Document jgNzkyzgbJykqmeZnxGbJJwGQ

1274 ) L'/ -'x' is.. NATURE. VOL. 216. DECEMBER 30. 1987 nature, vp Fractions and Multiples fraction 10*' 10-' 10-* I0-* 10-' 10-` 10-1* 10-* prefix deal eenti mill! micro anao pico temto s otto symbol d 0 'm A n P f multiple prefix ' 10 10* 10' 10* 10* 10 dska hoeto kilo megs g'8* tars *T bt mtrtoUd m Slack m pcwlW*. _ , symbol da* h* k M O T . Compound prefixes should not bo used. Thus 10-* metro Is represented bv 1 ran, not 1 rajim. The attaching of a prefix to a unit in effoot constitutes a now unit, so that . ) km1 - 1 (km)' - 10'ra* not 2 k(m*) -- lO'm*. Whore possible any numorioal prefix should appear in the numerator of an expression. phy*tc*l quantity length volume density force pressure Examples of Units Contrary to SI, with their Equivalents t unit ansstrOm inch foot yard mile nautical mile square inch square foot square yard square mile cubio inoh cubio foot U.K. gallon pound lug pound/cubio inoh pound/oubio foot dyne poundsl Kund-force ograromo.force atmosphere torr pound (f)/sq.in. equivalent I0- 0-0251 m 0-3048 m 0-9144 ms 1 800 34 km 1-833 18 km 845-18 nm* 0-092 003 m1 0-838 127 m* 2-889 00 km* 1-838 71 x 10-* m' 0-028 318 8 m* 0-004 848 092 re* 0-483 692 37 kg 14-893 9 kg 2-707 90* TO* kg m- 18 0195 kg ra*' 10-*N 0-138-235 if 4-448 22 N 9-808 68 N 101-325 N n-> 133 322 N nr* 8894-76 Nm- , 1 I i , l ! . S 1 } , I PC-200 silisaf coatod wish fluorostlieoMh nitrogen go* for diddna * was no stf '* While con .. residues Is P tntorfaronepl with p.p'-TD analytical efts and tho i alcoholic pa water-batHwith mixing sulphato *3 than sooty* technique, DDE, and tained, and tho original and p,p'-TI from tho V where pees affected, been used interftrersei The pek examined Organochlorine Pesticides in Seals in much i iowr sane and Porpoises Scottish p tione of ell tho DC-tt by e non- w Seals and porpoise* In Scotland and Canada, far from the sites of 25 por Canadiar A. V. HOLDEN K. MAUSDEN Freshwater Fliherlea Laboratory, Pitlochry, PtrthiMre application of pesticides, can accumulate high concentrations of residues In their blubber. These chemicals are spreading through the long food chain which ends with seals and porpoises and obviously cannot be confined to their place of discharge. DDT poo about M 30 par fi mtorfecer 1 materiel To presence of organoolUorine residuoa in marine life in aum/ arena of the world, including the Antarctio, has been reported recently1-*. In British waters the accumulation of rosiduo in the eggs of sea birds' and tho prucose of eonosntratioa of pesticides through certain food chelae in the marine environment* havo been etudiod, Analyeae harp soals [Phooa grotnlandica) on the Canadian Atlantis ooast luive also been examined and tho rosults of these analyses are reported horo. Examination of samples of aool blubbor from othor areas is oontinuing in order to assoss the variation botwoon difliwont rogions of tho marine environment. . S f ] ' value* in ference, I lysed, ft noticoab) combin* of various speeios of marine fish and mammals from Scottish waters during the past 8 years*-' hovo shown that organoohlorino rosidues sre now a normal occur rence. the highest concentrations boing found in organs or tiisuos with the highest lipid oontent. Thus the musolo All tissue samples from Soottisb waters wero frozen at --18* C until required for analysis. Tho Canadian samples woro preserved in 10 per cent formalin, wldch showed no svidonco of any influenco on tho analytical proeoduro, and in this and other cases involving Uh it tree* K. flrnrtt* tissue of salmonids, the Uvors of ood and tho blubber of eats aet ss storage sites for tltese rosidues. The aquatlo mammals, suoh as whales, seals and por poises, have a rolatlvoly high proportion oftho body weight In tho form of subeutanooue fut (btukbor). Sosls food ohiofly on gadoids and salmonids, and porpoises chiofly on msll gadoids and ciupooids. Tho process of concentration of poetieldfts through thoir food chain might be expocted to roiult in high posticido lovole in tho fat ofthese mammals, has not affected tho ofllctency of rocovcry of pesticide residues. Aliquots of tho samples (5 g) wero ground to s powder with anhydrous crystallmo sodium lulphato (Alt Srade) and oxtraoted in a Soxhlot apparatus with rc- istiiled Ait grado n-hoxano (proviousiy tested and found to bo free of olcctron-capturing materials by gas chromatography). Tho hoxano extracts woro mndo up to 100 ml. and 25 mi. aliquots were subjected to clean-up by the hoxano-dimothylformamido partition method of do j } ! j JT, ml w V.M4W ml paCtkn&d*? Jur.se itTtn CnnnSe.S mU(l fleet(smI wliiltj E. sad samples onalyscd at this laboratory confirm this Faubort .Vaundor et al.\ followed by column denn-up ! expectation. Jn rooont yoars, epooimons of tho grey seal using alumina containing 5 per cent water. Tho loss of j {ualiehotrus grypus), common seal (P/ioca vitulina) and posticido residues from fat extracts so treated is up to I, 0)11 porpoiso (Phoctttna phaoaena) havo been sampled from tho coasts of Scotland. Samples of blubber woro available for all tho specimens examined, and in a few casoa other organs woro also availablo. As well as recognized pesticide 20 por cent, but, as is customary in posticido analyse*, no correction has been mado for such losses in tho results presented hero. Tho donned-up hoxano extracts wero analysed by gas- | the ' AltcrU went S.al x residues, other olcctron-capturing substances havo been liquid chromatography on a Vnrian `Aerograph 205-2ZT doUctod by giw-liquid chromatography and, in order to instrument omploying two glass columns 5 Ft. long * } in. establish whether suoh wubstuncos are ns widoly distributed outor dinmotcr. On column was packed with `Cluomo- ing R adult intnp as the posticidos, blubbor samples from groy seals and orb \V AW/DMCS 80-100' mosh coatod with 10 per cent HUNS 08<289: OCK 30. 1907 to SI, valent t I1* m pi to K hi 144 m in 34 kin .*3 IB km JO mm* >8 003 m* LlO It? m* U 00 km* 3STI xl0"ro* b 3101m* M <40 009 tu* r*>3 903 37 kg >103 0 kg 'IT 09 k 10* kg m* 0139 kg nr* 21 38*399 N I0S3N Iw6 09 V (3itKnr1 VS N or' 1)1-70 H or1 pm the sites of ftCfttratlon< of aiding through j nd obvioutly (median AUouUo results of theso a of sample* of (ting In order to ins oftho marine ors were froten Tbo Canadian formalin, which tho analytical involving fish it ?ry of pestioldo ere ground to o tn sulphate (Aft srotus with ro* rsted ood found by go* eltromu* 1* up to 100 ml. o elcan-up by < method of do jolumn olean-up Jor. Tho lose of rested is up to ticid# analyses, *.' in tho results nalyicd by gasngreph 20G-2fl' ft. long x J in. with `Chrome'ith 10 por coat NATUKL. VUL 2 tc. 'JUtmutn aw. > w /K7.20O ailicono oiJ, and "*\thor with tho same support contained vc "Nw IovcIn of both dirldrin snd tho DDT coated with fl por coat J-200 + 7*5 por cont QF-X fluorosilicono. Tho ovoit temperature was 200" C, tho nilrogon gn* flow GO ml,/min and tho column resolution for dioldrin equivalent to 1,500 theoretical plates. There croup, whilo aA rf.rom th o C~ubot Stmils (Gulf of St. Lawrence) contained little dioldrin but higher DDT group rcmducs, similar to thoao of Scottish seals. Of the four porpoises oxamined, that from Orkney won thn least -m no significant degradation of DDT on tho columns. contaminated, but tho throe taken on tho cast coast of Whilo oomplvlo reparation of tho common pcsticido Scotland had markodly higher contents of all tho residues residues it poMiblo on ono or otiior of there columns, measured. Ono specimen contained a total residua eon intorfenmoo by polyohloriuntod biphonyl (I'CQ) residues*'* contrution (dicldrin and DDT group) of 73*3 p.p.m. with pip'-TDE and p,p.'-DDT poakt noeossitated a further snalytioai stago. Aliquots (5 ml.) of iomo of tho extracts ws.ro.ev.eporatod to dry_ noss in ia stream of cold filtered air,. and thn residues rofluxed with 2 ml. of 2*5 por pent Analysos of a fow tissues other than tho blubber havo boon mndo, but conconlrationg in tho blubber havo always boon found to bo tho highest (Table 2). Concentrations in oilier tissues soem likely to bo consistent with their lower alcoholio potassium hydroxide for It .raiiKunB wdrrh lipid^contonts. water-bath. After cooling, 3 ml. of n-hox^q^ wp gdiind^ with mixing, followed by 4d ml. of 3 por cent sodium Tsbts t. "'totax. oar ooscssnunoxs (p.p.m.) is r*raes nnu lulphQito--soltTfTon. Tho supernatant hexane layer was aunpis^ Blubbsr Liver Orsls KIlMp Bpleea Meeele ^Cffanolyecd by gas-liquid chromatography. By this onyml 0-77 OM technique, quantitative conversion of p.p'-DDT to p,p'- Orsysesj DDE, and of p.p'-TDE to p.p'-MDE (-DDMU), is ob^^'^i tained, and tho conversion products confirm tho identity of or*ei the original resiriuos. Tho rosiduol peaks intho-p^'-DDT on' * 0-30 0-16 0-07 0 21 -- 0-53 -- 0-4S Oil 0M 0-17 007 ---- 00*103* 0*04 0*10 ---- 0-M and p,p'*TDl positions, whoro present, catfos subtracted , from tho values of tltf. pesticides**originally determined The proportion of blubber extractable by hoxnno wee , --in-thcao.posltionenTydrolj'sis also dostroys a and t-HHC, determined for some samples. Veluos ranged from 72 to 86 f whoro prosont, but polychlorinated biphonyls aro un- P*r c^r,t (mean 80 per cont) for tbo Canadian seals, end I affected. A cyanosilioon (Xff-60) column" hoe also from 88 to 98 por cent (mean 93 por cont) for Scottish seals * been usod to separat p.p'-DDT and p.p'-TDE from PCB *mmI,Ies on * breeding grounds off the west coast. I interforonoo, confirming the latter. (Valuee for other seal sample* were not estimated.) Con I T)e principal pesticide residuos found in all sample* ocntrstions of pesticides in terms of sxtrsctsble fat for * sexnaminocda wore thnoossee.ooft.ttnhe DxjDuTi group, with dioldrin 1 in muoh smaller quantities. C~ ana;adian scale c. ontained (lower coneontrations of dioldrin than Scottish seals, while Scottish porpoises oontainod remarkably high ooncontraI done ofall posticido residues (soo Tablo 1). Interforenco on J tlie DC-200 silioono oolumn in tho p.p'-TDE position coused by a non-hydrolysablo residuo was responsible for about 29 per oent of tho total estimated pp'-TDE in tho Canadian and Scottish samplos examined. In the p.p'D__D_ T_ po__s_it_i_o_n_, _tho_ _n_o_n_-_b_y_d_r__l_y_*_a_b_l_e__r_e_s_id__u_e__c_o_n_s__ti_tu_t_e_d_ eboutri0 por cent in the Canadian samples and about theso samples would thus ba up to 40 per cent greeter than the value# m Table 1, but the gcnerel comparison is not significantly affected. The lower extrsetable fat values for the Canadian sample* may possibly be a result of being preserved in formalin. Concentrations of posticido residues in the extractable fat of various organs and tissues of one porpoise show en important relationship (Tablo 3). While the concentra tions of tho DDT group in tho original tissue* very widely. those expressed in terms of extractable fat are in much closer agreement, with the solo exception of the brain. 30 por cent in the Scottish samples examined for this A similar anomaly for tissues of trout woe described by interference, tho total amount of non-hydrolysable Holden1*. It seems likely that a largo proportion of the material being smaller In the Canadian samples. The P*{ of u*e bra,.n **y not contain pesticides, snd values in Tablo 1 have not boon corrected for this intor- brain lipid composition is known to differ considerably feronoo, for only a proportion of tho sample* wore hydro from that of depot fat. lysed. Rosults from the various spocies of soals were not notiooably different in * given area, and have been oombinod in Tablo 1. Tfcbfc i. ooKotxTSArroir stress or oxoAxoomoxRfs uffl>ni m M ei ss(ttUljMjMisxsadtlnorpsoassrrartoouUiiwtwsM(asp).<.m.) TUi a. eoxcmunoM or Torn, bdt (p.p.m.) m ruins or * TImuc or orsas Blubber Muaclc Liver Spites Xldsey CoaoeRtraUoRlnllMSe Percentage extract- able tat Concentration In extractable tat 037-00 00--519 1-0 0-X 0-59 0-18 13-2 l , 4-0 1-4 0l 0i1 3-0 Bmls *p0s8 0-27 Ko.ls aneta DlaMHo f.f >I>DB r.p-TDB .p'-DDT ^ The unidentified peaks on the chromatogrsms teem I. Scotland, adult IS 0-16-M o-oe-e-ie aduttMalaaees-Oe) (O-CO) i&'a,.,V. 4 W, Scotland, im-d-A luv. and adult aasla loot) (|M7) Canada, CatetStralta. S and adult atala (1M7) Scotland. Orksey, 1 ladult pmmIn(IMT) B, Scotland, adult porpolaea (ISOS, 1007) 10-11*1 <5'5) 1S-7-0 (3*4) X0-4-0 (t-6) P'07-1-9 (l- 0'S7-3jO (V*) e*17-OS3 (0*41) 0-13-0 50 0*0(00*-03*11)0 (0*W> 1-5-21-3 <T-B> 1-7-7-7 <3-S) X*(18--33-)7 e-ee-o-03 (0-30) to bo similar to those produced by polychlorinated bi phonyls and, to enable comparison to be made, the ratio* (fix) of the retention timos of ell regularly occurring peaks (relative to dieldrin* 100) havo been calculated for the operating column temperatureypf 200" C, these values being temperature-dependent. *The Rx values of PCB compounds from commercial PCB formulations were also determined for both type* of column (Table 4). At least seven PCB-type peaks were found, including tkono which interfere with p.p'-TDE and p,p'-DDT. Heptschlor epoxide and p.p'-MDE could not be confirmed on both columns and are not therefore recorded. Contamination by pesticides is greater in the seals on tho onsl- coast of Scotland (taken in an area roughly from Abordeon to the Tay estuary) than in specimens from the west snd north coasts, including the Orkney Island*. The most significant aspect of the results is that, although soals and porpoises inhabit sn environment far removed from the site of application or discharge of p.estic.ides,.they esn eontain couch _pester concentrations. Seal pups from tho Orknoy and Harris (west coast) breed- of dieldrin and DDT group residues than those recorded ing grounds oontainod only slightly lower residues than for most other species, including man. Robinson and adults from the same areas. By comparison, the Canadian Hunter1* found a moan concentration of dietdrin of 0-22 samples from tho Magdalen Island# (Gulf of St. Lawtenco) p.p.ro. (range 0-10-0-73. p.p.m.) and a mean total con- MONS 082893 i i- -V;t 1 t'i. -,i m; Ik-! V I: V l! H. I' -- \J 1270 NATURE, VOL. 2 Id. DECEMBER 30. 1967 Osntrotlon of DDT of 4*0 p.p.m. (rango 10-IM p.p.m.) in samplos of human depot fat in England in 1964. No videneo of any significant change was found durins 1903-65. * T*M . trumi iRinnoi tuou (JL*> ot usidoii (muouk-ioo) DO-SOO/Of-l eolum NB Ui MiSF l -wo PC F.F-TDS ftp .-DDT Fill FCH -131' -129 -N. -iro -174/ -SOS, VCB - 00* Kr'-DD* - 14 tldrio -100 WiTD`:!!j ECU -140-6 FF-DDT -147 ftO -394 Kb -243 The teals and porpoitet from the eatt coast of Scotland Avtre usually more soriously Contaminated than those from the north and west coasts. This, at least in respect of seals, may be because, as is believed, the populations in the two areas como from different brooding sites. The seals smith of Aberdeen breed principally on the Fame Islands, off th# north-east coast of England, while the aeals of north and west Scotland are primarily from the breeding grounds of the Orknoy Islands (n the north, and other islands off llio west ooast of Sootland. Tho sea off eastern Seotloml is also likely to receive more con tamination from estuarine discharges than that off north and west Sootland. Similarly, the two eeparato seat populations sampled off tho east coast of Canada may inhabit areas with different levels of contamination. Pups contain pesticide residues in concentrations only slightly lower than in the parent population. Common seals in Holland have been found with concentrations of residue similar to those of seats on tho Scottish east coast'*. While tho residue concentrations in subcutaneous fat ore high, those of other tissues and organs arc found to be much lower. This suggests that there is no risk of physiological effects, unless the metabolism of much of the fet in times of stress leads to a considerable increase In the concentration of the rceiduo in circulating lipids, and thus in residue concentrations in other organs or tissues. Grey seals on the ooast of the Scottish mainland feed primarily on salmon ISalmo so/or) and cod (<?,/ morrAuo)14. The bighost concentrations of pesticide m salmonida in the marina environment have so for t**n found in sea trout {S. trutta) on the tost oo%st with up i> 0-2 p.p.m. (dieldrin + total DDT) in muscle tissue", ami salmon from the same area would probably have similar contents. Cod sxamined from tho east const have cun. tainod up to 0-35 p.p.m. (dieldrin 4- total DDT) in muscle tissuo (mean 0*12 p.p.m.) and from the west coast up to 0*66 p.p.m. (moan 0-22 p.p.m.), while ood livors ooutnini-d up to 4-0 p.p.m. and 12-0 p.p.m., respectively. Grey m-itl are estimated to eat about l 3 lb. of food daily, and thim mi adult seal could oonsomo its own weight in food in 20 days. Assuming a high proportion of the pcstioido intake to be stored in body fat rather than to bo excreted or metabolised, an increase of two orders of magnitude in pesticide concentration from food to body fab within a few years is feasible. This degree of accumulation nf residue in an environment not doiiberatoly contaminated, and in species ecologically far distant from the target organisms of porsistont pesticides, underlines the im possibility of confining such ohemicais to the sreas of application. We thank Dr B. B. Roe for obtaining the Scottiah samples, and Dr C. J. Kerswill for tho Canadian samples. lUetlved December IS. 1M7. 1 itrs. Pruiitnl'i Sti. Ait. Cemm. (US Oort. Printlns 001ee, YTaaMsstas, 1003). 1 Tattoo. 7. O'O., end Ruiloka. 7. K. A., .V<,f.SlS, 344 <m?). * Moorr, K. W.. m4 Tattoo, J. O'O., ,Ymr#.807. 42 (1003). * Boblmeo. 7,, Richardson, A.. Crabtree, A. X.. Coulion, J. C.. and Poili. O. SL, nature, 314.4307 U007). * Departmeat of Asrfeultura and Fisheries (hr Scotland, Fisheries of Scot land. Report for 10*2. . * Department of AsrleqUure and Fisheries for Scotland, Fisheries of Jot- land. Report for 1000. * Do Faubrrt Maunder. M, 7.. E*nn, It., Godly, R. W., Hammond, K. W,, Rubnre, 3.. and Thomson, 3., Anal**, St, IW (1904). * Jenern, 3.. Xem SeifMitt, 32.013 (1000). ' Holme*. D. C,,Simmon*. J, 11.. and Tlun, J. O'O.. S10.2^7 (10*7). "Simmons, 7. If.,and Tatton. 7. O'O., J. CA/omo/wp..37, 3r.J (iMT). " HoUlen, A. V., Ann, Apr*. DM., 00.t#7 (IIHtt). * Robtuwn. 7., and limiter, C. U., .IrvA. Kitrirun, If/aftA. IS. 039 U0O9V. " Kocman.j. K..and van Oemloren, 11., J. Apt*. A'eot.. t(Sii|ipl.>, W(|t*au>. Rae. D. It.. Afar. /*., X. 3.30 (1000). ** llolAen, A. V.. J. Apt*, ffrof., 3 (Sui-l'l.), 45 (IWfl). i ( I r The North Pacific an Example of Tectonics on a Sphere by a r. McKenzie R.'.L PARKER IdiUtuts ( Gsophytia sad Plsnsctry Physics, UnlvsnltV ot California at San'DIego Individual tselsmlc areas move as rigid plates on the surface of a sphere. Application of the Mercator projection to slip vectors shows tnac the paving stone theory of world tectonics is correct and applies to about a quarter of the earth's surface. 1 | J Tub linear magnetic anomalies'*' whioli parallel nil native ridges can only bo producod by reversals of tho Earth's mnguetio field* If tho oceanic orust in formed eloso to tho ridgo axis', Modola* hnvo shown that the anomalies eunnot bo obsorvod in tho North Atlantic unioss most dyko intrusion, and honco crustal production, occurs within 5<km of tho ridgo axis. Tho spreading non floor* thon corrios thc-uo anomalies for great horizontal distances with littlo if any doformation. Tho opicontrcs or earth quakes also accurately follow tho axis and aro offset with it by transform fault*'-1, Tho structure of island ares is Isms denri though tho narrow band of shallow earthquakes suggests (that crust. in consumed along a linear feature. These observations are explained if tho sea floor spreads ns a rigid pinto, nnd interacts with other plates in setsmicaliy activo regions which also show recent tectonio activity. Foe tho purposes of this artiolc, ridgvs ami trendies aro respectively defined as lines along which crust is produced and destroyed. They need not also bo topographic features. Transform faults conserve crust and ore lines of pure slip. They aro always pnmllcl, therefore, to tho rulntivo velocity vector between two plntes-- a most useful proporty. Wo Imvo tested this paving stone theory of world tectonics in tho North Pacific, where it works woll. Loss detailed studies of other regions also rapport the thorny, [ I [ l { t | '. j | j j j NATUR TIS.L Th* r on s sp carriM < axisthn tion. T feion sb motion about it Atlantir nrovomc ouvo po botwoon mall et that pot lino of ilto tine tvaucU 4 Xviihor crust, snudt tm Thi* |*rv uin'ful in ooiwuqw acruss rvHsou along h rotutionnot do no sigai tion poi son's* motion* tionul asuismie surfaco Thor* of tlw* At suvii th* plot bceivusov tlu* thi met Ivnd than imi from Dm from a wise, th tho din.Simtl.ir are vodor circuit MONS 06Z894 l t