Document 2q0y1OyqyXbJj0ZxJvyoNp3k7

feature [PESE3,s=piJ*wa52KS aradl persistent; Intensified research is needed to minimize their dangers Carl Q. Guftafaonr Federal Water Quality Administration, Athens, Ca. T^^uring the pul three years, a special elau of compounds, called polychlorinated biphenyls (rca'e), hae claimed the attention of ecologists and pesticide analyst! in this country. These compound! were not discovered in the environment until 1966 In Swo* den and 1967 in the U.S., daspite the fact that they have been available com* mercially for 40 years. Interest in fee's has arisen because they ere frequently found in flih, bird, water, sediment, end other environmental samples when such samples are exam<r.cd for chlori nated pesticide residue . That a wide variety of samples containing rcs's hae been collected from England, Scandi navia, The Netherlands, Antarctica, Central America, and many different parts of the U S makes them truly ubiquitous pollutants. Polychlorobiphenylt are mads by substituting chlorine atoms for one or snore of the hydrogen atoms at the The Monsanto Co, elated recently in a letter to Congressman WUUam F. Ryan of New York that as of August J0, it would no 'onger sell sea's to eusiotners for i,se In gt neral plasticizer operations win-re liltpo*, I of the endproducts catin.<' *>r cont i'lied. ifter some lag period--the t.me it takes to eventually dispose of the rudncis made from rc.a's and cu reiuy in processor's inventories-- in- quantity of ven t getting into the env'ron-nent nmy he substantially red.u ru. // Monsanto's former customers U nk for res substitutes, rather han puri nosing ft n's from ir.inafacim j>.\ in Jo -an and Europe, the projci ted Jeer* use could besom. a reality i liir; U. ti<iiuf*on SI4 Stinou A TvctuM>hr numbered positions of the biphonyl stroewrs. Aroclor. rca'e are also manufactured in Europe and Japan, under trade names such as Phsnochlor and Clophen. The various Aroclors are dif ferentiated by a four-digit number, with the last two digite indicating the percentage of chlorine la the mixture. In the process of replacing hydrogen atoms with chlorine alemi, a large number of substitution combination* arise. For example, three monochlorobiphenyl isomers are possible, 12 dichlorobiphenyl isomsn^ 21 trichlorobiphenyl isomers, and ao on. Theoreti cally, 210 compounds can be prepared by this substitution prooess; a typical exampie would be 2,4,6,2'4'-pontachlorobiphenyl. Whenever aromatic hydrocarbons such as biphenyls are chlorinated, the preduet is a mixture of earnpounds, in cluding isomen. It is quite difficult to synthesize single, specific chloro biphenyl compounds in the laboratory unless involved procedures are em ployed. Consequently fcfw of (he indi vidual compounds hash been prepared in the pure form for study. In the commercial process for t*cs manufacture, biphenyl is chlorinated writ anhydrous chloride in tat! cy lindrical towc:' with cither iron lilingx or ferric chionv.o as tho c....iiy\t The by-product is hydrogen chloride, the produot is s mixture of several r^u'i. The degree of chiorlnetion T deter mined by measuring the spccihc gravity of the mixture oi, when iltv product is morn viscous the balWnd-rmg soft ening-point lest is used. The " i *lc pro cess tokos from 12 to 26 hours In tho U.S.. tho solo manufacturer of rep's is the Monsanto Co., which murtots them under tip trade name Properties The three most important physical properties of the oca's are low vapor pressures (they have high boiling .-oints), low water volubility, and high dielectric constant* They are mis- vlblo with most organic solvents and compatible with many typos of. fply- meri. Although some individualjtAfr chlorobiphenyl compounds Aryi- ' tallinc, the Aroclor mixtures are either liquids or resins. The chemical propu'ties that make sea's desirable Indu-trial materials are their excellent thermal stability, their strong resistance to both LddJc and basic hydrolysis, and .heir general in ertness. They arc qute resistant to oxidation. Monsanto reports, in s tech nics! bulletin on res'*, that they can be heated to 140 C under 260 p.s.i. of oxygen pressure "without showing any evidence of oxidation as judged by de velopment of ae.o/y or fc '..t on of sludge." The physiolojii j| properu* ,ti the rca's make then, noumially v.hc.int contaminant' 11 i,v . i.viroi i . >r. Tor any poliutant, iw .Yctoraerc involved: acute toxicity, *htci, is iiv.uu u:cly evident bces.Mti of i high dc.t.h , or other maiming ciik.v'i ..nd ch \ ,, i, \- iciry, which is the of a Y a, cumulation of th. >o>>on in the ood> and is a suhlah. .'tfcct. Whvo.'* acute ioxicn\ is ,. j, pollutant wP bo readily reeogm. cd and . ;>re remedial actions wi.l Iv introduced. If, on iho other hand. acute toxicity ts low. 'v MUNS 0b232b the phyatological effects will go un noticed until the chronic effects make themselves evident. When this happens, the problem may have advanced be* yond immediate or easy correction. Acute toxicity All studies of pen's in animals indi cate that acute toxicity is not a signifi cant factor. Their acute toxicitics are on the order of those of other chlori nated aromatic compounds. Monsanto has sponsored two investigations of the acute toxicitics of Arocior mix tures. In the first, at the Kettering Laboratory at the University of Cin cinnati, Dr. J. F. Treon and his co workers investigated the toxicity of Arocior vapors for guinea pigs, mice, rabbits, and rats. All animals survived a 24-day exposure to 0.83 p.p m. of Aiodor 1242 for 7 hours per day on 17 of those days. Even after more pro longed tests, there were no severe ef fects from Arocior 1242- In (he second investigation, still in process, three groups of beagles arc fed Arocior 1242, 1234. and 1260, respectively, at a rate of 100 p.p.m. in their diets- After three months no significant abnormalities have been noted. Similar studies on fish have been perfoimcd in several laboratories. Dr. Richard Schoctigcr of the Sport Fish eries and Wildlife Fish-Pesticide Re search Laboratory in Columbia. Mo., n porls that 96 hour-TLnn toxicitiei of the Aroclore to trout range from 1.17 to 60 p.p m. Compared to dot, whose 96 liom-u,-,,, toxicity is 0.002 to 0.009 p.p m. for trout, the pcb's have a rela tively low acute toxicity. With the more sensitive blucgill, the 96 hour-TL-.n for Arocior 1248 is 0.278 p.p.m., while that of dot is 0.008 p.p.m. Arocior toxiclilts appear to be inversely propor tional to the chlorine content of the mixture Shellfish, oysters, and shrimp are more sensitive to pen's. Dr. Tom Duke, at the bureau of Commercial Fisheries Pesticide Field Station, re ports 100'J mortality of juvenile pink shnmp exposed to 0.10 p.p.m. of Aroclot 1254 in water for 48 hours. This concentr.iinm >f Arocior 1254 will cause ,i ini)'* decrease in shell growth i oysikis .tlier 9ft hours. To achieve die saniv effects with DDT in these ex periments, only 0.0006 p.p.m. and 0.01 p.p.m., respectively, were required. There ik very littlo evidence that PCn'a are toxic to insects. Studies io date show ih.it they lire less toxic than dicldrin or dot. As with fish, their tox icity appear* to be inversely propor tional to the chlorine content qf the mixture. Based on the above data, it is un derstandable why the polychlorobiphenyls, commercially available for 40 years, have only recently attracted attention as toxic environmental con taminants. Chronic toxicity The chronic toxicitics of pea's pre sent a more disturbing situation; several chronic effects have been observed. It was discovered, quite by accident, that pea's have a toxic effect on chickens. Profeasor E. L. McCune and his co workers at the University of Missouri found their chickens dying after they were placed in a feeding home, parts of which had been freshly painted with an opoxy pnint. Careful investigation revealed that the toxic factor was Aro cior 1242, a binder in the paint. When Arocior 1242 was fed to the chicks it produced the same characteristic effects as chick edema factor. McCune re ported: ''Cross pathology included hy dropericardium, hydroperitonium, en larged heart, liver, and kidneys, and hemorrhage of internal organs. Mi croscopically the kidneys showed marked tubular dilation and numerous casts." Another chronic effect of pea's is related in wildfowl. The accumulation of high concentrations of chlorinated hydrocarbons in birds resulted in dis ruption of normal breeding behavior and in the formation of thin-shelled eggs. A dramatic example of this effect has been observed in the case of the brown pelican. On the Anacapa Islands off the California coast, no young were hatched last year from 300 pairs of nesting birds. The shells of most eggs laid were so thin that a dent occurred when the egg was picked up. Thero are two possible causes for the laying of thin-shelled eggs by wild fowl. One is a low calcium reserve in the bird; the other is the inability of the bird to deliver the needed calcium to its oviduct, where the eggshell is forming. The calcium level in the avian biosystem and the calcium reserve in the secondary bone structure or medul lary bone, found only in female birds when they are breeding, are controlled by the hormone estrogen. A high es trogen level is associated with the for mation of this calcium reserve. Chlo rinated hydrocarbons, such as dot, Viiltmw- 4, Ntmb,-r 10. October I Oil) fclS MONS vhh'ndime, dieWrm. and ofnV aciivulc enzyme* in the liver which tramdnrm cMiog.'ii mil* .1 nunc wuici-sultihlc compound that i readily eliminated from the bird'* body. This mean* that wlwn estrogen level* are low, calcium rennet will alto Iv low, and there* fore very little eiilemm will he avail* able for strong cg.tshcll production. DieMrin and rot's arc more effective than nor in this type of cnxymc-Jnduc- tion activity: Aroclor 1262 has an es tradiol degrading potential four to five times that of p,p'-doe or technical grade dot. The ability of the female bird to deliver calcium to her oviduct during the Inst 20 hours, when the eggshell is bcihg formed, is related to the func tioning of the enzyme carbonic an* hydrate. When birds that have ex hibited the ability to lay normal egjp are injected with a metabolite of dot (doc) just prior to the formation of the eggshell, they will lay thin-shcllcd eggs. This indicates that dot also in hibits the activity of carbonic anhy- drase, the enzyme that controls the flow of calcium from ;hc blood stream of the bird into its oviuuct. Since dieldrin teem* to have no effect on carbonic anhydrate, we may assume that neither do the ten's. How ever, these compounds delay breeding time significantly. Many ornithologists feel that late breeding hat a stronger influence on the reduction of bird populations than docs the laying of thin-shelled eggs. If this is true, pea's arc a more potent threat than dot to our declining bird populations, es pecially for predatory birds that ac cumulate fairly high levels of nee's be cause they eat smaller animals that al ready have concentrated fee's in their own tissues. Other investigators have produced evidence to show that fee's are simi tar to dot in their activity. Dr. Joseph Street at Utah State University has shown that when pcb'i accumulate in the liver, they induco microsomal cnxyme activity by bringing about more rapid metabolism of drugs, insecticides, and other foreign compounds. He fed rats a diet containing p.p.m. of A rodo 1254 or Aroclor 1260. After 10 days on this diet, the test animals were administered bcxobarbitol at a dose o/ 100 p.p.m. to induce sleep. In comparison with a control group, the sleeping time for these rata was reduced by 65 to *0%. Street also found that Aroclor. when fed at tho SIS Environment*! sclmc* 6 Tociiitolefr same level, will rcduco dieldrin stor age in adipose tissue by 90 to 95%; in crease aniline oxidation by 200 to 300%; and increase bpn detoxication by 430 to 470%. In addition, the pcb'i cause activation of organothiophosphato compounds, which adversely af fect the system. This fatter c/Tcct coun terbalances the detoxification of diel drin. Normally, when a substrate activates an enzyme, it it converted to a watersoluble form that will be eliminated from the system; however, this is not the case with rca'a. Because they re main in tho system for prolonged pe riods of time, their enzyme induction activity is always present. In this way tho normal concentration >f important body chemical* may be lowered to the point of bringing about malfunctions in the system. For example. Street be lieves that the pcb's bring about steroid degradation, which can lead to altered endocrine relationships. The chronic toxicity to man is as follows: Like the chlorinated naphthalenes, the chlorinated diphenyls have two distinct actions on the body, namely, s skin etTect ana a toxic action on the liver. The lesion produced in the liver is an acute yellow atrophy. This hcp.uo-toxic action of the chlorinated Ji* phenyls appears to be increased if there it exposure to carbon tetrachloride at the same time. The higher the chlorine content of the diphenyl compound, ihc more toxic it is liable to be. Oxide* of chlorinated diphenyl* are more HONS 082330 tnvic than the unoxidized ma terials The skin lesion is known .is eltloi.icue. ami consist* of small pimples .nut dark pigmentation of the exposed areas, initially. Later, comedones and pustules develop. In persons who have suffered systemic intoxication. Ihc usual signs and symptom* arc nausea, vomiting. loss of weigld. jaundice, edema, anil abdominal pain. Where the liver damage has been severe, (he patient may pass into coma and die. Sax, N. li ving, "Dangerous Prop atics of Iniiustrlal Materials," 3rd of-. Van Soxlrand-Reirthold, New York, 1968 The ubiquih of pcb's is related to the wide spectrum of applications that haw been found for them. The largest single use of net's is related io (heir electrical properties--as coolant-insu lation fluids in transformers. For (his purpose (he Aroclors are also sold under such trade names as Chlorcxtol (Allis-Chalmcrs Mfg. Co.). Dykanol (Federal Pacific Electric Co.), Incrteen (Weslinghouse Electric Co.), No* fiamol (Wagner Electric Co.). Pyranot (General Electric Co.), and Thccminol (Monsanto Co.). Other uses oi mi's include formula tion into ballasts for fluorescent fixlitre*; impregnation of cotlon and as bestos for braided insulation of elec trical wiring: a plasticizer in wire and cable coatings; capacitors and askarcltype transformers; and plasticizers of vinyl ch'oridc polymer films. Because of their thermal stability and fire re sistance. the rco's also find application in high-pressure hydraulic fluids, spe cialized lubricants and gasket sealers, heat transfer agents, and machine tool cutting oils. Miscellaneous uses in clude: formulation into some epoxy paints; protective coatings for wood, metal, and concrete; adhesives; and in carbonless reproducing paper. One of the primary manufacturers of carbon less reproducing paper also sells Aro clors in an encapsulated form. Gcncraliy the kinds of applications Joscribcd above mean that the pen's will be m many types of products that eventually And their way to Ihc domes tic market. When used in manufacture of ballasts lor fluorescent fixtures they will be found in kitchens, bathrooms, stores, and offices throughout the coun try. Wherever office forms are used that do not use carbon paper, one moy And FCO'S formulated into tho micro capsules of dye that comprise the re Gat chromatogram A it of a standard pesticide mixture, B it typical of Arocior 1254. and A + B it tha chromatogram of a 50 : 50 mixture of both. The concentration of Arocior 1254 it approximately 10 timet thote of the pesticides in A. hence It it un derstandable why PCB'a were not readily recognized in pesticide chromatograms. Gat chromatograph (Packard 7620) conditions: gat flow 80 ml./min. nitrogen: tem peratures--oven, 210* C.. inlet. 230* C,, detector. 216* C.; Ni" electron capture detector: 5' x Vi" glass column packed with 87# SE-30 on Chromotorb Q 80*90 mesh. producing layer of the business form, pen's have also been found on the transparent receipts used in credit card charge forms. As plasticizers they can be expected to appear in many con sumer plastic*. Since the chronic toxicitics arc so significant, it becomes important to know just how extensively the pen's are distributed in tho ecosystem, and just how they And their way into the environment. Rainwater in En gland, brown seals oil the coast of Scotland, white-tailed eagles in Swe den, cod in the Bailie Sea. mussels in The Netherlands, adelie penguin eggs in tho Antarctica, brown pelican egg* in Panama, Arctic terns, shrimp in Florida, river water in Japan, waters in the Great Lakes, human hair, and human adipose tissue--samples of all those have been found to contain pen's. MQNS 08^331 ihiik making them a clast oi widely dispersed pollutant*. Readily absorbed The properties of ecu'* that make them industrially useful are the tame properties ih.U cause them lo persist in the environment. These in clude thermal stability, resistance to oxidation and hydroKsis. sohihility in it wide range of organic solvents, water insolubility. high dkloctric constant, and compatibility with many types of macromolcculcs. Their resistance to oxidation and hydrolysis also makes pea's more stable and persistent than dot. Consequently, they could even tually accumulate to a higher concen tration than dot, especially If the use of ddt is sharply curtailed in the U.S. The solubility of fen's in nonpolar solvents explains why they are readily absorbed into fatty tissue and into the liver. Their resistance to oxidation or other types of chemical degradation explains their persistence in the en vironment and accumulation in animal tissue. The latter effect is enhanced both by their insolubility in water and solubility In organic solvents. Their chemical inertness and resistance to metabolism account for their low acute toxicity. But as they slowly build up in a living system their con centration approaches toxicity levels, at which point chronic effects make themselves evident It has been established that Ash-eat ing birds will accumulate large eoncennaiions of Pea's, as in the case of the white-tailed eagle, which has been found to have os much is 14,000 p.p.m. of pea's. Peregrine falcons, taken off the coast of California, were found to have as much os 2000 p.p.m. in their lipid tissue. When shrimp were exposed to 10 p.p.b. of Aroclor 1254 for 48 hours, they accumulated 1300 p.p.b. of pci's, which represents a J 30-fold con centration in a very short lime. Oysters, exposed to an identical concentration of Aroclor 1254 for 96 hours and then placed in pca-frcc water for four days, still had a concentration of 33,000 p.p.b. of Pea's, which constitutes a 3300-fold concentration. This means that even though the concentrations of Pea's ere in the parts-pcr-billlon rango in the environment, their high lipid solubility causes them to collect in fatty tissues of lower animal* and marino life. Therefore, species at the lop of a food chain will Ik <ecoimiloto pea's in ilieir bodies, piiri.ciiUrly in their lipid tissue und liver, mi much the same SIS fcAfirmnMMitl Nctn.ci A Ttux4*y ^ way os they accumulate ddt and other chlorinated pesticides. Because of the low solubility of pea's in water, when a solution or dispenion of them Is discharged into a river or lake, they will accumulate on the sedi ment in relatively high concentrations. Subsequently, they will redissolve,very slowly in the water as conditions change. Therefore, it will usually take a tong time to flush out a contaminated area. Accidental occurrence The reason that PCi't have not been found in the ecosystem as extensively as ddt, end ere not present in environ mental samples at os high a concen tration os dot, is that pce't And their way into the environment accidentally. dot la deliberately spread because this is the oaly way its insecticidal proper ties can be utilised. Pea's are not in tended to get into the environment, but they do because their unique chomical properties prevent them from being de stroyed by our usual waste disposal methods. Thus, they inadvertently ecupc und become widely dispersed. In Sweden, where the use of nor has been banned, and where ihe main power oourco is hydroelectric, investi gators And tint the concentration of pcb's in the environment is os high as that of dot. Thera ore several ways by which pci's get into the ecosystem. One of these is by Incineration. Products con* mining rc', such as carbonless re producing paper in business forms, plastics (especially polymer Aim and sheeting that contain pci's as plasti cizers), spent bsllasts from fluorescent light fixtures, and objects coated with rca-formulatcd coatings, ell And their way to the city dump or incinerator for burning. The pea's do not burn but arc vaporized. They are then carried into the atmosphere, where they* collect on particulate matter and are subse quently returned to (he surface oi the earth, into the rivers, lakes, and oceans. In this way they become widely dis tributed throughout the global environ ment. Another source is probabtv land run-off from industrial w,im* and dumps. A third source is the point of manufacture and the plants where ren's are processed into other products. They can escape through the plant ven tilation and exhaust systems into the nimosplwrc ami through it* waste treat ment system into newer* or directly into waterway*. HONS 082332 ' |i i< inicrcating to noic that tho inci- * jciwc of rftiV ii\ environmental saml>U> ^ highest m iiuluiMriuiixcd und uriMiiued .uvuv Birds whose primay habitat is the San Francisco Bay area have a larger concentration of pen's per unit of body weight than those lo cated in Baja, Calif., which is com pletely rural. Aquatic life in tho Archipclntso of Stockholm, the most indus trialized area of Sweden, were found to have a higher concentration of rex's than fish samples taken from the west ern coast of Sweden, a leu developed area. Sediment samples taken from southern portions of Lake Michigan have a higher concentration of Pen's than those from other parts of the lake. Monsanto states that until a recent change in marketing policy (see inset, page 614), sales of Aroclors were in creasing at the rate of 8% per year. While this increase docs not seem sig nificant. it may be important if the in creased consumption was in consumer products and thus would And (heir w.iy into our normal solid watte ditpot-U systems. Such an occurrence would mean a definite increase of pea residues in the environment, and therefore a marked increase in their chronic tox icity effects. (Selection pen's were nut discovered i t environ mental simplex until very recently for scvernl reasons. First, as indicated shove, they have not been deliberately distributed about the ecosystem. Sec ondly, because of (heir relatively low acute tokiciliex, their presence was not immediately evident. Finally, they are difficult to detect analytically. The I'Cii'x were first deleted as in terfering pe.ilu in the gas chromato graphic analysis (oc) of environmental samples being analyzed for chlorinated pesticide residues. When pea's ant pres ent in a sample they give a pattern of several oc peaks, whose retention limes are simitar to those of dicUlrin, dot, one. sldrin, and hcptachlor oxide. Be cause the peeks were not large or sharp, investigators tended to ignore them until S. Jensen, in Sweden, and ft. Risebrough, at the University of California et Berkeley, identified them as corresponding to common constitu ents of environmental samples being analyzed for persistent pesticides. The problem of the interferences of rca's with the analysis of otlur chlori nated pesticides has been largely over come by prior treatment of tho ^am ple. Several investigators have used column chromatography to aoparate pen's from chlorinated pesticides. At a recent meeting, sponsored by the rwQA's National Water Quality lab oratory, Duluth, Minn., a general pro cedure wav recommended for separa tion of pen's from pesticides. In this procedure for biosamples, tho sample Is cxtractod with hexane as in regular pesticide analysis- It is then partitioned with acetonitrile to remove fats, the clcaned-up extract is passed through a Fluorisil column and then through a silicic acid column. Finally, the sample is analyzed by gas chromatography, with a chloride-specific detector. In this way the pesticides are retained on the silicic acid column for later elution and identification. Resoareli needs To assets fully the significance of pen's et environmental pollutants, ad ditional research is needed. No one really knows the extent of the chronic effects of these chlorinated hydrocar bons. Some problems that need to be considered are: Although pea's are known to ac cumulate in human organa we do not know at whut concentration they will begin to exhibit toxic effects. Will these chronic effects be similar to thane shown in animal*--microsomal en zyme activity, calcium metabolism in hibition, and so on? What arc other possible chronic effects? * Which of the many pen com pounds in the commercially available mixtures arc responsible for their tox icity? Can commercial Pen mixtures be modified to eliminate the toxic com ponents? Pure samples ore required to answer these questions. At the present lime work is continuing at the fwqa's Southeast Water Laboratory to sep arate each of the Aroclor mixtures into its many components, and to identify each component. Wc need to know all the uses for tho PceY What is the annual produc tion of pcb's? Our knowledge of these fact* is limited und needs to be ex panded. These facts should be known if we ere to accurately determine how they get into the environment, and take steps to prevent further environmental contamination by them. * In view of the complexity of the isolation and accurate quantitative analysis of pea's in chlorinutcd resi dues, a straightforward, unambiguous measurement of them needs to bo de veloped. 1 * What is the fate of pen's in nat ural waters? More need* to be known of their partition coefficients between bottom sediments and water. This it vitul if wc arc to estimate how long it will lake for i river bed to doun itself of contamination, ft will also be uteful when assessing the effects of pea's on marine life that feed on the bottoms of lakes, rivers, and estuaries. We should also learn more about pcs solubility in water of various ionic strengths. * Are present waste treatment sys tems adequate to handle pea's? Do spe cial measures need to be taken when pea's arc part of the waste efflueot be ing treated? By trying to get some of these an swers now, we may find that we arc in a position to control the escape of pen's into the environment before ad ditional damage is dona. So frequently, action is taken only after it is evident that massive damage has resulted from a particular pollutant In the ceae of the pea's we may have an opportunity to resolve the situation before that happens. Additional Hooding Hubbard. H. L, ''Chlorinated Biphenyl end Related Compounds," Encyclo pedia of Chemical Technology, 2nd od., 5, Intcrseionce Pubi.. New York, N.Y., 1964. pp. 289-296. Reynolds. L. M., Buff. Environ. Confe/n. Toxicol. 4. 128 (1969). Risebrough. R. N., et. ai,, Nature 220 (1966). Carl C. Gustafson, chairman of the Department of Chemistry ut King's College, DriarcHff Manor. V Y., re ceived a Ph.D. In Organic chemistry from the University of Delaware In 1937. During the 1969-70 academic year, he war on leave at the fwqa Southeast Water Laboratory In Athene, On., where he studied trace organic analysis in waste effluents. As a mem ber of the National Water Couhtmlriant* Characterization Research Pro gram, he worked with pea'/ and pulp and paper mill effluents. Volume *, NwttUt tO. Qctofcor 1970 St* MONS 002333