Document 44RQ4wKMw4JV1RXevZz6wEjJj

I HEPPNER, ORE. GAZETTE TIMES I. 1.851 _ OEC_1 0 1970 &mJrUL Chemical News The bolychlorlnate^ J>iphftny^ (PCB'bJV'X *clR8T"rf industrial compounds with a wide variety of uses, have been suspected since 1966 of causing many of the same ill effects In organ isms as DDT and other chlor inated pesticides. Gradually the evidence has accumulated, and now there is little doubt of their danger (SN: 3/28, p. 321). Depending on the degree of chlorination, the PCB's are as toxic or more toxic than DDT. One experiment, for example, established that a PCB with 02 poreem Chlorine was almost twice as' effective as DDT In breaking down the sex hormone cstradlorin birds; this is regard ed as the initial step in the mechanism by which egg shells of predatory birds (which have very high tissue 'concentration of both chlorinated pesticides and PCB's) are thinned, leading to high chick mortality and eventual extinction. The most recast evidence came this month from the work of Drs. Lawrence McCloskey and Richard' Chesher, who exposed corals 'to chlorinated pesticides and PCB's while they were Tektlte 2 'dtjuanauts (SN: 10/10, p. 396). PCB's apparently act synerglstically with chlorinated pesticides add enhance their ef fects, says Of. Chesher. One of the potentially most serious re . suits oi -the work was the find ing that* mixture of PCB's and. chlorinated ; pesticides - 'Will teduos ' oxygen production by plant* associated with Ihe coral afUreeelatlvely brief expos ure at'one'part par million.*' In' th* Meantime, Mortsaftto Co., the sole United States manr ufacturer of FOB'S, has greatly restricted, the UBM of these eprapounds claiming 1C is IwW tee* ' omfno0dlng use only as issulating JImW* In .electrical and heat trenper aystems .where, the PCB* i sfecompletely enclosed and not likely, to get. ) to the ^environment. | BliL. Myx Dr. Robert*-Wee-1 brough if pm VaUaiMi *C C*l-| llotrii rf Berlwtejr. toe at -Tm not vrfr *, tlmUlW, TpV olectfttil 1 .way evAtuUy. .With pandlag technology. .1 sra afraid we Wfll continue to have large amounts of these chemicals en tering', the' environments- - And' just how the FOB'S have entered the environment -- where'they are now ubiqitlous. although there are greater a mounts near Industrial areas-- is st111 unknown. But many of the tmes before Monsanto's Aug. 30 restrictions clearly were cap able elf releasing large amounts into the environment. Among these .uses: plastlxera, coatings for paper and fabric fire-retard ant compounds, asphalt, adhes ives, paraffins, printer's ink, rubber products, solvents for pesticides, lacquers, coatings for water repellent canvas and hydraulic fluids. Recent work, however, has be-| gun to provide at least an in-, dlcatlon of sources, says Dr. Risebrough. PCB's have been found, he says. In municipal1 sewage entering Lake Michigan and In California. Further work may allow researchers to learn Just how the PCBs enter the sewage. . u__________Ik. ....k km hM Monsanto's reluctance to cooper | ate, claims Rep. William F. Ry an (D-N.Y.) a crusader against PCB's. Ryan say* Monsanto ha* refused to provide him with a list of all uses, claiming Ihls "would serve no useful nonpoUtica) purpose." And Dr. RisebrougH says Monsanto also has refused to provide statistics on amounts of PCB's manufactured. A Monsanto spokesman admit- \ted both charges this week, say ing secrecy was necessary be cause Monsanto is the sole pro ducer of PCB's. The' PCB's have unique ad vantages industrially because of their chemical stability. This stability Is called persistence, howevfer, In substances such as PCB's and chlorinated pesticides that do not degrade in the en vironment and thus are con centrated in food chains. Says Dr. Risebrough: Badly needed are programs for assessing the environmental impacts of new commercial substances before they become so widely used that we are economically dc-< pendent upon them. (Science News). MONS 032445