Document DMBYRrvwkO7Zg9geJbw62roB
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potin Victoria
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Monsanto
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' Monttnto Ausl'tlU Limited
C*lt Tow( Frinei* Gttt
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151 Flindvtt Sirttt Melbourne
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Uaibamaa Vlstirn JOOt
________
, , than* 854-4333 />/# 30-238 raiatfmt 'Mominia' M.lboum,
30th March, 1972.
The Manager,
.
General Electric Co. of Australia,
G.P.O. Box 4C6F,
BRISBANE A001, Queensland.
Dear Sir,
,
As you have probably beard, Monsanto is engaged in a volun
tary program to limit sales of products containing poly
chlorinated biphenyls to uses as a dielectric in manufacture
of transformers and capacitors from which escape of PCS'a
to the environment can be prevented by our customers.
( This action ha
because of Monsanto's concern
about certain studies which indicate FCB's may be accumintin-
in the environnone, and in some instances, have beo-n found
food or in the feed chain. As a purchaser of RGB-contain'1.
products, re f eel certain you are aware of the interest and
concern being demonstrated around the world by scientists
about this pro olsn. nevertheless, we call to your specie],
attention the attached article on RGB's by Carl G. Gustafson
of the United States Federal V.'ater Quality Administration
appearing in Environmental Science and Technology''.
V/e believe if you are fully advised of the potential problems associated with the continued use of PCB-c cnt'air.ing products (in these applications) you can, by the ex ere ice of care and appropriate cautionary warnings to your cu atoners, and the exercisSe of care on their part? assure tha t RGB's purchased by
you do not escape into the environment.
Monsanto would lilre to continue to sell you its RCB-contai r.g products for use as a dielectric fluid c.n its normal sales
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Conditions, but must make such sales subject to the under
takings requested below. You will appreciate that 7/e "must also reserve- the right to change our" sales policy as ' additional facts nay become known about PCB's.
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The undertaking^ with which we would request-you to agree are as follows:
1. You agree to use Monsanto's PCB-containing products .only as dielectric fluids in capacitors and transformers.
2. You acknowledge that you have been advised by us of and that you are aware of the potential harm to the environ ment and to food and the food chain by the escape of PCB's into the environment.
3. You agree to take all care in handling use and disposal
of PCB's to ensure they do not enter the environment and to so advise your customers.
4. You acJcnowledge receipt of the attached handling pre cautions for Monsanto's ?C3-containing produces.
5. You agree to notify your customers of the hazards of
FCB's .
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If you agree to the above, would you kindly sign and return to us the enclosed duplicate of this letter where indicated. To enable us to give you satisfactory servicing on your .
future orders, your prompt reply would be appreciated.
Yours faithfully, MONSANTO AUSTRALIA LIMITED.
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R.F. Gamsworthy</ Prpiuct I'rvnjr^ Che
Encs.
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PCB*s-pirewa|Qnt
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Intensified research is needed to minimize their dangers
Carl O. dustafserif Federal Water Quality Administration, Athens, Ga.
I 3uring the past three years, a
special class of compounds, called polychlorinated biphenyls (pcb's), has claimed the attention of ecologists and pesticide analysts in this country. These compounds were not discovered in the environment until 1966 in Swe den and 1967 in (he U.S.. despite the fact that they have been available com mercially for -tO years. Interest in pcb's has arisen because they are frequently found in fish, bird, water, sediment, and other environmental samples when such samples are examined for chlori nated pesticide residues. That a wide variety of samples containing peas has been col'cctcd from England, Scandi navia. The Netherlands, Antarctica, Central America, and many different pans of the L'.S. makes them truly ubiquitous pollutants.
Polychlorobiphenyls are made by substituting chlorine atoms for one or more of the hydrogen atoms at the
The Monsanto Co. stated recently in a letter to Congressman William F. Ryan of Sew York that as of A ugust JO. it would no longer sell PCS'* to customers for use in general plestidssr operations where disposal of the endprodnets cannot be controlled. After some lag period--the time it takes to eventually dispose of the products made from pcb's and currently in processor's inventories--the quantity ot pcs'r petting into the environment may be substantially reduced. If Monsanto s `ormer customers look for pcs substitutes. 'other than purchasing PCS'r from manufacturers in Japan and Europe, the projected decrease could become a reality.
Carl G. Gustafson
numbered positions of the biphenyl structure.
In the process of replacing hydrogen atoms with chlorine atoms, a large number of substitution combinations arise. For example, three monochlorobiphenyl isomers are possible. 12 dichlorobiphenyl isomers. 21 trichlorobiphenyl isomers, and so on. Theoreti cally, 210 compounds can be prepared by this substitution process: a typical example would be 2.4,6.2'4'.peniachlorobiphenyl.
Whenever aromatic hydrocarbons such as biphenyls are chlorinated, the product is a mixture of compounds, in cluding isomers. It is quite difficult to synthesize single, specific ehlorobiphenyl compounds in the laboratory unless involved procedures are em ployed. Consequently few of the indi vidual compounds have been prepared in the pure form for study.
In the commercial process for sea manufacture, biphenyl is chlorinated with anhydrous chlorine in tall cy lindrical towers with either iron filings or ferric chloride as the catalyst. The by-product is hydrogen chloride: the product is a mixture of several pea s. The degree of chlorination is deter mined by measuring the specific gravity of the mixture or. when the product is more viscous, the ball-and-ring soft ening-point test is used. The whole pro cess takes from 1 2 to 36 hours.
In the (J S . the sole manufacturer of pcs s is the Monsanto Co., which markets them under the trade name
Aroclor. pcb's are also manufactured in Europe and Japan, under trade
names such as Phenochlor and CIophen. The various Aroclors are differentiated by a four-digit number, with the last two digits indicating the percentage of chlorine in the mixture.
Properties
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The three most important physical*.
properties of the pea's are low vapot
pressures (they have high boiling'
points), low water solubility, and high
dielectric constants. They are mfs-
cible with most organic solvents and
compatible with many types of poly-
".er>. Although some individual poly-
chlorobiphenyl compounds are crys-
alhne. the Aroclor mixtures are either
I liquids or resins.
The chemical properties that make
pea's desirable industrial materials are
thetr excellent thermal stability, their
strong resistance to both actdic and
basic hydrolysis, and their general in
ertness. They are quite resistant to
oxidation. Monsanto reports, ia a tech
nical bulletin on pea's, that they can
be heated to 140 C. under 260 p.s.i. of
oxygen pressure "without showing any
evidence of oxidatibn as judged by de
velopment of acidity or formation of
sludge."
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The physiological properties of the
pcb's make them potentially significant
contaminants of the environment. For
any pollutant, two factors are involved:
acute toxicity, which is immediately
evident because of a high death rate or
other maiming effect: and chronic tox
icity. which is the result of a slow ac
cumulation of the poison in the body
and is a sublethal effect. Whenever
acute toxicity is high, a pollutant will
be readily recognized and appropriate
remedial actions will be introduced. If,
on the other hand, acute toxicity is low,
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,he physiological effects w,li 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 teilelty
All studies of pci's in animafs indi cate that acute toxicity is not a signifi cant factor. Their acute toxicides are on the order of those of other chlori nated aromatic compounds. Monsanto has sponsored two investigations of the acute toxicides of Aroclor 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 Aroclor vapors for guinea pigs, mice, rabbits, and rats. All animals survived a 24-day exposure to 0.83 p.p.m. of Aroclor 1242 for 7 hours per day on 17 of those days. Even after more pro longed tests, there were no severe ef fects from Aroclor 124'. In the second investigation, still in process, three groups of beagles are fed Aroclor 1242, 1254. 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 per formed in several laboratories. Dr. Richard Schoettger of the Sport Fish eries and Wildlife Fish-Pesticide Re search Laboratory in Columbia. Mo., reports that 96 hour-n.,,, toxicities of the Aroclors to trout range from 1.17 to 60 p.p.m. Compared to dot, whose 96 hour-TL,:,, 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 bluegill. the 96 hour-n.5u for Aroclor 1248 is 0.278 p.p.m.. while that of dot is 0.008 p.p.m. Aroclor tox icities appear to be inversely propor tional to the chlorine content of the mixture.
Shellfish, oysters, and shrimp are more sensitive to pcb's. Dr. Tom Duke, at the Bureau of Commercial Fisheries Pesticide Field Station, re ports 100% mortality of juvenile pink shrimp exposed to 0.10 p.p.m. of Aro clor 1254 m water for 48 hours. This concentration of Aroclor 1254 will cause a 100% decrease in shell growth f oysters after 96 hours. To achieve 'he same effects with oor in these ex periments. only 0.0006 p p.m. and 0,01 P P-m.. respectively, were required.
There is very little evidence .that "Cl's are toxic to insects. Studies to
show that they are less toxic than
dieldria or oor. M with fish, their tox icity appears to be inversely propor tional to the chlorine content of 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.
Chronle toxicity
The chronic toxicities of pcb'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. Professor E. L. McCune and his co workers at the University of Missouri found their chickens dying after they were placed in a feeding bouse, parts of which had been freshly painted with an epoxy paint. Careful investigation revealed that the toxic factor was Aro clor 1242. a binder in the paint. When Aroclor 1242 was fed to the chicks it produced the same characteristic effects as chick edema factor. McCune re ported: "Gross pathology included hy dropericardium, hydroperitonium, en larged heart, liver, and kidneys, and hemorrhage of internal organs. Mi
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0r0,^^ICa^7 the kidneys snowed mar e tubular dilation and nu merous casts.'
Another chronic effect of pcb's is related m wiidf0W( j^e accumulation of high concentrations of chlorinated hydrocarbons m birds resulted in dis ruption of normal breeding behavior and in the formation of ihm-snelled 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.
There are two possible causes for the laying of thin-shelled eggs by wiidfowl. One is a low calcium reserve m 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 bloxystem and the calcium reserve in the secondary bone structure or medul lary bone, found only in female bfrds when they are breeding, are controlled by the hormone estrogen. A higir es trogen level is associated with the for mation of this calcium reserve.Chlo rinated hydrocarbons, such as dot,
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WATER PCB-SD0000001872
" cruorcune. u.eiunn, ,inu r -3 ' acuva(c . cnzymes ia <he livcr which tr3nsforTT1
estrogen into more water-soluble
compound that is readily eliminated
from the bird's body. This means that
when estrogen levels are low, calcium
reserves will also be low, and there,
fore vers- little calcium will be avail
able for strons eggshell production. Dieldrin and fee's are more effective than ddt in this type of enzyme-induc tion activity. Aroclor 1262 has an es tradiol degrading potential four to five times that of p.p'-oot or technical grade oor.
The ability of the female bird to deliver calcium to her oviduct during the last 20 hours, when the eggshell is being formed, is related to the func tioning of the enzyme carbonic an* bydrase. When birds that have ex hibited the ability to lay normal eggs are injected with a metabolite of dot (ooe) just prior to the formation of the eggshell, they will lay thin-shelled eggs. This indicates that oor also in hibits the activity of carbonic anhydrase, the enzyme that controls the flow of calcium from, the blood stream of the bird into its oviduct.
Since dieldrin seems to have no effect on carbonic anhydrase, we may assume that neither do the pcb's. How ever. these compounds delay breeding time significantly. Many ornithologists feel that late breeding has a stronger influence on the reduction of bird populations than does the laying of thin-shelled eggs. If this is true, pcb s are a more potent threat than dot to our declining bird populations, es pecially for predatory birds that ac cumulate fairly high levels of pcb's be cause they ea: smaller animals that al ready have concentrated pcb s in their own tissues.
Other investigators have produced evidence to show that pcb's are simi lar to dot in their activity. Dr. Joteph Street at Utah State University has shown that when pcb's accumulate in the liver, they induce microsomal en zyme activity by bringing about more rapid metabolism of drugs, insecticides, and other foreign compounds. He fed rats a diet containing SO p.p.m. of Aroclor 1234 or Aroclor 1260. After' 10 days on this diet, the test animals were administered hexobarbitol at a dose of 100 p.p.m. to induce sleep. Ln comparison with a control group, the sleeping time for these rats wax reduced bv 65 to 30?. Street also found that Aroclor, when fed at the
same level, will reduce dieldrin stor age in adipose tissue by 90 to 95%; in crease aniline oxidation by 200 to 300%; and increase epn detoxication by 430 to 470%. In addition, the pcb's cause activation of organothiophosphate compounds, which adversely af fect the system. This latter effect coun terbalances the detoxification of diel drin.
Normally, when' a substrate activates an enzyme, it is converted to a watersoluble form that will be eliminated from the system: however, this is not the case wuh pcb's. Because they re main in the system for prolonged pe riods of time, their enzyme induction activity is always present. In this way the normal concentration of important body chemicals may be lowered to the
814 Earirammal Sdnt & T^etwotety
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, a skin effect and a toxic action on the liver. The lesion produced in the liver is an acute yellow atrophy This hepato-toxic action of the chlorinated di phenyls aopears to be increased if there is exposure to carboo tetrachloride at 'he same time. The higher the chlorine content of the diphenyl compound, the more toxic it is liable to be. Oxides of chlorinated dtrhenyls are more
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toxic chin the unoxidized ma
terials.
The skin lesion is known as chloracne, and consists of small pimples and dark pigmentation of the exposed areas, initially. Later, comedones and pustules develop. In persons who have suffered systemic intoxication, the usual signs and symptoms are nausea, vomiting, loss of weight, jaundice, edema, and abdominal pain. Where the liver damage has been severe, the patient may pass into coma and die.
Sax, iV. frving, "Dangerous Properttes of Industrial Materials," ird edVan Nostrand-Reinhald, New York. 1968.
The ubiquity of pcb'i is related to
the wide spectrum of applications that
have been found for them. The largest
single use of pci's is related to their
electrical properties--as coolant-insu
lation fluids in transformers. For this
purpose the Aroctors are also sold
under such trade names as Chlorextol
(Allis-Chalmers Mfg. Co.). Dykanol
(Federal Pacific Electric Co.). fner-
teen (Westinghouse Electric Co.), No-
flamol (Wagner Electric Co.), Pvranol
(General Electric Co.), and Thermi-
nol (Monsanto Co.).
Other uses of pci's include formula
tion into ballasts for fluorescent fix
tures; impregnation of cotton and as
bestos for braided insulation of elec
trical wiring; a plasticizer in wire and
cable coatings; capacitors and askarel*
type transformers; and plasticizers of
vinyl ch'oride polymer films. Because
of their thermal stability and fire re
sistance. the pcs's also find application
in high-pressure hydraulic fluids, spe
cialized lubricants and gasket sealers,
beat transfer agents, and machine tool
cutting oils. Miscellaneous uses in
clude: formulation into some epoxy
paints; protective coatings for wood,
metai, and concrete: adhesives: ini
carbonless npodociti
e#
Gas chromatogram A is of a standard pesticide mixture. 3 is typical of Arocior 1254. and A B is the ehromatogram of a 50 : 50 mixture of noth. The concentration of Arocior 1254 is approximately 10 times those of the pesticides m A, hence it is un< derstandable why PCB's were not readily recognized m pesticide chromatograms, Gas chromatograph (Packard 7620) conditions: gas flow 80 ml./mm. nitrogen; tem peratures--oven, 210* C., inlet. 230* C., detector, 218* C.; Ni** electron capture detector; 5' x '/' glass column packed with 8^ SE-30 on Chromosoro Q 80-90 mesh.
Generally the kinds of applications described above mean that the pea's will be in many types of products that eventually And their way to the domes tic market. When used in manufacture of ballasts for fluorescent fixtures (hey 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 may find pea's formulated into the micro capsules of dye that comprise the re
producing layer of the business form, pea's have also been found on the transparent receipts used in credit card charge forms. As plasitcizcrs they can be expected to appear m many con sumer plastics.
Since the chronic toxicitics arc so significant, u becomes important lo know just how extensively the pen's are distributed in the ecosystem, and just how they find their way into
the environment. Rainwater in En gland. brown seals otf the coast of Scotland, white-tailed eagles m Swe den, cod in the Baltic Sou. mussels m The Netherlands, adelie penguin eggs tn the Antarctica, brown pelicjn eggs in Panama. Arctic terns, shrimp in Florida, river water in Japan, iters m the Great Lakes, human hair, and human adipose tissue--samples of all these have been found to contain pen's.
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^ thus making tncm a class of widely dispersed pollutants.
Readily abwtoed
The properties of rca's that make them industrially useful, are the same properties that cause them to persist in the environment. These in clude thermal stability, resistance- to oxidation and hydrolysis, solubility in a wide range of organic solvents, water insolubility, high dielectric constanti and compatibility with many'types of macromolecules. Their resistance to oxidation and hydrolysis also makes pcb's more stable and persistent than odt. Consequently, they could even tually accumulate to a higher concen tration than dot, especially if the use of dot is sharply curtailed in the U.S.
The solubility of pcb'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 fish-eat ing birds will accumulate large concennations of pcb's, as in the case of the white-tailed eagle, which has been found to have as much as 14,000 p.p.m. of pcb's. Peregrine falcons, taken off the coast of California, were found to have as much as 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 pcb's, which represents a 130-fold con centration in a very short time. Oysters, exposed to an identical concentration of Aroclor 1254 for 98 hours and then placed in rcs-free water for four days, still had a concentration of 33,000 p.p.b. of pcb's, which constitutes a 3300-fold concentration. This means that even though the concentrations of pcb's are in the parts-per-billion range in the environment, their high lipid solubility causes them to collect in fatty tissues of lower animals and marine life. Therefore, species at the top of a food chain will also accumulate pcb's in their bodies, particularly in - their lipid tissue and liver, in much the same
way as they accumulate dot and other chlorinated pesticides.
Because of the low solubility of pcb's in water, when a solution or dispersion 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 long time to flush out a contaminated area.
Accidental occurrence
The reason that pcb's have not been found in the ecosystem as extensively as dot. and are not present in environ mental samples at as high a concen tration as dot, is that pcb's find their way into the environment accidentally. dot is deliberately spread because this is the only way its insecticidal proper ties can be utilized, pcb's are not in tended to get into the environment, but they do because their unique chemical properties prevent them from being de stroyed by our usual waste disposal methods. Thus, they inadvertently es cape and become widely dispersed.
In Sweden, where the use of odt has been banned, and where the main power source is hydroelectric, invests-
gators find that the concentration of pcb's in the environment is as high as that of dot.
There are several ways by which PCB'S get into the ecosystem. One of these is by Incineration. Products con taining pea's, such as carbonless re producing paper in business forms, plastics i especially polymer film and sheeting that contain pcb's as plasti cizers). spent ballasts from fluorescent light fixtures, and objects coated with PCB-formulated coatings, all find their way to the city dump or incinerator for burning. The pcb's do not burn but are vaporized. They are then carried into the atmosphere, where they collect on paniculate matter and are subse quently returned to the surface of the eanh. into the rivers, lakes, and oceans. In this way they become widely dis tributed throughout the global environ ment. Another source is probably land run-otf from industrial wines and dumps. A third source is the point of manufacture and the plants where pcb's are processed into other products. They can escape through the plant ven tilation and exhaust systems into the atmosphere and through its waste treat ment s> stem into sewers or directly into waterways.
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It is interesting to note that the inci
dence of fee's in environmental Jampies is highest in industrialized and ur
banized areas. Birds whose primary
habitat is the San Francisco Bay area have a larger concentration of res'* per unit of body weight than those lo cated in Baja, Calif., which is com pletely rural. Aquatic life in the Archi pelago of Stockholm, the most indus trialized area of Sweden, were found to have a higher concentration of pea's than fish samples taken from the west ern coast of Sweden, a less developed area. Sediment samples taken from southern portions of Lake Michigan have a higher concentration of pcs'i than those from other parts of the lake.
Monsanto states that until a recent change in marketing policy (see inset, page 814), sales of Arodors were in creasing at the rate of 8% per year. While this increase does not seem sig nificant. it may be important if the in creased consumption was in consumer products and thus would find their way into our normal solid waste disposal systems. Such an occurrence would mean a definite increase of pcb residues in the environment, and therefore a marked increase in their chronic tox icity effects.
Detection
pea's were not discovered in environ mental samples until very recently for several reasons. First, as indicated above, they have not been deliberately distributed about the ecosystem. Sec ondly, because of their relatively low acute toxicities, their presence was not immediately evident. Finally, they are difficult to detect analytically.
The pen's were first detected as in terfering peaks in the gas chromato graphic analysis (oc) of environmental samples being analyzed for chlorinated pesticide residues. When pea's are pres ent in a sample they give a pattern of several oc peaks, whose retention times are similar to those of dieidrin, dot. ddc, aldrin, and heptachlor oxide. Be cause the peaks were not large or sharp, investigators tended to ignore them until S. Jensen, in Sweden, and R. Risebrough, at the University of California at Berkeley, identified them as corresponding to common constitu ents of environmental samples being analyzed for persistent pesticides.
The problem of the interferences of pcb's with the analysis of other chlori nated pesticides has been largely over come hy prior treatment of the sam ple. Several investigators have used
column chromatography to separate Pen's from chlorinated pesticides. At a recent meeting, sponsored by the fwqa's National Water Quality Lab oratory, Duluth. Minn., a general pro cedure was recommended for separa tion of Pen's from pesticides. In this procedure for biosamples, the sample is extracted with hexane as in regular pesticide analysis. It is then partitioned with acetonitrile to remove fats, the cleaned-up extract is passed through a Fluoristi 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.
Research needa
To assess fully the significance of pen's as 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 pcb's are known to ac cumulate in human organs we do not know at what concentration they will begin to exhibit toxic effects. Will chronic effects be similar to those shown in animals--microsomal en zyme activity, calcium metabolism in hibition, and so on? What are other possible chronic effects?
Which of the many pcb com pounds in the commercially available mixtures are responsible for their tox icity? Can commercial pcb mixtures be modified to eliminate the toxic com ponents? Pure samples are required to answer these questions. At the present time 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.
We need to know all the uses for the pcb's. What is the annual produc tion of pcb's? Our knowledge of these facts is limited and needs to be ex panded. These facts should be known if we are to accurately determine how they get into the environment, and take steps to prevent further environmental contamination by them.
la view of the complexity of ihe isolation and accurate quantitative analysis of pcb's in chlorinated resi dues, a straightforward, unambiguous measurement of them needs to be de veloped.
* is the fate of pcb's in nat ural waters? More needs to be known
of their partition coefficients between
bottom sediments and water. This is
vital if we are to estimate how long it
will take for a river bed to clean itself
of contamination. It will also be useful
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 pcb solubility ia
water of various ionic strengths.
* Are present waste treatment sys
tems adequate to handle pen's? Do spe
cial measures need to be taken when
pcb's are part of the waste effluent be
ing treated?
By trying to get some of these an-
5wen now, we may find that we are in
a position to control the escape of
pcb's into the environment before ad
ditional damage is done. So frequently,
action is taken only after it is evident
that massive damage has resulted from
a particular pollutant. In the case of
the pcb's we may have an opportunity
to resolve the situation beforC (tut
happens.
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Additional Reading *
Hutrtwd, M. L, "CWorineted Biphenyl
and Related Compounds," Encyclo
pedia of Chemical Teeh-olovy, 2nd
ed,, S, Intsrocien.ee PuSi.. New York,
N.Y., 1964. pp. 289-293.
,
Reynolds, L M., Bull, Environ. Contam.
Toxicol. 4, 128 (1969).
Risebrough, R. N., at. al., Nature 220
(1968).
Carl G. Gustafson, chairman of the Department of Chemistry of Kind's College. BriarcliQ Manor, S.Y.. re ceived a Ph.D. in organic chemistry from the University ol Delaware in 1957, During the 1969-70 academic year, he was on leave at the FWQs Southeast Water Laboratory m Athens, Go., where he studied trace organic analysts in waste effluents. Asa mem ber of the Sationnl Water Contami nants Characterization Research Pro gram, he worked with rea r and pulp and paper mill effluents.
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