Document B8eVky2yBzmg2wLL2R88MLznX

The Toxicity of the Vapors of Aroclor 1242*and Arochr 1254* J. F. TREON, Ph.D., F. P. CLEVELAND. M.D., J. W. CAPPEL. and R. W. ATCHLEY The Kettering Laboratory. Department of Preventive Medicine and Industrial Health College of Medicine, University of Cincinnati Reprinted from American Industrial Hyoiene Association Quarterly, 17:2, 20-1-213, June 195G. ' (Copyright, 1956, American Industrial Hygiene Association) DSW 030652 o STLCOPCB4014614 The Toxicity of the Vapors of Aroclor 1242and Aroclor 1254* J. F, TREON, Ph.D., F. P. CLEVELAND. M.D., J. W. CAPPEL, and R. W. ATCHLEY The Kettering Laboratory, Department of Preventive Medicine and Industrial Health College of Medicine. University of Cincinnati nvestigation of the physiological re Aroclor 1242 per liter of air is equivalent I sponse of animals to the inhalation of to 96.9 ppm by volume. two Aroclors, namely 1242 and 1254, svas Aroclor 3254, which corresponds to penta- undertaken because in the earlier literature1 chlorobiphenyl, is a light, straw-colored, dealing with the toxic effects of Aroclors, viscous liquid. The positions of the chlorine no distinction has been drawn between the atoms have not been established. The mo toxic effects of chlorinated biphenyls and lecular weight of pentachloi obiphenyl is those of chlorinated naphthalenes, despite 326.445, of which 54.3% is chlorine. Ben the differences in the chemical composition, ignus has reported that Aroclor 1251 con physical characteristics, and industrial ap tains 65.0 i 0.5% of chlorine. Bulletin No. plications of these classes of compounds. In O-P-115 describes Aroclor 1254 as having a the case of the chlorinated biphenyls, at specific gravity at 25/25C of 1.538 to least, further toxicological investigation and 1.548; a distillation range of 365 to 390C, consideration were required to demonstrate a refractive index (D-line at 20C) of 1.639 the relationship between the extent of their to 1.643, and a Saybolt Universal viscosity chlorination and their toxicity. at 100 F of 1,800 to 2,500 seconds. The vapor pressure at 150C is about 1.3 mm, Properties and at 2005C is about 9 mm. The material A ROCLOR 1242 is a light, straw-colored, rao- is soluble in most organic substances, but it bile liquid. According to Benignus, of is insoluble in water and glycerine. At 745 Monsanto Chemical Company, it contains mm of mercury and 25C the concentration 42.0 0.5% of chlorine, an amount which of 1 mg of Aroclor 1254 per liter is equiva corresponds to a chlorinated biphenyl with lent to 76.5 ppm by volume. three chlorine atoms in unassigned posi tions. The physical and chemical properties Experimental Method are given in Monsanto Application Bulletin PXPOSURE TO the vapor: In a preliminary No. O-P-115. Ita specific gravity at 25"/ experiment (No. 1) with the vapor of 25C is 1.378 to 1.388; it has a distillation Aroclor 1242, a group of animals was con range of 325 to 300C; a refractive index fined for seven hours on each of five days (D-line at 20C) of 1.627 to 1.629; a Saybolt per week in a rectangular plywood chamber Universal viscosity at 100F of 80 to 93 (volume 600 liters), of which the inner seconds, and a flash point (Cleveland Open metal lining was coated with a baked chemi Cup) of 176"-180C. Its vapor pressure is cally resistant plastic, through which was about 4 mm at 150DC and about 30 mm at passed a stream of air laden with Aroclor 200"C. Although insoluble in water and gly 1242 in a known concentration. The stream cerine, it is soluble in most organic sub of air, conditioned with respect to tempera stances. At 745 mm of mercury and 25C, ture (75" 3F inside the chamber), dust the concentration of 1 mg of the vapor of nnd humidity, entered the chamber through rr*cnlrd the Seventeenth Annual Meeting of the Amkrican lNDDfiTRiM. Hygicnc Association, Philadelphia, April 26, 1<*&6. an "Anemostat," located at the center of its top, at the rate of 600 liters per minute, as measured by an inclined manometer attached SW 030653 STLCOPCB4014615 to the Aroclors, in another cham ber supplied only with condi tioned air. A second set of experiments with each of the Aroclors at lower concentrations was con ducted in the same chambers. In the third experiment with Aro clor 1242, which was heated to 55 to 60C, the air pnssed over the liquid at the rate of 800 liters per minute. In the second ex periment with Aroclor 1254, the liquid was maintained between 115 and 125C while 700 liters of air per minute passed over its surface before entering the chamber. The animals exposed in each of these experiments, as well Fig. I. Sehma(ic diagram of aquipmant for voUfiliting Aroclor, chambar, and aqulpmanf for combupion and collacfion of aamplas. as a second group of controls, were confined in separate 600 liter chambers during a seven hour period on each of five days per week during the week pre to a venturimeter (Fig. 1). The air was ceding the initial exposure of the test ani withdrawn by suction from the chamber mals to the vapor of the respective Aroclors. through an exit tube located on the real- In all experiments, the period of exposure wall near the floor, equidistant from the or confinement (controls) was seven hours sides. per day on five clays per week for several Aroclor 1242 was volatilized from a weeks. In all instances, the original group heated glass well maintained at 132 to consisted of one cat, six guinea pigs, ten 138'C. The ail- passed over the surface of mice, four rabbits, and ten rats. Among the liquid before entering the chamber both the experimental and control groups, (Fig. 1). several animals died from extraneous causes In c second similar experiment performed during the course of these experiments and on the same Aroclor (No. 2), the tempera were replaced very soon thereafter. In the ture of the liquid was kept at 100 to 105'C. second experiment with Aroclor 1242, in While the second experiment with Aroclor the first experiment with Aroclor 1254, and 1242 was in progress, an experiment involv in the comparable group of controls, repre ing the vapor of Aroclor 1254 (No. 1) was sentative animals were killed throughout the carried out in a second chamber similar to experiment. the first except for the absence of a plastic Method for the determination of the inner lining. The rate at which air flowed aroceors IN AIR: These materials were de over liquid Aroclor 1254, which was main termined quantitatively by virtue of the fact tained at 130 to 135C, was 400 liters per that, on thermal decomposition, they yield minute. hydrochloric acid which with silver nitrate, In order to accustom the animals to the forms a suspension, the density of which experimentiL1. procedure, they were kept in could be measured by means of the Beckman their respective chambers for seven hours spectrophotometer at 500 mg. on each of four consecutive days during the On each day, two samples of nir from each week prior to the introduction of the Aro chamber were collected by passing nir at the clor vapor into the chamber. For purposes rate of one liter per minute (for 15 min of control (No. 1), a third group of animals utes in the case of the higher concentrations was confined, throughout a like period be and for 45 minutes in case of the lower con fore and during the period of the exposure centrations; through a fused silica combus- ^ nn---*'' 1 O DSW ................ ..... 030654 STLCOPCB4014616 *jmK7 rA^-*T mOCm her chnmth condi- periments odors at was conmbcr8. In ivith Aroheatcd to issed over 800 liters econd ex125-1, (he between 700 liters d over its ring the 'xposed in ts, ns well controls, irate GOO a seven live days peck pre test aniA rodors. exposure ren hours >r several :ial group pigs, ten i. Among >1 groups, )us causes nents and :r. In the 1242, in 1254, nnd >ls, repreghout the N OF THE were de>f t he fact, hey yield r nitrntc, of which Beckman from cneh air nt the r 16 minintentions ower cona combus- , j | * , . Fig. 7. HumidiCsr, lunuci, and sampling towars. Fig. 3. Sampling towars. (Midget Bubblers) tion furnace, and then through two midget bubblers, in series, each containing 10 ml of 0.1 N sodium hydroxide. A quartz tube (13 mm outside diameter. 7 mm inside diameter and 16.25 inches in length) contained sev eral strips of folded platinum foil. The mid dle nine inches of the tube were wrapped with a heating unit. The heating unit of the furnace (Fig. 2) consisted of 20 feet of B. and S., gauge 22, nichrome wire (1 ohm per foot), and was covered with as bestos cement. The sample of air was hu midified by a cotton wick saturated with water placed 0.5 inch upstream from the quartz tube. With the furnace maintained at 860C, the Aroclor was decomposed in the presence of H^O to form HC1; this was absorbed in 0.1 N sodium hydroxide in midget bubblers (Fig. 8) equipped with fritted-glnss bubblers (Mine Safety Ap pliance Company No. 438G7). The 0.1 N sodium hydroxide was pre pared by dissolving 4.0 g of pellets (ACS specifications 0.01 % Cl) in about 60 mi of double-distilled water. To this were added 10 g of arsenic, trioxide (chloride-free) dis solved in water nnd filtered through What man No. 42 filter pnper. The combined solu tions were diluted to 1,000 milliliters. The sample was transferred to a 25 ml graduated cylinder to which one drop of a solution of phenolphthnlein was added (1 g of phenolphthnlein dissolved in 500 ml of CP methanol I. The solution was neutralized with 3N nitric acid (100 mi CP concen trated nitric acid diluted to 1,000 ml with double-distilled water) and diluted to 23 ml with double-distilled water. One ml of 3X nitric acid was added to obtain a pH of 1. After adding 1 ml of a solution of silver nitrate (3 g of AgXOH diluted to 1,000 ml with double-distilled water), the sus pension was mixed by inversion. After standing 30 minutes, the transmission of wave-length 500 my was measured in a 50 cm cell by moans of a Beckman spectropho tometer which wns set against a correspond ing cell containing a reagent blank. The amount of Aroclor was estimated by means of a standardized curve prepared from known quantities of sodium chloride. A curve presenting the transmission values at 500 m/i of suspensions prepared from sodium chloride ranging from 5.0 to 120 micrograms per 25 ml of final suspension is shown in Fig. 4. On the basis of 42.0(o of chlorine in Aroclor 1242 and 55.0 rr in Arc elor 1254, one microgram of sodium chloride is equivalent to 1.442 micrograms of Aroclor 1242 or to 1.1028 micrograms of Aro clor 1264. Experimental Results J^fOltTAUTY--AROCLOR 1242: No signs of intoxication were observed in any of the members of n group of 31 animals (F.xperiment No. 1), all of which survived throughout a period of 24 days, on 17 of which they were subjected to the inhalation of air bearing 8.6 micrograms of Aroclor 1242 per liter (0.83 ppm) for seven hours (Table 1). One cat, four guinea pigs, six mice, two rabbits, and eight rats survived without DSW 030655 STLCOPCB4014617 signs of Intoxication throughout their exposure (Experiment No. 2) for seven hours on each of 82 days over a period of 120 days to air bearing the vapor of Aroclor 1242 in the concentration of 6.83 microgrnms per liter (0.66 ppm). Certain other survivors (two guinea pigs, three mice, one rab bit, and two rats) were subjected to fewer periods of exposure (cf. Table I). The deaths from ex traneous causes among the ex posed animals were fewer than those which occurred among the corresponding group of controls (No. 1, Table I). One cat, three mice, three guinea pigs, three rabbits, and eight rats survived following confinement for seven hours on 84 days over a period of 122 days, in a chamber in Id Of Of aoy tor tor to* toy TO, toy toy >00 toy (toy (toy MO, i m r--n------- Fig. 4. Standard curve for Ih# determination ol Aroclor 1242 and Aroelor I2S4. which the air, conditioned with respect to In another experiment (No. 3, Table I-A) dust, humidity and temperature, contained in which animals were exposed to air bear no vapor of either Aroclor. Ten more survi ing Aroclor 1242 in the concentration of 1.0 vors (three guinea pigs, four mice, one rab micrograms per liter (0.18 ppm) for seven bit, and two rats) were subjected to fewer hours per day on 150 days over a period of periods of confinement (cf. Table I). 214 days, the incidence of mortality among Table I. Summary of Data on Mortality Among Animals Exposed to the Vapor of Aroclor 1242 or Aroclor 1254 in Am (Higher concentrations) Material Concentration v/l ppm of Expoaurt (hour*) Cat* Number of Animals that Survived Guinea Pig. Mice Rabbit* RaU Expt. No. Aroclor IZii Aroclor 1242 Aroclor 1264 Control 8.60 t.BS 1.40 0 0-8$ 0.(6 0.41 0 n*7 82 x 7 Mx 7 84 X 7 1 1 1 I e .* 6'.'.* 8V.1 10 9'.*,, 10*.* 7`. 4 *> 4'. 4* 10 10M 10* J0\* 1 2 1 l 'Ont of the animal* wu exposed on only 65 to 77 day* *ne of the animal* was exposed on only 41 to 58 day* One of the animal* was expoaed on only 20 to 88 days Five of the mice were exposed on only 74 day* *Thr** of the mice were exposed on only 14 to 19 days *One of the rabbit* was exposed on only 19 day* Table 1-A. Summary of Data on Mortality Among Animals Exposed to the Vapor of Aroclor 1242 on Aroclor 1264 in Air (Lower concentrations) Material Concentration r/i l>pm of Eipocur* (hours) Cat* Number of Animals that Survived Guinea Fig. Mice Rabbit* RaU Expt. No. Aroclor 1242 Aroclor 3284 Control 1-90 3.50 0 0.18 4.U 0 150 x 7 160 X 7 150 x 7 1 1 1 8* 7V. 61 8V 8\V Iflt rM M Kt M 10* IX* 101 8 2 2 'One of the animals wmk exposed on only 2S to 87 days *One of the animal* wai exposed on only 41 to 55 days One of the animal* wm exposed on only 150 to 189 day* One of the animal* was exposed oa only 5 to 18 day* 'One of the animnb was expoeed on only 107 to 120 days fOne mouse was exposed on only 95 day* DSW 030656 STLCOPCB4014618 i0*r COM* r i o WOl N>y rso OO* OO, ** MO i M0| 1242 *nd Table 1-A) i air benrtion of 1.9 for seven i period of ity among OR Eipt. 6U No. 91 0'.* t 0' 1 0',* 1 lays to 19 day* > dnyi DR ExpU ata No. 0* 8 l1 t 0* 2 o 18 days 7 to 120 day* j the various species, with the exception of the rabbits (which died during an epidemic of pneumonia), was no greater than that en countered among a similarly constituted control group (Experiment No. 2, Table Table II. The Avfaage Chances in Weight of Experi mental and Control Animals (Higher concentrations) I-A). One cat, five guinea pigs, six mice and nine rats survived throughout the entire period of their subjection to the vapor of Aroclor 1242. Seven additional survivors (one guinea pig, two mice, three rabbits, and one rat) were exposed intermittently to the vapor of Aroclor 1242 over a shorter period of time (cf. Table I-A). Among the group of controls (Experiment No. 2, Table 1-A), one cat, five guinea pigs, four mice, two rabbits, and nine rats survived through out the entire period of confinement, for seven hours on each of 150 days over 213 days in a chamber supplied with condi tioned air. Eleven other control animals Specie* of Animal Number of Animals Average Change In Weight Average Expressed as Initial Weight Percentage of <k> Initial Weight Aroclor 124? * 8.6b /I Experiment No. I Cm Guinea Mouse Rabbit Rat Pig 1 6 10 4 10 2.863 0.640 0.024 S.01 0.328 + S.I - 2.0 + .t + t.t + 2.1 Aroclor 1242 - 6.83 y/1 - Experiment No. 2 Cat Guinea Pic Mouse Rabbit Rat 1 6 9 8 10 2.271 0.404 0.021 2.587 0.212 22.2 +66-4 +21.2 +60.6 + 17.6 Aroclor 3264 6.40 y/\ * Experiment No. 1 (one guinea pig, six mice, three rabbits, and one rat) survived during a shorter total period of intermittent confinement (Table 1-A). No signs of intoxication were ob Cat Guinea Pis Mouse Rabbit Rat 1 6 20 4 20 2.620 0.409 0.02! 2.722 0.227 + 22.1 + 40.7 + 28-9 + 30.7 + 6.9 served among experimental or control ani Conditioned Air - Control* Experiment No. 1 mals. Mortality--aroclor 1264: One cat, three guinen pigs, four mice, two rabbits, and nine rats survived throughout their expo Cat Guinea Pig Mouse Rabbit Rat 1 6 7 4 10 2.388 0.418 0.022 2.764 0.211 + 6.0 +6C.6 +n.< +44.S + 16.4 sure, for seven hours on each of 83 days over a period of 121 days, to air containing Aroclor 1254 in the concentration of 5.40 micrograms per liter (0.41 ppm). Certain other animals (three guinea pigs, six mice, Table 11-A. . The Average Chances in Weight of the Sur vivors Among the Original Groups (Lower Concentrations) two rabbits, and one rat) were killed for examination after 33 to 74 periods of expo sure (Table 1). The incidence of mortality from extraneous causes among the exposed Species of Ankna) Number of Animals Average Chang* In Weight Average Expressed as Initial Weight Percentage of (kg) Initial Weight P and control animals (Experiment No. 1), with the exception of the rabbits, was com parable (.Table I). One cat, four guinea pigs, six mice, four rabbits, and 10 rats survived (Experiment Z, Tabic I-A) following their exposure for seven hours on each of 150 days over a period of 213 days to air containing Aroclor 1254 in the concentration of 1.5 micrograms per liter, (0.11 ppm). Eight other animals Aroclor 1242 * 1.0 y/1 - ENpcriment No. S Cat Guinea Pig Mouse Rut 3 6 6 0 1.730 0.6)4 0.0238 0.214 + 136. U + 43.1 + 1.5 + 89.9 Aroclor 3254 - 1.5 '1 * Experiment No. 2 Cat Guinea Pig Mouse Rabbit Rat I 4 C 4 10 .638 0.487 0.0243 2.958 0.222 + 15.2 + 82.6 + 17.0 + 44.4 + 2B.7 _ >0.05 \ 0.05 >0.03 _ >0.05 >0.05 >0.05 > 0.05 (three guinea pigs, four mice, and one rat) Conditioned Air - Control* * Experiment No.. 2 survived through 30 to 139 periods of ex posure. The incidence of fatalities among the exposed group was slightly less than that encountered among the controls (Ex Cat Guinea Pig Mouse Rabbit Rat 1 5 0 4* 9 8.820 0.600 0.0257 .622 0.218 - 7.8 + 54.7 + 13.2 + 52.Z + 83.7 __ -- -- -- -- periment 2, Table I-A). 'Includes two early replacements. DSW 030657 STLCOPCB4014619 A s? V .U- JU~ No general or specific signs of intoxica tion were noted among the experimental animals during or after their exposure. Growth: The pertinent dntn relating to the changes in weight of the animals of the various groups are presented in Table II and II-A. Although comparable controls were not weighed during the first experiment with Aroclor 1212 (17 x 7.0 hrR.--8.60 micro grams per liter) all of the animals, except the guinea pigs, uppeared to gain normal ly in weight during the period of exposure. Despite a small net loss by the guinea pigs in this experiment, they wen: actually gain ing weight at the termination of the period of exposure. The animnls exposed to the vapor of Aro clor 1242 in the concentration of 6.83 microgvairm per liter (Experiment Xo. 2) or to Aroclor 1254 in the concentration of 6.40 microgrnms per liter (Experiment Xo. 1), with the exception of the guinea pigs that were exposed to the vapor of Aroclor 1264, grew equally as well as the controls (Experiment No. 1, Table 11). The growth of the surviving experimental animals in the groups initially exposed to the lower concentrations of the vapor of Aroclor 1242 (Experiment No. 3, 1.9 micro grams per liter) and Aroclor 1254 (Experi ment No. 2, 1.5 micrograms per liter) was unaffected. No significant differences in the average change in weight of the experi mental and the control groups were found by the use of the "t" test (Table II-A). WEIGHT OF LIVER AND KIDNEYS: The weights of the livers and kidneys and the relationships of their weights to the body weights (expressed as grams per 100 grams of body weight) of the animals that sur vived following exposure to the vapor of Aroclor 1242 In the concentration of 6.83 microgrnms per liter, are shown in Table 111, which also gives the corresponding data on the controls. Comparison by the "F" test of the variances of the ratios of the livers or kidneys to the body weights of rats, guinea pigs and rabbits exposed to the va por of Aroclor 1242 (6.83 micrograms/ liter), with those of the controls, revealed no significant differences (P>0.05) ex cept in the case of the livers of the rats. Application of the "t" test to the mean values (Table III) revealed no significant differences between the test and control groups of guinea pigs, rats, and rabbits. Comparable values for rats, guinea pigs and rabbits exposed to Aroclor 1254 in the concentration of 6.40 micrograms per liter Table III. Summary of the Data on the Relationship of the Weight of thf. Liver or the Kidneys to the Body W'eicht of Animals Exposed to the VAroa of Aroclor 1242 oh Aroclor 1254 Aroclor 1242 - C.83 y/1 - 82 x 7 hrs. Aroclor 1254 - 6.40 y/1 - 88 x 7 hrs. Controls - 0 y/l - 84 X 7 hrs. Compound Aroclor J24Z Amclor 1242 Aroclor 1242 Aroclor 1264 Aroclor 1ZM Aroclor 1254 Aroclor 1242 Aroclor 1242 Aroclor 1242 Aroclor 1254 Aroclor 1264 Aroclor 1254 Control Control Control Control Control Control Organ Liver Llv.r I.lvri Liver Liver Liver Kidney* Kidney* Kidney* Kidney* Kidney* Kidney* Liver Liver Llv.r Kidney* Kidney* Kidney* 8pec(e* of Animal Rat Guinea. Pig; Rabbit Rat Guinea Pi? Rabbit Rat Guinea Pic Rabbit Rat Guinea Pic Rabbit Rat Guinea Pic Rabbit Rat Guinea Pic Rabbit n 9 6 3 10 6 4 9 6 8 10 4 10 6 4 10 4 Aveinpc Organ Weight <K> 11.2 29.6 122.0 12.8 26.P 120.0 \.9b 6.0 16.6 2.1 4.C .K 9.0 20.3 102.3 2.0 4.8 105 Average Body Weight (a) 240 640 4.023 230 661 2.637 240 640 4.023 280 681 2.637 248 266 i.m 243 660 8.903 Ratio of Weight of Organ x 100 to Body Weight 4.64 4.68 8.04 6.34 4.61 8.63 0.778 0.805 0.468 0.770 0.808 0.464 (.u <A1 1.41 0.807 0.781 0.604 t 1.2381 0.4291 1.5066 8.89D2 0.0000 1.0122 0.6842 0.7267 0.4177 0.4190 0.5411 0.3168 -- -- -- -- -- -- P 0.20-0.80 >0.50 0.10-0.20 <0.01 >0.60 >0.50 >0.50 0.40-0.60 >0.50 >0.50 >0.60 >0.60 -- -- -- -- -- -- DSW 030658 STLCOPCB4014620 I (Expertter) was es in the experire found I-A). YS: The and the the body 00 grams that, survapor of t of 6.83 in Table sponding : the "F" >8 of the s of rats, 0 the varograms/ revealed .05) exthe rats, he mean [gnificnnt 1 control tbbits. inea pigs 54 in the per liter IDNEYS TO Lott 1254 . : * < r 0.20-0.80 >0.80 0fl0-0.20 <^0.01 >0.80 >0.50 >0.50 0.40-0.60 >0.60 >0.50 >0.60 >0.60 are also given in Table III. Application of the "t" test to the differences in the mean values which characterized the experimental and control animals (.Table III) shows that the weights of the livers of the exposed rats were significantly greater than those of the controls, the ratio of the liver to the body weight of the former being 5.34 g per 100 g of body weight, that of the latter being 4.15 g per 100 grams. In all other instances tested (livers and kidneys of both guinea pigs and rabbits and kidneys of rats) the differences were statistically insignificant. The organs of the animals exposed to the lesser concentrations of the vapor of the Aroclors were not examined in this manner because of the borderline character of the results associated with the higher concen trations. Liver function: Data were obtained as to the apparent prothrombin activity of the blood (measured by the method of Kato2) of certain animals that had been exposed (1) to the vapor of Aroclor 1242, in the con centration of 6.83 micrograms per liter; (2) to the vapor of Aroclor 1254 in the concen tration of 5.40 micrograms per liter; and (3) to conditioned air alone. In Table IV the percentile relationships of the clotting power have been calculated arbitrarily by dividing 100 times the average clotting time of the blood of the control animals by the clotting time of the blood of the experi mental animals on the same day. No dimin ution in the clotting power of the blood, as a measure of the impairment of the function of the liver, was induced by the exposure of the animals to the vapor of Aroclor 1242 in air in the concentration of 6.83 micro grams per liter, or to the vapor of Aroclor 1254 in the concentration of 5.40 micro grams per liter. This functional test was not applied to animals subjected to the lower concentra tions, because of the negative results ob tained when the animals were subjected to the higher concentrations. Hematological results: Determina- Table IV. The Effect of Exposure to the Vapor of Aroclor 1242 oa Aroclor 1254 in Air for Seven Hours Per Day on Five Days Per Week Over a Period of Several Months Upon the Ap parent Prothrombin Content of the Blood of Cats and Rabbits Rotation of "Prothrombin Time" of Control and Exposed Animnls fcxpruNNrd Arbitrarily in Tcihii of Percentage Change in Clottinp Time of Blood 100 x ('lolling Time of Hk>od of Confrol Animal* Clotting Time of MimkI of Exposed Animnls Atvclor Vi 42 - 6.S3 7/1 * Experiment No. 2 Time of Sampling in Relation to Period of Exposure Days Before Virmi Period 8erial Number of Period After Which Blood Was Drawn Cat A-446 Rabbi U (Average) 100,0 90.3 118.0 101.& 07.4 116.2 89.6 03.8 10&.1 99.0 98.0 108.7 101.6 100.0 3 2 10 30 46 69 82 i Aix>clor 1264 * 6.40 7 T - Experiment No, 1 Cat A-444 Rabbit* (Average) 100.0 100.0 98.6 118.6 101.6 92.6 90.0 97.1 06.9 81.8 90.0 99.6 102.0 112.1 97.0 95.4 96.2 100.0 3 9 10 16 to 82 46 69 83 i 'Determination made 16 day* after 62nd period of exposure. TDctermlnation made 14 day* after 83rd period of exposure. DSW 030659 o STLCOPCB4014621 Tabu: V. Tut: Average Numbers of Erythrocytes and Leucocytes and the Average Concentration of Hemoglobin in the Peripheral Blood of Experimental and Control Animals Compound Aroclor 1242 1 Aroclor 1264 Controls Concentration <>/!> Ml 5.40 t Experiment Number S 1 1 Spe.'ir* of Animal Gain** Me Rabbit Gulna* Pi* Rabbit Gulata Pi* Rabbit Erythrocytee: (Thuuxands) per mm* 1.701 6,088 6.8SC .186* 9.729 5.909 Leucocyte*: per mm* 10.112' 9.765 12.927 10.911 12.124 11.600 HemorJoblr */100 ml i.> 12.1 14.6* 12.2 12.9 12.2 'Va'ue fffMfleant!y Imb than that yielded by controls. `Valur nisnincuiitly greater than that yielded by controls. tions of the numbers of erythrocytes and leucocytes and of the hemoglobin content in the peripheral blood of the guinea pigs and rabbits subjected to inhalation of the vapor of Aroclor 1212 in the concentration of 6.83 micrograms per liter, are given in Table V, which also includes comparable results on control animals. Application of the "t" test to differences in the mean values for the experimental and control animals yielded borderline evidence of significant differ ences in the number of leucocytes and in the concentration of the hemoglobin in the blood of the guinea pigs. These differences were small and of opposite sign (the num bers of leucocytes in the blood of the test animals were low, while the hemoglobin con tent was high), as well as being subject to individual variations, and they cannot be regarded ns of physiological significance. Somewhat comparable results were ob tained when guinea pigs and rabbits were subjected to Aroclor 1254 in the concentra tion of 5.40 micrograms per liter. No physi ological significance is attached to the slightly elevated hemoglobin content of the guinea pigs. Pathological findings: in all of the ex periments, animals were killed from one to 15 days after tlui final period of exposure. In the first experiment with Aroclor 1242 (8.GO micrograms per liter), all of the. ani mals were examined postmortem, and since gross examination of the viscera did not reveal any significant alterations, the tis sues of only representative animals (one cat, four guinea pigs, six mice, four rabbits and six rats) were sectioned and examined microscopically. No abnormalities were found in the viscera of these animals. In the second experiment with Aroclor 1242 (C.83 micrograms per liter), and in the first experiment with Aroclor 1254 (5.40 micrograms per liter), which were carried out simultaneously, the deaths that occurred among the test and control animals were the apparent result of an appreciable in cidence of pneumonia. The lesions of cer tain of the animals were those of frank pneumonia: in others such lesions were not fully developed. Degenerative changes in the viscera were usually found, in varying de grees of severity, in association with the pneumonia, but in certain animals, test and control alike, the degenerative changes were more evident than the pneumonia. The similarity of the lesions in test and control animals, and the lack of characteristic evi dence of chemical pneumonitis, led to the reasonable, but not altogether certain, con clusion that nil of these fatalities resulted from intercurrent disease among the ani mals, and not from the effects of their ex posure to the Aroclors. For practical pur poses, this conclusion was subjected to the critique of further experiments involving more prolonged exposure of animals to some what lower concentrations. Except in the case of the rats exposed to Aroclor 1254, the survivors subjected to the higher concen tration of either Aroclor had normal viscern. All of the animals exposed to the vapor of Aroclor 1242 in the concentration of 1.9 micrograms per liter were examined post mortem, and the viscera of most of them were examined microscopically. The few deaths among the exposed group were at tributed to incidental infectious pulmonary disease. All exposed survivors, except two rabbits that had hepatic lesions of coccidiosis, had normal viscera. The control animals (Experiment No. 2) thnt died were found to have had pneumonia. Of those that sur- lyiaii hmwmi.............I m . y DSW m -nni mi,i.iW, 030660 STLCOPCB4014622 . 11 JtJX1 .. INTRATION CJMALS Hnoelobtn: f/100 ml IV.4* IM uv 11.2 11.9 It.2 154 (5.40 e carried . occurred inis were nuble ina of ccrof frnnk were not ges in the rying de wit h the , test and iges were nin. The id control ristic evied to the tain, con i resulted the nnitheir extieal pur,cd to the involving s to somepi in the 1254, the r coneenirmnl vis- the vapor ion of 1.0 mod post : of them The few were atlulmonarv xcept two f coccidioo) animals ere found that Bur- vlved, one rat, two guinea pigs, and one ment, liver function or hematological mouse had focnl or diffuse cytoplasmic vacu- changes. olation of the hepatic cells. The remaining More prolonged exposure of animals to a control animals had normal viscera. lower concentration of Aroclor 1242, (1.9 All of the animals exposed to the vapor of micrograms per liter) over the period of Aroclor 1254 in the concentration of 1.5 seven months was likewise without harm in micrograms per liter were examined post terms of growth, mortality and the absence mortem, and the viscera of most of them of pathological changes. ` were examined microscopically. A guinea In view of this evidence it is suggested pig that died exhibited chronic pyelone that the tentative allowable concentration of phritis, pulmonary hyperemia and edema, the vapor of Aroclor 1242 should be at least , and degenerative lesions in the brain and two micrograms per liter (2 mg per cu liver. The visceral lesions were related, no meter), which is twice that recommended doubt, to the renal infection. The deaths of by the American Conference of Govern four mice were attributable to acute bron mental Industrial Hygienists3 for a chlorin chitis and pneumonia. The viscera of the cat ated diphenyl of unstated chlorine content. that survived were normal. Of the seven The exposure of animals to the vapor of guinea pigs that were living when the ex Aroclor 1254 in the concentration of either periment was terminated, three had normal 5.40 or 1.5 micrograms per liter failed to viscera and four had slight alterations of induce harmful effects in the form of re hepatic cells characterized by cytoplasmic tardation of growth (except in the case of vacuolntion. Ten mice survived, and of these guinen pigs exposed to the higher concen six had norma! viscera and four had slight tration), or of mortality, but histopatho degenerative changes in the liver. Four rab logic evidence of apparently reversible bits killed one to 15 days after the last hepatic cellular injury wa3 found in the ). iriod of exposure had diffuse hepatic de- animals. These findings cannot certainly be 1' deration. The character of the lesions attributed to the effects of Aroclor 1254 be vr.ried from cloudy to hyaline or hydropic cause of the appreciable incidence of pneu d< generation and included varying degrees monia among both experimental and con of fatty metamorphosis. The other viscera trol animals. When these nonspecific toxic of these animals were normal. All of the changes in the viscera of the animals were rats were examined and found to have associated with pneumonia, they were readi slightly to moderately severe degenerative ly explained thereby, but they were also lesions of the liver. The lesions of greatest found in animals that had been exposed to severity were found in the rat that was the vapor of Aroclor 1254 and were free of killed and examined on the first day after pneumonia. That these may have repre , the last period of exposure. Two rats had sented toxic effects of exposure to Aroclor ' chronic pyelonephritis, and the remainder 1254 finds support in the fact that the livers I had slight degeneration of the renal tubules. of the exposed rats (5.40 micrograms per Discussion: In terms of mortality, growth liter) were significantly heavier in relation (except that of guinea pigs) and non-occur to their body weight, than were those of rence of pathological changes, the vapor of control rats. It would appear that this ma Aroclor 1242 in the concentration of 8.6 terial, which is reported to contain 55rc- of micrograms per liter (approaching satura chlorine, is somewhat more toxic than is tion) appeared lo be non-iujurious to ex Aroclor 1212, which contains only 42 rr of perimental animals subjected thereto for chlorine. Therefore it is suggested that the seven hours on each of 17 days over a peri threshold concentration of 1 mg per cu meter od of 24 days. of air recommended tentatively for safe in Experimental animals subjected to but a dustrial practice by the American Confer . slightly lower concentration of Aroclor ence of Governmental Industrial Hygien ! 1242 (6.83 micrograms per liter) for seven ists3 is reasonable. hours per day on each of 82 days over the It should be noted that it was necessnry to period of 120 days suffered no injury on the heat these Arorlors in order tn increase the basis of any of the following criteria: mor rate of volatilization sufficiently to at tality, growth, pathology, organ enlarge tain the concentrations maintained in these OSW 030661 STLCOPCB4014623 n i n **- w experiments. To the extent that their indus trial usage is carried out at ordinary tem peratures, the hazard of their inhalation may well be slight or entirely absent. sponsored by the Monsanto Chemical Com pany, whose financial support is gratefully acknowledged, as is also their assistance in supplying the materials for Investigation. Summary Prolonged intermittent exposure of ani mals to the vapor of Aroclor 1242 (1.90 to 8.63 micrograms per liter) demonstrated no injury. Prolonged exposure to compa rable concentrations of Aroclor 1254 re sulted in reversible degenerative changes in certain viscera. The work described in this article was References 1. Drsnkk*. C. K.: Further Observation* on the Pos sible Syatemlc Toxicity of Certain of the Chlorinated Hydrocarbon* with 8utffcBtlon* for Fcrml**lbl* Concen tration* In the Air of Workroom*. J. ind. Hvq. <fr Tom., 21:155, 1859. 2. Kato, K.:Micro-prothrombin Teet with Capillary Whole Blood: Modification of Quick** Quantitative Meth od. dmer. J, Clin. Path., 10:147, 1940. I. American Conference of Governmental Induttrial Hyricnials. Threshold Limit* for 1855. AMA Arch. /ad. Health. 11:521, 1955. I o OSW 030662 STLCOPCB4014624