Document Lm7dYG5g25n1NzDej3bQ7zE3

( .o - PRESENTATION To The INTERDEPARTMENTAL TASK FORCE ON PCBa WASHINGTON, D. C.' May 15, 1972 by MONSANTO COMPANY PLAINTIFF'S EXHIBIT 1001170 _ ADM 0002 Introdp tion B1 W. 3. Parageorme Considerable interest has been continues to be expressed by many involved in studies of PCBlIanid the 4bvlronment concerning their degradability. Monsanto HaS rec^vrai many inquiries relating to results of our studies. V/e novt have, accumulated seme meaningful data which we believe would be appropriate to present in a status report to the Interdepartmental PC3 Task Force. We sincerely appreciate this opportunity to share this information with you this afternoon. Slide -^1 - We plan to discuss current results of laboratory biodegration studies of PC3s and the levels of PC3 residues observed in the tissues of laboratory animals which were used in our toxicity studies. V/e will review briefly actions Monsanto has taken to reduce PCS usage and environmental losses. We will also discuss the application of our laboratory findings to the development of a modified more readily degradable PCB mixture for use by the capacitor Industry as a dielectric fluid. As many of you are aware, we have designated this material as Aroclor 1016. Slide =2 - Our presentation will begin with Dr. Tucker discussing primary bacterial degradation and PC3 residues in fish, fowl and mammal tissues. Dr. Munch will review evidence that demonstrates disappearance of PC3s from the environment and Dr. Paton will discuss Monsanto's PCB sales and use actions and the impact these actions will have on the environment. Because of the limited time available, may I suggest that questions be held until all the speakers have completed their reports. Following the presentations there will be opportunity for further discussion of information which may be of particular interest to you. Dr. Tucker, Research Group Leader, will now present a status report of his laboratory results. 1001171 AO* CC0223 r ~ i f a a ' u u i-i t_i i-- it; --3 r:: :.5 ! . ,, J o x I oo fo\J rvi OBJECTIVES o PROGRESS REPORT ON LABORATORY BIODEGRADATION OF PCB'S O RESIDUE ACCUMULATION STUDIES IN FISH, BIRDS Aim UAiMMAI O O TO SHOD REDUCTION IN LESS BIODEGRADABLE PCB'S AS A RESULT OF MONSANTO ACTIONS ON SALES AND PRODUCTS Vi.tL.lMl ADM COC2* O INTRODUCTION AGENDA I. B. PAPAGEORGE O.PCB STUDIES E. S. TUCKER PRIMARY BACTERIAL DEGRADATION RESIDUES IN FISH, FOWL AND MANUALS O EVIDENCE FOR LOSS OF PCB FROM THE ENVIRONMENT O MONSANTO PCB ACTIONS R. H. MUNCH C, PATON O DISCUSSION 1 !** . f -TT* 'ASSZSSre^O^THj-BICICSICAL. FEHSISTEifcJIKgfr POLYCHLORINATED BIPHENYLS" TCZZl^T: By Dr. E. S. Tucker The rescarch-I wj.ll review today will. iocu:; ur-n one aspo.c t o.(; 1:0.1scinto's efforts, to understand l.rn: niiviroiii'uv.tcil. impact and behavior of our polychlorinated biphenyl or yen produce:;. \ This research was initiated early in 19CD after development of the necessary PC3 analytical methodology ar.d subsequent confirmation of Dr. Soren Jensen's identification of PCS residues in fish and birds in Sweden. ' At this point in time, PC3 residue data from Monsanto and external environmental monitoring programs indicated that at the previous rate of use and release of these products that some PCB homologs were beginning to reach detectable levels in fish, birds and mammals. Conversely, these data indicated to us that with the exception of localized, controllable contamination, PCB homologs with less than five chlorine atoms per molecule had not accumulated to detectable levels; even though it was known that significantly greater amounts of the PCB homologs with less than 5 chlorine atoms per molecule had been manufactured and used over the years. L Now, before discussing our biological studies, I would like to review for you the gross homolog composition of our Aroclor products and then in a very brief fashion, try and illustrate to you the I complexity of these materials and hence the complexity of the problem. ! In the first slide (=1) , is shown the most recent data on the weight compositio'n of four of. our Aroclor products as a function of each detectable PC3 homolog. The first column on the left lists the I homolog in question and the subsequent columns under each product show the weight 5 distribution of each PCB homolog in each product. As most of you probably know, with the exception of /vroclor 3.016, the last two digits of each product number refer to the degree of chlor ination. For example, Aroclor 1221 contains 215 chlorine by weight, and. so on. ] Aroclor 1016 is a special case in that whiJa it contains about 41% chlorine by weight, its penta, hexa, and hcptachloro biphenyl ] content has been significantly r>?ducnd with respect to Aroclor 1242, a product produced by direct chlorination, containing 425 by weight chlorine. Please note that the penta, hexa, and heptachloro biphenyl 1 homologs in Aroclor 1016 have been reduced by factors of about 3, 10, and 10, respectively, with reference to Aroclor 1242. As you can also see, the chief constituents of Aroclor 1221 arc the ! i mono- and dichioro biphenyls, while Aroclor 1016 and Aroclor 1742 contain predominantly di-, tri-, and tctrachloro blwhenyls, and Aioclor 1254, totra, penta, and hexachloru biphenyls. 3 ADM .00022* and'as sucir-tt- nttrfle1o^yc*#nuay have seen estimation ft bf5 th<r hdaeriom content of these: products, which ere significantly different. Th<r analytical mnthadolo'iy used is currently in a very dynamic state and our understanding of the contents of these products incroases ar the. methodology is improved- At this point in-time, we regard*these numbers as the most accurate ones currently available. In the next slide (C2) are shown examples of low resolution - packed column electron capture chromatograns of Aroclor 1221, Aroclor 1242, Aroclor 1254, and Aroclor i2G0. This is what these products look like to a residue analyst using the most commonly employed detection systern. From these chromatograms, it can be readily seen that we are dealing with multi-component products, which of course, increases the com plexity of assessing every aspect of this problem - relative to a well defined single component system such as DDT. I should mention at this point, that the PCS residues generally found in wildlife are most similar to Aroclor 1254 and Aroclor 1260 chromatograms. The next slide (#3) demonstrates that in reality, these materials are even more complex than is generally realized. 'In the upper right* portion of this slide is again shown a low resolution electron capture gas chromatogram of /vrcclor 1242 under the optimum conditions normally employed by residue analysts. Under these conditions, Aroclor 1242 would appear to be a 15 component system. In the lower portion of this slide is a flame ionization gas chromato gram of the same material using a high resolution S.C.O.T. column. If one carefully inspects this chromatogram, our simple 15 component product has now been resolved into 55 different components. These facts simply indicate that all PCB products cannot be lumped together in terms of either their environmental impact or persist ence. The. type of biological studies which we have carried out to date are shown in the next slide (#5). For discussion purposes, they can be conveniently divided into two categories: "Primary Bacterial Degradation Studies", an area in which research on PCBs is just beginning, and "Residue Accumulation Studies". Most of our bacterial degradation work, has been centered around the fairly well known semicontinuous activated sludge degradation test. Our residue accumulation studies have been fairly extensive and have involved the exposure of better than 2100 fish, chickens, rats^ and dogs to the various Aroclor products; resulting in the collection of over 1200 samples of which approximately 500 pooled samples were eventually analyzed for PCD residues. The prime objective of these studies is given on slide 6. M ill 175 ADM 00022: Slid' 7. The sa^i-continuous ocf.ivr.bcil l iwdge tmi- v/rnr;pc!ur we* urr*ii tc cva iuriwc the primary hacterial degr.vi/iticm Latex; of the" ' fwoclor products is the test method rcet'r.'r.-.-nded by Lhe Soc-n Cuic'i Determents Association for the evaluation of the bice]egrelability cif linear alkyl benzene sulfonate type surf act.-mts [JAGCS 47., 92 (19G5) & 46, 432 (1969) J. Prj.:a5rv njodegradaticm - Minimum alternation of the chemical structure of\the material in question to an extent that characteristic properties of the original material are no longer evident. This procedure employs sludge from a sewage treatment plant as the source of microorganisms to which a specific amount of the material being evaluated and a synthetic sewage mixture are fed on a periodic basis in a specially designed aeration chamber. The next slide (#8) graphically illustrates what the aeration chamber looks like. It is simply a large glass cylinder with provisions for aeration, auxiliary stirring, a siphon for periodic removal of the supernatant and a septum for introduction of the test material. The mixed liquor (sludge + water) obtained from the sewage treatment plant is initially adjusted with tap water to a suspended solids concentration of about 2500 mg/1, and 1500 ml of this mixture is then charged to the aeration chamber. The mechanical cycle employed is shown in the next slide (#9). Each cycle is initiated by the addition of the synthetic sewage and 1 mg of the-PCB product being tested. Since the PC3s are quite water insoluble, they are fed to the unit via injection of 200 pis of a concentrated ethanol solution. In this manner, homogenous dispersion of the PCBs on the bacterial sludge is obtained. After about one hour of aeration an aliquot of the mixed liquor is withdrawn from the chamber and analyzed for PC3s via UV spectro photometry and/or electron capture gas chromatography. Aeration is continued for about 48 hours and a second sample is withdrawn for analysis. At this point, the aeration is stopped and the sludge allowed to settle, the sludge volume and pH are then checked to insure that the unit is operating satisfactorily. Two-thirds of the supernatant is withdrawn and replaced with tap water; aeration is then resumed. The cycle is re-initiated by the addition of the synthetic sev/age and Aroclor in question. This cycle is continuously repeated until a steady state and consistent degradation rates are obtained. The per cent degradation rate is calculated as shown in the equation on the slide from the amounts found in the samples analyzed during each cycle. Degradation testing of the Aroclor products shown in the next slide (rlO) have been carried out over an eight month period in our laboratories. In this slide, we have shown graphically the results observed to date. Here we have plotted the mean per cent degradation . F n n i i 76 ACM rp l:cr. fo r b f ,ihvn^TiT." r o d o r JZ71 r* MC5 1043, a r om* -arcl i w t e r i cenVitfrircg 30t ly v a ig h t c h lo rin e -, A tu c lo r 103 c-CVC c h lo rin e ) , ArosJov 124:*, nd Avne lo r 1254 v e rs u s the. w i-ight. per c : h t ch i.o rin e j53"crjcVit in (,ru>li 'J:? itwilt*1 cihjbt'n pfil CLiiti . r i etij.'uwd1.1.oi rate.* md important point to note herci, is that as the degree of chlorination decreases the deg*radation ratie increases. In order to give you a feeling for the degradation rates observed with other materials, Aroclor 1221 degrades at about the same rate as a non-linear AES surfactant. We have also used this technique to study p,pr-DDT and have at this point in time noted no significant primary degradation. The next slide (#11) shows the changes in honolog distribution observed for Aroclor 1242 via electron capture gas chromatographic analyses. The upper chromatogram shows the character of the residue one hour after addition. The numbers above each peak indicate the dominant homolog or hoinologs present in each. The lower chromatogram is of the residue after 72 hours of exposure to the bacterial sludge. It can be readily seen by comparing the two chromatograms that all the dichloro biphenyls, most of the trichloro biphenyls, and a significant portion of the tetrachloro biphenyls are degraded in 48 hours under these test conditions. The conclusions v/hich we draw from this preliminary data are shown in the next slide (12) Next, I will discuss our "Aroclor Residue Studies" (Slide 13) Our white leghorn chicken studies (Slide 14) have consisted of a 90 day oral exposure of Aroclor 1242, Aroclor 1254, and Aroclor 1260 at 1, 10, and 100 ppm feed levels and a repeat 90 day study of Aroclor 1242 at the 2, 4, and 8 ppm feed levels. 336 Chickens were employed from which a total of 521 tissue, chick, and egg samples were collected. Of these 112 pooled samples were analyzed for PCB residues. . In the next slide (#15) are shown the results of the 90 day oral exposure of white leghorn chickens to Aroclor 1242. On the left side, we have shown the oral exposure levels which were 1, 10, and 100 ppm, the theoretical residue in ppm, which would have been found in the lipid if the chickens had retained all of the Aroclor 1242 which they orally injested. As you can see, these levels are ^125, 1250, and 12,500 ppm. Next is shown the actual average level in ppm found in the lipid of the muscle, fat, and liver samples and then the levels found after 30 days on a TCB free diet. The important points to note arc that ^90$ of all the Aroclor 1242 consumed ir. directly excreted and/or metabolized and that after 30 days on a PCD free diet 35$, 44$, and 57$ of the PCRs retained after* 90 days of continuous exposure at the 1, 10, and 100 ppm levels was excreted and/or metabolized. * f o m 1 77 ADM C0C22 __ __ slide is shown the houiclnf? d3;;fcr>bunion or thr*' product- f e ^ n n d that of the ro.siclv.es i.sol ai-cd from the tissues p.fttjiHSu days of exposure ar.d 30 day;; on a PCD Ircc. diet. The number* across the top simply refer to the number of chlorine atoms- pur biphenyl molecule. As you can see, Aroclor 1242 contains dominant amounts of the di- through pontncklorobiphenyls ontX 1 minor amount of hexachlorobiphcnyl. After 90 days of exposure the dicHlorobiphenyl was no longer ohservable and the dominant components were the tri- through pentachloro biphenyl homologs. After 30 days 6n a PC3 free recovery diet, the hexachloro biphenyl is now a-dominant component because of continued excretion and/or metabolisfa. of 'the lower chlorinated horr.ologs. In the next slide (516) are shown the results for the 90 day oral exposure of Aroclor 1254 in white leghorn chickens at the 1, 10, and 100 ppm exposure levels. The theoretical residues are the same as before and we have again shown the actual levels found in the tissues after 90 days of continuous exposure and 30 days on a PCB free diet. In this instance, ^70-72% of the Aroclor 1254 ingested was directly excreted and/or metabolized and after 30 days on a PCB free diet, M S S of the residues retained were excreted and/or metabolized. ] The homolog distribution of the product and residues is shown on the right of the slide, t.-.e product Aroclor 1254 contains minor . 1 amounts of the tri- and heptachloro hom.o'logs and dominant amounts of the tetra-, penta-, and hexachloro biphenyls. The residue after 90 days of exposure did not contain detectable amounts of the tri-' chloro biphenyls and the tetrachloro biphenyls were no longer a dominant component. The dominant homologs were penta- and hexach2oro biphenyls. After 30 days on a PC3 free diet, the tetra chloro biphenyls were now.not detectable, the pentachloro biphenyls ] were a minor component, and the hexachloro biphenyls the dominant component. .] In the next slide (517) are the results for Aroclor 1260. Again, the oral exposure level and theoretical residue levels are the sane and the PCB residues found in the tissues after 90 days of 3 continuous exposure and 30 days on a PCB free recovery diet are 'shown. After'90 days of exposure, 57-525 of all Aroclor 1260 consumed was directly excreted and/or metabolized and after 30 days on a PCB free diet *v405 of the residues retained were excreted and/or metabolized. .1 _ As shown on the right, Aroclor 1260 contains dominant amounts of penta-, hexa-, and heptachloro biphenyls and a minor amount of octachloro biphenyl. The residues after 90 days of exposure and 30 --i days on a PCB free recovery diet contain minor amounts of the pentaj and octachloro honologs. In both cases, the dominant homologs were i the hexa- and heptachloro biphenyls. 1 q Our albino rat work (Slide 513) has consisted of 30 day oral, 2 year chronic oral and a 3 generation rat reproduction exposure study with Aroclor 1242, Aroclor 1254, and Aroclor 1260 and a 90 day subacute. 2 1 Font 178 ADM 00023C ShB^r7.gBei@stiEtSE fton* v R d r o>ouJR Vlfr e;u c mil' f.ifc/nninpIiM*" fl*s*^'OTZXfecTOfC Two'- hundred- cjl th ese- e iUKVly/.ed for PCS residues.." levels were 1 i.0, and 100 ppm and tlic theoretical residues were ^300, 0000, 00/000 ppm, respectively. The actual residues found in the tissue lipid are shown after 3, 12, and 24 months of exposure. Comparison of the residues found after 24 months to the theoretical residue levels indicates that 99% of the Aroclor 1242 fed was directly excreted and/or metabolized at all exposure levels. As is shown on the right, Aroclor 1242 contains dominant amounts of the di- through pentachloro biphenyl homologs and a minor amount of the hexa-. The residues after two years did not contain a signifi cant amount of the dichloro biphenyls and the dominant components were the tri-, tetra-, and pentachloro biphenyl homologs. In the next slide (#20) are shown the results of the two year chronic oral exposure of albino rats to Aroclor 1254. The exposure and theoretical residue levels are the same as with Aroclor 1242. The residues found after 3, 12, and 24 months of exposure are also shown. Comparison of th residues after tv/o years to the amount ingested ; demonstrates that 95-98% of the Aroclor 1254 consumed is directly excreted and/or metabolized. The hcnolcg distribution of Aroclor 1254 and th residues are shown on the right. Aroclor 1254 contains minor amounts of the tri- and hcptachloro biphenyl homologs and dominant amounts of the tetra-, penta-, and hexachloro biphenyl homologs. The residues did not contain detectable levels of the trichloro homologs and the tetrachloro biphenyls were no longer a dominant component. The dominant homologs were the penta- and hexachloro biphenyls. ^* The next slide (#21) shows the the results for the two year exposure of Aroclor 1260 in albino rats. Again, the exposure and theoretical I residue levels are the same and the residues found in the tissues ! after 3, 12, and 24 months of exposure are shown. In this case 93-952 of all Aroclor 1260 ingested was directly excreted and/or j metabolized. The dominant homologs in Aroclor 1260 and the residues isolated . ^ from the tissues were similar in all cases. ^ In order to demonstrate the relationship between residue storage^ levels and the degree of chlorination of the product fed (slide #22). ] I have plotted the average ppm PCD found in the lipid vs the weight i per cent chlorine in the product fed. These data were taken from our 90 day subacute albino rat studies with Aroclor 1221, Aroclor J* 1242, Aroclor 1254, and Aroclor 1260 at an exposure level of 100 ppm. As von can see, the residue storage levels decrease exponentially as the weight per cent chlorine decreases, simply demonstrating the relationship between the higher homolog content of an Aroclor ] product and the tissue storage level. F o n i179 ACH 000231 23 J ht*VQ-- C0I1C5.55VGii Of Q tW#>- year 1242, Aroclor 1254, and Aroclor 12 6n ci >u uu/ ----j * Ar oc lor 1.2.21.x.. Imn tchnccssec rr..tuuudaie&ir;., ]j0o3 beagle dogs vrcrcr.uncd, resulting in the collection of 2S3 snm.;>1 g 5i, and the analyses _of 14 6 for l'C3 residues. The next slide '("24) shows the results of one two year study of Aroclor 1242 at exposure levels of 1, 10, and 100 ppm. In this study, the theoretical residue levels arc ^500, 5000, and 50,000 ppa respectively. We have also si\own on this slide the residua levels found after two years of exposure and after 30 and 60 day periods on PC3 free recovery diets. The beagle dogs directly excreted and/or metabolized 99.65 of the Aroclor 1242 consumed and after 60 days on PCS free diets, 50-605 of PCS residue retained after two years of exposure was excreted and/or metabolized. Aroclor 1242 contains dominant amounts of the di-, tri-, tetra-, and pentachloro homelogs and -a minor amount of the* hexa- homolog. The residue found after two years of exposure contained no detectable levels of the dichlcro hcm.olcgs and dominant levels of the tri-, tetra-, hepta-, and octachicro biphenyls. The pentachloro hcmolog, although dominant in the product fed, was not a dominant component of the residue. After 30 days on a PC3 free recovery diet, the di-, tri-, and tetrachloro biphenyls were not detectable components of t h e residue. At this point, the dominant components were the hexa-, hepta-, end octachloro biphenyls. The trend toward excretion and/ nr metabolism of the lower chlorinated homologs continued to the extent that after 60 days on the recovery diet the hexachloro biphenyl was no longer a dominant component, and the hepta- and octachloro bi phenyls became the dominant constituents in the residue. In the next slide (25) are the results for the two year exposure of beagle dogs to Aroclcr 1254. The oral exposure and theoretical residue levels are the same and the PC3 residue levels found in the tissues after two years of exposure and after 30 and 60 day periods on PCI3 free recovery diets are again shown. In this instance, the dogs excreted and/or metabolized 98-99% of all Aroclcr 1254 consumed over a two year period. After 60 days on a PC3 free recovery diet, 30-40% of the residues retained were excreted and/or metabolized. The product fed, Aroclor 1254, contains minor amounts of the tri- and heptachloro biphenyls and dominant amounts of the tetra-, penta-, and hexachloro homologs. After two years of exposure, the residue retained from the product did not. contain detectable levels of the tri- or tetrachloro biphenyls, the penta-, and hexachloro biphenyls remained dominant components, and the heptachloro biphenyls became dominant constituents. After 30 days on the PCD free recovery diet, the pentachloro homologs became a minor component of the residue, the hexa- and heptachloro biphenyls remained dominant components and the octachloro homologs iccame a minor component. After 60 cays on the PC3 free recovery diet, the pentachloro biphenyls were excreted and/or metabolized to the extent chat the octachloro homologs became a dominant constituent of the residue. F,nnn80 ADM 00C2 The next slide Cf2C> shows the results for the two year oral exposure residue skudy of Aroclor 1260 in beagle dogs. The exposure? and theoreticsl residue levels are the same us theme for the Arocloir 124V. and Aroclor JL254 studies, Next is shown the residues-which accumulated after two years of continuous exposure and the residues retained after 30 and 00 day recovery periods on PCD free diets. With this Aroclor 93-99% of ttys amount consumed over two years was directly excreted and/or metabolized. After 60 days on the recovery diet *13% of the retained residues were excreted and/or metabolized. * The homolog distribution of Aroclor 1260 is as shown, dominant amounts of the penta-, hexa-- , and heptachloro biphenyls with a minor amount of the octachloro homologs. After two years, the PCS residue contains no detectable level of the pentachloro hcmologs, a .minor amount of the heptachloro biphenyls, and dominant amounts of the hexachloro and octachloro homologs. After 30 days on the recovery diet, the dominant homologs are new the hexa-, hepta-, and octa chloro biphenyls becoming a dominant component of the residue via loss of some of the hexachloro biphenyls. After 60 days on the recovery diet, the hexachloro biphenyls are no longer dominant components of the residue and it is now mainly the hepta- and octachloro biphenyls. , The next slide ($27) illustrates the residue fall off as a function, of Aroclor and recovery period. These data are from the two year beagle dog studies and the exposure level is 1 ppm. In this graph, t have plotted the average ppm PCB found in the lipid for Aroclor .260, Aroclcr 1254, and Aroclor 1242 after two years of continuous oral exposure and then after 1 month and 2 month recovery periods on PCD free diets. This plot simply demonstrates that the PCB residues retained frem Aroclor 1242 fall' off more quickly than those retained from Aroclor 1254 and Aroclor 1260. ?hc table in the next slide (23) shows the relative ability of fowl, xr.all mammals, end large mammals to retain orally ingested PCSs. These data are for Aroclor 1242 at the exposure levels and periods ;hown. The concentration factor is calculated by dividing the '.aximun PCD level found in the lipid by the exposure level. As you ran see from the factors, chickens retain PCBs to a greater extent .hen do rats or dogs. nr fish residue work is not very extensive at this point - rimariiy because we have had problems in finding consulting aboratories capable of carrying out dynamic low level fish exposure tudies, and secondly, because government laboratories such as those n Duluth, Minnesota, Columbia, Missouri, and Gulf Breeze, Florida are, and are, still in better positions to carry out and evaluate hese types of studies. 3 have done some very preliminary 21 day dynamic exposures of cat-sh and blucgiil fingcrlings to some of our Aroclor products and generally supports the conclusions which can be drawn from -taraturc data. \c general conclusions which wo draw from these residue studies are lown in the next three slides. FOOU^l. Slide 30 - Fall^Off - Conclusions Slide i31 r Alteration of Homo-log Distribution - Conclusions In sunnaryf we fool that tha results of our preliminary research support, what has and is bcipg observed via residue analysis of environmental samples; that is to say, from a residue viewpoint, that tha bull: of the PC3 hom^logs released to the environment (PC3s with less than 5 chlorines) are subject to environmental degradation of one sort or another at measurable rates and as such have not accumulated. E. S. Tucker m m 182i ADM 00023*1