Document 6wn4Mym3zRvjKkLYbMjo9nL64

} i `' N the alphabet of environmental contamination, PCBs have a wide variety of uses. Production and J PCB may become as well known as DDT, and for shies figures are not available, but a Monsanto bulsome of the same reasons. Like ddt, pcb contains|metin lists many pi'oducts in which PCBs may be used chlorine, hydrogen and carbon; like DDT, it is not| as plasticizers, flame retardants, insulating fluids, soluble in water, it is soluble in fat, and it is ex ; or to impart some other useful quality. Among these tremely persistent in the environment, i products are natural and synthetic rubber, electrical i The chemical similarity between the two also sug- : products, floor tile, printer's ink, coatings for paper i. gests similar physiological effects in the bodies of and fabric, brake linings, automobile-body sealants, ! fish, birds, and perhaps people. In one particular paints, varnishes, waxes, asphalt, and many kinds j respect which will be discussed later, this has been of adhesives and resins, pcbs are also recommended j confirmed in the laboratory. by Monsanto for mixing with chlorinated insecti A striking difference is that DDT has been used in cides to suppress their vaporization ;ui extend tholr ; the open environment with intent, because of its "kill-life." j toxic effects, to destroy insects; PCB, although known The amounts being used are suggested by the fact : to be toxic, has been used for its other qualities, and that pcbs are available in containers ranging from , has escaped into the environment by accident. It is 50-pound cans to 600-pound steel drums and by the ' not yet known exactly how and where this happens, tank carload. ! nor how much is escaping. As with many of the chemical compounds so Polychlorinated biphenyls, to give PCBs their widely used in this age of synthetics, concern about ' proper name, are chemical compounds manufactured the hazards of pcbs has been limited to the possible ! in this country by the Monsanto Chemical Company exposure of industrial workers. Until I960 it did not ; and in Europe and Japan by other manufacturers. occur to anyone to ask whether pcbs might be re , .. . A Monsanto spokesman says that PCBs were first leased into the environment, or if they were, what - ' ' produced in 1929 by the Swan Corporation which they might do to birds or fish or human beings. later became part of the Monsanto Company, and The first revelation that these compounds had that European production followed, probably about been dispersed in ways which made them available ten years later. Aroclor (the Monsanto trade name) to living things came in 1966 with a report by Sorer oegan to be used extensively during World War II. Jensen, a Swedish scientist, that he had identified _ 16 - ' Environment Yol. 12, Xo. l DSW 552176 STLCOPCB4090593 By Robert Risebrough with Virginia Brodine PCBs in the bodies of 200 pike (taken from different parts of Sweden), in other fish, and in an eagle. Dr. Jensen had also analyzed eagle feathers which had Robert Risebrough, Ph.D., is Associate Specialist at the Institute of Marine Resources, Department of Nutritional Sciences, University of California at Berkeley. been preserved in a museum, some of them going back as far as 1880; he found pcbs first in feathers brought it to our laboratory at the Institute of Ma collected in 1944. rine Resources, University of California in Berkeley. A colleague of Dr. Jensen, Gunnar Widmark, re The egg was found to contain five milligrams of ported later in 1966 to an international commission DDE, the ddt compound that is apparently the most studying pesticide analysis. One of the problems in abundant synthetic pollutant in the environment. isolating and identifying residues of ddt had been The analysis also showed the presence of other com the presence of what Dr. Widmark described as "un pounds which could not be identified. These same known but chlorine-containing compounds" so simi compounds had been evident in the analysis of other lar to dpt that they may sometimes have been mis species of birds and of fish. Because of the impor taken for it. These compounds he and Dr. Jensen'? tance of the peregrine, an attempt was then "made had identified as pcbs. The polychlorinated biphe- ^ -t4dentify~the compounds, but without success until nyls had been found in fish and sea birds, in conifer the Swedish papers came to the senior author's at needles, and in some samples of human fat. tention. With this clue, further work in his labora Scientists in Britain and the Netherlands have tory made it clear that the hitherto unknown com now identified pcbs in wildlife of their respective pounds were polychlorinated biphenyls. countries. Jensen and his colleagues have recently The Monsanto Company, according to a statement reported details of their analysis of Swedish wild supplied by the company and printed in full on life. pages 26 and 27, is not yet ready to accept the con The detection of pcbs in North America began in clusion that the formerly unknown chlorinated com the spring of 1967 when Monte Kirven of the San pounds are indeed pcbs. However, because similar Diego Natural History Museum was searching the results were obtained independently in the labora southwest for peregrine falcons, those swift-flying tories of Sweden, England, Scotland, the Nether and now fast-disappearing birds of prey. He found lands, and the United States, supported by detailed a nest with a single, unhatched, abandoned egg and descriptions of the analytical techniques used (in- January-February, 1970 17 DSW 552177 STLCOPCB4090594 which mm^aVkeo +thlienmm ^deoosiivraqWbled ffAorr vvfalrriiAoiuiQs iinr dustrial uses. They are also among the qualities which make them of great concern as environmental pollutants. Because they have these characteristics, they are extremely persistent -- iust how persistent is not known -- and they can be carried, like DDT, far and wide over the globe by air currents, (ddt is one of the most stable and least water-soluble of the chlori Immature bird. California breast muscle (wet)* 14.4 9.4 1.5 nated hydrocarbon pesticides.) I liver (wet) 7.7 4.5 1.7 The pcbs that have already been found in the f brain (wet) 2.8 1.5 1.9 environment could not all have come from the one brain (lipid) carcass (wet) carcass (lipid) Adult bird. California breast muscle (wet) liver (wet) brain (wet) brain (lipid) carcass (wet) 36 20.2 300 127 77 49.5 595 85 19.3 10.8 160 98 57 34.6 415 65 1.8 insecticide use mentioned in the Monsanto bulletin. 1.9 There are four other possible sources, all of which 1.9 should be explored. The first is the stacks of the \ plants which manufacture Aroclor and the pi ints 1.3 \ which manufacture the products incorporatin g Aro- 1.4 1.4 Iclor. The second is other forms of industrial waste. 1.4 (For example, PCBs, other synthetics, and oil are 1.3 mixed to make a fire-resistant hydraulic fluid, one \ carcass (lipid) 2,600 1,980 1.3 of the "closed system" uses of pcbs referred to in the Immature bird. Arctic Monsanto statement. Yet the amount of hydraulic breast muscle (wet) breast muscle (dry) liver (wet) I brain (wet) body fat (wet) carcass (wet) 2.3 7.8 1.0 0.43 50.3 9.3 0.16 0.54 0.10 0.037 3.2 0.80 14 14 10 12 16 12 fluid that escapes from this "closed system" is sug gested in a Mobil advertisement stating that "indus try wastes almost four times as much hydraulic oil as it uses." The third possible source is gradual wear and weathering of Aroclor-containing products carcass (lipid) 63.7 5.5 12 which may result in slow release of PCBS as vapor or Second year bird. Arctic minute particulate matter into the atmosphere; for breast muscle (wet) 99 28 3.5 example, asphalt which may contain PCBs, is sub- breast muscle (dry) 296 84 3.5 brain (wet) 85 21 4.7 carcass (wet) carcass (lipid) 70 5,000 19.7 1,420 3.5 3.5 TABLE 2 `Concentrations in parts per million -- wet weight, dry weight or lipid (extracted fat) weight. "Total DDT includes p,p' DDT, p,p' DDE, p,p' DDD, p,p' DDMU, o,p' DDT and o,p' DDE. Adapted from Risebrough et al., "Polychlorinated Biphenyls in the Global Ecosystem," Nature 220 (5172): 1098, Dec. 14, 1968. eluding mass spectrometry) and the results ob tained, this conclusion is now generally accepted in the scientific community. The amounts found, which the Monsanto statement refers to as "in the parts per million range," have been as large as 1,980 parts PCB per million parts of body fat in North American peregrine falcons and 17,000 parts per million in the fat of the white-tailed eagle in Sweden. The distribution of these compounds is highest in the areas where men are concentrated and carry on industrial activity. They appear in smaller amounts in organisms found at greater distances from urban. centers. (See Tables 1 and 2 and the sixth reference under Notes which begins "Jensen. . . .") The Monsanto bulletin previously mentioned re fers to the chemical stability of PCBs and their in solubility in water. These are among the qualities Species PCB Content of Eggs of Sea Birds Locality Number o; Samples P3C* Brandt's Cormorant Pelagic Cormorant Murre Pigeon Guillemot Cassin's Auklet Western Gull Black-crowned night heron Caspian Tern Forsters Tern Least Petrel Peregrine Falcon Farallon Islands 17 113 San Mateo County, Calif. 2 62 Farallon Islands 6 553 Farallon Islands San Mateo County 1 20 1 62 Farallon Islands 2 15 Farallon Islands San Mateo County San Francisco County 1 118 1 112 1 483 San Francisco Bay San Francisco Bay 1 330 1 24 San Francisco Bay San Diego Bay 2 805 5 1,010 San Diego Bay 2 114 Baja California 2 3.1 Baja California 1 471 Where sample included more than one egg, value given is the average. `In micrograms. 18 Environment Vol. 12, No. 1 DSW 552178 STLCOPCB4090595 Kxther Ht-aAv- 1 jected to constant friction, and may be a source of either vapor or particulate matter, containing pcbs. Fourth, many products containing PCBs eventually wind up in the city dump, where they may be , burned. Although fire resistant, at sufficiently high ] temperatures PCBs may be released as a vapor in the j form of highly toxic fumes. (Oxides of PCBs which i : would be produced in burning are more toxic than the unoxidized pcbs.) pcbs have not yet been de tected in samples of airborne particulates, but have been shown to be present in rainwater. More study is obviously needed to show the ways in which PCBs enter the environment. Evidence of Ubiquity The worldwide distribution of ddt and related pestiI cides by a variety of mechanisms, but primarily by 1 air currents, is now known (see "Earth, Air, WaI ter," Environment, July-August 1969). Even with out knowing the exact sources of PCBS, it would be January-February, 1970 Both ddt and pcb affect the hormone systems of birds and rats, and for this reason, may threaten the survival of exposed species such as the least tern shown above with young. possible to discover, by the analysis of various forms of wildlife, whether a similar distribution of PCBs is taking place, or whether pcb contamination is local. In the' past two years our own work in California, and that of scientists elsewhere in this country, Brit ain,'"land^SwMeirTiave^foylded^moUTitmgTrvMence for the worldwide dispersion of PCBs. The levels of pcbs found in wildlife near industrial centers may be very high, frequently higher than the amount of ddt. Birds and fish from more remote areas may contain less PCB than DDT. In Table 1 the concentrations of DDT and pcb found in various tissues in two peregrine falcons from California and two from the Arctic are shown. The final column shows the ratio of ddt to pcb--in the California birds, between one and two times as much ddt; in the arctic birds, from three-and-a-half to six - 19 DSW 552179 STLCOPCB4090596 teen times as much DDT as pcb. The most extensive.research on PCRs in wildlife in this The constrast between the immature and the older birds from both areas is also interesting:. The imma country has been undertaken along the California coast, but PCBs have also been found in terrestrial and freshwater organisms. ture California bird had 160 parts per million pcb I in its carcass lipid (extracted fat), while the adult California bird had 1,980 parts per million. The contrast between the immature and older migrant birds from the Arctic was even greater, with an in milligram per cubic meter of air). Among the Aroclors listed for sale by Monsanto are chlorinated biphenyls that are up to 68 percent chlorine and mix i I Ii ifi j i 1 j crease from 5.5 parts per million in the young bird to 1,320 in the older one. The arctic birds migrate through the U.S. and winter in the tropics. Evidentlv they pick up both ddt and PCB during their migration and on their wintering grounds. Analyses of Western Gull eggs show that eggs from San Francisco Bay contained more PCB than eggs from the Farallon Islands, 27 miles west of the Golden Gate Bridge, which in turn contained more PCB than eggs from Baja California, a location much further from any industrial center. Samples of bird tissue and eggs from a variety of species were collected off California (see Table 2). Some of these birds breed in New Zeland and Australia, others on the coasts of British Columbia and Alaska, still others in Alaska and the Canadian Arctic. It is not clear how much DDT and PCB the birds ingested at their native breeding grounds, and how much in the vicinity of California. What is quite clear is that PCB is widely distributed among marine birds which are at the top of a complex mesti of food | 1 jjI/, \? tures of chlorinated biphenyls and chlorinated tri phenyls that are up to 65 percent chlorine. Tire more heavily chlorinated PCBs have been reported in~ wildliFe G)ofh Tn tlic U.S. and in Europe, and have been found to bo highly persisfeimTTtlie bodies of fish and birds, while the more lightly chlorinated PCBs lire somewhatrTess pgrslsTent.~an<l are metabolized or excreted more rapidly. This was confirmed by a laboratory experiment by Koeman in which Japanese quails were fed a mixture of PCBs. After the birds died, it was found that some of the PCBs, particularly the more lightly chlorinated ones, had been metabolized. Howmver, this is not necessarily reassuring. Little is knowm about the metabolites -- the breakdown products -- of PCB; one of the metabolites of DDT (DDE) affects the reproduc tive systems of birds. PCBs are described in Dangerous Properties of In dustrial Materials as affecting human skin and liver at high concentrations, although howr high is not stated. The toxicology is described as follows: chains in the sea. One source of PCBs in the birds is clearly the fish on which they prey, as PCBs have been found in a variety of fish from many different waters. The lesion produced in the liver is an acute yel low atrophy. This hepatotoxic action of the chlori nated diphenyls [same as biphenyls] appears to be increased if there is exposure to carbon tetra PCBs have also been found in freshwater fish and chloride'at the same time. The higher the chlorine terrestrial birds, although there is less published content of the diphenyl compound, the more toxic data on them than for marine organisms. it is likely to be. Oxides of chlorinated diphenyls are more toxic than the unoxidized materials. What is the Hazard? The skin lesion is knowm as chloracne, and con The American Conference of Governmental Indus sists of small pimples and dark pigmentation of trial Hygienists (acgih) recommends levels of haz ardous materials which should not be exceeded in the exposed areas, initially. Later comedones [blackheads] and pustules develop. In persons occupational situations. The acgih recommendation for PCB containing 42 percent chlorine is the same who have suffered systemic intoxication the usual signs and symptoms are nausea, vomiting, loss of as for ddt, namely, a maximum or "threshold limit value" of one milligram per cubic meter of air. (A "threshold" is said to be an amount below which no wmight, jaundice, edema and abdominal pain. Where the liver damage has been severe, the pa tient may pass into a coma and die. effect is noted.) But some PCBs are more heavily chlorinated, and for those with 54 percent chlorine, the ACGIH threshold limit value is half as much (0.5 Cases of occupational chloracne and of systemic damage w'ere reported in the early years of PCB use. Experiments writh laboratory animals also revealed the high toxicity of PCBs injected, fed or applied to DDT reaches the environment the skin. v There is no evidence to indicate that PCBs in the by intent, PCB by accident. environment are likely to reach levels which would cause severe injury or death from short-term ex posure. The possible PCB hazard, like so many en vironmental hazards, is one of long-term, low-level 20 12, No. 1 DSW 552180 STLCOPCB4090597 J < \ t1 .1i 5 1 11 [ exposure and perhaps of effects from its combi nu' tion with other poisons. There is also the more in direct, but no less real danger of destroying other \ forms of life -- part of the vast interconnected web1 of species of which man is but one part and on which he depends. ' The accumulating evidence that no part of the world-is now tree ol pesticide residues,_ the products of-atomic expiosTOirsi~dr ~of~a variety of industrial pollutants, has induced subtle but profound changes in our concept of our position in the global ecosystemandTrTour individual conceptions of remoteness and isolation. There has never been any question that local ecosystems could be irreversibly changed by the introduction of synthetic chemicals, whether these introductions be purposeful or incidental. Since the sea, however, is the dominant feature of the worldwide ecosystem, interpretations of environ mental contamination in terms of local ecosystems, whether terrestrial or aquatic, may be misleading. The accumulation in marine organisms of signifi cant amounts of several pollutants -- those such as PCBs which are insoluble in water, but soluble in fat -- not only elicits an uncertainty about the long term utilization of the sea as a source of human food, but has suddenly raised the question of the ultimate survival of a number of species of sea birds. These species comprise a very large fraction of the world's wildlife, and doubts about their future would have been considered preposterous and un tenable only three or four years ago. Massive re productive failures have been noted in 1969 in the brown pelican in Southern California. The jack | mackerel fishery out of Los Angeles has just been \ closed because of the high levels of DDT in the fish. \ In terms of the exposure of many forms of life and of people of all ages and states of health to PCBs, is there really a "threshold limit value"? Is there really an amount of polychlorinated biphenyl which is safe to breathe or to ingest? No threshold has been found for the effect of DDE on eggshell thick ness, one of the problems which appears in the re productive systems of birds that have ingested the pesticide. Very small amounts of DDE were found to ' REMINDER ` - ; This issue is the January/ \ ! February issue, one of tvro s : double issues published during : i ine year (the other will be the j July/August one). The next ) \ | magazine you receive will be the ;3 ! March issue. ' . -- '. . , i cause some thinning of the shells. The close similarity of DDT and i*CB suggested the possibility that PCB might have similar physiological \effects. Accordingly, David Peakall of the Langmuir (/Laboratory at Cornell University, investigated the effect of PCB on pigeons, and found that, like DDT, ; it induced (stimulated the production of) enzymes in the liver, enzymes which broke down estradiol, a sex hormone. The entire reproductive cycle in birds, from the development of the male and female reproductive organs to the laying of the egg and the birth of the chick, is mediated by various sex hormones. When the work of a hormone has been done, it is broken down by enzymes in the liver. However, if the en zyme activity is artificially increased by the intro duction into the body of a chlorinated hydrocarbon, it appears that the hormone will be broken down at a much faster rate. Among the effects of chlorinated hydrocarbon pesticides that have been found in birds are delayed laying of eggs, thin egg shells (some times so thin as to break) and chicks that die at hatching. In Peakall's experiment, four groups of four birds each were used. The first group was given no chlori nated hydrocarbon. The second was injected with DDE (the persistent breakdown product of ddt) ; 40 milligrams of DDE per kilogram of body weight were injected. The third group was injected with 40 milli grams of DDT per kilogram of body weight, and the fourth with 20 milligrams of PCB per kilogram of body weight. The pcb used was Aroclor 1262, which is approximately 62 percent chlorine. Qne_jveek later, the birds were killed, ,,ana the.portion of the liver containing enzymes was removed. To each liver was added a tiny amount of the sex hormone, estra diol. The breakdown of the estradiol was increased two-and-a-half times by DDE, almost three-and-a-half times by ddt and five-and-a-half times by PCB, in spite of the fact that only half as "much pcb was used. J. C. Street and his co-workers at Utah State Uni versity investigated the effect of a series of ten PCBs ranging from 21 to 68 percent chlorine on female rats. All of them stimulated enzyme induction; the 1 amount of stimulation increased regularly with the percentage of chlorine in the PCB. PCBs containing \ more than 50 percent chlorine were as potent in \ enzyme induction as DDT. ThisJs_particular.ly .inter esting in view of the Monsanto statement that "no adverse-effects" "have been found in rats or other laboratory species fed up to 100 parts per million. (Street fed rats from 50 to 100 parts per million.) Induction of these enzymes would be one of the ex pected effects of the polychlorinated biphenyls in people. Normally the lifetime of the induced enzymes is short. The foreign, water-insoluble compounds (continued on page 23) 22 oSM\l 552^ Environment Vol. 12, No. 1 STLCOPCB4090598 Little is known as yet about what happens between the manufacture of fobs and their appearance in the bodies of birds, fish and people. One possible source of the FCBs in the environment is manufactured products incorporating PCBs which are eventually thrown away and may be burned, as in the apartment house incinerator shown at right, releasing the compounds or their more toxic oxides into the atmosphere. Ki \iits W.. . n"CiLv-i;- I. 1 ( * hi ff. Kdrrvr.,:'i''^ujrTv. - (continued, from page 22) Very little data is available about pcbs in people. that act as inducers are usually converted to water- Both Swedish and British scientists have-reported soluble derivatives that can be excreted by the kid finding them in a few samples of human fat. In ney. Enzyme activity falls as the inducers are me North America the profile of the pcb compounds on tabolized in this way. The polychlorinated biphenyls, gas chromatograms of human milk samples was however, particularly those with greater amounts of found by Dr. James Enderson and Fred Beland of j chlorine, are relatively resistant to biological break- the Colorado College in Colorado Springs. Although i down. They might therefore persist as inducers the air of Colorado Springs is much cleaner than the without being broken down themselves. As the en air of our larger cities, it was not evident whether zymes are continually induced, hormones and per the people of Colorado Springs were obtaining the haps other classes of molecules as well might there PCB in their food or were inhaling it. The senior fore be metabolized at rates faster than normal over author then measured the PCB in a series of mothers' the whole life span of the organism,. The long-term milk samples from Berkeley and from Los Angeles. significance of this phenomenon is as yet unknown- Every sample tested contained both PCB and ddt investigation of various possible effects of the compounds. As is well known, the DDT content in enzyme activity might be undertaken in workers mothers' milk is above the maximum concentrations with a long history of exposure to pcbs. permitted in cow's milk. The Berkeley mothers' milk January-February, 1970 ' 23 DSW 552182 STLCOPCB4090599 rcB is widely distributed among marine birds which are at the top of a complex mesh of food chains in the sea, including the Leach's petrel shown . here. The accumulation of significant amounts of several pollutants, including pcbs, in marine wildlife, not only elicits an uncertainty about the long-term utilization of the sea as a source of human food, but has suddenly raised the question of the ultimate survival of a number of species of sea birds. <! '<? \1}'\ < I 3 contained about four times the legal tolerance limit. exceed the tolerance or if no tolerance limit has been I I The Los Angeles mothers' milk had somewhat less set for that particular food. The jack mackerel of j DDT, but because of the wide variation within each the Pacific coast and the coho salmon of Lake Michi | series, the differences were not significant. The PCB gan, seized and condemned by the Food and Drug j concentrations in both series averaged about 0.06 Administration because they contained high levels ! parts per million of the whole milk. of ddt, contained pcb in addition to the dot com We can no longer assume that the Berkeley air is pounds. . cleaner than the air of Los Angeles, and we still do A thorough investigation of the physiological ef not know therefore how much of the PCB in people fects of the agricultural and industrial chlorinated 'J. derives from food and how much is absorbed by the hydrocarbons, including their effects on the repro lungs from the air. We did find, however, very small ductive systems of both birds and mammals, is ur I amounts of PCB in a sample of cow's milk, and it is gent. We would do well to act on the basis of data present in higher concentrations in fish which are from laboratory animals and wildlife rather than eaten by people. waiting for definitive knowledge from studies of Establishment of tolerance limits of PCB in food is people. Effects on people might not show up for clearly7 essential. Under present law a manufacturer many years and would be extremely difficult, if not ~of pesticides must petition for a tolerance limit for impossible, to relate to one specific cause. An effect each pesticide on each food __crop treated witlWthe might derive from the interactions of two or sev particular pesticide. Food shipments contaminated eral pollutants. The white-tailed eagles studied by ft with pesticides are subject to condemnation if they Jensen in Sweden contained pcb, ddt and mercury compounds. ! Iif if PCBs are available in F containers ranging from I 50-pound cans to 600-pound The pcb in birds, fish, and people might derive from only a few of the PCB uses which release a comparatively large amount of these compounds in to the environment. Release of hydraulic oils con taining pcb into waterways might be one of these. It is also possible that each manufactured product containing pcb, which like all manufactured prod ucts eventually becomes a waste product, will even I; steel drums, and by the tank tually release PCB into the environment, just as any DDT use will eventually increase the environmental carload. \ burden of DDT. We very much need Therefore to ii establish the sources of the environmental residues \ of PCB and to trace the paths by which they move through our environment. If PCB should prove to be 24 DSW 552183 Environment Vol. 12, No. 1 STLCOPCB4090600 plaiit and at a plant in Anniston, Alabama. No data is available on the loss to the environment of rCBs in the course of the manufacturing process, nor on the losses at other plants where products are manufactured which contain pcbs. Swedish scientists have found pcbs in mussels, plaice, cod, and dogfish from remote parts of the west coast, like that shown at left. DSW 552184 25 STLCOPCB4090601 * an uncontrollable chemical like ddt, it will not be possible to speak of "controlled" uses. ' PCB therefore appears to be another waste product of our technology that is not recycled to primary .^materials. TSlthough there are unquestionable eco nomic advantages derived from their use, the dimin ishing capacity of our global environment to absorb Our own wastes should prompt us to consider whether -- and how --- we can develop a technology that can use its waste materials again and again and that does not permit any persistent wastes with bio logical activity to accumulate. g It I 1II i i :3 i4 ii :? !; ; a Monsanto Statement on PCB When this article was in preparation, the Monsanto Company was invited to provide a statement of its position on PCBs. A series of questions was also ad dressed to the company. The answers to some of these questions have been incorporated into the text of the article. Others follow the Monsanto statement. Late in February, 1969, a West Coast newspaper carried a major feature about "a menacing new pol lutant" found in the San Francisco Bay area. The arti cle was based on marine life research carried out by Dr. Robert Risebrough of the University of California. The article stated that residues of pesticides (DDT and DDE) and polychlorinated biphenyl (PCB) were threat ening the welfare of certain birds and posed a long term threat to humans. Monsanto manufactures polychlorinated biphenyl and markets it under our Aroclor trade name. (There are other manufacturers in Europe and Japan.) We, therefore, would like to present some additional facts. The work done by Dr. Risebrough dates back to earlier research by other scientists who, while analyz ing pesticide residues in wildlife, soil and water, en countered unknown or "interfering" substances in the parts-per-million range. Several years ago, two Swedish scientists at Stock holm University's Institution of Analytical Chemistry, Professor Gunnar Widmark and Soren Jensen, reported they had identified these other substances. They said some of the materials were polychlorinated biphenyl or PCB. Since PCBs are not "broadcast" or spread around the land as are pesticides, the scientists the orized that the source must be the industrial wastes of PCB users. In addition to the work of Dr. Risebrough and the Swedish scientists, there have been other studies which indicate the presence of PCBs in the environment. Mon santo is concerned over the situation and is cooperat ing fully with these studies. The common uses of commercial PCB would not nor mally lead to its release into the natural environment. A principal market for PCB is in electrical applica tions where they are used as insulating fluids for transformers and capacitors. In this use, the chemical is completely sealed in metal containers. Another mar ket is for heat-transfer applications where the PCB fluid functions in a closed system. PCBs are also used in several applications where the chemical is incorporated into a polymer as cr; in tegral part of the solid material. Such polymers are used in highly specialized applications as an adhesive, elastomer or surface coating. Polychlorinated biphenyls are not sprayed or dusted on crops, woodlands or any other areas, as are pesti- cides. To our knowledge, they are not used in tires, house paints, household products, or major vinyl plas tics, as has been charged. Therefore, conclusions as to the source of PCB reportedly found in the environment are difficult to make. It has also been implied that polychlorinated bi phenyls are "highly toxic" chemicals. This is not true. Just like other industrial chemicals and home products now in widespread use, PCBs are not hazardous when properly handled and used. During more than 40 years of U.S. production and use, cases of any toxic eifect have been extremely rare -- and then only where the simple precautions recommended for use were not followed. Monsanto has research programs under way to identify the compounds, reported to be PCB, and iocate their source. The programs involve precise analysis o' environmental samples of water and soil. Also under v/ay are studies to determine the biological effects of deliberate dosage of PCBs on fish and mammalian animals. Special emphasis is being paid to endocrino logical effects, mineral metabolism and reproduction physiology. Some preliminary biodegraaability studies ere under way. Further studies to clearly demonstrate this phe nomenon are contemplated. Very early results of chronic toxicity studies contirm that PCBs are not highly toxic. In 90-day studies on rats and other normal laboratory species, there have been no adverse elfects when feedings of up to 100 . parts per million were administered. Monsanto has always cooperated on a regulcr basis with federal, state and university laboratories in their analysis of chlorinated hydrocarbon residues. We will 26 .Environment You 12, No. 1 DSW 552185 STLCOPCB4090602 NOTES .- p. 16. . .. but a Monsanto bulletin...." Technical Bulletin O/PL-306, Organic Chemicals Division. Monaanto, St. Louis, Mo., 1968. We are informed by a Monsanto spokesman that supplies of this bulletin "have been exhausted for several months, and it is in the process of being revised . . . the old bulletin . . . covers only the plasticizer applications, continue to do so. Additionally, Monsanto will continue to exercise the highest degree of control in its manu facturing, shipping and storing of PCB -- as we do with all products. In the functional fluids market, we have carried out a program for several years for the reclamation of used PCBs to reuse these valuable materials. The source of the marine life residue identified as PCB is not yet known. It will take extensive research on a worldwide basis, to confirm or deny these initial scientific conclusions. Questions from ENVIRONMENT and answers from MONSANTO. Environment: At which Monsanto plants is Aroclor manufactured? . Monsanto: In the United States, Monsanto presently manufactures its Aroclor products at plants located in Sauget, Illinois, and Anniston, Alabama. Environment: Have you monitored emissions at those plants for the presence of PCB? If so, what were'"the- results? `* Monsanto: Extensive efforts are in practice at these plants to prevent PCB losses to the environment. These practices have been in use for many years and con trols are continually being improved. Environment: Does Monstanto itself incorporate PCB into some of its other products? If so, at which plants? Have emissions from these plants been monitored for the presence of PCB? With what results? Monsanto: Controlling practices are also in effect to prevent loss in those manufacturing operations where Aroclor is incorporated into other Monsanto products. Environment: Could you tell us what control measures you use to keep the PCB concentrations below the Threshold Limit Value in the plant atmosphere? Monsanto: (No answer) Environment: We would be pleased to receive any ad ditional information, such as scientific reports, adver tising copy, or any other material you may have on PCB. We would appreciate very much seeing copies of the original work you have done on the toxicity of Aroclors. Monsanto: Our research department summarized some of their work and ... I am making it an enclosure. Editor 8 note: The enclosure dealt only with residue analysis, not with toxicity. 1970January-February, many of which are only- suggested applications. To our knowledge. Aroclor plasticizers are not used in all. the applications sogg* in the bulletin. Primary markets arc chlorinated rubber, styrenebutadiene copolymers and polysulfide -sealants. Aside from plas ticizers, the principal market for i>olychioii anted biphenyls is in electrical applications where the insulating fluids used in trans formers and capacitators are completely sealed. In another major market, heat transfer applications, the fluid is used in closed systems." ". . . report by Soren Jensen. . . "Report of a New Chemical Hazard," New Scientist 32:612, 1966. p. 17. ". . . Gunnar Widmark . . . human fat." Widmark, G., "Possible Interference by Chlorinated Biphenyls" in "Pesticide Residues" Report of the IUPAC Commission on the Development, Improvement, and Standardization of the Methods of Pesticide Residue Analysis, Journal of the Association of Official Analytical Chemists 60:1069, No. 6, 1967. "Scientists in Britain. . . Holmes, D.C., J. H. Simmons and J. O'G Tatton, "Chlorinated Hydrocarbons in British Wildlife," Nature 216:227, 1967. Koicien. A. V., and K. Marsden, Nature 216:1274. 1067. . . and the Netherlands. . . ." Koeman, J. H.. M. C. Ten Noever De Brnuw and R. H. De Vos. "Chlorinated Biphenyls in Fish, Mussels and Birds from the River Rhine and the Netherlands Coastal Area," Nature 221: 1126, March 22, 1969. "Jensen and his colleagues . . . Swedish Wildlife.*' Jensen, S. et al., "DDT in Marine Animals from Swedish Wa ters," Nature 224:247, 1969. . . unknown compounds ivere polychlorinated bi phenyls Note: Laboratory procedures in this and subsequent analyses for PCBs are described in the papers listed above and in the author's scientific papers. See especially, Risebrough, R. W., P. Rc-iche. D. B. Peakall, S. G. Herman and M. N. Kirven, "Polychorinated Biphenyls in the Global Ecosystem," Nature 220:1098, 196S. Riscbrough, R. W., P. Reiche and H. S. Olcott. "Current Progress in the Determination of the Polychlorinated Biphenyls," Bulletin of Environmental Contamination and Toxicology 4:192, 1969. p. 18. ". . . 1,980 PCB . . . 17,000 parts per million. .. ." Risebrough, et al., "Polychlorinated Biphenyls in the Global Ecosystem," op. cit. Jensen, S., op. cit. p. 19. ". . . may be released as a vapor in the form of highly toxic fumes." Sax, N. Irving. Dangerous Properties of Industrial Materials, 2nd Ed., Reinhold Publishing Co., New York, 1963, p. 34, p. 20. ". . . a complex mesh of food chains in the sea. . . Risebrough, R. W. "Chlorinated Hydrocarbons in Marine Eco systems" in Chemical Fallout, Morton W. Miller and George C. Berg, editors, Charles C. Thomas, 1969. . . `threshold limit value1 of one milligram.. . Sax, N. Irving, op. cit. p. 34. . . . more lightly chlorinated PCBs. . . Jensen, S. et al., op. cit. . . laboratory experiment by Koeman. . . ." Koeman et al., op. cit. ". . . laboratory animals . . . high toxicity. . .." Miller, J. W. "Pathologic Changes in Animals Exposed to a Commercial Chlorinated Diphenyl," U.S. Public Health Record 69:1085, 1944. McLaughlin. Joseph, Jr., Jean-Pierre Marliac. M. Jaqueline Verrett, Mary K. Mutchler and O. Garth Fitzhugh, "The Injection of Chemicals into the Yolk Sac of Fertile Eggs prior to Incubation as a Toxicity Test," Toxicology and Applied Pharmacology 5:760, 1963. p. 22. ". . . jack mackerel fishery. . . ." "DDT Report Halts Fishing," The New York Times, Dec. 7, 1969. "The breakdown of the estradiol . . . ." Results were in average amounts of polar metabolites formed in millimicromoles for each group of four birds: Control -- 29.r, plus or minus 6.6: DDE -- 76.2 plus or minus 13.1: DDT -- 93.1 plug or minus 11.2: PCB -- 160.0 plus or minus 10,6. . "J. C. Street and his co-workers. . . Street, J. C., F. M. Urry. D. J. Wagslaff and A. D. Blau. "Comparative Effects of Polychlorinated Biphenyls and Orgar.ochlorine Pesticides in Induction of Hepatic Microsomal Enzyme*." presented at the 168th American Chemical Society national meet ing, New Yoric, Sept. 8-12, 1969. - '' DSW 552186 27 STLCOPCB4090603