Document Ozj7dbMJnxapL07BzGKkp6XZ1

by John Noble end Horry Rothman la September lost year the corpses of over 8,000 sea birds were washed up on our coasts from Northern Ireland, Ayrshire, CtimlH'rl.iml, I -uiicuslilrc to Nm tli WuU-s. We nmy never folly uiuimluiHl how this ilisii.l.i' eiune uhout for only eil>hl of the deml birds were properly examined for toxic chemicals etc. However, they all contained larger than usual amounts of one particular rompmiiiil. polychlorinated hipticovl or 1HU To most ituliuiilivl. the name ft It meant nothior,. for this ivu.im no ftvl that it is mo itintiite Miinitiiirislnu tin* ciincitl state ol hnonlcitrte in ciivii'oiiioeotal piilllition tiv I't 'll. PCD is not a single compound but a general name for a whole famil- -f compounds with a common basic Si. - taro. Mixtures ol PCE compounds have interesting properties enabling them to be lived in divene technical areas. Our awareness ot the ecological implications of PCB is comparatively recent and so it comes as a surpriso to many people that commercial manu facture of PCB was begun as far back as 1929 by the Chemical Company of America. It was noted recently that the effects of exposure to PCB are not limited only to the immediate location of its use. Since then PCB production has spread to most major industrial coun tries, including Britain. Monsanto are still the msjor manufacturer hcrc and market PCB mixtures under the trade name Arochlor. PCB is made by adding chlorine to bipt$nyls, terphenyls and other more complex poly-phenyls. Chlorination is done in special cylindrical steel towers three feet in diameter and eighteen feet high using special catalysu and heat. The technical uses of PCB depend on their great chemical stability and special physical properties, which may bs varied to auit specific applications. PCB has a number of uses in the elec trical Industry, in paints and varnishes where they have a similar role to oil except that they do not oxidise and lose their flexibility with age. Resinous products of PCB are an integral part f synthetic ntllicsives. Lubricants for use muter extreme conditions often contain PCB. The national and imcnuiikmut pro duction litfurcs for PCB haw never been published but we can see irom the list of its applications that PCB is used on a Urge scale. For such a widely used compound, toxicological data were pretty sparse, yet it was noticed recently that the ctfiVi* tif ca|*>mmv ii> IVH nra not lim ited only in (Ite himtcdmU* Uvution of its use. AltWtv shin mid liver In the MiMiiltnti text on industrial in*holo)'.v. Mihkvmh.v p/o/wrie.* t*f in* /* vr/iitf t7n o*Vo/f by Siu. IS'll In re ported to "have two disijj.ct ac.K>ns on the body, namely & skir effect i nd a toxic action on the liver, lie lis.on produced in the liver is an acute yeUow atrophy... The higher the chlorine content of tho diphenyl ( biphenyl) compound, the more toxic it is liable to be... The skin lesion is known os chlorache, end consists of small pimples and dark pigmentation of the exposed areas initially. Later comedones and pustules develop. In persons who have suffered from systemic intoxication the usual signs and symptoms are nausea, vomiting and loss of weight, jaundice, edema and abdominal pain. Where the liver damage is severe the patient may pass into a coma and die. PCB is also recognised as a disaster hazard, for highly toxic fumes are given of? when it is heated to decomposition. Of count these are acute effects resulting from exposure to very high concentrations. Such a danger could only arise in the event of an industrial accident" A very disturbing finding about the biological effects of PCB is that they can have an insidious effect on the hormonal system of birds. Hormones are vital in co-ordinating the complex biochemical reactions of living organ isms. Any interference with the norma) body-regulating effects of hormonaa could have a profound effect on an organism, for they control rates of growth, ultimate body size and shape, masculinity or femininity, menial and physical alertness. Effect on birds The way in which PCB interferes with the hormonal systems of birdi, is com plex and not yet fully ur.darttood Only a small quantity of PCB car speed up the production of certair enzymes produced by small bodies Ir tho liver, a process called enzyme in duction. As a result, the calc.urn tneu bolism so vitul in egg proouctioo, L* disturbed. This information becomes crucii when it is realised tha PCt has bee* found throughout much of ti.c {tlob.. environment, even in iiwusurah amounts (0.06 parts per million) i mother's milk samples in Catifomi. Fnviromtwmal scientists arc becomin mcrc.-tKiiijtly concerned about an chemicals which can persist in the cr viroumccu ;uul Iv accuntua led :ikn fiHHt chains. How do (Ivy :u*( irto t. cnviionmcnt and wh;.( long term to\ hn/nrd do they present even in vc: HONS 031800 i'CB.has been found livt-rs. fat ami eggs ol birds, parlicu* or his whole family, inc.uiing .. five ly terrestrial predators such as spar* no old baby. Jensen looked for ' - throughout much of the global row hawks and kestrel*., and in marine, PCj, ,n eagle feathers in a inuscj.n and environment, even in fcc-lcrs like guillemots and kittiwakes. only found it in specimens caug.n after measurable amounts in mother's milk samples in California. They were also found in fresh water fish. Small amounts were detected in human fat samples, t.iough in much smaller proportions than in the birds. 1944. This is probably indicative of how long PCB has been an environ mental contaminant. A little later, the British workers. Holmes, Simmons and In 1966 workers in Scotland found the Tatton, announced that the previously minute dossib? In many ways PCD re* same compounds in fish and seals in unidentified compounds associated aerobics ODT and related orgtno* Scottish waters, the levels were low in with analyses for organochlorine in chlorine inseciieides, They arc both fat* tho fish, whereas in the seals they cor* secticides were PCB. Their findings soluble, persistent and able to induee responded to (he larger levels found in were repeated in the Netherlands and liver microsomal enzymes. They are birds. North America and soon PCD was fairly close chemical relatives and their The solution to the mystery of the found to be distributed throughout liv ` ecological properties are literally inter* identity of the compounds was pro ing creatures in the Northern Hemi ' woven. vided by a Swedish scientist, Soren sphere. History of PCB pollution i The tragic post-war decline of certain ' species of birds of prey and sea birds in Jensen. At the end of 1966, the New Scientist reported, that Jensen had found PCB in pike, and also in the hair More PCB in industrial areas Riseborough and his American col* 1 many parts of the world is now well . known. The story of the discovery of Monsanto takes a big step> PCD pollution is intimately related to i \ | tho unravelling of the mystery of this ^ decline. The chemicals implicated in the (! In the late 1950s, Derek Ralcliffc of massive slaughter of seabirds of the pollution does not exist in the PCB manufacture stage. , the Nature Conservancy sounded the off the north-west coast last The only place in Britain where : first warnings about the mysterious dc* | cline of the British peregrine popula* lion. When other birds of prey were similarly studied it was found that the golden eagle was declining in Western Scotland. Much circumstantial evi* autumn may soon be tiie . subject of a voluntary ban, ' Monsanto Chemicals, one of the principal manufacturers of the industrial chemicals PCBs are produced--under the market name of Arachlor 1254 --is at Monsanto's Newport, Monmouthshire plant. But the production process is dry Bnd : dcncc pointed to orgaoochlorino in* polychlorinated biphenyls--;., no PCB waste goes down the secticide residues as the guilty agent and appropriate changes in the use of these compounds prevented a complete disaster, Ratcliffe also noted behav* ioural changes in the peregrine, birds known as PCBs--is trying K> get other manufacturers to limit the application of the product. Monsanto want PCBs plant's pipeline into the Bristol Channel. Monsanto will have to work hard to gel co-operation, if .* [ eating tlteir eggs, increased incidence to be confined to closed-system only because rival of broken eggs. Ho also showed that uses, like its application in .manufacturers are of different the thickness of egg shells had dc* electrical insulations. This . nationality. But the value of a t creased during the period since the introduction of organochlorine inaecti* , cides. This was the first evidence that ' the resulting widespread change In the would mean a ban on the use of PCBs in paints and varnishes and coatings. 7 , voluntary ban is highlighted by the recent disclosure of the Government Chemist. In chemical environment had in some way It is this second type of his annual report, he reveals : 1 1 affected the calcium metabolism of the usage that causes the pollution. that the highest ever ; birds. ` These events initiated routine anal* ' * yscs of wildlife cadavers in Britain. ' It was during theso analyses for organo* . chlorine pesticide residues that several Factory waste pipes leak PCBs while manufacturing or using paints and surface coatings. The chemicals are carried in concentration of PCBs has been found in wildlife by his laboratory. The Chemist gives the results of an analysis of workers noticed the presence of strange effluent into the sea where it is PCB levels in herons. Levels 1 organochlorine compounds which they believed that unusual weather more than twice the previously could not identify. These unidentified compounds were so similar to DDT etc., that they actually interfered with DDT measurements causing a certain amount of confusion. The unknown compounds occurred most frequently conditions can cause local concentrations. Tire amount of PCBs in these concentrations is still very low, but it can be lethal. . recorded ''highs" in seabirds were found. This is very ' disturbing, given the effects of PCBs on calcium metabolism. and in tho largest proportions In tho. Without a doubt the source Jeremy Bugler HONS 0 3 1 8 0 1 !' I ; t\ ` > I 1- r r t. V .... o.'. :.r.ic..l 1/ .. is .l.c.vl'oro OAVC it in;*) the environment. .1 is i.Liv ;,uu a steady .>uiM-tij< is occurring. iuve reported that the highest wvels of PCI-- arc found in wild life i'll':)) inJ.i.s.ri.iliscd areas. In the fow kt.tj l ii*is and fresh water species ex. mined by /American scientists I*CB " in khu>1, and n is quite likely that the compound is mm distributed in the continental ecosystems of the United Mates. l.xaclly how PCB gets into wild life is not yet known, for unlike organochlorine insecticides, PCD is not de liberately sprayed into ecosystems, 'lucre are however several possibilities. I he fact that PCB residues arc gener ally highest in creatures living near to industrial areas, leads us to suspect that ITU might escape from the fac tories manufacturing or using it. It could be released in effluent or PCBconta.nii.it hydraulic oils ituo the rivers, eventual.v reaching the sea. Another poie.ui.il ITU source is air pollution. It has met; suggested that transport by a.r c.iiivn \ exploits the presence, of IV; in remote. tvy.KMts like Alaska. As far as we know no one has recorded and measured the presence of PCB in die air, !l might escape into the atmos phere during its manufacture at a point when high temperatures arc reached. Alternatively, the burning of waste emitainiiig ITB mtiy lead to Mines- ' *. iv ;*o'!utoii. Y iV.inist. y of l-.ous* i.' ul 1..ic.i> (iouvmnc;.'. ita:. .tUrteu i .v .car*h project to examine li nou.ccs of PCB pollution which w.H no doubt throw more light on this prob lem. Long lerm effects? PCB |xisosscs great chemical liability and is therefore highly persistent once it escapes into (he environment. It is likciy that a steady build-up is occur ring. Small amounts of PCB have been shown experimentally to have sublethal physiological effects on birds, and small amounts are now found in people. Will they have any long term toxic clfcct? Nobody knows, but do we have to wait? The best move might be lo suspend furtner use of PCB in industrial processes until one has estab lished its effects on ecosystems and human health. Such firm action would also act as a spur to industry to work more seriously in the future on the ecological implications of their action. U'llS re.. l * ,;ivc us grc.it con idem e :.i li. pic .. environmental monitor.r.g cho.t. 'k.ic.life populations are a* someone one: said "our miner's ca.iary", nut only very rarely is there t.,< necessary in formation about popi.iaiion dynamic* io say with any accuracy whether a particular population is oehiving in a peculiar fashion. It is neccssaiy lo (tr ance, on u world scale, studies of 3 carefully selected range of species ? that we can biologicaV.y monitor c.vironmcmal changes. Any change ;: the numbers, behaviour or chemic-d composition of an indicator population would be noted and its cause scarchcc for. It is a priority task, and the sca.c of activity in such monitoring ought ; least to be tied to the increasing rate of. industrial activity. The cos; of such a "doomwatch" activity may be hign. but if it helps mankind to avoid large scale ecological disasters, it is a price that has to be paid. SYSTEMATICS Journal of the Institute for the Comparative Study of History, Philosophy and the Sciences Editors J. C. Bennbtt and Kaju. S. Schaffer Vol. VllI No. 3 December, 1970. HONS 0 3 1 8 0 2 MINI) AND MATTER J. G. Bennett /*.r }%<'"mu. aged i\ a gi.idnate a .nut J,*s a deep interest in C'oa.gi a.iil its political implications, iic icc.uio in the De;xirtna*m of I ilvr.d .Studies in Science, Manchester I'mvcjs.ty cn die smial relations of science ami technology. In 1071 his bmk on industrial Society nnti Pollu tion wj.l Ik* published by Hmt-DaviK in UK ,m*i Bobbs-Merill in USA. Till! AMBIGUITY OF -ONI!- AND `TWO' IN THE DESCRIPTION OF YOUNG'S EXPERIMENT H. Borioit WILL TYPE INVESTIGATION G. H. Edwards IDEA DEVELOPMENT AND ADVANCEMENT TN ENGINEERING E. Match.-.t J-d. .Vi fhl<\ aged 22. grnduutcd from H.c i mci.il Stmiies in Science Depart* .n.-.i, li.sl war < 1**70). There ae read s, i.-uvc in,mis'* tut honours eourse .1. . ........... d,-*Vtp ".'.tiriHlJlC I'yinTIll. ,as-' 7 he Journal is published quarterly in March. June, September ant. December. S,*svnjMUro rates ;m* 13s. 6d. ($2.00', per copy nr 112. lOv Oil. \ $7.50) per unm.m. .*,a,'MTipiions1 contribution* or correspondence it>; The bailors, Systematica, .M ItniKHwiek Uti.M1, Kmgston-upon-Thumes, Surrey, England. |4