Document Z4pVO0vwzdGoog2RLeVXox6QV

FRO fl (NAM E -- LO CATION -- PHONE) G. J. Levinskas - G2WF (4-8809) July 19, 1984 DATE SU BJECT REFERENCE A. A. M. Ford - G3WD W. J. McCarville - G3WG G. Roush - G2WG I have read through the three volumes of Dr. Silbergeld's deposition which you provided on Monday. I have dictated comments relating to several sections of those depositions. These have been typed, and I presume you have received them by now. In some places, she had made very specific statements about various compounds which I would question. However, I have not had time to go back and check specific sources to ascertain whether or not they are accurate. If you desire, I will proceed to do so in consort with other staff toxicologists. Kindly let me know whether this would be a worthwhile exercise or whether the need for such action has passed. /dkr SUBJECT TO PROTECTIVE ORDER. C03738 Page 399, line 12 - Cyanosis is not the accumulation of cyanides in the body because of lack of oxygen. Cyanosis is a blue coloration of the skin which results from an inability of tissue enzymes to obtain oxygen. The body has a fairly effective system for removing cyanide by converting it to phytol cyanate. That is a two detoxification mechanism since phytol cyanate is about l/200th or l/300th as toxic as cyanide itself. In acute cyanide intoxication, death results from anoxia because the body's mechanism for conversion of cyanide to phytol cyanate is exceeded. She compounds that error on line 20. The body does not overproduce metabolic cyanides in analine poisoning. Page 446, line 20 - The implication is that despite the fact that $30 million has been spent, dioxin is still present in Times Beach. While the commitment has been made to buy out Times Beach at a cost of over $30 million, nothing like that sum has yet been spent. Certainly, that sum has not been spent on attempts at removal or cleanup of dioxin contaminated soil. Page 465, line 11 - The references made to animal studies using pure 2,4,5-T. In the March 22 deposition on page 254, line 9, she questions whether any of these studies purported to have used pure 2,4,5-T actually were using pure material. One ought to declare and hold a consistent position. One should not accept the claim of purity, and then contest the claim of purity according to the points one wishes to make. Page 468, line 1 - She is not convinced that TCDD is much of a mutagen. However, in the March 21 deposition, page 118, line 4, she is attempting to implicate TCDD in genetic damage. Mutagens damage genes. If TCDD is not much of a mutagen, how can it produce those transmittable, non-hereditary diseases, that she discusses on this and the following page. Page 472, line 13 - The determination of causation is not a statistical exercise. Application of a chemical to skin or eye will determine whether the material is an irritant or corrosive. No statistics are necessary. If a chemical is fed to animals, and they all develop cancer, no statistics are necessary. The rigorous mathematical formula that she describes are used to determine whether observations are likely to have occurred by chance or not. Having determined the probability that these events may or may not have occurred by chance, the experimenter then makes a decision as to whether or not the observed effect was produced by the chemical. In other words, statistical analysis is an aid to making decisions. Decisions should not be made on the results of statistical analysis alone. Unfortunately, there is a current vogue, particularly with respect to risk assessment of carcinogens, to accept these statistical result as a final, definitive, invariably reliable conclusion. SUBJECT TO PROTECTIVE ORDER. 6 Page 473, line 13 - The approach she describes here is good. In arriving at a conclusion as to what may have caused an effect, every effort should be made to rule out all possible causes. Does she do this when she "critically reevaluates" data. As mentioned in earlier instances, does she apply that same rigid standard to everything she reviews, or does she selectively abstract those points which support her view or accept data she considers favorable without subjecting it to such scrutiny? Page 509, line 16 - The catalog of differences and similarities in the responses of different species to dioxin can be compared to that appearing on page 333, line 1. There are some differences between those two sections. Page 510, line 3 - A statement is made that it would be very difficult to generalize about neurologic effects because these have not been very systematically studied accross species. Since the majority of the dioxin work has been in rats and mice, the adequacy of testing accross species for the various effects could be explored. Page 510, line 13 - She is greatly over simplifying the problem of extrapolating from animals to man. In fact, she make it sound more like a science than the art it is. After stating that the mechanism of the reactions is known and similar in all animals, including man, she states on line 19 that the only remaining issue is does dioxin get to those mechanisms in humans as it does in animals. Page 512, line 1 - She states that the sensitivity of the guinea pig appears to be related to the distribution of dioxin. The question is how does one determine the distribution or, as she says on line 6 of this page, the "differences of internal dose" between animals and man. Earlier, on page 300, line 8, she notes that the biological half-life can be determined from toxical kinetics in a number of animal species. Those curves can be used for predicting effects in man. However, while the curves can be used to make the prediction, what is the mechanism by which one can test the validity of the predictions? In other words, while people do manipulate numbers, make extrapolations, etc., and they may even put faith in the conclusions that are reached from those manipulations, there should be some basis for testing or verifying in some fashion, the validity of the conclusions which have been drawn. Page 512, line 18 - Guinea pigs are more sensitive to TCDD than mice or rats. They are at least one, possibly even two orders of magnitude more sensitive. I am surprised that she is not sure of that fact because the extreme sensitivity of the guinea pig to TCDD is frequently cited in the lay press as well as in technical journals. Page 516 - line 8 - Parathion inhibits the enzyme acetylcholinesterase. That enzyme inhibits these cholinesterase which is the chemical messenger between nerve connections and nerve muscle connections. Thus, when cholinesterase is inhibited, the effect is similar to repetitive stimulation of a nerve. The net effect of this would be muscle tremors, and in severe cases, convulsions. It does not produce muscular paralysis. 7 SUBJECT TO PI Cl IVE ORDER. Page 516, line 20 - The effect on peripheral nerves will last as long as the parathion is present. In organic phosphate poisoning, such as parathion, the signs of intoxication, including the effect on nerves, appears relatively shortly after exposure. Depending on the dose, it may be rather rapid or it may be delayed as long as 24 hours. Upon removal from exposure to parathion, recovery will ensue in 24-48 hours. Any toxicologist familiar with organic phosphate pesticides could testify on this subject. Dr. Wayland Hayes at Vanderbilt would be an excellent choice for this. Page 517, line 6 - Parathion does not produce a delayed neurotoxic action in the same since as triorthocresyl phosphate, the classic example of this neurological condition. Page 520, line 7 - If chlorinated phenols can denature membranes, then would they not denature the skin before they got into the body to denature nerve membranes? In other words, can one have serious systemic effects from chlorophenols without first having had severe, or at least detectable, external skin injury? Page 521, line 6 - Halowax is a chlorinate naphthalene. I do not see how it can form dioxin. This a point which the chemists can decribe better than I. Page 533, line 10 - Just a reminder that she is expressing her "opinions on dioxin". CONFIDENT SUBJECT TO PROTECTIVE ORDER. 8 1 .yes. 2 Q. You can't take the amount, the dose with 3 t h e s e m i c e and in any f a s h i o n e x t r a p o l a t e t h a t to m a n ? 4 A. T h a t ' s not w h a t I ' m s a y i n g , Mr. L o v e . T h a t 5 o n e d o s e , t h a t o n e e x p e r i m e n t w h i c h we d i s c u s s e d , in a 6 tota lly d i f f e r e n t context I might state for the record, 7 by i t s e l f , h a s r e l a t i v e l y l i t t l e to c o n t r i b u t e to w h a t 8 we are p r e s e n t l y talking about. P e o p l e have done 9 s p e c i f i c s t u d i e s to m e a s u r e the t o x i c o k i n e t i c s , 10 i n c l u d i n g the b i o l o g i c a l h a l f - l i f e w h i c h is a d e r i v e d 11 n u m b e r f r o m t o x i c o k i n e t i c s , of T C D D in a n u m b e r of 12 a n i m a l s p e c i e s . T a k i n g t h o s e c u r v e s , t h e r e a r e 1 3 m e t h o d s for r e l a t i n g t h o s e on a p r e d i c t i v e b a s i s to 14 humans. 1 5 Q. But y o u h a v e not d o n e t h a t . 1* A. T h a t ' s n o t ray i n t e r e s t in T C D D . M a n y p e o p l e 17 h a v e d o n e it. It is c o n t a i n e d at l e n g t h in the EPA 18 d o c u m e n t on T C D D , the C a n a d i a n g o v e r n m e n t ' s d o c u m e n t 19 on T C D D . T h e r e is no n eed for me to do it. 20 Q. Is t h e r e a ny r e a s o n w h y y o u c a n n o t t e s t i f y 21 a b o u t it? 22 A. I w o u l d be h a p p y to t e s t i f y a b o u t it. B u t xrt'vrt SUBJECT TO PROTECTIVE ORDER. Principal In v e s t ig a t o r : Dr. E.E. McConnell C o lla b o ra to rs: Ms. M. H a rris, Dr. P. Albro, Dr. R. Hass Objective: To determine b io a v a i l a b i l it y of dioxin in M issouri so il samples. Spe cie s: Guinea p igs, Hartley, male, 200-250 grams, 6 animals/group. Experimental Groups: 1. 2,3,7,8-TCDD in corn o i l , lyg/kg bw, volume O.lml/lOOg bw 2. 2,3,7,8-TCDD in corn o i l , 3yg/kg bw 3. Corn o il control - vol O.lml/lOOg bw 4. Times Beach contaminated so il - quantity to equal lyg TCDD/kg bw 5. Times Beach contaminated s o il - quantity to equal 3ug TCDD/kg bw 6. Times Beach contaminated s o il - quantity to equal 10pg TCDD/kg bw 7. Minker s it e contaminated s o il - quantity to equal lug TCDD/kg bw 8. Minker s it e contaminated s o il - quantity to equal 3ug TCDD/kg bw 9. Minker s it e contaminated s o il - quantity to equal 10pg TCDD/kg bw 10. Uncontaminated s o il - weight equal to amount used in Group 6 11. Uncontaminated Missouri s o il spiked with 2,3,7,8-TCDD, 0.8ug/gram s o i l , quantity administered to equal 10pg TCDD/kg bw, Group 6 12. Red clay s o il sample spiked with 2,3,7,8-TCDD, 0.8ug/gram s o i l , quantity administered to equal 10pg TCDD/kg bw 13. Sandy s o il sample spiked with 2,3,7,8-TCDD, 0.8yg/gram s o i l , quantity administered to equal 10ug TCDD/kg bw 14. Loam s o il sample spiked with 2,3,7,8-TCDD 0.8ug/gram s o i l , quantity administered to equal 10pg TCDD/kg bw. Experimental Design: Guinea pigs w ill be allowed to acclimate for 6-7 days after a rr iv a l at NIEHS. Guinea pigs w ill be in d iv id u a lly housed in d i s posable cages (45x20x20cm) with food and water availab le ad lib itu m . One day p rior to dosing, animals w ill be transfered to the high hazard animal f a c i l i t y , Room 1421. *A11 animals w ill be l i g h t l y anesthetized with Metafane. Guinea pigs w ill be weighed and randomly assigned to experimental groups. Food w ill be withheld for 24 hours p rio r to dosing. CONFIDENT! &L SUBJECT 10 PROTECTIVE ORDER. Those receiving TCDD in corn o il and corn o il alone w ill be gavaged using a 20 gauge 1 and 1/2 inch s t a in le s s steel needle. Guinea pigs receiving s o il samples w ill be intubated using polyethylene tubing, PE190. Animals w ill remain in high hazard room fo r a minimum of 48 hours before being transfered back to Bldg. 15 animal f a c i l i t y . Guinea pigs w ill be observed d a ily and weighed three times per week fo r 30 days. Parameters Evaluated: Body weight changes Organ weights Histopathology Deaths On day 30, guinea pigs w ill be weighed and euthanized using carbon dioxide. Animals w ill be observed fo r any gross changes with organs in s i t u . The follow ing organs w ill be removed and weighed and fixed in NBF, 10%, fo r subsequent histopathologic evaluation: brain, thymus, spleen, r ig h t kidney, l i v e r and r ig h t te stic le . These organs w ill be removed and fixed in NBF, 10%, for subsequent histopathology: liv e r / g a ll bladder, thymus, spleen, l e f t kidney, urinary bladder, stomach and l e f t t e s tic le . Any animals becoming moribund or dying during the 30 day experimental period w ill be weighed and opened, observing organs in s i t u . Tissues lis t e d above w ill be fixed in Neutral Buffered Formalin, 10%, for subsequent histopathology. Preliminary analyses of M issouri s o il samples by Analytical Chemistry Group indicate ^ GOOppb 2,3,7,8-TCDD in the Times Beach sample and ^ 800ppb 2,3,7,8-TCDD in the Minker s it e sample. Mean body weights of experimental groups w ill be used for c a lc u la tin g quantity of so il required fo r each group. The so il sample for each animal w ill be mixed with 5ml d i s t i l l e d water for administration. Soil Samples: Four so il samples collected from 4 areas in Missouri on March 1, 1983 and delivered to NIEHS on March 3, 1983 were stored in Special Handling Laboratory, NIEHS Warehouse. A ll manipulations of bulk s o il samples were carried out in this laboratory. Samples, id e n tifie d as AK8201, AK8202, AK8204 and AK8205, were spread on s t a in le s s steel trays and allowed to a i r dry for approximately 40 hours. Each sample, with the exception of AK8204, Minker s it e uncontaminated, was sieved through 1/4" s t a in le s s steel mesh screen to remove rocks and vegetable matter. Sample AK8204 was not s u f f i c ie n t l y dry at th is point for screening or mixing and was put aside fo r late r processing. Each of the three sieved samples were mixed for 20 minutes in a P-K Twin Shell Laboratory Blender. The blended samples were stored in individual 24 quart s t a in le s s steel con tainers with tops in Special Handling Laboratory, NIEHS Warehouse. An aliq uot of each blended s o il sample was analyzed and re s u lts reported by Dr. J.R. Hass in a memorandum to Director, NIEHS dated April 25, 1983. SUBJECT TO PROTECTIVt ORDER. Preparation of Soil Samples fo r B io a v a il a b il it y T e stin g: Sample AK8202, Times Beach contaminated s o il - analyzed TCDD concentration 0.6yg/lg s o i l . 100 grams of sample AK8202, Times Beach contaminated, w ill be passed through a 60 mesh sta in le ss steel standard testing sieve, collecting fines. Particles not passing through w ill be weighed and put into gla ss containers fo r subsequent disposal by Health and Safety Office personnel. Fines w ill be collected and put into g la ss v i a l s with te flo n -lin e d caps in quantity required for each guinea pig in the three groups (no. 4, 5, and 6) receiving th is sample. Quantity required w ill be calculated using mean body weight of each group. An a liq uot of fin e s w ill be submitted to Analytical Chemistry Group for analyses. Remaining fines w ill be stored in a solvent cleaned glass v ia l in Special Handling Laboratory, NIEHS. Sample AK8205, Minker s it e contaminated so il - analyzed TCDD concentration, 0.8ug/lg s o i l . Eighty fine grams of sample AK8205 w ill be processed in same manner as sample AK8202 and administered to Groups 7, 8 and 9 in quantities required. Sample AK8201, Times Beach uncontaminated s o i l . One hundred f i f t y grams of th is sample w ill be processed in same manner as samples AK8202 and AK8205. Fines w ill be placed in gla ss v ia l s in quantities s u f f i c ie n t to equal that given guinea pigs in Group 6. A 30g sample of fine s w ill be spiked with 2,3,7,8-TCDD at a level of 0.8yg TCDD/gram s o il by Dr. P. Albro and appropriate amounts of th is sample w ill be given to each animal in Group 11. An a liq uot of th is sample w ill be submitted for analyses to Analytical Chemistry Group. The clay, sand and loam samples w ill be sieved and spiked in the same manner as sample AK8201. Each animal in Groups 12, 13 and 14 w ill receive appropriate spiked sample in amounts calculated on mean body weights for each group. 3