Document gaz2normg8kn8jb3JjG9R1823

a BIBRA INFORMATION BULLETIN APRIL 1975 VOLUME 14. no.J inn OP ARTICLES ARC ABSTRACTS ARTICLES OF GENERAL INTEREST LIyIar with polychlorinated biphenyls R-ABinoproplonltrlle and the foetus 12; 129 TOXICOLOGY: ABSTRACTS AND COMMENTS FLAVOURINGS, SOLVENTS AND SWEETENERS Aloobol laperlie tne genee More about propylene glycol in anlael experloentatlon ANTIOXIDANTS The fate of thlodlproploneteo AGRICULTURAL CHEMICALS Getting rid of aldrln Bthylene thiourea In the cooking pot Hires In the enYlronaent Rilling in on pentachlorophenol More toxio effects of tetraohlorodibeneo-p-dioxin FEED ADDITIVES Pbotoeeneltlsation to qulndoxin MO 141 141 142 143 143 144 145 146 MONS 0S411*6 THE CHEMICAL ENVIRONMENT Mor* data on children exposed to lead Telluri.ua on the train Chlorinated hydrocarbons and the liver Carcinogenesie by 3*3'-dichloro-4,4'-<U*iaodiphenyl ether Hexane and the liver aicroeooee 146 147 147 148 149 NATURAL PRODUCTS The noD-hepatotoxleity of oongenere Pepper and the duodenua Taanlo aold in the eneae 149 150 191 COSMETICS, TOILETRIES AND HOUSEHOLD PRODUCTS Lauryl vulphatee and the akin 192 HONS 084147 '*\J0 fcffUCT IBSOCIATIOM Ul.v H.R.C.P., F.I.Biol Ll.C., F.I.Mol. L, B.C.P., H.R.C.Psth. A.X.Arb. t ORA" BIBRA INFORMATION BULLETIN CONTENTS Pin DO. EDITORIAL ARTICLES OF GENERAL INTEREST Living with polychlorinated biphenyls P-Aainopropionltrile and the foetus 121 12} 129 REVIEWS OF RECENT PUBLICATIONS Plfty Residue Reviews Oontaot dermatitis in brief Eighth edition of "Behove" published A hygienic approach to Industry Detergent pollution declines Keeping Britain healthy Books fieoelved for Bevlev 1J1 131 132 133 134 133 196 LEGISLATION United Staten United Kingdom! Vest Germany! Amendmente to Title 21, Chapter I of the Code of Federal Regulations Standards for metal release from vitreous enemel-vare Reoonsendatlona. for polymeric naterlalei Coonunloetion 111 137 138 133 TOXICOLOGY: ABSTRACTS AND COMMENTS Flavourings, Solvents and Sweeteners Antioxidants Agricultural Chemicals Feed Additives The Chemical Environment natural Products Coamatlost Toiletries and Household Products 140 141 142 146 146 149 132 AO**S 3`*V<% o #I Pap no. NEWS IN BRIEF 153 NEWS OF B1BRA 1*4 PREVIEW OF "FOOD AND COSMETICS TOXICOLOGY** RESEARCH SECTION In yIyo ntvmmninnfl leanglnp effect of eyclohexylaaine in the Chinese haaster Lack of offoot of blood aaapl ing-Induced haeaatopolesis on to Tlyo chroaoeoae daaage by cyclohexylsnine In Chinoco mutoco Pailuro to induce tuaouro to guinea-pige after oonaurront adnlnlstratlon of nitrite end diethyleaine Study of the possibility of a coabined effeot of a nheaioal autagen and radlatlon-aterlllsed diet In utagenlclty and reproduction teatsIn the mouse Dominant lethal autationa is aala alee fed y-lrradiated diet Sou eubaoute effeota of lindane on the hepatic aloroeoaal ensynee of the rat Tiaeue distribution, excretion and biological effaota of P^Cjtetraohlorodibenio-p-dioxin in rata 166 166 166 167 167 166 166 Voodaaneterne Road. Carehalton, Surrey, 8M5 42* 01-643 4411 'PIS 01 lame no.3 April 1975 HONS 004149 j--.. in vftvidh " ll , ^ IfCUt* . ,r i.tati.. .ttdrd in . rj of the ^ t rational ' -..J lorn 4 Mmol* rvl ullfil IT *e It* ' life innf Urn if ; , ; ; | j ! : i f | ! i \> } 4i } i I 71 \ \ - 125 - & P. Wheeler ARTICLES OF GENERAL INTEREST LIVISG WITS POLYCHLORINATED MFHEKYLS ftte widespread ocourrence of polychlorinated biphenyls (PCBe) throughout the environment, their relatively high toxicity and their exceptional reeletanoe to biodegradation have all served to draw attention to these unwelcome companions and to dictate a careful watch on their progress In natural ecosystems. We have already taken a broad view of the challenge posed by PCBe and have noted that the prompt action of tho Monsanto group, the eole manufacturer in the USA and UK. in restricting the use of PCBe to oloeed systems such as transformers and capacitors, has alleviated the natural anxiety of toxicologists and eoologiats (BIBRA Bull. 1972. 21' 32)). About this til*. Hough (Science M.Y. 1972. YfU, 580) sumarlted reports of tbs distribution of PCBe in ths biosphere. They had appeared in the tleeuee of polar bears and oeale in Canada, in 54' 3# of 2169 samples of hman sdlpoes tiseue eolloctod throughout the USA. in nearly 20# of some 5500 aosplee of fishi milk, eggs and cheeao investigated by the FDA. and (at levels as high M 5*2 ppm) in tho bottom sediments of lakes, which were, in some eases, far from likely industrial sources. Concentrations of about 1 ppm seem to be generally acoepted as offering no toxic hazard to man* and indeed the FDA has adopted interim tolerance limits for foods ranging from 0*2 pin in infant roods to 5 ppm in the edible parte of fish (JV^ral P.egie+er i?7*, 22, 49747). Th*r <e, guarantee that other animal species can withstand similar concentrations of PCBs without harm. Kink farmers have had reason to deplore the high ueceptibillty of their animale to the levels of PCBe found in seme types of fish from the Great Lakes, while some PCBe (52-54# chlorine) adversely affbot hatchabillty in chicks. Many planktonic organisms, which play an essential role in the food chains of both fresh- and salt-water fiah. may be euaeeptlblo to low concentrations of PTBs and may servo to ooncentratc then In the food chain (Maui, loc.clt.). Ooourrence of PCBe Flnklee et al. (An. J. publ. Kith 1972* 62. 645) has remarked that PCBs of industrial Importance are oomplieatod mixtures of aany of the 210 theoretically poeniblo halogenated biphenyls plus possible contaminants. They have been used in synthetic rubbers, painte, plastics, insulating materials* caulking materials, flaroo rotardanta. cutting oils* eynerglsts for peetlcidoo. udheeiveo. eoalante, printing Lnks. duplicating papers and heat-transfer media, uoce for which their high boiling point, low wetersolubility, miscibility with organic colvento, high dielectric constant, thermal stability and high resistance to chemical and biological degradation rvndcr them particularly suitable. Many of theeo properties, however, aloo ensure their place among the sorlouo and pornintent envlronmantal pollutanta. Tlkcrma) duetmet Ion. for example, occuro only above shout 950C which mssna that wauto oJln burnt at ordinary fumaoe temperatures. and oolid wastes ooutidning PCBe. fora a ready source of atmoepherio oontaminetlon (Jenaen. Amblo 197?. I. 1?5) Muugh (Sri<-ner. N.Y. 1975. JB0> 570) has reported that PCBs can be produced by irradiation of liDT vapour- with ultraviolet light of wavelengths prooent in sunlight in tho lowor utmoophore (290-510 nm). This throws new MOMS 064150 * ! 4 i light on the problem of contamination with other organochlorine compounds, a situation which for ao long lad to tha overlooking of PCBe in analyses of a vide variety of samplee from the environment. It may also help to explain the dleorepanoy between, on the one hand, the degree of accumulation of DOT and DOE to be expeoted In the biosphere from the known use level* of DOT and It* assumed resistance to atmospheric degradation and, on the other, the amounts that can actually be accounted for by current methods of monitoring snd oaleulatlon. DDE Is an Intermediate In the photodegradation of DOT to FCBs. Fortunately, photodagradation may be expeoted to Increase environ mental levels of PCBs only In respeot of the leas chlorinated homologuoe, vhloh are probably leas troublesome in biologloal systems and less persistent. Sewage treatment is a further aouroa of PCBs, significant quantitive of whioh were found in the effluent from a plant which took in waste from a textile mill using biphenyl as a dye carrier (Gaffney, ibid 1974, 185, 587). This vasts wea treated with chlorine* and a suspension of filter scrapings was found to contain 16 ppm FCBs* vhloh Interfered vlth normal savage treatment FCBs in human tlssuea end milk In a study of human perirenal fatty tissue obtained from 52 post-mortem samples taken in tbs Vienna district, Pesendorfer at al. (Visa. kiln. Vsohr. 1975* 0J* 218) found a moan oonoentratlon of 5*5 ppm PCBe, ranging from 0*5 ppm in a woman aged 81 to 0*5 ppm in a male aged 76. Associated with tbs FCBs was a mean fatty tissue content of 5*6 ppm total SOT end DIB. In vlev of tha faot that, when body fat is consumed, stored orgmaoohlorine deriv atives are liberated into the circulation, an investigation by Eesselberg 4 Boherr (Bull, env* oontem. 4 Toxlool. (V.8.) 1974. 11 202) le relevant, line patients suffering from severe wasting disease were studied end compared vlth apparently normal subjects. DIB residues in the blood were much higher In thee* patients than in the controls, the mean levels for the two groups being 21 and 5 ppb (b 10'), respectively. Tbs oaoheotlo patients also shoved a mean blood oonoentratlon of 47 ppb FCBs, which vere not detectable in tbs controls. The authors dismiss the DOB residues In the oaeheetlo patients as being less than those found among apparently healthy workers in a SOT plant, but they suggest that the levels of olroulatlng PCBe may have been high enough to be harmful, although the patients' multiple sfiitnme would probably have masked any such affaota. In contrast to tha figure reported from Vienna, a survey of human fatty- tissue samples analysed In Japan (Curley at al. Mature, Lond. 1975. 55) shoved that while all the tissues analysed were positive for FCBs, the level la 00# of the samplee was lass than 1 ppm and tha overall range was 0*V1*4# ppm* Tbs tissue levels of PCBs In ordinary persona In Japan and In others suffering from 'Yuaho' disease, attributed to the consumption of rlee oil contaminated vlth PCBs, have been compared by Nasuda at al. (Bull. env. eontam. 4 Toxlool. (U.8.) 1974. 215). The average oonoentratlon of FCSe In the fatty tissue of the Yuaho patients was 2*5 ppm (6*5 ppm In Isolated fat) oompared with 0*9 ppm (2*6 ppm in fat) in the eontrole. The livers of Yuaho patients contained 0*1 ppm PCBe (6*5 ppm in fat). The ga^ohromato- graphio (GLC) patterns of the tissue samples and of the FCBs present in the rloe oil suggest that while the overall PCB levels dtoreassd substantially during tha year following the accident, this largely reflected a decrease In the FCBs of lower chlorine oontent; retention of the hex*> and heptaehloro- bipher/ls was more prolonged, apparently for as muoh as 4 years or more. The long retention of FCBs In body fat raises the question of how muoh may be excreted into breast milk and passed on to the infant. Masuda at al. MONS 084151 125 - floo.olt.) reported an average of 0*014 ppo end a maxima of 0*02 ppm PCS* in milk from 12 normal Japanooe women; milk samples from soother group of 19 normal women showed an average level of 0*03 PP" and a range of 0*010*06 ppm. Tho oaaple available from the one appropriate Yusho patient aleo eontainod 0*06 ppm PCBs and gave a GLC pattern similar to reaidusa from tho liver and adipooc tiscuoo of tho patientn. Siyali (Mod. J. dust. 1973* 815) dotected LOT and other oommon peoticidc reoidues in tle milk of 45 woman In a metropolitan area of Hew South Vt&lee but Old not find any PCBs* and suggested' therefore* that the human food chain in that region vae possibly not contaminated by PCBs. Savage ct al. (Bull. env. oontsm. 4 Toxicol. (U.S.) 1975* 2* 222) reported low concentrations of FCBs in milk from some of a group of 39 women in rural Colorado. Only eight of the ample* contained PCBs* six at a level of 0*04 ppm* one at 0*05 ppm and one* from a 25-y#ar-old woman who had apent her entire life In Colorado, at 0*1 PPm* Routes of entry into the rnnA Seas and lakee are known to contain low concentrations of PCBs. In a study of Horth Atlantic waters* Harvey et al. (Science* H.T. 1973* 180* 643) found that open surface water contained a mean concentration of 55 ngylitre* while water from 200 m down contained 10 ng/litre. The surface waters of the Sargasso Sea shoved slightly lower concentration* (27 ne/litre) but these warn no observed relationship between PCB concentration and tha proximity of lead masses* and it seems that the atmosphere must be the predominant mode of transport of those contaminants. The earns group of workers recently published son* encouraging data derived from subsequent studies of Horth Atlantic surface waters uoem, nature* Lena. i974* o2 >37). TLs that by the end of 1973 tho levels of PCBs in these waters were acme 40 times lower than those found in 1972. In the Sargasso Sea* a rapid deollne la con centration to 1 ng/litro In April 1973 had levelled off at 0*8 ng/lltxe by the end of the year. These reductions in surface-water concentrations rouglily oolnoldod with a tenfold deereaeo in PCB contamination of the atmosphere over the Horth-west Atlantic during 1973 (Harvey 4 Steinhauer* Atmos. Environ. 1974* g* 7J7) and a fivefold deexeaae in the PCB ouulonl of mixed plankton from this area between 1972 and September 1973 (Harvey et al. J. mar. Rea. 1974. %. 103)* Ware & Addison (Mature* Load. 1973* ?46, 519) have described how the concentration of PCBs in plankton from the Gulf of St. Lawrence varies with the mem else of the plankton species and the time of year. PCB 000cantratlons were inversely proportional to particle size* even with a 34 fold difference in residue levolo between composite plankton samples* and the acquisition of organochlorine contaminants from the environment therefor* appear* to bear a direot relationship to the surface area of the partielee. Plankton particles in the 73-202 pm group contained what waa thought to bo the highest PCB concentration ever reported for natural plankton* namely 31 ppm (wot weight) in June. Ovorall PCB concentrations in the plankton varied greatly* from 93*10" r/wP at tho beginning of Juno to 2x10" g/a* at the boginning of August, showing on irregular incremental pattern indicating that PCBo ontorod the plankton In discrete pulceo* largely from the air and rain water. Thio explanation woo supported by the observed correlation betvaon PCB contamination and tho cumulative rainfall during the 10-20 days preceding tho campling. During perlodo of light precipitation the *. karence of PCBs by amall-plankton biomoooes would account for the low PCB residua: afterwords. Ware 4 Addison (loc.clt.) were careful to ollmlnate tho interfering effoct of PCBo in tlw antifouiing paint on tlie hulls of their sampling vessels by oheoklng the water of the wukc. Jenoen et al. (ibid 1972* 240, 358) had 08415^ ' 4*4 Mlait - 126 . previously reported that Id sampling plankton in Stockholm harbour they found that oomplas from tha wake could bs heavily contaminated with PCBs and other lipophilic organoehlorine compounds derived from tha bottom paint. It seems likely that lnnhore water may regularly be oontwinated with PCBs from shipping in this way, and that plankton may thereby acquire high con centrations of PCBs. Tha offset of PCBs on plsnkton communities was described by Moore & Barries (ibid 1972, 740> 356), who studied the effects on photosynthesis of different concentrations of PCBs added to heterogeneoue plankton aamplea taken from the Gulf of Mexico. Radiocarbon uptake by the sample# waa more depreaeed by the PCB mixtures, Aroolor 1242 and 1254, than by equivalent mounts of ,g'-BDT or pure 2,4'-dichlorobiphenyl. Inhibition indicating toxicity was evident with 1-2 ppb in the case of the Aroclors, whereas BUT and 2,4 '-dlehlorobiphenyl caused comparable inhibition at 5 and 7 ppb respectively. These effects on total plankton communities were mere i than those previously observed with isolated laboratory cultures of selected epeeioe. Troa plankton, PCBs snter fish and seabirds. As regards sarins amnia* 8asohenbrecker (Can. J. oomp. Mad. 1973* 203) has remarked that it is mt known whether whales ingest PCBs in their planktonic diet or absorb them direotly from the water; but widespread oil pollution of the Worth Atlutle may produce an enriched surface stratum from which lipid-soluble contamin ants, including PCBs, might be absorbed. Blubber tissue from 12 Worth American fin-back whales, collected in 1970 and 1971 showed a Miof 0*105 ppm PCBs, compared with levels of BBT metabolites of to 9*55? rym. A large proportion of the published observations saem to have beam made on freshwater fish in the lakes of North America. Bachs at al. (Boleses, 1.1. 1972, 177, 1191) have reported that trout from Cayuga Lake in lev Tozfc State showed an overall rise in PCB levels with age and maturity, the eos- oentratlono found ranging from 0*5 ppm In Juvenile fish to 12-JO ppm in adults (8-12 years old). The presence of PCBs containing 54$ chlorine was verified in a 12-yean-old trout containing 26*2 ppm PCBs, the msec spectra of which were essentially identical with those of the isomers of Areolar 1254* Zltko (Bull. env. contam. A Toxicol. (0.8.) 1974, 12, 406) has demonstrated the uptake of Aroolor 1254 under experimental conditions in Juvenile Atlantic salmon maintained in aerated fresh water containing, in a eomoentration of 1 g/litrs, a suspension of sllloa contaminated with 0*10 Aroolor 1254* In fish killed after 24, 48 end 144 bourn, whole-fish analyses indicated PCB concentrations of 19*91 29*3 and 134*0 pg/g wet weight, respectively. Under comparable conditions, the uptake of ehlofismtsii paraffins waa much lower, concentrations equivalent to 0*2-0*75 ug/g (expressed as chlorine) being obtained after 48 or 144 hours. The GLC pattern of the absorbed PCB componcnto compered with that of an Aroelor 1254 standard indicated a relatively high uptake of components with shorter retention times, particularly after the shortest exposure time, ftiis pre ferential absorption wan not obeerved, however, when food contaminated with 4 Aroolor 1254 was fed to Juvenile Atlantic salmon for 3V181 days, although again there woe a marked discrepancy botween uptake of the PCB and that at similarly administered chlorinated paraffins- Vhon Aroelor 1254 was fed at a diotary lovsl of 10 ppm, the 1*01) lovelo in the floh reached equilibrium, at 5*&-3*9 ws/e wot v>- -ht, within 33 days, but with a dietary level of 100 ppm residues of 13*9* *4*0 and 30*0 uc/g were found after 33, 109 mod 181 days, respectively. In a study of PCBs in the Lako Poinsett end Dry Lake waters is South MONS 084X53 - 127 - Dakota* Greichuo ot al (Dull. env. contaa. 4 Toxicol. (V.S.) 1973* 321) found that tha concentration of organochlorine inaectioidao in bottom sediments was about seven tines hitficr than that in the water, while fish In tho two lakes contained concentrations of PCBa sons 12 tinea higher than those in botton oedincnts. Thero ia thus a concentration gradient rising into the food chain. Creichua et al. (loc.cit.) found* moreover, that adult cormorants feeding on the fish in these two lakes contained concentrations of organochlorino ooapoundo that wore ?50 tines higher than those in the fish* while levels in tho local pollcons were 260 tines hltfier, FCBs in these two bird species were* respectively, 60 end 30 tints higher than in the fish they fed on* and PCBa were deteotad in the cormorants' eggs. In both types of bird* the highest PCB concentrations were in the body fat (22*4 and 31*4 ppm wet weight on average in cormorants and pelicans* respectively) and paralleled the body-fat concentrations of total organs ehlorlne compounds. Bogan 4 Bourne (Nature* lend. 1972* 240* 35) reported relatively low concentrations (0*1-1*0 ppm) of organochlorine residues lm | auka and ahoarwatoro from the North Atlantic and higher levels (l-10 ppm) I in more pelagic birds* such as kittlvokee, fulmars and storm-petrels. the ! , highest concentrations* exceeding 10 ppm* occurred in large guile and skuas feeding around trawlors in winter and seabird-breeding stations in simmer* ' However* tho finding that a fulmar carrying 42 ppm PCBa In its body fat bad i only 1*3 pjei in its stomach oil* which la fed to the chick* suggested only a low transfer froa one generation to the next in food. Arctio glaucous gulls had* on average* 24 ppm PCBa in the liver* while one had 333 ppm in its body fat. One gull* observed to convulse* had a llver-PCB concentration of 311 ppm. The preoonoe of PCBa in the Arctio* over 230 miles north of a major land mass* ia somewhat disturbing. j PCBa in human foodstuffs ------y (ft. Bull. Ass. Pd Drug Off. 0.8. 1973* JI* 43) has published aat analysis of PSA findings during surveys of food intended for human con sumption. No PCBa were found in fresh fruit and vegetables, end the most frequontly contaminated food was fish, particularly freshwater fish. This was perhaps to bo expected in view of the incorporation of PCBa into aquatlo food ehalns noted above. Samples of shredded-wheat biscuit# contained email concentrations of PC3s derived .'rom paperboard dividers used in packaging. These dividers had been manufactured from recycled paper* which had included carbonless oopy paper. In a survey started in 1971 * about 19K of all the - foods sampled contained PCBa. The overall average oontent of PCBs in packaged food waa 0*1 ppm* and in some cases PCBa were found in tho packaging materials but were not present in the food itself. Nearly ItiM of the total samples of food examined contained PCB residues end were packaged In recycled materials, while contaminated food contained in virgin . material accounted for only 3*4# of the total samples. Also in 1971* Shahlod et al. (Bull. env. contam. 4 Toxiool. (0.8.) 1973* 10* 60) analysed 69 samples of paper pulp* newsprint* recycled paper and liner board and found rCB lovele of more than 10 ppm in 1196* ^10 ppm in 4# and 1-3 ppn in ?3# of the sanplce. However, 5*# of the total contained Kea than 0*3 ppm. Tho prosencc of PCBn in virgin newsprint and bond paper ' ehowod that recycling waa not the only source and suggested that the manu facturing process night aleo be involved in PCB contamination. larly in 1972. VJllcncuvo ot nl. (J. Aae. off. analyt. Chen. 1973* $6, 999) studied the PCB content of 309 packnglnomaterial samples from 120 manufacturers in Canada, finding looo than 1 ppm in 0*17#, 1-10 ppm in 14*9# and mora than 10 ppm in 3*4%* Of 77 foodo toetod* only two contained more than 1 ppm PCBa. Of 73 foods teotod lor polychlorinated terphenyle (PCTe) in the seme study* Uiwi i' mi. Nime MONS 08<tl54 128 - son* contained more than 0*03 ppm. Level* of FCT residues in 449 p-"**gfg staples were reported to be lees than 1 ppm In 84*50, 1-10 ppm la 11*40 and acre than 10 ppm la 4* 10. That packaging may be carried out la auch a way aa to provent any significant transfer of PCJJe into the food ia evident from a study by Stnnovlck ct a). (Bull. env. contain. & Toxicol. (O.S.) 1973* V0 101), who investigated the migration of Aroclor 1242 from treated paperboard containing thla PCS at a laval of 15 or 150 ppm. Pood aanplaa ware stored at room tsmparatura In jara lined with the paperboard for 2-90 days end were then sseayed for PCBs. Barrier materials Interposed between the paperboard liner and the food significantly reduced migration of the PCBs, the extent of the reduction being in inverse proportion to the gas-peaceability of the barrier substance. Polyvinylidine ohloride-coated paper prevented PCB migration for the full 90 days. Vexed gUiiins paper wee the next most effective barrier* but polyethylene fils was relatively ineffective over long periods of storage. In hi* review of TOA food eurveye* Sassay (loo.clt.) atreeaad that* by 1973* KB contamination of both food and packaging materlala had tftowm same reduction oompsred with the findings of the 1971 studies, and it seems that thla trend ia continuing. In addition to possible contamination from packaging, however, PCBs may also be introduced into the human diet la meat, milk and egga derived from farm stock fad contaminated foodstuffs* end la thla situation the concentration of residues demonstrated la natural food *>**** may again oparata. Teaks at al. (J. agrlo. M Gfcea. 1974* 900) found In chicks fad from 9 days of age cn a dial containing 10 ppa Aroclor 1254, the PCS zaalduaa ia dissected fat and muscle, respectively, ware 110*6 and 109*0 ppm after 6 weaka end 49*5 and 102*8 ppm after 32 weeks. Depletion rates of administered Aroelor Indicated a biological half-life of 2*93 weeks. Tat and musols levels of residues In chicks fed 10 ppm in the diet for 52 days from ths onset of egg production ware 35*4 and 70*1 ppm* respectively. PCB residues la eggs from chicks fad thla diet from 3 days of age seet'md a peak of 9*73 ppm about 4 weeks after the onset of egg production end subsequently deoxeaaed. Vhen PCB treatment wen delayed until tbs onset of egg-laying, tbs pattern wes similar but ths highest residua level was only 2*54 ppm. PCS concentrations la day-old chleks closely paralleled ths concentrations In tbs egg*. Cooking has bass shown to affect a significant reduction ia the FOB residues la the edible tissues of PCB-treated chicks (Zebik, Poult. Sol. 1974* 5i> t7B5). Contamination of animal feeds may result from exposure during pro duction, processing or storage, a few savers oases involving chicken feed having bean due to the leaking of PCBs from s hast exchanger (Zebik. loc.clt.). Tbo us* of spent transformer-oil In herbicide spraya mid of plastics containing PCBs in alloc and poultry-feed wrappers say also be a source of contamination. Savage et cl. (Bull. env. contam. & Toxicol. (O.S.) 1973* 12* 97) took allege samples from 21 pit ailoe and tan upright alio* (in which PCB sealants are sometimes used) on Colorado rsnehaa. Detectable PCB contamination Involved both pit and upright siloe but waa limited to samples from silos on only two ranches and in no oaaa exceeded 0*08 ppm. One of those two ranches was concerned with dairy operations, but mo PCBs were datooted In milk from the silage-fad cattle. It saama therefore that the pzoblom of PCB contamination say be leas severe than it seamed a few years ago. Beverthelees, a dose watch must MOMS 084155 I l 1 .jr ! ,vi*r \ rtr t (' c > - 129 Bats and nice treated with O-aminopropionitrile (BAPN), the toxlo principle of Lathyrue odoratui , have produoed offapring with both horlsontel and vertioal forme of daft palate but showing no retardation in growth (BIBRA Bull* 1972* 11, Hi). Further studies have bean undertaken to determine the distribution of BAPN and its main metabolites In asternal and foetal tissues. Hatabollsn and distribution A study of the metabolism and teratogenlolty of BAPN in rata has been published by Vilk at al. (Teratology 1972, , 41). Banal,as weighing 230-260 g ware given an oral dose of 106-270 mg BAPN (as BAPN flnarata) on day 14, 15 or 16 of gestation, and were killed for examination on day 20, just prior to parturition. Others were given 500 mg of the major BAH! metabolite, eyanoacetie acid (CAA), or alee 75 g ('-alanine, 75 *6 cyanoethanol or 250 ag fuaaxic acid (aa the eodlm ealt), again on day 14, 15 or 16. fcbryoe and placentas and natexnal tlsauee, eerum and urine contained both BAM and CAA after BAPN administration. Peak oonoentrationa of BAPN were zeaohed In eena end tissues at 6 hours, but they declined after 9 hours and became negligible after 24 hours. In these rate, tieeue and asrun oonoentrationa of CAA, unlike those of BAHI, showed a gradual increase end remained high at 24 hours, by which time over 609$ of a rine of ?70 mm jmpn had b**n eroreted unchanged In the urine and about % had been excreted a* CAA. The incidence of oleft palate In the enbryos correlated with the dose of BAPN given and with the observed coneentratione of BAH! In maternal and embryonio tissue, indicating that BAPN itself was the teratogen. This was supported by the finding that despite the appearanoe of high oonoentrationa of CAA in maternal and sabryonlc tissues, direct administration of CAA failed to produce cleft palate. Bo abnormalities followed dosing with alanine or cyanoethanol, two probable metabolites of BAPN, or with sodium fuaarate. Although similar tissue oonoentrationa of BAPN were produoed by doses given on any of the 3 days, a positive correlation of cleft-palate incidence with dosage and tieeue lavele appeared only with the dose given on day 15, when embryonio concentrations of 106, 42 and 16 Mg BAFN/g tissue were associated with a cleft-palate incidence ef 96, 26 and Opt respectively. Vaddell et al. (ibid 1974, , 211) injeoted BAPN labelled with 14c Iv into mice on day 12*5 or 15*5 of gestation. After 20 minutes, whole-body autoradiography shoved the highest radioactivity to be in the salivary gland and in the urlno preiont in the bladder. Some aotivity was also demonstrated in the pylorio but not the cardiac atomaoh. The radioactivity in foetal tleeuee wan In general Joao than that in the maternal tissues, and was most Intense throughout the central nervous system. After 1 hour, the foetal radioactivity oxooodcd that in maternal tleeuee, with higheet concentrations in the central nervous tlaoue, eye, yolk see and the tiesuos lining the oral oavity. After 3 and 9 hours, maternal oonoentrationa of radioactivity were high in tho cyo, liver, kidney, salivary gland, intestinal wall, inner ear, aorta and vortobrul 1^ntn- When labelled BAPN wee injected ee In con junction with u large exooee of unlabelled compound, Intense radioactivity o