Document JK914DR1GKJO1MLXYpK3BmNe
13 WEEK REPEATED INHALATION STUDY ON ETHYLENE DIBROMIDE (EDB) IN MALE AND FEMALE RATS
K. D. Nitschke, R. J. Kociba, D. G. Keyes, R. C. Childs, and M. J. McKenna Reviewed by: J. C. Ramsey
February 11, 1980
Toxicology Research Laboratory Health and Environmental Sciences, USA
Dow Chemical, U.S.A. Midland, Michigan 48640
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ABSTRACT
Male and female CDF (F-344) rats were exposed to 0, 3, 10 or 40 ppm ;
ethylene dibromide, 6 hours/day, 5 days/week for 13 weeks for a total of 67-
68 exposures in 95-96 days. Scheduled sacrifices occured after 1, 6, and
13 weeks of exposure. Additional rats were held for a recovery period |
of 88-89 days and subsequently necropsied. Body weight data was obtained;
throughout the study and the animals were observed daily for signs of (
toxicity. Hematology, urinalysis and clinical chemistry parameters were
measured. Gross and microscopic pathological examinations were conducted
on selected tissues of all animals. Weights of various organs were
recorded and organ/body weight ratios were calculated.
Rats exposed to 3 ppm EDB showed no consistent effect in any
parameter measured. At 10 ppm, EDB caused slight epithelial hyperplasia of the
nasal turbinates in animals necropsied after 1, 6 or 13 weeks of exposure;
however, 88 days after the last exposure to EDB, no morphological
(
difference from control animals was observed. Rats exposed to 40 ppm EDB [
showed a definite adverse response characterized by a decrease in body
weight gain throughout the 13-week exposure period, an increase in liver
and kidney weights after 6 and 13 weeks of exposure, and pathologic
effects in the nasal epithelium. At this concentration the nasal
turbinates of rats progressed from very slight hyperplasia of the
epithelium after 1 week of exposure to EDB to hyperplasia and nonkeratizing
squamous metaplasia of the epithelium after 13 weeks of exposure to ED8.
After a recovery period of at least 88 days, only a single focus of
hyperplasia of the nasal epithelium in one rat and increased relative
liver weights were apparent as residual effects from the subchronic
exposure. It is believed that these observations would have returned to
control limits if allowed a longer recovery period.
Therefore, while this study has shown that repeated subchronic
exposure of rats to 10 or 40 ppm EDB induces pathologic changes in the
respiratory epithelium of the nasal turbinates, a subsequent postexposure
phase revealed a lack of progression of the lesions, with almost complete
reversion toward normal histologic appearance of the nasal turbinates.
In view of these findings, and the lack of any lesion subsequent to
repeated exposure to 3 ppm EDB, short-term repeated exposure to
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these concentrations of EDB would not be expected to result in any long term irreversible effects upon the nasal turbinates or other tissues of the body.
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INTRODUCTION
The toxicological properties of Ethylene Dibromide (EDB) have been assessed in a number of studies over the past 25 years. Currently, the American Conference of Governmental Industrial Hygienists has listed EDB as having carcinogenic potential without an assigned TLV. Rowe et al. (1952) reported the single oral dose toxicity of EDB for several species of animals. These are listed In the following table.
Species
Single Oral LDgg, mg/kg
Mice - Females Rats - Males Rats - Females Chickens Guinea Pigs Rabbits - Females
420 146 117
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EDB can also be absorbed through the skin in toxic amounts. The LD^q for skin absorption in rabbits is between 300 and 650 mg/kg. EDB is also irritating to the skin and the eyes.
Acute inhalation toxicity data are also included In the report of Rowe et al. (1952). The maximum survival times for rats exposed to EDB vapor are reported as follows:
Rats both sexes
Guinea Pigs both sexes
EDB, ppm
3000 1600
400 200 400 200
Maximum Survival Times
6 minutes 12 minutes 36 minutes
2 hours 2 hours 7+ hours
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Examination of female rats given single inhalation exposures to EDB gave
these results (Rowe et al. , 1952):
EDB, ppm
Hours of Exposure
With Adverse
Without Adverse
Effects
Effects
800
0.15
0.10
200 1.0 0.7
100 4.0 2.5
50 -- 7.0
The adverse effects following these acute inhalation exposures included pulmonary congestion, edema, hemmorhage and inflammation. The livers showed hepatocellular degeneration and necrosis and the kidneys had slight inflammatory and degenerative changes.
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Ethylene dibromide is reported to produce irritation of the mucous membranes, headache, vertigo, giddiness, nausea, vomiting, drowsiness and coma when inhaled (St. George, 1937). Thomas et al (1927) reported that guinea pigs exposed to 0.2-0.8% EDB for 30-150 minutes had nasal irritation.
Data on chronic vapor exposure of animals to EDB were also reported by Rowe et al. (1952). Animals were exposed for 7 hours/day, 5 days/week for periods of up to 6 months. The data are summarized in the attached Table 1.
In a carcinogenic bioassay conducted by the NCI (Olson et al., 1973) EDB was given by oral intubation to rats and mice. Squamous cell carcinomas of the stomach were found in rats as early as 10 weeks after the start of the study. The doses were changed within the 40-200 mg/kg/day range several times during the study. Table 2 summarizes the number of tumors noted.
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t
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Recent information indicates that a 2-year inhalation study being completed by NCI has identified nasal tumors in rats and mice exposed to 10 and 40 ppm EDB. In view of the local irritating properties of EDB on the upper respiratory tract, this study was conducted to assess the possibility of EDB-induced nasal epithelial changes that may precede or accompany the development of nasal tumors in rodents. This study would give perspective to the forthcoming tumor data from the NCI study by: 1. Allowing an assessment of whether or not various inflammatory,
degenerative, necrotic, hyperplastic or metaplastic changes occur in the nasal epithelium prior to (or at doses lower than those leading to) the development of tumors, 2. Allowing an assessment of whether or not the exposure levels shown to induce nasal tumors in rodents are associated with adverse effects that would indicate a maximal tolerated dose (MTD) may have been exceeded in the chronic study at NCI. 3. Allowing a comparative assessment of those possible effects noted at higher exposure levels of 40 or 10 ppm with effects at a lower exposure level (3 ppm).
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MATERIALS AND METHODS
s
General Study Design A 13-week inhalation study of EDB at concentrations of 0, 3, 10,
or 40 ppm was conducted with interim sacrifices of male rats after 1 week (5 exposures) and 6 weeks (29 exposures). Groups of control and exposed rats were retained for at least 88 days after the last exposure to assess the reversibility of effects observed after 13 weeks of exposure to EDB.
Body weights were obtained at least weekly throughout the study. Basic hematological and urinary parameters were measured prior to the 6 week and 13 week sacrifices. Urinalysis was also performed on animals in the recovery group. Clinical chemistry values were measured at the 1, 6, and 13 week scheduled necropsies. Weights of the brain, heart, liver, kidneys, testes (males only) and thymus were obtained and compared with the body weights of the rats. Tissues of lungs, bronchi, trachea, nasal turbinates, liver, kidneys, testes, ovaries, uterus, and oviducts were examined histopathologically from rats of all exposure levels at all scheduled necropsies.
Material. Production grade ethylene dibromide supplied by The Dow Chemical Company, Magnolia, Arkansas was used for this study. Gas chromatographic analysis of the test material was made prior to study initiation. The test material was also analyzed twice during the study and after the final exposure by the Dow Analytical Lab (Table 3).
Generation and Sampling of Vapor Concentrations of EDB. EDB was vaporized by metering the liquid at a calculated rate with a precision pump into a warmed vaporization flask (100C). The vapors were swept from the flask with compressed air into the main chamber airflow. The chambers were 1 m stainless steel and glass Rochester-type chambers. The nominal concentration was calculated from the rate at which liquid EDB was dispensed and the total chamber airflow. The chamber concentra tion of EDB was analyzed at least 3 times/day by gas chromatography using a flame ionization detector. A 6' x 1/8" 0D nickel column packed
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with 10% SP-1000 on 100/200 mesh Chromosorb W (Supelco, Inc.) was used for the analysis. The carrier (helium), hydrogen and air flows were 54, 20, and 300 ml/min, respectively. The column and detector temperatures were 140 and 200C, respectively. The retention time for the EDB peak was approximately one minute after injection of the air sample.
Animals. Four groups of CDF rats (9 weeks old) (Fischer 344 derived,
j
Charles River Laboratories, Portage, MI) consisting of 40 male and
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20 female rats were used. Rats were acclimated to the conditions of
(
this laboratory for at least 13 days prior to the initial exposure to EDB.
The animals were randomly assigned to the four groups using numbers
generated by the program GRAND.CLIST (Computation Laboratory, The
Dow Chemical Company). The CDF strain was chosen because of its
current use in chronic toxicity/carcinogenicity studies in this
laboratory and many other laboratories.
Serial sacrifices of 10 male rats/group were conducted after 1 (5 exposure days), 6 (29 exposure days) and 13 weeks (67 exposure days) and 10 female rats/group after 13 weeks (68 exposure days); the remaining 10 rats/sex/group were held and sacrificed after an 88-89 day post-exposure period for the purpose of assessing reversibility of any lesions that may be associated with exposure to EDB for 13 weeks.
Procedures. The concentrations studied were 0, 3, 10 and 40 ppm EDB. Exposures were 6 hours/day, 5 days/week. The animals were housed 2/cage during nonexposure periods and 5 or 10/cage for females and males, respectively, during exposure periods. Control animals were also housed in a chamber during exposure periods. Water and food (Purina Rat Chow) were withheld during the 6-hour exposure period but were available ad libitum at all other times. Rats were weighed twice prior to the start of the study, twice weekly for the first two weeks of the study and once weekly thereafter. Male rats exposed to the various concentrations of EDB for 5 days were initially exposed to EDB 6 days after the other groups were initially exposed. Consequently, their body weights were
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statistically analyzed separately from the other groups. The groups necropsied after 6 or 13 weeks of exposure and the recovery groups were initially exposed to EDB at the same time and were statistically analyzed together. Animals were observed at the end of each exposure period and signs of toxicity noted and recorded. Particular attention was paid to the eyes and nose for clinical indications of irritation.
r
Clinical Determinations. Basic hematological and urinalysis determinations were conducted on 7 male rats/exposure level prior to their necropsy after 6 weeks and also on 7 rats/sex/exposure level prior to their necropsy after 13 weeks of exposure. Urinalysis on 7 rats/sex/exposure level was performed prior to the necropsy on animals in the recovery group. Clinical chemistry determinations was performed on all 10 animals/sex (if applicable)/exposure level at the time of necropsy for the serial sacrifices after 1, 6 and 13 weeks. Hematological parameters3 included
a total erythrocyte count (RBC), total (WBC) and differential leukocyte counts, hemoglobin concentrations (HGB), and packed cell volume (PCV). Urinary parameters^ measured included specific gravity, pH, glucose,
ketones, bilirubin, urobilinogen, occult blood and protein. Clinical chemistry measurements included blood urea nitrogen (BUN), serum glutamic pyruvate transaminase (SGPT), serum glutamic oxalacetic transaminase (SGOT), serum alkaline phosphatase (AP), glucose, and bilirubin. Serum bromide levels of rats exposed to EDB for 6 weeks were measured by neutron activation^.
Pathology. Gross examination of the eyes of all rats was performed by a microscope slide technique at necropsy with observations recorded as part of the gross pathologic examination. At the time of each sacrifice, the eyes from 5 rats/sex (if applicable)/group were preserved In Zenker's solution. The eyes of the remaining rats were preserved in 10% formalin.
aPCV-Microhematocrit Centrifuge, Clay-Adams Company, New York, RBC, WBC counts, Hgb - Coulter Counter Model 2B1 and hemoglobi nometer, Coulter-Electronics, Hialea, Florida.
specific gravity - T.S. Meter American Optical Company, Buffalo, NY, pH, glucose, protein, ketones, bilirubin, urobilinogen, occult bloodBililabstix, Ames Company, Elkhard, Indiana.
cSerum - Centrifichem System 400, Methods File, Union Carbide Corp., Rye, NY.
^Dow Analytical Lab Report 79-10895.
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Gross necropsies were performed on all rats, with special attention given to assessing the presence or absence of inflammation of the upper respiratory tract. Rats were fasted overnight prior to necropsy. They were anesthetized with methoxyflurane and decapitated after clamping the trachea. The lungs and trachea of all animals were removed as a unit and inflated with 10% formalin from a hand held syringe. The nasal passageways were perfused with formalin fixative. Fasting body weights and organ weights for liver, kidneys, brain, heart, thymus, and testes (males) were obtained from all rats at each necropsy.
Representative specimens of the tissues indicated in Table 4 were taken from all animals and fixed in phosphate-buffered 10% formalin. The target tissues (lungs, bronchi, trachea, nasal turbinates (4 transverse planes), liver, kidney, testes, ovaries, uterus and oviducts) were processed by conventional histological methods, stained with hematoxylin and eosin and examined by light microscopy from all 10 rats/sex/group of each of the serial sacrifices after 1, 6, 13 weeks and the recovery group. Transverse sections through the decalcified nasal cavity were made perpendicular to the plane of the hard palate and the plane of the nasal septum at or near the following levels: 1 immediately caudal to the upper incisor teeth, 2)at the incisive papilla, 3)at the second palatal ridge, and 4)at the first upper molars.
Upon examination of the nasal turbinates, special attention was given to assessing the presence or absence of discernible inf1anmatory, degenerative, necrotic, hyperplastic or metaplastic changes.
Statistical Evaluation. Body weights, body weight gain, organ weights, urine specific gravity, hematology and clinical chemistry data were evaluated using an analysis of variance and Dunnett's test (Steel and Torrie, 1960). The level of significance was p<0.05.
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RESULTS
Chamber Analysis. Results of the chamber analysis are summarized in Table 5. Since the actual analytical concentrations are very close to the desired concentrations of 3, 10 or 40 ppm, these concentrations will be used throughout the report. The temperature range was similar within the chambers. Likewise, the relative humidity was nearly identical between the 4 chambers.
Animal Observations. Male rats exposed to 40 ppm EDB for 5 days exhibited eye and nasal irritation during the first exposure period. This was not observed in other animals scheduled for longer exposure or at different concentrations of EDB. No other effect relatable to ethylene dibromide exposure was observed.
Two non-exposure related deaths were observed in female rats from the 3 and 10 ppm exposure groups during the 88 day recovery period.
Body Weights. Mean body weights for male and female rats inhaling 0, 3, 10 or 40 ppm are shown in Tables 6-8. A decrease in body weight was observed in male rats exposed to 40 ppm EDB during the 13-week exposure period. Male rats exposed to 10 ppm EDB showed a significant decrease for the first two weeks of the study and occasionally thereafter. A statistically significant decrease in body weight was observed in female rats inhaling 40 ppm EDB on day 4 of the study. However, these significant differences were not nearly so evident when body weight gains were statistically analyzed (Figures 1-3 and Tables 9-11). The male rats inhaling 40 ppm ethylene dibromide still showed statistically decreased body weight gain during the 13-week exposure period but no change in body weight gain was observed at lower concentrations. The female rats inhaling 40 ppm EDB showed a decrease in body weight gain on day 4 and 14 of the study.
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Hematoloqy. The female rats exposed to 40 ppm EDB for 13 weeks had a statistical decrease in hematocrit and in hemoglobin that may have been the result of exposure (Table 12). No other measured hematological parameters revealed an effect attributable to exposure to EDB; the statistical increase in hematocrit of males exposed to 3 ppm EDB for 13 weeks and the statistical decrease in total white blood cell counts of males exposed to 3 or 10 ppm EDB for 6 weeks were considered to be of no toxicologic significance due to a lack of a dose response and the expected variability in this parameter.
Urinalysis. No treatment-related effects on urinalysis parameters were observed in any male rats exposed to EDB (Table 13). However, female rats exposed to 40 ppm EDB for 13 weeks showed a statistically significant decrease in specific gravity of the urine (Table 14) which was interpreted as treatment-related. After a recovery period of 88 days, the decrease in specific gravity was not observed.
Clinical Chemistry. As expected, serum bromide levels were significantly elevated in a dose-related manner above control values for all groups of male rats exposed to EDB for 6 weeks (Table 15). No other parameters, of those measured, exhibited a consistent effect due to exposure to ethylene dibromide; the statistical increases in total bilirubin noted in rats exposed to 3 or 10 ppm EDB for 13 weeks and the statistical decrease in SGPT values in rats exposed to 40 ppm EDB for 1 week were considered representative of the normal variation seen with these parameters and of no toxicologic significance.
Organ/Body Weight Ratios. Values for terminal body weights, organ weights, and organ/body
weight ratios for male and female rats are listed in Tables 16 and 17, respectively. After one week of exposure, there were no statistically significant differences in organ weights at any exposure level, although the absolute and relative liver weights were elevated slightly. The relative liver weights of male rats exposed to 40 ppm EDB were increased at each of the 3 subsequent necropsy intervals; this was considered to be the result of the exposure to 40 ppm EDB and the accompanying decrease in body
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weight of this group. Female rats exposed to 10 or 40 ppm EDB for 13 weeks had elevated absolute (40 ppm only) and relative liver weight values. These liver weight changes observed in the female rats after exposure to 10 or 40 ppm EDB for 13 weeks were most likely due to exposure; these changes were not observed at necropsy in rats after an 88 day recovery period.
Kidney weights of male rats were increased after 6 weeks of exposure to 3 (relative basis only), 10 (relative basis only) and 40 ppm (absolute and relative basis) EDB. However, after 13 weeks of exposure,, kidney weights were increased on a relative basis only in males exposed to 40 ppm EDB. Thus, the transient increase in relative body weights noted after 6 but not 13 weeks of exposure to 3 or 10 ppm EDB was considered to be of questionable significance. Kidney weights of female rats were not statistically different from control values at any of the exposure levels, but there was a trend toward increased relative kidney weights in female rats exposed to 40 ppm EDB for 13 weeks.
The weights of the brain, heart, thymus and testes were not considered to be directly affected by exposure to 3, 10, or 40 ppm EDB. The statistical increase in relative brain weights noted in males exposed to 40 ppm EDB for 6 or 13 weeks or 10 ppm EDB for 6 weeks were considered secondary reflections of the lower body weights of these groups. The statistical increase in relative weight of the thymus of male rats exposed to 10 ppm EDB for 13 weeks was considered an expression of the normal variability historically encountered in recording the weight of the thymus. The increase in relative weights of testes noted in the recovery group subsequent to exposure to 3, 10, or 40 ppm EDB were considered to be a secondary reflection of the lower body weight as compared to the control group sacrificed at that time. The same explanation applies to the decreased absolute testicular weights in males exposed to 40 ppm EDB for 13 weeks.
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Pathology. Due to the numerous interim sacrifices and recovery
,
portion of this study, the results of the gross and microscopic patho
logic examinations (Tables 18-25) will be discussed separately.
6-Day Interim Sacrifice. The results of the gross pathologic
I
observations for male rats terminated on day 6 of the study (5 exposure1 periods) are listed in Table 18. There were no grossly visible lesions considered to be related to treatment.
Histopathologic observations and the actual number of tissues examined microscopically from male rats terminated on day 6 of the study are listed in Table 19. Effects attributable to EDB were seen only in the most anterior section of the nasal turbinates. All male rats exposed to 40 ppm EDB showed very slight to slight scattered to diffuse hyperplasi^i of the respiratory epithelium of the turbinates. Five of ten male rats of this group showed very slight focal individual epithelial cell necrosis of the respiratory epithelium. Nine of ten male rats exposed to 10 ppm EDB showed isolated to scattered hyperplasia of the respiratory epithelium graded very slight to slight in degree. One rat of this group showed focal individual epithelial cell necrosis of the respiratory epithelium, very slight in degree. Examination of sections of nasal turbinates of rats exposed to 3 ppm EDB revealed no hyperplasia or other lesions related to exposure.
Most of the male rats of the control group showed varying distribution of slight submucosal and epithelial inflammation of the respiratory epithelium with focal aggregates of inflammatory cells in the lumen of the nasal turbinates. In addition, the tracheal submucosa of all male control rats showed a similar inflammatory response, accompanied by a hyperplastic response of the mucosal epithelium. This inflammation occurs at a highly variable rate in this laboratory. Male rats exposed to 3, 10 or 40 ppm showed a substantial decrease in the inflammatory reaction noted in both nasal turbinates and trachea in comparison to controls. This decrease in inflammation noted in the nasal turbinates
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and trachea may or may not have been the result of exposure to EDB. All other histopathologic observations were considered to be spontaneous in nature and typical of rats of this age and strain.
0^.
40-Day Interim Sacrifice. The gross pathologic observations of male rats terminated on day 40 of the study (29 exposure periods) are listed in Table 20. There were no gross observations which were considered to be the result of exposure.
Histopathologic observations of male rats terminated on day 40 and the actual numbers of tissues examined microscopically are listed in Table 21. EDB exposure-related effects were again limited to the most anterior section of the respiratory epithelium of the nasal turbinates.
All male rats exposed to 40 ppm EDB showed very slight to slight multi focal to diffuse hyperplasia and very slight to slight multifocal individual epithelial cell necrosis of the respiratory epithelium. All male rats exposed to 10 ppm EDB showed very slight to slight hyperplasia of the respiratory epithelium with an isolated to diffuse distribution. Nasal turbinates of rats exposed to 3 ppm of EDB had no lesions attributed to the exposure. Male rats exposed to 40 ppm EDB had an increased incidence of slight focal atrophy of the renal tubules. This effect was not observed in rats necropsied after 1 or 13 weeks of exposure to EDB. In fact, after 1 week of exposure to EDB a decrease in the tubular atrophy of the kidneys was observed from the control group. No other histopathologic observations were considered to be related to exposure to ethylene dibromide.
95-96 Day Sacrifice. The gross pathologic observations of male and female rats on study for 95-96 days (67-68 exposure periods) are listed in Table 22. Five of ten male rats exposed to 40 ppm of EDB showed a decreased carcass size at the time of necropsy. In addition, five of ten female rats exposed to 40 ppm EDB showed very slight to slight diffuse paleness of the liver. No other grossly visible effects attributable to ethylene dibromide were observed.
Histopathologic observations on male and female rats sacrificed on day 95-96 of the study are listed in Table 23. Effects considered to be
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r*. related to EDB exposure were primarily limited to the most anterior sections of the nasal turbinates.
All male and female rats exposed to 40 ppm EDB showed very slight to slight diffuse or focal nonkeratinizing squamous metaplasia and hyper plasia of the respiratory epithelium. In addition, all male and most female rats exposed to 40 ppm showed very slight focal individual epithelial cell necrosis of the respiratory epithelium.
Nine of ten rats of each sex exposed to 10 ppm showed very slight to slight degrees of isolated to multifocal hyperplasia of the respiratory epithelium. One female rat of this exposure level showed very slight focal individual epithelial cell necrosis of the respiratory epithelium. The nasal turbinates of rats exposed to 3 ppm exhibited no lesions due to the exposure to ethylene dibromide. The increased incidence of subpleural mononuclear aggregates observed in the lung of rats exposed to EDB occurs at a highly variable rate in this strain of rats in this laboratory and is considered not toxicologically significant.
In view of the grossly observed very slight to slight degree of hepatic paleness, in 5 of 10 females, and the presence of hepatocellular cytoplasmic vacuolation in H&E stained sections of livers of 2 of 10 females exposed to 40 ppm EDB, Oil Red 0 stained liver sections from all female rats exposed to 0 or 40 ppm EDB were also examined. This revealed a very slight increase of fat within the liver sections of females exposed to 40 ppm EDB. Due to a lack of any significant increase of fat in the livers of females exposed to 40 ppm of EDB, and the absence of any grossly visible hepatic paleness at lower levels, tissues from the lower exposure groups were not stained with Oil Red 0 Stain.
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88-89 Day Recovery Sacrifice. The gross observations of male and female rats on study for 94-95 days (67-68 exposure periods) and subsequently held for a recovery period of at least 88 days are listed in Table 24. One female each from the 3 and 10 ppm groups died spontaneously during the recovery period. Necropsy of these two female rats showed a generalized acute bacterial septicemia, with bacterial organisms noted in various organs and tissues. These deaths were not considered to be related to previous exposure to vapors of EDB. There were no gross pathologic observations which were considered to be related to exposure.
Histopathologic observations of male and female rats of this recovery group are listed in Table 25. Examination of the sections of the nasal turbinates revealed no evidence of progression of the epithelial hyper plasia or metaplasia that had been previously noted at the 1, 6 or 13 week sacrifices. The nasal turbinates of all 10 males previously exposed to 10 or 40 ppm ethylene dibromide had no discernible changes in comparison to controls as a result of the exposure. Of the 10 females previously exposed to 40 ppm EDB, 9 of the 10 females had no evidence of hyperplasia, metaplasia or other exposure-related pathologic effects within the nasal turbinates. One female rat exposed to 40 ppm EDB had a single focus of epithelial hyperplasia noted in the respiratory epithelium of the nasal turbinates which was probably the sole remnant from the previous exposure to EDB.
Examination of the nasal turbinates of females previously exposed to 10 ppm of EDB revealed no evidence of epithelial hyperplasia that had been noted during the exposure. As with the interim sacrifices, there were no exposure-related observations in the nasal turbinates of male or female rats exposed previously to 3 ppm of EDB.
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CONCLUSIONS In this study, rats were exposed to 0, 3, 10, or 40 ppm EDB for 1, 6 or 13 weeks and an additional group of rats were held for an 88-89 day recovery period following the 13 week exposure. Rats exposed to 3 ppm EDB showed no consistent effect in any parameter measured. Exposure to 10 ppm EDB caused hyperplasia of the respiratory epithelium of the nasal turbinates, but no effects in the other tissues examined. Examination of the nasal turbinates and other tissues from the recovery group revealed no differences from controls in the 10 ppm group thus Indicating a lack of progression of the lesion.
Rats exposed to 40 ppm EDB had multiple indications of toxicity as indicated by a decrease in body weight gain, an increase in liver and/or kidney weights and pathologic changes in the nasal turbinates. At this concentration the nasal turbinates of rats progressed from very slight hyperplasia of the respiratory epithelium after 1 week of exposure to hyperplasia and nonkeratinizing squamous metaplasia of the respiratory epithelium after 13 weeks of exposure. After a recovery period of 88-89 days there was essentially complete reversibility of the lesions, with only a slight hyperplasia in the nasal epithelium of one rat that would have been expected to return to within control limits if allowed a slightly longer recovery period.
A preliminary report from the NCI Bioassay Program revealed a high incidence of tumors of the respiratory system of rats exposed to 10 and 40 ppm EDB for 2 years. These tumors in rats were primarily located in the upper respiratory system and described as primary adenomas, and carcinomas and adenocarcinomas of the nasal cavity. These findings appear consistent with those of the study reported herein which demonstrated that exposure of rats to 10 or 40 ppm EDB for as little as five days was sufficient to produce hyperplastic (10 ppm) and focal necrotic (40 ppm) alteration in the nasal respiratory epithelium. That such effects would progress in severity even to neoplasia following two years of exposure to these EDB concentrations is not surprising. However these considerations must also be tempered by the finding that the lesions of the nasal turbinates produced by exposure of rats to EDB for 90 days in the present study were reversible and nearly completely
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so within about the same time span used to produce the effect. In view of these findings and the lack of any observable effect In rats of the 3 ppm exposure group, these data indicate that short term exposure to EDB would not likely result in any irreversible effects on the upper respiratory tract or other tissues of the body.
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Written by:
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K. D. Nitschke, B.S. Study Director Research Biologist Inhalation Toxicology
A.S.C.P. Research Medical Technologist
/*,S
R. C. Childs, H.T., A.S.C.P. Histologist
at is rS'-~u
R. J.[ Kociba, D.V.M., Ph.D. Dipl ornate, American College of Veterinary
Pathologists Group Leader, Pathology
M. McKenna, Ph.D.
>/
Group Leader, Inhalation Toxicology
Reviewed by:
J. C. Ramsey, Ph.H.-- Research Specialist Biotransformation
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QUALITY ASSURANCE STATEMENT
This report represents data generated prior to the enactment of the FOA Good Laboratory Practice Regulations. The study was conducted according to standards used in this laboratory at that time. The report accurately reflects all of the data generated. All data and reports are located at the submitting laboratory.
Study Started: 15 January 1979 Report Issued: 11 February 1980
Protocol Audited:
______
Reported:______ --
Data Audited: 8 January 1980
Reported: 9 January 1980
Final Report Audited: 8 January 1980
Reported: 9 January 1980
Quality Assurance Toxicology Research Laboratory Health and Environmental Sciences, USA 1803 Building Dow Chemical U.S.A. Midland, MI 48640
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REFERENCES Kochmann, M. Possible Industrial Poisonings with Ethylene Dibromide,
Mirench. Med. Wochenschr., 75, 1334-36, (1928). Olson, W. A., Habermann, R. T., Weisburger, E. K., Ward, J. M.,
Weisburger, J. H., Brief Communication: Induction of Stomach Cancer in Rats and Mice by Halogenated Aliphatic Fumigants, J. Natl. Cancer Inst., 51 (6), 1993-5, (1973). Rowe, V.K., Spencer, H. C., McCollister, D. D., Hollingsworth, R. L., Adams, E. M., Toxicity of Ethylene Dibromide Determined on Ex perimental Animals, A.M.A. Arch. Ind. Hyq. and Occup. Med., 6, 158-73, (1952). Steel, R. G. D., Torrie, J. H., Principles and Procedures of Statistics, McGraw-Hill Book Co.,, New York, (1960). St. George, A.V., The Pathology of the Newer Commercial Solvents, Am. J. Clin. Path., 7, 69-77, (1937). Thomas, B.G.H. and Yant, W.P., Toxic Effects of Ethylene Dibromide, U.S. Health Reports, 42, 370-75, (1927).
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Species Rats (10 r)
TABLE 1
CHRONIC VAPOR TOXICITY OF ANIMALS EXPOSED TO ETHYLENE DIBROMIDE3
Concentration foo ppa
Humber of Exposures
7 in 9 days
Results
3 of 1(1 died after one, five and seven exposures) survivors looked "unhealthy''; blood in stomachs) lung, liver and kidney weight increases) blood nonprotein nitrogen, DUN and plasm prothrocJbin clotting tine values normal) Microscopic exam.) Thickening of alveolor walls, leucocytic infiltration of lungs, cloudy swelling of liver, congestion and hemosiderosis of spleen.
Rabbits (4 F)
100 ppa
4 in 4 days
3 of 4 died after second and third exposures) Microscopic exam.t widespread central fatty degeneration of liver with seme necrosis.
Rats (20/sex/group)
30 ppa
S3 in 91 days
301 mortality of male rats duo to pneumonia and upper respiratory tract infections (not compound related). Males) increased lung, liver and kidney weights
decreased testes weights
Females) increased liver and kidney weights decreased spleen weights
Blood normal) lung damage in males but no histopsthological changes in heart, liver, kidneys, spleen or testes.
Guinea Pigs (H, P 8/group)
SO ppa
57 in 80 days
Ho lncicase in mortality; Body weight decrease; Organ weight increase) Microscopic exam.) Slight central fatty degradation in all liters and slight interstitial congestion and edema with slight
parenchymatous degeneration of the tubular epithelium in 8 or 14 kidney sections examined.
Rabbits U F, 3 H)
Hontoya (1 F,, 1 H)
50 ppm SO ppm
59 in 04 days 49 in 70 days
Ho effects except slight liver and kidney weight increases
Both appeared ill, nervous and unkempt) Body weight loss) Blcod chemistry normal) Liver weight increase with slight central fatty dogenaratloni Slight kidney weight increase) Other organs normal
Kata (10 F, 10 M)
Guinea Pigs ( F, 0 M)
Rabbits 11 r, 1 H)
Monkeys (1 F. 1 HI
J5 ppa 25 ppm 35 ppm 23 ppm
131 in 213 days Ho effects 145 in 205 days Ho effects 132 in 214 days Ho effects 15C in 220 days Ho effsets
D0 130656
conftdfnttai
aRowe. V.K.. Spencer, H. Ct, McCollister, D.D., Hollin Ethylene Dibromide Determined on Experimental Animals A.M.A, 6, 158-73 (1952).
TABLE 2
NUMBER OF STOMACH SQUAMOUS CARCINOMAS IN RATS RECEIVING ETHYLENE DIBROMIDE BY ORAL GAVAGE3
)
Comp und Week Species Sex EDB 54 Rat M
BO-200 mg/kg/day
Stomach Squamous Carcinoma
Died Without Tumors
Sur viving
31 19 0
40-100 mg/kq/day
Stomach Squamous
Carcinoma
Died Without Sur Tumor s viving
49 1 0
Controls
Stomach Died Squamous Without Sur Carcinoma Tumors viving
0 11
9
EDB 54 Rat r
14
27
5 24
17 9
00
19
EDB
42 Mouse M
1
20 29
3*
41
0 1 19
EDB 42 Mou6e F
1
20 29
2
1 47
0 0 20
a01son, W.A., Habermann, R. T., Weisburger, E. K., Ward, J. M., Weisburger, J. H., Brief Communication: Induction of Stomach Cancer in Rats and Mice by Halogenated Aliphatic Fumigants, J. Nat 1 Cancer Inst.
o 51 (6), 1993-5, (1973).
oo zo
LS9QZV
TABLE 3
ANALYSIS OF THE ETHYLENE DIBROMIDE SAMPLE USED IN THE 13-WEEK INHALATION STUDY
Analysis la
Ethylene Dibromide Unknown (probably ethylene) Vinyl Bromide Ethyl Bromide Methylene Chloride Bromochloromethane Methylene Bromide and/or l-bromo-2-
chloroethane
2-Chloroethanol Bromoform 2-Bromoethanol 1,1,2-Tribromoethane Bis(2-bromoethyl)ether
99.84 ^0.03
Weight %
Analysis 2b
Analysis 3b
99.58 0.02 0.01 0.29 N.D. N.D.
0.01
0.02 0.02 0.01 0.02 0.02
99.64 N.D. 0.01 0.27 N.D. N.D.
0.01
0.02 0.01 0.01 0.02 0.01
Analysis 4b
99.6 N.D. 0.01 0.25 N.D. N.D.
0.01
0.02 0.02 0.03 0.02 0.03
N.D. = Not detected.
Personal communication from J. C. Warren, Jr., Quality Control Lab., Dow Chemical USA, Magnolia, Arkansas.
^Dow Analytical Lab
DO 130658 CONFTOFNTTAl
-23-
TABLE 4 REPRESENTATIVE TISSUE SPECIMENS OBTAINED AT AUTOPSY FROM ALL RATS
esophagus salivary glands stomach small intestine large intestine pancreas 1ivera kidneys3 urinary bladder prostate accessory sex glands epididymides testes3 ovaries3 oviducts3^
brain
cerebrum cerebellum brain stem
pituitary gland spinal cord
peripheral nerve
trachea3 lungs (bronchi)3
j ^
a
nasal turbinates
sternum
1 |
spleen
thymus
lymph nodes (thoracic, mesenteric)
heart aorta skeletal muscle
1 1i
adrenal glands
thyroid gland
parathyroid gland
adipose tissue
skin any gross lesion or mass uterus3
aThese target tissues were examined by conventional histological methods.
^Tissue was evaluated histologically only to the extent that it was included in routine sections of the adjacent larger organs.
r>n r?n6'^ T4t
TABLE 5 CHAMBER AIR ANALYSIS FOR ETHYLENE DIBROMIDE EXPOSURES
Exposure Concentration (ppm)
0
Analytical Concentration X S.D.
1 week exposure 6 week exposure 13 week exposure
Nominal Concentration X S.D.
1 week exposure 6 week exposure 13 week exposure
3
3.1+0.2 3.00.2 3.00.4
3.510.7 3.310.5 3.210.4
10
9.711.0 10.7+2.2 10.311.7
9.710.5 10.912.3 10.711.7
Coefficient of Variation, %
1 week exposure 6 week exposure 13 week exposure
Daily Temperature, C, cumulative
Minimum, X S.D.
211
Maximum, X S.D.
261
Daily Relative Humidity, % cumulative
n oo zo o iO "Tl o ZH-t TOO' T>
46+5
6.5 6.7 13.3
2312 27+2
4313
10.3 20.6 16.5
2011 2611
4412
40
39.610.5 39.612.2 39.811.8
39.411.9 40.312.3 40.312.2(males) 40.212.4(females)
1.3 5.6 4.5
2311 2811
4313
Days on test
-2 1 A
TABLE 6
MEAN BODY WEIGHT VALUES OF MALE BATS EXPOSED TO ETHYLENE DIBROMIDE FOR ONE WEEK
Control
DOSE LEVEL PPM 3 10
21A.1+8.5 223.6+8.A 232.5+8.1
216.2+ 8.A 22A.9+ 7.9 231.3+15.3
213.5+12.8 222.1+12.6 231.5+12.9
AO
215.7+ 9.3 229.1+10.8 229.1+10.8
No values were significantly different from controls by Dunnett's test, p <0.05.
DO 130601 OONFTDFNTTA
26TABLE 7
MEAN bODY WEIGHT VALUES (GRANS) Or HaLE RATS MAINTAINED On ETHYLENE DlSkbMlUt PCk 13 nEEK
DAYS ON TEST
-2
COniTRL iyo+ e
1 212+ 6
l-CSE LEVEL PPM
3 192+10
10 139+10**
208+10
206+10*
90 lb9+10**
207+11
A 21S+ e 7 222+ 9
219+11 213 + 11
212+10* 2K + 10*
206+11** 212+12**
11 291 + 9 19 299+10
235+13 239+13
231+11** 236+11*
228+11** 232+11**
2D 235+12
232+16
226+15
220+18**
29 253+11
298+19
296+13
237+15**
27 259+ 6 35 253+15 92 269+13 99 3C7+13 55 217+19
251+15* 259+17 282+17 299+1b 309+17
297+12** 251+13 276+13 29b+19 309+15*
238+19** 250+19 272+13** 290+19** 297+19**
63 69 76 S3 90 97 109 111 110 125 131 139 196 152
327 .+ 19 325+15 337+16 399+13 351+19 357+22 367+20 363+19 379+19 339+19 376+19 365+2: 392+21 335+21
319+17 329+16 331+16 335+17 391+17 395+20 353+22 360+22 363+22 363+22 3 70 + 23 375+23 379+25 376+29
315+16 320+16 326+17 333+17 337+17* 392+17 39b+18 355+17 357+16 361H7* 369 + 17 369+17 371+16 372+17
307+13** 311+19* 316+13** 320+19** 326+15** 335+18* 399+16* 355+20 356+20 3 6 0+1 9 * 363+2 0 373+21 373+20 375+19
DO 1.3066? CONFIDENTIAL
-27-
TABLE 7 CCONT.)
MEAN bOUY WEIGHT VALUES (GRAMS) OF MALE RATS MAINTAINED On ETHYLENE DlaRUrilUE FCR 13 w&EK
DAYS ClN TEST
COSTRL
59 399+21
LOSE LEVEL PPM
3 ID
381123
377+16
hG 383+20
66 A01+23
73 H06+21
365 + 22 387+25
380+16 381+16*
38 5+22 366+21
80 A 071.2 3
398+27
386+17
392+25
* STATISTICALLY SIGNIFICANT DEVIATION FROM CONTRI TEST, p <0.05.
DO 100663 CONFIDFNTTAI
-28-
TABLE 8
MEAN bODY WEIGHT VALUES (GRAMS) OF FEMALE RATS hAINTA INEU ON EThYLENE DIBROMlOE FUR 13 WEEK
DAYS UN TEST
-z
CONTRL 129 + 6
1 139+ 6
A 1A1 + 6
7 1A1 + 6
11 152+ 6
1A 15A + 8
20 153+10
2A 161+10
27 159+11
3b lol+12
A 2 172+11
A9 179+12
55 182+11
63 185+11
69 ies+12
76 192+11
83 193+10
90 196+10
97 199+11
10A 197+12
111 193+13
118 189+13
125 192+ 1A
131 191+13 139 190+12
1A6 192+12
152 192+13
ELSE LEVEL PPM
3 127+ 6
10 127+ 6
139+ 6
139+ 7
1A2+ 7
1A2+ 7
1A1+ 8
1A1+ 7
151+ 7
152+ 7
152+ 7
15A 8
151+ 8
153+ 8
159+ 7
161+ 9
157+ 6
161+ 9
161+ 7
162+11
171+ 8
173+11
178+ b
179+10
179+ 7
181+11
185+ 8
188+11
168+ 6
190+11
191+ 9
193+12
192+ 9
195+11
19A+ 5
195+13
195+15
192+1A
195+1A
195+1A
193+13
196+13
18e+12
192+13
197+12
199+12
192+11
196+13
189+12
19A+1A
191+11
196+1A
169+10
19A+16
AO 129+ 5 139+ 6 135+ 7* 1A0+ 6 150+ 6 151+ 7 151+ 8 158+ 6 158+ 7 162+ 6 171+ 8 179+ 7 179+ 7 185+ 8 188+ 6 18tt+ 9 192+ 9 193+10 195+10 190+13 197+13 189+12 192+12 195+13 190+13 192+11 190+13
00 130664 CONFTDFNTTAl
-29table 8 (CONT.)
MEAN bODY WEIGHT VALUES (GRAMS) OF FEMALE RATS MAINTAINED ON ETHYLENE DIBKuMlDb FOR 13 WEEK.
UAYS UN TEST
COMTRL
159 39S+21
ELSE LEVEL PPM
3 361+25
10 377+16
*40
3b3+20
166 901+23
365+22
360+16
365+22
173 906+21
367+25
361+16*
36 6+21
160 907+23
39b2 7
366+17
392+25
* STATISTICALLY SIGNIFICANT DEVIATION FRUM CONTROL USING DENNETT'S TEST, p <0.05.
^0 ]30665 ^ONFTDFNTTA/
-30-
r
TABLE 9
MEAN BODY WEIGHT GAIN VALUES (GRAMS) OF MALE RATS MAINTAINED ON ETHYLENE DIBROMIDE FOR ONE WEEK
Days on test
Control
DOSE LEVEL PPM 3 10
40
-2 0+0 0+0 0+0 0+0
1 9+3 8+2 9+2 114
4
183
19+3
18+3
13+4*
*Statistically significant from control value by Dunnett's test, p <0.05.
HO 130666 OONFTDFNTTAL.
-31 w
TABLE 10
4'J 300f W = 13Hr
VtLJ-3 CHA'IS) Or 'UL: UTS
UHTAnSD 3% EHfLEME 0t3*3-1lD FDfc 13 WEEK
MfS 0\ rE3T -?
1
33 m_ 0+ 3
lit 2
DOSE LE^EL ?31
3 0+ 0
13 31 3
15+ 2
17t 2
VO 0+ o
19+
V 22 + 3
22+ 3
23+ 3
1b+ 3**
7 25i 3 n '+5 + V u V7+ V
27+ V + V+ Vbt ?
25+ 3 V3t '+ 93 + V
23+ 3 39+ V**
VV+ 5**
20 3 9 tl 3
Vl + 1?
'+3 +13
32+1V*
2 ^ 5 5+ 9
57t 0
5 51 3
99+ 9**
27 5 3+ 5
59 +1 C
53+ 5
50tlD*
35 5 2 tl 3
57 + 13
53+ 9
611 S
'2 511 3
9 0 + 12
3 91 3
B5+ 7
+ 9 139+ 5
135tl2
137+ 3
103+ 3
5 5 113+ 9 53 123+13
117+11 127+11
115+ 9 127+13
110t 3* 120+ 7*
59 125+13
132+10
131+13
12V+ B
75 139+11
159+10
139+11
129+ 7**
33 tV5+13
1+3+11
1'+ V11 3
13V+ 9$*
93 153+1V
1+9+12
1V5+11
139 + 10* *
97 1 5 7 tl 7
155+15
153+12
1VS+12
m 157+15 111 l 5 3 +1 V 113 179+13 125 l 3V + 1 +
153+17 159+17 172+17 172+17
153+11 1 55 tl 1 153tl2 171+12
157tl3 I67tlV 170+1V 172+13
131 175115
1 33+.1 3
175+13
177+15
139 135115
1 5V +1 P
133+13
135+15
IV 5 132115 152 12 5H5
13V+20 135+19
131+ 3 153+13
iesti5 1E? 7 + 1V
DO 130667 CONFJDFNTTAI
-32TABLE 10 CCONT.)
HE4N BOOr WEIGHT 3MN V4LJES (3UHS) Or H4L; UTS HhrilNcD 3\ ETHVLENE 0I3*3HI3E F3K 13 WEEK
04YS Os TEST
D3m_
15? I93il5
155 >31+15
173 205+15
13 0 207+17
DOSE LEVEL ?3H
3 10
190+20
133+10
195+17
190+10
157+20
192+10
205+23
197+10
90 195+15 197+17 198+15 205+20
* STUI S TI: At_LY SI GN'ICI D4NT 0EVIUI3N *931 CON T*0L USING DJMNETT'S TEST, p <0.05.
rn? 1306f>B
^NF JDFNT T Al
r = sr -?
1 ! 7 11 u 20 Z'f 11 35 92 99 55 53 59 75 33 3D 37 13V ll1 113 1 >5 1 31 139 l V5 132 1 5^
1 1M 3 jOt WEIGHT 1UN V4LJES (3RMS) OF ==M4 iUHTUMSD 3N.; E HVlEWE D13R3HIOE = DR 13 WE
CO 3= LEVEL ?31
cm? 0; D
ot o
10 0; D
VO 0; 0
10; 2 12; 3
12; 2* lv; v
12; 2 19; 2
10; 2 6*
12; 3
lv; 3
lVt 3
lit v
Z 31 * 25; 9
29; 2 25t 3
25; 3 25; 3
21; 3 22; V*
2 9; 7
23; 5
25; 5
22; 5
32; 5 30; 7
3 2; V 29; 5
33; 5 33; 5
29; 5 29; 5
331 3
33; v
35; 7
33; V
L3; 2
92; 6
*5; 7
V2; 5
50; 3
50; 5
5 2; 7
50; 5
33; 7
52; 5
59; 7
50; 5
5 7; 5
57; 7
50; 3
56; 7
39; 3
50t 7
52; 7
59; 5
53; 7
52; 7
55; 9
59; 7
55; 5
5v; 7
55; 3
63; 3
5 7; 5
57; 6
63 9
6V; 9
71; 9
71; 7
55; 3
67; 3
7D; 3
72; 7
59; 3
69;11
55; 9
70; 5
59; 9
69;11
51 ;1 D
53; f.
55; 7
61;1 0
55;11
79; f
73; 3
6V;1 0
5 '*; 1 3
53; v
59; 7
67;1 2
52;1D
35; <*
57; 3
62;1 2
i-7;l D
53; <*
70; 3
6v;L 1
5; 11
5 6; 3
55 ;l 0
62;12
35;1 D
72; v
73;1 0
6&;l 1
-33RATS
DO 130669 OONFTDFNTIAL
TABLE 11 CCONTO
-34-
1EAN 3jDr W = IS-tT GUN /4LJES (GUNS) OF =zlA-E UTS
HimiNED ON' EMf-ENE
D= = 3R 13 4 = = <
13? b? + 13
COS: LE /EL P=>-1
72 + A
73 + 1 3
66 + 11
lib bit 9173 6 7 + 13
b9t 711 L
73+ ? 73 + 11
6** +1 2 67 + 12
13? 6 7 + 1 1
72 5
73 + 11
6 7+12
* 3TMISTI :a_lv sig ni=[:ant 3E/MTI D s; = 0*1 CONTROL USING OJNNEfT'S TEST, p <0.05.
^() 1306 70 ^onftofnttai
J ::
TABLE II MEAN (1SD) HEMATOLOGY VALUES FOR RATS EXPOSED TO ETHYLENE DIBROMIDE BY INHALATION
Differential Count X
Exposure
Length of
1ICT RBC
Kgb
wuc Neut
level
Sex Exposure (weeks) X x lO*')TM1 gm/lOOoc x 10 '/mm1 Seg B/J Lymph Mono Eoa
0
Mile
6
50.6*4.1 8.1310.49 16.510.6
16.411.7
23 1/0
69
61
3
Mile
6
40.4*1.9 8.1610.29 16.310.5
14.211.1 *
24 1/0
69
51
10
Mute
6
41.9*0.7 8.2610.24 16.3*0.5
14.310.8 *
23 1/0
69
52
40
Male
6
47.4tl.6 8.2610.14 16.2*0.2
16.711.7
29 1/0
63
61
0
Hale
13
47.9tl.l 8.5110.33 16.210.6
15.111.8
26 0/0
68
51
3
Rile
13
S1.3H.7* 8.4410.17 16.510.6
15.812.3
20 1/0
73
51
10
Male
11
49.6*1.4 8.3510.41 16.2*0.6
15.412.9
26 1/0
68
50
40
Hale
13
49.7H.O 8.6710.23 16.1*0.3
12.610.6
17 1/0
77
50
0
Female
13
49.6*1.9 8.0710.26 16.610.4
12.511.3
16 1/0
76
6l
]
Female
13
4B.610.9 7.8310.17 16.210.4
13.212.7
20 1/0
73
51
10
Female
13
48.110.9 7.87*0.44 16.1*0.5
11.811.1
24 1/0
69
51
40
Female
13
47.4*1.6* 7.74*0.44 15.710.8*
12.011.3
19 1/0
73
61
`Significantly different from control by Dunnett'a test p <0.05.
Baao
0 0 0 0
0 0 0 0
0 0 0 0
n
25^ Oow'
x>
s
TABLE 13 KEAN (1S.D.) URINALYSIS VALUES FOR HALE RATS EXPOSED TO ETHYLENE DIBROMIDE BY INHALATION
Exposure Level (|>pin)
0 3 10 40
0
3 10 40
0 3
10
40
Length of Exposure (weeks)
6 6 6 6
13
13 13 13 13c 13c
13c
13c
Sample Size
7
Specific Crnvlty
H
1.05610.017d 711
Glucose . _b
7 1.05310.005 711
7 1.04210.021 711
7 1.04710.017 711
6 1.06410.002 611
7 1.06710.002 6l0 7 1.05910.007 711 __ 7 1.05710.007 610 _
7
1.06510.006 710.5
-
7 1.06410.007 711 -
7
1.06410.007 7.511
-
7 1.06010.005 7il _
Protein*
l+{2> 2+(5> l+(4) 2+(3> l+(3) 2+(4) l+{3) 7+741 .
l+{2> 2+(2) 3+(2) 2+(6) 3+(l> 2+(5) 3+(2) 2+(7)
3+(3) 4+(4) 2+(l) 3+(3) 4+(3) 2+(l) 3+{5) 4+{l) 2+<2) 3+(3) 4+(2)
Ketones a l+(7) l+(7) l+{6) l+(7)
l+(6) l+(7) l+(6) l+(7)
Bilirubin
.
_
*Nunber la parenthesis la the number of samples la vhlch the Indicated observation vas aade. ^Indicates a negative finding. cAnluela were exposed to EDB for 13 weeks, allowed'an 88-89 day recovery period and then necropeled.
X t S.D.
~
No values were significantly different fron control by Dunnett's test, p<0.05.
Blood* tr(l) tr(l)
_
'Jroblllnogi 1(7) 1(7) 1(7) 1(7)
1(6)
1(7) 1(7} 1(7) K7) 1(7)
1(7)
K7)
CaO cn
DO 1 3 0 6 7 ?
OONFTDFNTTAl
\
i
TABLE 14 HEAN (S.D.) URINALYSIS VALUES FOR FEMALE RATS EXPOSED TO ETHYLENE DIBROMIDE BY INHALATION
Exposure Level (ppm)
0 3 10 40
0 3 10 40
Length of Exposure (weeks)
13 13 13 13
13c 13C
13c 13c
Sample Sire
Specific Gravity
!i
7 1.06610.O04d 6l0
Glucose _b
7 1.06U0.005 7lJ. 6 1.06310.006 610
--
7 1.04310.010* 710
7 1.06510.006 710.5 7 1.06410.007 71
7 1.06810.008 610.5 7 1.06710.005 6.510.5
Protein8
l+(4) 2+(2) 3+(l) l+(4) 2+(3) tr(l) li2 2+(4) tr(5) 11(2)
3+(3) 4+(4) 2+(l) 3+(3) 4+(3) l+(4) 2+(2) 3+(l) l+(4) 2+(3)
Ketones*
Bilirubin
--
"
l+(6) l+(7)
tr(2) l+(5) tr(3) l+(4)
"
Blood8 tr(l) "
"
Urobilinogen8 1(7) 1(7) 1(7)
Kl)
K7) K7) 1(7) 1(7)
8Number in parenthesis is the Rusher of samples in which the indicated observation was made. ^Indicates a negative finding. cAnisela were exposed to EDB for 13 weeks allowed an 86-89 dap recovery period.and then nocropaled.
d
1 SeD.
*Values were significantly different from control by Dunnett'e teat, p <0*05-
CNJJ
i
DO 1 3 0 6 7 3
CONFTDFNT TAl
Exposure level
TABLE 15 MEAN (S.D.) CLINICAL CHEMISTRY VALUES OF MALE RATS EXPOSED TO ETHYLENE DIBROMIDE
Length of Exposure (weeks)
BUN mg/100ml
SGPT mU/ml
SGOT' mU/ml
AP mU/ml
Glucose mg/lOOml
T. Bilirubin mg/lOOml
Serum Bromide ppm
01 31 10 1 40 1
06 36 10 6 40 6
0 13 3 13 10 13 40 13
141 141 141 14+2
14+1 142 131 14+2
14+1 13+2 131 131
192 183 18+3 164*
215 203 19+5 214
19+3 214 203 201
8829 8225 893 81+34
10118 11831 10834 10630
7713 8725 71+7 838
16711 170+13 174+13 17010
102+18 98+8 94 8
1015
683 698 673 735
156+8 17015 1539 154+15
13519 128111 12919 132112
14219 135110 137117 144125
0.210.0 0.2+0.1 0.210.1 0.210.1
0.310.1 0.210.0 0.210.1 0.310.1
O.liO.l 0.210.1* 0.210.0* O.liO.O
N.D. N.D. N.D. N.D.
10.310.1 4212*
11413* 379112*
N.D. N.D. N.D. N.D.
*Significantly different from control values by Dunnett's test, p <0.05. N.D No data
t
00
TABLE 16 MEAN (iS.D.) ORGAN WEIGHTS AND ORGAN TO BODY WEIGHT RATIOS
FOR HALE RATS EXPOSED TO ETHYLENE DIBROMIDE BY INHALATION
2SS S gg S22S
tpoqure Length if
vi*l
Exposure (whs)
Body Weight
Liver S r/IOOr
Kidney 1 b/IOOr
Iraln 8 g/l00|
Heart
8 _ s/ioo*
Thysui B t/lOOa
Teat** l^lOOl
0
1
106.St 6.6
6.0910.18
1.9510.05 1.6910.07
0.8110.01 1.7610.01
0.8510.03 0.6810.04
0.3110.01 0.2910.03
0.1410.01 2.7410.11
1.3310.04
1
1
106.7114.6
6.0710.51
1.9610.11 1.6410.11
o.eoio.oi 1.7510.07
0.8610.06 0.6810.05
0.1310.01 0.1810.04
0.1410.02 1.6910.20
1.3110.04
0
1
106.9*11.B
6.1410.46
1.9710.13 1.7110.11
0.8310.03 1.7710.05
0.8610.03 0.6710.04
0.3110.01 0.3010.02
0.1410.01 2.6910.15
1.3010.04
.1*
1
204.Bt 9.3
6.1410.44
3.0410.10 1.7210a11
0.8410.03 1.7710.04
0.8610.04 0.6510.04
0.3110.01 0.1810.03
0.1410.01 2.7310.11
1.3310.05
0
6
161.11 7.5
7.1010.11
1.7110.10 1.9010.06
0.7310.01 1.8610.03
0.7110.01 0.7910.03
0.3010.01 0.3010.03
0.1110.01 2.8410.11
1.0910.06
3
6
253.1*12.9
6.8510.46
1.7110.10 1.9310.11
0.7610.01* 1.85*0.05
0*73*0.03 0.7910.05
0.3110.01 0.3010.05
0.1210.02 2.9010.12
1.1510.06
10
6
252.9H0.1
7.0010.17
1.7710.06 1.9510.10
0.7710.03* 1.8710.03
0.7410.03* 0.7810.05
0.3110.01 0.3310.06
0.1310.02 2.8810.11
1.1410.04
*0
6
146.Sill.1* 7.1610.51
3.0110.11* 1.0610.11* 0.8410.03* 1.8410.04
0.7510.03* 0.7610.01
0.3110.01 0.1910.04
0.1210.01 2.7710.25
1.1310.07
0 11 1 11 10 11
>0 n
111.1114.9 110.6114.1 111.0116.1 199.0110.1*
7.9910.40 8.1110.61 8.3010.47 8.1010.48
1.4710.07 1.5310.10 1.5910.05 1.7410.09*
1.3310.08 1.3710.15 1.3810.10 1.4110.11
0.72*0.03 0.7410.01 0.7410.01 0.8010.04*
1.9610.01 1.9510.04 1.9410.06 1.9110.03*
0.6110.03 0.6110.01 0.6010.03 0.6410.03*
0.9110.04 0.9110.05 0.9310.05 0.8610.03
0.1810.01 0.1810.01 0.2910.01 0.2910.01
0.2410.03 0.1710.01 0.1810.02 0.2510.05
0.0710.01 3.0510.13 0.0810.01 3.1210.15 0.0910.01* 3.0810.17 0.0810.02 2.8410.17*
0.9510.04 0.9710.04 0.9610.04 0.9510.07
0
n*
390.ll11.6 10.1910.76
1.6410.10 1.7710.19
0.7110.03 1.9610.06
0.5010.03 0.9810.05
0.2510.01 0.1910.02
0.0510.01 3.2010.14
0.8210.04
3
171.6110.7
9.4110.64
1.5310.08 1.6110.16 0.7110.01 1.9510.06
0.5310.03 0.9510.06 0.2610.01 0.1910.03
O.OSlO.Ol 3.1910.14
0.8610.03*
to
iij
166.4116.9* 9.4910.45
1.5910.09 1.6010.13
0.7110.03 1.9610.04
0.5410.03* 0.9810.03
0.2710.01 0.1810.03
0.0510.01 3.1310.11
0.8810.03*
0
n`
170.8119.1 10.1810.69
1.7510.13* 1.7410.10
0.7410.03 1.9610.04
0.5310.01 0.9710.05
0.2610.01 0.1710.02
0.0510.00 3.1810.09
0.8610.03*
j RailI leantIf different Iron control by Winnett'a tail, p <O.OS.
An inula were expoaed to EDB for 11 veelta, alloved an 08-09 day recovery period and than nacropalad.
TABLE 17 MEAN (tS.D.) ORCAN WEIGHTS ADD ORGAN TO BODY WEIGHT RATIOS
FOR FEMALE RATS EXPOSED TO ETHYLENE DIBROMIDE BY INHALATION
Exposure Length of
Level
Exposure (whs)
0 13
] 13
10 13
40 13
Body Weight
164.1t9.3 181.117.6 181.019.1
176.317.9
Liver 8 g/lOOg
4.5710.17
2.4910.08
Kidney 8 g/lOOg
1.4410.04 0.7810.04
4.6010.15
2.5410.08 1.4410.07
0.8010.04
4.7910.34
2.6510.14* 1.4810.06
0.8210.02
4.9710.22* 2.8210.10* 1.5010.08 0.85*0.05
Brain B g/lOOg
1.8210.02 0.9910.05
1.82*0.02 1.0110.02
1.8210.03
1.0110.05
1.82*0.06 1.0310.05
Heart B g/lOOg
0.6010.02
0.3310.01
0.6010.04
0.3310.02
0.6010.04 0.3310.02
0.5910.03 0.3410.02
Thymus 8 g/lOOg
0.2110.03
0.1210.02
0.2210.03
0.1210.02
0.2410.05 0.2310.03
0.1310.02 0.1310.02
0
a 13
186.2114.4
4.7510.71
2.5410.22 1.4610.12
0.7810.04 1.7910.05
0.9610.07 0.5810.04
0.3110.02 0.1410.01
0.0710.01
]
a n
181.0110.3
4.4910.38
2.4810.13 1.4710.14
0.8110.04 1.7810.05
0.9810.05 0.6H0.06
0.3310.02 0.1410.02
0.0810.01
10
a 13
185.4115.9
4.7510.38
2.5710.10 1.54*0.12
O.B310.06 1.7710.05
0.9610.06 0.6210.06
0.33*0.02 0.1410.02
0.0810.02
40
a 13
181.8112.2
4.6210.35
2.5410.08 1.4910.12
0.8210.03 1.7810.03
0.9810.06 0.6110.04
0.3310.02 0.1310.02
0.0710.01
Significantly different fro* control by Dunnett's teat, p < 0.05.
a Animals were exposed to EDB for 13 weeks, allowed an 88-89 Day recovery period and then necropsled
I 01
n o2 zO> T--|I --* o u>
o
Z O'
--t -si
3-H> O'
>
TABLE 18
GROSS PATHOLOGIC OBSERVATIONS ON MALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (6 DAYS ON STUDY)
Exposure Concentration (ppm) _0310
Number of rats examined
__________ 10 _______ 1010
No visible lesions
224
GENERAL
Accessory spleen present Necrosis and atrophy of the tip
of the tail
100 100
SALIVARY GLANDS Edema
100
EYES Corneal cloudiness
4 24
LUNGS
Single circumscribed red focus Few circumscribed red foci
1 42 4 10
LIVER Diaphragmatic hernia
00 1
URINARY BLADDER Organized plug within lumen
110
Data listed as number of rats with the listed observation.
i 40 10 5
0 0
0
1
0 2
0
0
OO 130677 CONF TDFNT T AL
-42-
TABLE 19
HISTOPATHOLOGIC OBSERVATIONS ON MALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (6 DAYS ON STUDY)
Exposure Concentration (ppm) Number of Rats Examined
NASAL TURBINATES (Number of tissues examined microscopically)
Hyperplasia of respiratory epithelium - isolated, very slight to slight - focal, very slight to slight - scsttared, very slight to slight - multifocal, very alight to slight - diffuse, very slight to slight
Individual epithelial cell necrosis, respiratory epithelium - focal, very slight
Epithelial Inflammation, respiratory epithelium - focal, slight - multifocal, slight
Submucosal inflamation, respiratory epithelium - focal, slight - scattered, slight - multifocal, slight
Submucosal inflammation, olfactory epithelium - focal, slight
Inflammatory cells in lumen - focal, very slight
0 10
10
0 0 0 0 0
0
5 0
z 3 5
1
4
TRACHEA (Number of tissues examined mlcroscopicallv)
Submucosal aggregates of mononuclear cells - focal, alight - multifocal, slight - diffuse, moderate
Epithelial hyperplasia - diffuse, slight
Inflammatory cella in lumen
- focal, slight
10
0 0 10
10
3
LUNGS/BRONCHI (Number of tissues examined microscopically)
Peribronchiolar aggregates of mononuclear cells - focal, slight
Subpleural aggregates of mononuclear cells - focal, slight - multifocal, alight
Aggregates of alveolar macrophages
- focal, slight
Interstitial Inflammation - focal, slight
Perivascular aggregate of mononuclear cells
- focal, slight
Inflammation and fibrosis of pleura
- focal, slight
10
10 8 1 2 1 1 2
LIVER (Number of tissues examined microscopically)
Aggregates of mononuclear cells
- focal, slight
Periportal aggregates of mononuclear cells
- focal, slight
Single focus of hepatocellular necrosis and accompanying Inflammation
- slight
Single area of biliary hyperplasia, fibrosis, and inflammation
- moderate
Single focus of hepatocellular alteration
- slight
Biliary hyperplasia
- multifocal, slight
10
6 0 0 0 0 0
3 10
10
0 0 0 0 0
0.
0 0
1 0 0
0
0
10
2 0 0
3
0
10
10
4 0
1
0
0
0
10
3
1
2
0
0
1
10 10 10
1 4 4 0 0
1 0 1 0 0 1
0 0
10
0 0 2
6 0
10
9 8 0 2 0 0 0
10
5 1 0 1 1 0
40 10 10
0 0 3 3 4
5 0 0
0 0 0
0
0
10
3 1 0
8
0
10
10
6 0
1
1
0
0
10
8
2
2
0
0
0
f
DO 130678 OONFTDFNTTAl
TABLE 19 (cont.)
HISTOPATHOLOGIC OBSERVATIONS ON MALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (6 DAYS ON STUDY)
Exposure Concentration (ppm) Number of Rets Examined______
KIDNEYS (Number of tissues examined microscopically) Atrophy of renal tubules
- focal, slight Aggregate of mononuclear cells
- focal, slight
TESTES (Number of tissues examined microscopically) Unilateral decreased spermatogenesis
- focal, very slight - focal, moderate
SPLEEN (Number of tissues examinedmicroscopically) Accessory spleen
J)3 10 40 10 10 10 10 10 10 10 10
A 100 I010
10 10 10 10
0 100 0 010
1 000 1000
THYROID (Number of tissues examined microscopically)
Hemorrhage - focal, slight
Aggregates of mononuclear cells and debris within follicles - focal, slight
4335
0 100 0 100
Additional tissues examined microscopically and showing no visible lesions
ESOPHAGUS AORTA LARGE MEDIASTINAL ARTERY THORACIC LYMPH NODE PARATHYROID PANCREAS THYMUS PHARYNX
10 10 10 10 5 4 10
5 787
4 233
2 112 1001 0101 0 142
130679 CONF TDFNT TA(
-44-
TABLE 20 GROSS PATHOLOGIC OBSERVATIONS ON MALE RATS EXPOSED TO
VAPORS OF ETHYLENE DIBROMIDE (40 DAYS ON STUDY)
r
Exposure Concentration (ppm) _03 1040 Number of rats examined 10101010
No visible lesions
66
6
EYES
Corneal cloudiness Decreased in size with cataract
formation - unilateral (possibly congenital) Focal intraocular opacity
22
00 0 .0
3
0 1
LUNGS
Single circumscribed red focus Few circumscribed red foci
10 11
2 0
LIVER Diffuse paleness
11
0
URINARY BLADDER Organized plug within lumen
01
0
STOMACH
Hemolyzed blood clot within lumen Pinpoint focus on glandular mucosa
0 0
1 1
0 0
MESENTERIC TISSUE Tag of strangulated omental fat
10
0
Data listed as number of rats with the listed observation.
4
2 2 0
3 1
0
0
0 0
0
DO 1306S0 CONFTDFNTTAt
45
TABLE 21
1
HISTOPATHOLOGIC OBSERVATIONS ON MALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (40 DAYS ON STUDY)
Exposure Concentration (ppa) Number of Rats Examined
NASAL TURBINATES (Number of tissues examined microscopically)
Hyperplasia of respiratory epithelium - isolated, very slight to slight - focal, very slight to slight - scattered, very slight to slight - multifocal, very slight to slight - diffuse, very slight to alight
Individual epithelial cell necrosis, respiratory epithelium - focal, very slight - multifocal, slight
Epithelial inflannatlon, respiratory epithelium - multifocal, slight
Submucosal lnflamsatlon, respiratory epithelium - focal, slight - scattered, slight - multifocal, slight
Submucosal lnflamsatlon, olfactory epithelium - focal, moderate
Submucosal inflammation of olfactory epithelium - multifocal, slight
TRACHEA (Number of tissues examined microscopically)
Submucosal aggregates of mononuclear cells - focal, slight - multifocal, slight
Epithelial hyperplasia - diffuse, slight
LUNGS/BRONCHI (Number of tissues examined microscopically)
Peribronchiolar aggregates of mononuclear cells - focal, slight
Subpleural aggregates of mononuclear cells - focal, slight
Aggregates of alveolar macrophages - focal, slight
Interstitial inflammation - focal, slight
Inflammation and fibrosis of pleura - focal, slight
LIVER (Number of tissues examined microscopically)
Aggregates of mononuclear cells - focal, slight - multifocal, slight
Periportal aggregates of mononuclear cells - focal, slight
Increased cytoplasmic vacuolization - diffuse, slight - diffuse, moderate
Capsular fibrosis focal, slight
Aggregate of mast cells - focal, slight
KIDNEYS (Number of tissues examined microscopically)
Atrophy of renal tubulea - focal, slight
Aggregates of mononuclear cells - focal, slight
Dilated renal tubule with eosinophilic cast formation - focal, slight
Interstitial inflammation - focal, slight
0 3 10 40 10 10 10 10
10 10 10 10
0030 0020 00 10 0032 0018
0005 0005
0001
0201 0001 0001 1000
0001
10 9 10 10
3401 0 0 01
0001
10 10 10 10
10 10 10 10
77 73
1021
1101
0001
10 10 10 10
4244 6865
0 1 1 0
1000 0 1 00
1 0 00
0001
10 10 10 10
3 2 18
13 00 0 100
00 01
DO 130OR OONF TDFNT
-46-
TABLE 21 (cont.)
HISTOPATHOLOGIC OBSERVATIONS ON KALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (40 DAYS ON STUDY)
Exposure Concentration (ppm) Number of Rats Examined______ _________________________ _______ _____________
0 10
TESTES (Number oftissues examinedmicroscopically)
Hyperplasia of spermatogcnlc cells - focal, slight
Unilateral decreased spermatogenesis - multifocal, pronounced - focal, moderate - diffuse, pronounced
Sperm granuloma Mineralisation
- focal, slight
10
1
1 1 0 0
0
THYROID (Number oftissues examined microscopically)
Aggregates of mononuclear cells and debris within follicles - focal, slight
6 0
LACRIMAL GLAND (Number of tissues examined microscopically)
Interstitial lnflasmatlon - focal, slight - diffuse, moderate
2
1 1
Additional tissues examined microscopically and showing no visible lesions
ESOPHAGUS
10
AORTA
4
LARGE MEDIASTINAL ARTERY
7
THORACIC LYMPH NODE
5
THYROID
6
PARATHYROID
3
THYMUS
2
PHARYNX
0
PANCREAS STOMACH
0
0
3 10 1010 10 10
00 00 00 00 00 00
77
10 00 00 00
9 10
22 64 43 77 27 30 00 10
17 0
40 10 10
0 0 1 1 1 1
7
0
2
0
2
10
2 5 5 7 5 2 2 0
0
D0 I306B? CONF1DFNTTAI
-47-
TABLE 22
GROSS OBSERVATIONS ON MALE AND FEMALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE (95-96 DAYS ON STUDY)
Sex Dose in ppm Number of rats In group
No visible lesion*
General
Inflammatory reaction in ear at site of identification tag
Alopecia reaction in ear at site of identification tag
Alopecia on bridge of nose Decreased size of carcass Strangulated tag of epldidymal fat
Liver Pale focus Scattered pale foci Diaphragmatic herniation Diffuse paleness -
very slight to slight
Kidneys Fibrous adhesions and contraction of
central portion of one kidney
Lungs Feu circumscribed foci
Eyes Corneal cloudiness - unilateral Corneal cloudiness - bilateral
Stomach
Focal gastric hemorrhage
Urinary Bladder Organized plug in lumen
Males
03
10
10 10
10
23 4
40
10
2
2 3 12
0001 0000
0005
0001
01 00 0000 01 00 0000
0000
7232
113 23 2
5 0
10
10
00
10
Data listed as number of rats vith the listed observation.
Females
_0
3 10
40
10 10 10 10
7 764
1111 0 00 0 001 0 000 0 0 00 0
0 00 0 000 1 002 0
000 5
0010
000 0
2 20 2 0000
0000 0000
on 130983 CONFTDFNTTAl
TABLE 23
HISTOPATHOLOGIC OBSERVATIONS ON MALE AND FEMALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE VIA INHALATION (95-96 DAYS ON STUDY)
Sex __________________________________________________________ Male*_______________
Dose in ppm
0 3 10 40
Number of rats examined
10 10 10 10
Nasal Turbinates (Number of tissues examined microscopically)
10 10 10 10
Nonkcratinizing squamous metaplasia and
hyperplasia of tha respiratory epithelium
- focal, very slight to slight
0 0 00
- diffuse, very slight to slight
0 0 0 10
Hyperplasia of the respiratory epithelium
- isolated, very slight to slight
00 30
- focal, very slight to slight
00 20
- scattered, very slight to slight 0 0 2 0
- multifocal, very slight to slight
0
0
2
0
Individual epithelial cell necrosis of the
respiratory epithelium
- focal, very slight
0 0 0 10
Epithelial inflammation of the respiratory
epithelium
- focal, very slight
2 3 01
Submucosal inflammation of the respiratory
epithelium
- focal, alight
5 6 62
- scattered, slight
10 00
- multifocal, slight
1 2 30
Submucosal inflammation of the olfactory
epithelium
- focal, slight
00 13
Trachea (Number of tissues examined microscopically)
10 10 10 10
Submucosal aggregates of mononuclear cells
- focal, slight
3 5 32
Lungs/Bronchl (Number of tissues examined
microscopically)
10 10 10 10
Peribronchiolar aggregates of mononuclear
cells
- focal, slight
10 10 10
Subpleural aggregates of mononuclear cells
- focal, slight
025
Aggregates of alveolar macrophages
- focal, slight
00 1
Interstitial inflammation
- focal, slight
001
Hemorrhage
- focal, slight
00 1
Perivascular aggregates of mononuclear cells
- focal, slight
000
Granuloma
- focal, very slight
100
Thickening of pleura
- focal, slight
001
9 1 1 1 0 0 0 0
Liver (Number of tissues examined microscopically)
10 10 10 10
Aggregates of mononuclear cells
- focal, slight
10 9 6 8
Aggregates of mononuclear cells
- multifocal, slight
01 10
Periportal aggregates of mononuclear cells
- focal slight
00 2 1
Data listed as number of rats with the listed observation.
_____________ Females 0 3 10
10 10 10
10 10 10
000 000 00 1 004 001 003
001
020
54 5 213 121
000
10 10 10
67 2
10 10 10
10 10 12 02 00 00 20 00 00
9 3 1 0 0 0 0 0
10 10 10
6B6 000 202
r
40 10 10
1 9 0 0 0 0
9
0
3 0 0
0
10 0
10
9 4 0 0 0 0 0 0
10 4 3 0
130684 OONFIDFNTrAl
-49-
*
TABLE 23 (cont.)
HISTOPATHOLOGIC OBSERVATIONS ON MALE AND FEMALE RATS EXPOSED TO VAPORS OF ETHYLENE DIBROMIDE VIA INHALATION (95-96 DAYS ON STUDY)
Sex __________________________________________________
Dose in ppm
0
Number of rats examined
10
Males_______________
3 10 40 10 10 10
_____________ Females
0 3 10 10 io 10
Liver (Cont'd)
Single focus of hepatocellular necrosis
and accompaning inflammation
- alight
0102
Subcapsular microgranuloma
- focal, slight
0000
Hepatocellular cytoplasmic vacuolatlon,
suggestive of fatty change
- diffuse, slight
00 0 0
LIVER - Oil Red 0 Scain
(Number of tissues examined)
Negative
v
1+ 2+
5+
00 00 0000 0000 0000 0000
2l0
0i0
000
900 700 10 0 100 000
Kidneys (Number of tissues examined microscopically)
10 10 10 10
Atrophy of renal tubules
- focal, slight
8899
Aggregates of mononuclear cells
- focal, slight
2122
Interstitial inflammation
- focal, slight
20 00
Dilated renal tubules with eosinophilic
cast formation
- focal, slight
0001
Mineralized debris
- focal, slight
00 0 0
Area of tubular atrophy, interstitial fibro
sis and Inflemma don, pigment accumulation't focal inflamnatory cells in collecting
ducts and hyperplasia of renal pelvis
epithelium
0000
10 10 10 211 201 010 000 00 2
00 1
Lacrimal Gland (Number of tissues examined microscopically)
Interstitial inflammation - focal, slight
2000 1000
000 000
Uterus (Number of tissues examined microscopically)
Dilatation of lumen
--
-
----
Additional tissues examined microscoplcallv and shoving no visible lesions
Testes Ovary(ies) Oviducts Esophagus Aorta Large Mediastinal Artery(les)
Thyroid Parathyroid Thoracic Lymph Node Thymus Hard Palate Stomach Urinary Bladder
10 10 10 10 ----
-* --
9 10 10 10 44 46 5641 3125 3004 6 7 76
1010 2000 1000 1000
10 10 10
333
10 10 10 10 10 10 10 10 10
234 313 10 2 10 2 654 10 i 000 000 223
Data listed as number of rats with the listed observation. - - Not applicable.
40 10
2 0
2
10 5 3 1 1
10
2 1 0
0 0
,0
0
0
10 4
10 10 10
4 4 2 1 4 0 0 0 3
00 13068s CONF TDFNJT TAl
-50
TABLE 24
GROSS PATHOLOGIC OBSERVATIONS ON HALE AND FEMALE RATS EXPOSED BY INHALATION TO VAPORS OF ETHYLENE DIBROMIDE (EDB) ( 94-95 DAYS ON STUDY) AND HELD FOR A RECOVERY PERIOD OF 88-69 DAYS
r
Sex Dose in ppm Number of rats dying spontaneously Number of rats In group
No visible lesions
~tr~
0
15
4
Males 3 10 00 10 10
53
General
Inflammatory reaction at site of ear tag Tag of strangulated omental fat Slight alopecia of the facial region Perineal soiling Soiling around external uares and oral cavity Very slight postmortem autolysis
111 020 000 000 000 000
Eyes
Focal corneal cloudiness - unilateral Focal lenticular cloudiness - unilateral Slight enlargement - unilateral
3 13 010
0 00
Liver
Pale yellow area
000
Pale areas
000
Nodular protrusion of liver into herniated diaphragm 0 0 0
Herniation of diaphragm involving the liver
sometimes producing a pale area
000
Congested
000
Slight pale accentuation of the lobular pattern
000
Kidneys Conges ted
000
Lungs
Few circumscribed foci Dark, congested and edematous
231 000
Pituitary Increased size
000
Thoracic Cavity Hydrothorax
000
Adrenal Dark focus
000
Uterus
Small structure free within lumen Distended with fluid containing few suspended
particles Inflammatory material in horns
000
000 000
Ovary
Periovarian cyst Increased size with accumulation of inflammatory
material
000 00 0
Data listed as number of rats with the lisced observation. Observation on rat dying during study.
40 0
10 4
3
0 0 0 0 0
2 0 0
1 0 0 0 0 1
0
2
0
0
0
0
0 0 0
0 0
Females 0 3 10 40 01 10 10 10 10 10 4757
10 1 0 0000 1000 0 0 1* 0 0 0 1* 0 0 0 1* 0
2 1 10 00 00 0 1 00
0000 1000 0 1* 0 1 21 00 0 0 1* 0 0000
0 0 1* 0
2001 0 0 1* 0
0 0 1* 0
0 0 1* 0
0 0 1* 0
00 1 0 0010 00 0 1
1010
0001
M/
TABLE 25
HISTOPATHOLOCIC OBSERVATIONS ON HALE AND FEMALE RATS EXPOSED BY INHALATION TO VAPORS OF ETHYLENE DIBROMIDE (EDB) (94-95 DAYS ON STUDY) AND HELD FOR A RECOVERY PERIOD OF 88-89 DAYS
Sex
Do** (PP"> Number of feta dying spontaneously Number of rate examined
NASAL TURBINATES (number of tissues cxemlned)
Epithelial hyperplasia of respiratory epithelium
- single focus
Epithelial Inflammation of respiratory epithelium
- focal, alight
Submucosal Inflasmatlon, respiratory epithelium
- focal, alight
Submucosal Inflammation, olfactory epithelium
- focal, alight
Inflammatory cells In lumen - focal, alight
Focal flattening of dilated respiratory
epithelium
- isolated, very alight
LUNGS/BRONCHI (number of tissues examined)
Peribronchiolar aggregates of mononuclear cells
- focal, slight
Peribronchiolar aggregates of mononuclear cells
- multifocal, slight
Subpleural aggregates of mononuclear cells
- focal, slight
Subpleural aggregates of mononuclear cells
- multifocal, slight
Aggregates of alveolar macrophages
- focal, slight
Interstitial inflammation - focal, very slight
Interstitial inflammation - focal, slight
Hemorrhage
- focal, slight
Perivascular aggregates of mononuclear cells
- focal, alight
Inflammation and fibrosis of pleura
focal, slight
Acute pulmonary edema and congestion with multiple
bacterial colonies
Alveolar hyperplasia and interstitial Inflammation
- multifocal, slight
Aggregate of mononuclear cells
- focal, slight
LIVER (number of tissues examined)
Aggregates `of mononuclear cells - focal, slight
Aggregates of mononuclear cells - multifocal, slight
Periportal aggregates of mononuclear cells - focal, slight
Single focus of hepatocellular necrosis and accompanying inflasnation - slight
Subcapsular microgranuloma - focal, slight Cytoplasmic vacuolization - focal, slight
0 0 10
10
0
0
0
0 0
3 10
7
3
6
0
0 0 1 0
1
0
0
0
0 10
7
3 5
2 2 3
Males___________ 3 10 40 00 0 10 10 10
10 10 10
000
001
00 1
000 001
00 3
10 10 10
8 8 10
000
343
000
110 000 020 010
000
010
000
000
000
10 10 10
678
12 1
022
010 100 344
Data listed as the number of rats with the listed observation. ^Observation noted only in rat dying during study-
__________Females 0 3 10 01 1
10 10 10
10 10
40 0
10
10
0 0 1 1
000 0
616 3
100 0 0000
000 0
10 10 10 10
9 10 10 10
1000
1
3 23 3
0 1** 0 0
000 0 000 1 000 0 00 0 0
0100
0000
0 0 1* 0
1000
001 0
10 10 10 10
335 3
300 1
235 5
000 0 000 0 0000
00 1^0687 CONFTDFNTT
52
TABLE 25 (cont.)
HISTOPATHOLOGIC OBSERVATIONS ON MALE AND FEMALE RATS EXPOSED BY INHALATION TO VAPORS OF ETHYLENE DIBROMIDE (EDB) v w".'5 DAYS ON STUDY) AND HELD for A RECOVERY PERIOD OF 88-89 DAYS
Sex Dose (ppm)______________________________ Mnitiher of rets dying spontaneously Number of rets examined______________
0 ~5 TB
LIVER (coat'd)
Cytoplasmic vacuolization - multifocal, slight
Biliary hyperplasia
- focal, slight
Biliary hyperplasia
- multifocal, slight
Retention cyst
Periportal fibrosis
- focal, slight
Bacterial colonies present in RE cells
Focal hepatic necrosis
- very slight
Capsular inflammation and bacterial colonies
- focal, alight
Capsular inflamaation and fibrosis
- moderate
4 5 1 1 0 0 0
0
0
KIDNEYS (number of tissues examined)
Atrophy of renal tubules
- focal, slight
Atrophy of renal tubules
- multifocal, slight
Aggregates of mononuclear cells
- focal, slight
Interstitial inflammation - focal, slight
Dilated renal tubules with eosinophilic cast
formation
- focal, slight
Mineralized debris
- focal, slight
Dilated renal cubules
- focal, slight
Bacterial colonies in renal tubules
10
6 2
4 3
6 0 1 0
TRACHEA (number of tissues examined)
Submucosal aggregates of mononuclear cells
- focal, slight
Submucosal aggregates of mononuclear cells
- multifocal, slight
Epithelial hyperplasia
- focal, slight
10
4 1 1
TESTES (number of tissues examined)
Unilateral decreased spermatogenesis
- focal, moderate
Sperm granuloma
Mineralization
- focal, slight
10
1 0 1
OVARY (number of tissues examined)
Pyogranulomatous inflazmatory reaction Acute suppurative inflammation and bacterial colonies
-
UTERUS (number of tissues examined)
Dilatation of the lumen
Endometrial hyperplasia
- slight
Endometrial changes consistent with phases of the
estrus cycle
-
_
Males___________ 3 10 40 000 10 10 10
202 122 000 000 000 000 0 0O
000
000
10 10 10 8 7 9 000
3 20 011
448 000 002 000
10 10 10
144
000 000
10 10 10
0 10 001 000
----_ ---
--___ ---
_ __
Data listed as the number of rats with the listed observation. - Not applicable. Observation noted only in rat dying during study.
__________ Females 0 3 10 011
10 10 10
40 0
10
0000 0 0 1* 1 0101 0000 000 1 0 0 1* 0 0 0 1* 0
0 1* 0 0
1000
10 10 10 10 01 1 0 000 0
1212 000 0
1110 0001 0000 0 1* 1* 0
10 10 10 10
2633
0000 0000
*- - -
____ -------
10 10 10 10 0001 0 1* 1* 0
10 10 10 10 1 01 0 0 0 0 1X
024 3
no 13068R GONFTDFNTTAl
TABLE 25 (cont.)
HISTOPATHOLOGIC OBSERVATIONS ON MALE AND FEMALE RATS EXPOSED BY INHALATION TO VAPORS OF ETHYLENE DIBROHIDE (EDB) (94-95 DAYS ON STUDY) AND HELD FOR A RECOVERY PERIOD OF 88-89 DAYS
Sex Dose (ppm) Number of rats dying spontaneously Number of rats examined
THYROID (number of tissues examined) Follicular cyst
MEDIASTINAL TISSUES (number of clssues examined) Acute suppurative inflammation, edema, and
congestion
PITUITARY GLAND (number of tissues examined) Focal hyperplasia
ADRENAL GLAND (number of tissues examined) Focal hematocyst
MISCELLANEOUS Generallted acute bacterial septicemia
~0~ rs0 ~
Males
03 10 0 10 10
7 9 10 00 1
10 10 10
000
000 000
000 000
00 0
ADDITIONAL TISSUES EXAMINED MICROSCOPICALLY AND SHOWING NO VISIBLE LESIONS
Esophagus Large Mediastinal Artery(les) Aorta Thoracic Lymph Node Thyroid Parathyroid Thymus Oviducts Pharynx Urinary Bladder Large Intestine
10 10
9
879
533
877
7 9 10
579
00 1 ---
000 000 000
Data listed as the number of rats with the listed observation. - Not applicable. Observation noted only In rat dying during study.
40 0
10
8 0
10
0
0
0
0 0
0
9 8 3 8 8 7
0 0 0
0
Females 0 3 10 40 0110 10 10 10 10
9 9 10 7 0100
10 10 10 10
0 1* 1* 0
00 1 0 0 0 1* 0
0010 0 0 1* 0
0 1* 1* 0
9 10 10 10 878 7 201 2 6 5 6 10 9 9 10 7 5694
1020
10 10 10 10
2 1 1 0.
544 4
100 0
00 130689 conftdfnttai
FIGURE 1
BODY WEIGHT GAIN FOR MALE RATS EXPOSED TO ETHYLENE DIBROMIDE FOR 1 WEEK
r>
oo
zn o
--( --1 z> -a o
z O' ----1s o>
1>
Days On Test
i in i I
FIGURE 2
BODY WEIGHT GAIN OF MALE RATS EXPOSED TO ETHYLENE DIBROMIDE FOR 13 WEEKS
DO 1 306)91 CONFTDFNTT
FIGURE 3 BODY WEIGHT GAIN OF FEMALE RATS EXPOSED TO
ETHYLENE DIBROMIDE FOR 13 WEEKS
i>
DO 1 3 0 6 9 ?
CONFTOFNTT