Document 6wYKxrz3X2YDwwLoqLQ1d1QgE

Transcript of tape (title below). Call 517-355-6584 and ask for tape number 13002. SUGGESTED ACTIONS REGARDING PZIiTACHLOEOPHENOL Iff ANIMALS Lee Shull and J. V. Thomas Hello, my r ^ m i3 Dr. Lee Shull of the MSU Dairy Science Department. The recent quarantine of T Michigan dairy herds va3 initiated March 11 by State "MDA" on the basis of the confirmed presence of pentachlorophenol (PC?; penta) and the suspected presence of highly toxic dioxins in the animals. Penta is a vood preservative that has been used widely since 1930. Dioxins are contaminants which are known to exist in preparations of penta. The MBA stated that the quarantine is & Uprecautionary 'measure designed to provide rtpyimra safety to human food supplies." FDA concern following the identi'- fication of both penta and dioxins in cattle of the George Leaunyon herd of Cedar Springs prompted the action. Neither of the materials-has heen identified in nilk but a primary concern is the possibility of dioxins in milk. Milk from all the quarantined herds is being tested for dioxins as rapidly as possible. If dioxins are not detected, the permits to ship milk will h e reinstated. The animal quarantine, however, may. not be lifted until tissue samples can be tested. There is not an established guideline (tolerance) for either penta or dioxins in either milk or meat. Therefore, a tolerance of zero for dioxins is legally applicable and likely to be enforced */ at least until a guideline is established. In light of the current situation, it is imperative that farmers react to the following reconmendations: l) Feed should nottbe allowed to come in contact with penta-treated wood. Feed bunks constructed of such wood should be replaced or covered with untreated limber or plywood. Silage within about 1 foot of the sides of bunker silos constructed of penta-treated lumber should be discarded. CO ^^FN TIAL SUBJECT TO PROTECTIVE ORDER C18540 -2- 2) Unless unavoidable, animals should not be allowed direct contact with penta-treated wood. In the case of free-stall dividers or uprights, where possible these should be replaced with non-treated wood. If replacement is not feasible, they should be covered. Animals can be exposed to dioxins by licking or chewing wood or by Just rubbing against treated wood. 3) Animals placed in new surroundings having penta-treated wood should have access to outside lots and the enclosed structure should have more ventilation than is usually considered adequate. Animals are exposed to penta by the breathing in of fumes. __ The above recommendations may appear to be too drastic. -It must be emphasize^, that as long as nilk and meat adulteration is suspicioned in conjunction with a zero tolerance-for dioxins, the best assurance one has is to remove the source of contamination. Further information about penta can be found in the March "Dairy Ifotes" article entitled, "Uood Preservatives," b y J. W. Thomas, D. J. ELlis and V. D. Davis. Thank you. (?d l*r ----- Fhone: 517-355-6581* Tape 13002 C13541 .-*-Mlii'/iOKAX-U>UM T O D irect^?; JIBIS rum.it: nr.AJ/rn .s: v k :;1. national inmiiuik*u; t;<ai.tm 1),\TK: I1r c h 1 , 1977* - Acting As see icits Director ,Research Resources Program * - S SUl;|KCT Studies on Possible FenfcachloiTiphcuiol/nibaiizodioxin Intoxication (Pregross Report) The National Institute of Environmental Health Sciences (Dr. Moore) was contacted by Mr. George U-Munyan in December 19/''*- Mr. LeMunynn owns a dairy farm in Cedar Springs, Mighigan. His farm was one which lost all of its cattle during the Michigan PD3 incident a couple of years aco. In'oddition,*bis farm buildings had burned soon after this incident. He. constructed new burn facilities and repcpulated his farm with dairy cattle from another state. For several months after tilts repopulation, his operation from a herd health standpoint was fairly nprm?V. ' After these first few months, however, he started experiencing various types of problems which included calf loss, illness and death in adult animals, apd loss of milk production. These losses continued through 1975. Late in 197G, several animals from the LeMunyan herd were transported to.the Veterinary Clinic of Michigan State University for surveillance and evaluation. Tissues from one of these animals collected at the time of necropsy were evaluated for the presence of a number of chemical toxicants The losults of this evaluation revealed the presence of pentachloropiK-nol (PCP) in the ports* pcr-bl 11 ion range. Mr. l.eMuny;:r. contacted mv cc see if I could ofiber any suggestions or assistance. I discussed this farm's problem with Dr. David Ellis of Michigan State University with a focus not on pentiichlarophanol intoxication per se, tut an intoxication that could-be a consequence of chemical contaminants associated with PCP; i.c,, dibanzodioxins and dibenzofurens/ In early January 1977, while in Lansing, Michigan, to attend a PDF meeting, I traveled to the'LeMunyan farm 1*iLii Drs. Ellis and Davis (Michigan Dept of Agriculture). It was agreed that one had to determine if the PCP exposure found in ti:e one animal was an isolated instance or a generalized circumstance. To this end. wa bled a number of ill animals. HSU had the blood samples evaluated for the presence of pen Lachi ofaphc-uol, .which was' found in most every instance. The level of POP detected is not of sufficient magnitude to be of prime toxicologic concern; it did indicate continual oud chronic exposure La PCP (through treated lumber in t..V: new horn). The rhronic exposure vr.dcrscoves the potential or cxcimimulation oi dibsriznriiuxinr. and c!iboneofurans which could he of tor.io*.ilogic r.ig;,i:*icunra. 1 eg reed to have t issues from an irr.a1s evo1ua Led for tire presence of dibenzodioxin at hI;FJ!5. Tissues (liver and fat) Cl8543 were sou!:'-'to films as was a piece of treated lumber from the barn. flibenzo.dtoxins r.an. only k: .dotec:Led UirouglrGC/KS methodolevies, an analytic^*method clearly within our cnpabilities and experience. We observed, the .presence of ocLa-COU and hapta-CDiJ In the wood sample. Analyses"of liver tissues (after extensive efforts to develop an effective extraction procedure suitable for the higher chlorinated dibanxodioxir.s) confirmed the presence of ci,iban7.*'.dio:;ins in. 15 of US livers. Oci>?.dioxin values are in the parts-per-bil'lion range with decreasing incidence and levels of heptaciioxins and three instances of hexadioxins in the partr.per-tri 11 ion range. These analyses are not yet complete. In my opinion, the presence of these dibenzodioxinS (and likely equivalent amounts of the toxic dibouzofurr.ns, although' we have not assayed for these) is of prime toxicologic, importance. P^o^ijius work at IlIF.rlS has { shown that the hexa-Cuil present (i.c., 1,2,3,7787^) is a r.ost toxic tL dibenzodioxin isomer with a single oral LD50 in guinea-pigs of less than 100'ug/Kg. Although the heptachl orinai.ee! dibenzodioxin present (1>2,3,4,6,7 has not received thorough toxicologic evaluation, its structure is such .that one would predict it to have significant toxicologic properties. - The octachlorinatod dibenzodioxins have been reported by nany to be of littln or diminished toxicologic significance. `This is based in large part upon its extremely poor solubility and consequent lack of absorption. Studies with this compound ore all seriously flawed in one way or another. ' -chronic toxicity of octa-COD has not been properly evaluated. The . .- "poor" absorption and therefore diminished toxicity cannot be reassuring in-this cirawstance sincc we are detecting it in 1iver. Its passible . toxicity c3rrr.ot be ignored. Early attempts to analyze fat for these compounds has been unsatisfactory. Most of the "fat samples" failed to yield much extractable lipid indicating that.the majority of tissue submitted is of connective tissue origin (this reflects possible cachexia). Whore sufficient lipid was extracted, ' early analyses suggest that dibenzodioxin levels in this tissue may be one to two magnitudes greater than that, found in liver. . One of the high values detected was from a young calf liver which, I believe, had be.*n allowed to-drink iniIk produced on the farm. Previous work at MIEH5. with 1CD0 showed this chemical to be readily secreted in the milk. One must consider the possibility that the excessive calf mortality experienced at the LeMunyeu farm may be due to the dibenrodioxins received in milk. Sum;ary Tfrfs-- w - o 4 - r c --e.y-op4r4on-iHrir-first-conftrn rd" inM:tirce-- erf-- This work is in my opinion the first confirmed instance of the presence .of clibenzodics.Ins in animal tissues as a l ikely consequence- of chronic exposure to PC? treated wood, it ha:; been mentioned to n:e by a number of practicing v::crinarinns that this circumstance, although clearly unusual in its severity, may not bo a unique situation. The public health:imp!ications are somewhat obvious; CONFIDENTIAL ^SUBJECT TO PROTECTIVE ORDER. C18544 l. "" . *"* #' # 1. * Possible po; nation exposure to dibenzodioxiu <u:d dibenzofuran contaminants through use of PCP or treated lumber. 2. Possible presence of these toxic contaminants in commercial milk. 3. The presence of these impurities in meat products. Note The LcMunyon herd is one which has had extensive press exposure. These results will ivecivo wide tunvr.Kio in Lb.* u.,:Jin. , # John A. Moore, D.Y.M. / C135.45 *7