
lindane from their systems. EPA, however, cannot determine how quickly or slowly lindane may be
eliminated from the human body. In comments, NRDC states that lindane is converted in to beta-HCH in
the body (EPA NRDC Comments at p. 1). NRDC provides no support for this statement and EPA has
found nothing independently to confirm or refute this statement. Beta-HCH accumulates to a greater extent
than lindane and cannot be as efficiently eliminated (EPA 2006 Assessment at p. 19).
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from treated seed; (3) consuming drinking water contaminated with lindane from the seed
treatment use; and (4) being exposed to lindane that volatilizes from the seed treatment
use. EPA believes that all of these are potential routes of exposure.
C. Infant Exposure to Lindane from Breast Milk and Resulting Risk
Infants will be exposed to lindane if they are fed contaminated breast milk.
Indeed, for women, lactation is the most important route of elimination for persistent
contaminants such as lindane (Jensen 1991 at p. 10). EPA is not able to conduct a
scientifically quantitative assessment of the risks associated with exposure to lindane in
breast milk due to the uncertainties regarding current monitoring data and the lack of a
validated method for quantifying the infant exposure. In general, concentrations of man-
made chemicals in human milk often are more than ten times higher than in cow's milk
from the same area. Frequently, limit values established for contaminants in cow's milk
are exceeded in human milk. Newborns and infants, whose main foodstuff is breast milk,
may have a higher relative daily intake of these pollutants than adults (Jensen 1996).
As far as EPA is aware, there have been no overt illnesses in infants from
exposure to lindane in breast milk. In addition, breast milk is the natural and superior
foodstuff for newborns, and infants, and nursing provides important immunological and
psychological benefits. Moreover, virtually all national and international experts agree
that women should not forgo breast feeding even though breast milk may be
contaminated with low levels of lindane, other organochlorine pesticides, and persistent
industrial chemicals like PCBs (Jensen 1991 at p. 288).
Nevertheless, there is a dearth of long-term studies of the effects of infant
exposure to lindane in breast milk. Thus, the potential long-term effects of newborn and
infant exposure to lindane in breast milk are difficult to assess. EPA is currently unable
to determine whether there are in fact adverse effects from exposure of infants to lindane
in breast milk. However, EPA believes that, because of lindane's prior detections in
breast milk, its physio-chemical properties, and its continued presence in the diet, the
potential for adverse effects to infants from consumption of breast milk cannot be
dismissed due to a lack of data.
VII. Impact on Growers
Lindane is registered in the U.S. as a seed treatment use on wheat, barley, oats,
rye, corn, and sorghum. An application to register lindane for use as a seed treatment for
canola is pending before the Agency. In support of the 2002 RED, EPA assessed the
potential impacts on growers of cancellation of the lindane seed treatment uses (U.S.
EPA 2002 BEAD Analysis). At the time of the 2002 RED, there were registered
alternatives for all lindane seed treatment uses except oats and rye. Imidacloprid and
thiamethoxam were identified as the primary seed treatment alternatives to lindane (U.S.
EPA 2002 BEAD Analysis at p. 1).
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For the wheat, barley, corn, and sorghum seed treatment uses, grower-level
effects of cancellation of lindane were expected to be minor. For these uses, EPA
estimated an increased treatment cost to growers using lindane ranging from 0.3% of
gross revenue to 4.4% of gross revenue. In some cases, these increased treatment costs
would be offset by the effectiveness of alternatives on other pests. For example, for
sorghum, EPA estimated increased treatment costs to growers using lindane of 3.5-4.4%
of gross revenue. However, the Agency found that this increase would likely be offset by
increased yields due to control of chinch bugs and aphids (U.S. EPA 2002 BEAD
Analysis at p. 9). Overall, for uses for which alternatives are registered, EPA concluded
the impact of cancellation of lindane to individual growers using lindane would be minor.
Further, the Agency estimated that only 6% to 7% of total acres of wheat, barley, and
corn planted and only 1% of total acres of sorghum planted were being treated with
lindane.
At the time of the 2002 RED, no alternatives were registered for oats and rye.
EPA estimated cancellation of the lindane seed treatment use could result in a 9% yield
loss to growers using lindane; however, the Agency estimated that only 1% of total acres
of oats and rye planted were being treated with lindane. For the growers affected, this
crop loss would be partially offset by a lower treatment cost, but the Agency concluded
that cancellation of the lindane seed treatment for oats and rye would have a major effect
on individual growers using lindane (U.S. EPA 2002 BEAD Analysis at pp. 3-4).
Since the time of the 2002 RED, additional alternatives to the lindane seed
treatment uses have been registered. Most notably, imidicloprid is now registered as a
seed treatment use for oats and rye. Thus, there are now alternatives for all lindane seed
treatment uses. The registration of imidicloprid for oats and rye significantly alters the
Agency's 2002 assessment of grower-level impacts. A 9% yield loss to growers using
lindane would no longer be expected if lindane were cancelled, though growers switching
to imidicloprid would experience increased treatment costs of 0.52-1.7% of net revenues.
The Agency considers this to be a minor effect (U.S. EPA 2005 BEAD Update). For all
uses, the Agency expects an average increase in treatment cost of 0.29% of net revenues.
In addition, it appears that use of lindane-treated seeds is declining. In 2002, EPA
estimated that approximately 4.8 million acres of corn crops were grown from lindane-
treated seed (7 percent of the total corn acreage). This translated to approximately 52,000
pounds of lindane used for corn seed treatment. Updated information shows a substantial
reduction in these figures. For 2004-2005, EPA estimates that less than three million
acres of corn crops were grown from lindane-treated seed (less than 4 percent of the total
corn acreage). This amounts to less than 30,000 pounds of lindane used for corn seed
treatment. These revised figures suggest that use of lindane to treat corn seeds has
declined by greater than 40 percent.
The Agency has received reports that some farmers using treated seeds will opt
for lindane-treated seeds because lindane-treated seeds appear to repel sandhill cranes
from corn crops. Two studies have estimated that sandhill cranes will damage 20 percent
of corn crops grown near wetlands. It appears that this use is most common in
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Wisconsin. EPA has no information indicating how much the potential 20 percent crop
damage would be prevented by the use of lindane-treated seeds. As a result, the Agency
is unable to quantify any resulting benefit from using lindane-treated seeds in this
manner. Due to reduced availability of lindane-treated seeds, Wisconsin has submitted a
FIFRA § 18 emergency exemption request to use anthraquinone to control sandhill crane
damage. EPA granted Wisconsin's FIFRA § 18 emergency exemption request and
believes anthraquinone is an alternative for protecting crops from sandhill cranes.
VIII. Regulatory Determination
Pursuant to FIFRA, EPA must determine, after submission of relevant data,
whether pesticide active ingredients are eligible for reregistration. (FIFRA § 4(g)(2)(A).)
In order to be reregistered, EPA must find that an active ingredient meets the standard in
section 3(c)(5) of FIFRA. (See FIFRA § 4(a)(2).) This requires EPA to examine, in part,
whether a pesticide causes unreasonable adverse effects on the environment. Pursuant to
section 2(bb) of FIFRA, "unreasonable adverse effects on the environment" is defined, in
part, as "any unreasonable risk to man or the environment, taking into account the
economic, social, and environmental costs and benefits of the use of any pesticide." In
other words, to determine whether a pesticide causes unreasonable adverse effects on the
environment, EPA must examine broadly the costs and benefits of the pesticide's use,
including economic, social and environmental costs and benefits.
Based on new information the Agency received since the 2002 RED, and the
review of existing information, EPA has determined that the seed treatment uses of
lindane are ineligible for reregistration under FIFRA because the current risks outweigh
the benefits of the use of the pesticide. As of July 27, 2006, the Agency had received
requests from all lindane technical and end-use product registrants to voluntarily cancel
all lindane product registrations. Once the cancellation process is complete, EPA will
propose to revoke the existing lindane fat tolerances pursuant to section 408(1)(2) of
FQPA.
EPA believes the costs and benefits associated with the seed treatment use have
changed significantly since the 2002 RED. At the time of the 2002 RED, there were no
alternatives to the seed treatment use for oats and rye for control of wireworm. EPA
estimated that without the availability of lindane-treated seeds, untreated plots might
suffer as much as a 9% yield loss. The Agency considered this to be a major impact on
growers who used lindane treatment for these crops. However, this was the only major
impact on growers. For all other lindane seed treatment uses, alternatives existed and
grower impacts were expected to be minor.
In March 2006, EPA registered imidicloprid as a seed treatment use on oats and
rye for wireworm control. The Agency believes imidicloprid is as effective as lindane for
control of wireworm. With the availability of imidicloprid, EPA no longer expects a
yield loss in the absence of lindane. Growers are expected to see increased treatment
costs of 0.52-1.7% of net revenues with use of imidicloprid. The Agency considers this
to be a minor impact. In addition, at least with respect to corn, use of lindane-treated
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seeds has dropped by over 40 percent, from approximately 4.8 million acres to less than 3
million acres (less than 4 percent of total corn acreage).
Overall, the benefits of the lindane seed treatment uses are now negligible. For all
uses, if lindane were cancelled, the Agency would expect to see average treatment costs
increase by $1.82 per acre. This is equal to 0.29% of net revenues. For some crops, the
increased treatment costs may be partially offset by better control of certain pests. In
sum, the benefits of the lindane seed treatment use to growers are very minor, and
cancellation of the lindane seed treatment uses is not expected to have an appreciable
impact on growers.
Under FIFRA, EPA must balance the benefits of the lindane seed treatment use
against the human health, environmental and social costs in determining whether the risk
posed is unreasonable. EPA has identified a number of sources of exposure to lindane
beyond the seed treatment. Past uses of lindane, consumption of imported meat, and
pharmaceutical uses of lindane are all current sources of exposure. For indigenous
populations who rely on subsistence diets, exposure to lindane or HCH isomers may
result from current or past manufacture or use due to the long-range transport of lindane.
EPA believes these sources of lindane have produced a reservoir of lindane in the
environment that may remain for some time due to lindane's persistence.
The seed treatment use adds to this current lindane exposure. There are multiple
routes by which individuals may be exposed to lindane from the seed treatment use. As
discussed previously, consumption of crops grown from treated seed, consumption of
livestock fed treated seed and consumption of drinking water are all routes of exposure to
lindane from the seed treatment use. There may be additional exposure due to
volatilization of lindane from treated seeds. The lindane seed treatment use will add to
the existing reservoir of lindane in the environment.
EPA believes this potential ongoing exposure may be of particular concern to
nursing infants. Due to lindane's tendency to accumulate in fatty tissues, it has been
detected in the breast milk of women in the United States and in many other foreign
countries. Although there is no current monitoring data for the U.S., EPA believes it is
reasonable to conclude that lindane is present in the breast milk of U.S. women given
ongoing exposure to lindane and the chemical's fate characteristics. EPA acknowledges
there is uncertainty on the level of risk posed to nursing infants and that no adverse
effects have been reported. However, the potential for adverse effects from consumption
of lindane in breast milk cannot be dismissed.
EPA finds the overall costs of continued registration of lindane for seed treatment
are high. The seed treatment use will only add to the existing sources of lindane
exposure. Ongoing releases of lindane into the environment are of concern due to the
environmental fate characteristics of the chemical. Lindane is persistent and mobile and
will accumulate in human fat tissue. This potential for ongoing and future exposure to
lindane is of particular concern for nursing infants because of the potential for exposure
to lindane via breast milk.
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In sum, EPA finds that these costs of continued lindane registration far outweigh
the benefits of the seed treatment use. Therefore, the lindane seed treatment uses are not
eligible for reregistration under FIFRA.
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