I??aii?gb 0? D. R. Bihs_hop af?x w' .September 27, 1979 TO Dr. C. F. Callis BZSA Dr. R. Gaffey - CZSH Mr. F. J. Holzapfel - Dr. W. J. McCarville A3NC Dr. F. C. Meyer - CZSH Mr. P. S. Park EZNE Mr. R. M. Scott 1670 Dr. E. Tillman - AZSB Mr. B. J. Wander - CZSA Mr. P. R. Wilkins - 1650 Mr. 'Mr. Mr. Mr. Berendt EZND Crosson - A3NC Papageorge - G4WA Spano - G4NH F.Y.I., the attached article from the September 24 issue of is a well-done, comprehensive update on the.dioxin issue. KEV Attachment . SUBJECT TO PROTECTIVE ORDER. (TV xvf/ 51- IO IREV. 8?77: It is worth your time to read it. Dan R. Bishop :34504 I - - 0? I. ?Foam-fang 3:51 Ellis-dqu Results of several recent emergencysuspension for manyuses . - from the Environmental Protection . {gm-3, studies don't Jlbe With DOW 3 Agency because of an enraged associci'? . . . ation between its use an increase 5 v, contention that dioxins enter miscarriages in a gmhup if 3,01,)livin near forests at a can enwronment "9m combustion? spraged with the hlerbilcidefin Alsea, . kg?. 7 .. - Ore. Detectable eves 2,3,7,8- .- emergmg TCDD also have been found in fish taken from the Tittabawassee .--. a River, which flows by Dow?s produc- 5" .. tion plant for the herbicide in Mid- '3 -- land, Mich. Presence.of_ the com- i pound in ?sh led Michigan?s De- - partment of Natural Resources to .7 ?i suspect the company of illegally - contaminating the river with this 5 .. i Taking potshots at Dow Chemical?s - compound. . i 3. theory that di- So Dow's theory that combustion benzo-p-dioxins are formed by all sorts of combustion processes and are, therefore, ubiquitous in the environ- rnent has become a popular sport among some analytics chemists, especially when there are reporters me The most recent opportunity "or .ictivity, the symposium and mess conference on the chemistry of libenzodioxins and dibenzofurans, sponsored jointly by the divisions of ?esticide Chemistry and of Chemical rlealth 8.: Safety (Probationary). had ts share of shooters. But the sessions also seemed to show, perhaps for the irst time, an emerging common ground shared by scientists on all tides of the issue. The issue is Dow?s theory, ?rst Jroposed last Nevember, that poly- :hlormated dibenzo-p-dioxins, di- ienzofurans, and biphenyls are armed in trace amounts in all forms If combustion. Therefore, they are Iot only ubiquitous in the environ? nent, but have been there since the I'dvent of fire. It is only their detec- Ion that is recent. due to advances in malytical techniques Feb. 2. page 23). The theory has gained so much at- ention because one of the mated, dibenzo-p-dioxins, the 1.3.7.8;tetrachloro species DD), is an extremely toxic com- that also is a carcinogen and a era 1 in laboratory animals-This Om id is a trace contaminant in he herbicide 2,4,5-trichlorophenox- acetic acid produced by our and others. he herbicide is currently under an is a major source of dioxins in the environment is more- than interesting chemistry. If true, it- goes a long way toward absolving the company's product and its manufac- turing process from responsibility for contamination of the environment by these very toxic compounds. Among the potshots the theory re? ceived at the symposium. two are most prominent: Brenda J. Kimble of the Department of Energy's Radio- biology Laboratory at the University of California, Davis, and Michael L. Gross, director of the MidwestCenter for Mass Spectrometry at the Uni- versity of Nebraska, Lincoln, have analyzed the smokestacl-t emissions of a coal-fired power plant in California. They find no in the emis- sions, down to their detection level of 0.6 of ?y ash. The Dow study looked speci?cally at the smokestack emissions of a power plant and con- cluded that this was a source of dioxins. Also, David L. Stalling of the US. Fish Wildlife Service and associates analyzed 16 samples of fish and other aquatic animals for dibenzofurans and dibenzodioxins. They found in only two samples. both from the Tittaba- wassee River. Further, was the most common isomer in these sam les, an isomer distribution that wou not be expected if the source of the isomer were Ordinary combustion. The most likely explanation, Stalling says, is that the Dow plant is the source of the isomer found in the fish. Crummett: complex and expensive Even these reports may be at least partially compatible with Dow's findings. For example, Warren E. Crummett, a research scientist with Dow?s analytical laboratories, ex- plained that the power plant where Dow found dioxins in the stack emissions was on Dow?s Midland fa- cility. During the sampling period it was burning primarily fuel oil, with a small amount of coal. Various scien- tists at the press conference suggested that possibly the fuel oil, or even the air in Midland, contains. chemical precursors to the dioxins found in the stack emissions that are not found in the California power plant. Crummett criticized the California study in two ways. He says the sam- ples were taken from too low in the smokestacks and that the particulates that were analyzed were primarily siliceous, whereas Dow had found that the dioxins in such emissions were associated with carbonaceous particulates. "The particulates we sampled were the same as those that come out the top of the smokestacl-r," Kimble says. The Dow study made sweeping claims about power plants being sources of environmental dioxins based on ex: tremely limited evidence, she says. What she and Gross have shown that at least oneimportant class of power plants. those that burn western coal, can be free of dioxin contami- nation. The question of the need to have I'll I??n?nr?n- ll.? . ,dlbenzofurans can form from burning precursors . h. I . . Eel-1'01 . rap-u- Payable-(Lites: 25.x: ?a Ti, . . potHorns piclurad in these structures. I. a - awninnbuni wuss-?inexhau? Hole: These compound. conlaln one or more. but not necessarin all, 0! the chlorine '11: 1* a ?hr\xjchamps-v -- - a it . recursors present in the material Being burned in order to generate chlorinated dioxins or dibenzofurans in combustion has become a central point- of dispute. Something, of course, has to provide the atoms that eventually end up in the?dioxins and dibenzofurans. Dow contends, based on its widespread finding of these compounds in combustion products, that just about anything that will burn can serve as a precursor. Others, particularly Christoffer Rappe of the l-ai-ri-rersity of Umea, Sweden, and :s-Rudolf Buser of the Swiss ieueral Research Station, Weider)- swil, think that chlorinated comgounds must be present before com ustion will yield chlorinated dioxins and dibenzofurans. Here, too, there seems to be some middle ground emerging. Crummett, for instance, seems to acknowledge that some materials produce more dioxins when they are burned than do others. He maintains. however, that precursor compounds are so wide- spread in the environment that tracking them down via combustion data is a task of such com lexity and expense as to be infeasi 1e. re- ported two new examples of how widespread is in the environment. Detectable levels of this compound now have been found in commercial sludge fertilizer made from treated sewa e. It also has been detected in the ational Bureau of Standards' standard sample of urban particulate matter. Buser and Rappe now say-that the chemical precursors for th dioxins and diobenzofurans can "Jund ?practically everywhere? in rn_v_ironment at low levels. They rim-"item, however, that, except in special circumstances, such as the combustion of chemical wastes or accrdental fires involving stores of 23 cast Sept. 24. 1979 certain kinds of chemicals, such combustion presents very little health hazard. And, like Dow, they think that the use of is a very much less important contributor of dioxins to the environment than is combus- tion. Even the dioxins that enter the environment from pesticide use seem to be much less hazardous than lab- oratory tests would letid one to be- lieve, says Capt. Alvin L. Young of the U.S. Air Force?s Occupational En- vironmental Health Laboratory,' Brooks Air Force Base, Tex. Young and his associates have analyzed the soil and animals at Eglin Air Force Base in Florida where 73,000 kg of was sprayed between 1952 and 1970. Much of this material con- tained much higher levels of than are now found in the herbicide. - Some was still present in soil samples taken in 1978. Concentrations ranged from less than 10 to 1500 ppt. (Young?s analyti- cal method cannot distinguish from all other chlori- nated dibenzo-p-dioxins. The con- centration he reports is for the com- bination of isomers that includes the 2.3.7.8-TCDD isomer.) The Air Force chemists did not ?nd detectable levels of in any plants taken from the site. How- ever, they did ?nd it in nine species of animals. including mammals, birds, fish, and reptiles. Levels varied from several hundred parts per trillion in the livers of beach mice and mea- to 1'3 in the whole bod- ies Hr two kinds oft-15h. Beach mice. which contained the highest concentrations of the com- pound, were singled out for further study. Eighteen types of tissue from 300 animals were examined for toxic effects. but none of the tissues were signi?cantly different from those of control group animals. Just how important the trace quantities of dioxins that are being found in the environment are likely to be is a point that was raised ire- gigently during the symposium. ppe, Buser, and Shilling all seemed to agree that the poiychlorinsted riir benzofurans, though less toxic in an absolute sense than the most toxic dioxins, are ofmore concern because they are present in higher concen- trations. They can be formed by combustion of b1- phenyls (PCB's), which earlier has shown are very widespread in the environment. Stalling, along with Donald W. Kuehl of Duluth, Minn" re- search laboratory, Iialph C. Dou- gherty of Florida State University, and Rappe, finds dibenzofurans and naphthalenes in aquatic animals living in waters that contain PCB's and their breakdown products. The results are somewhat preliminary, since only 16 samples have been analyzed and, so far. no samples have been checked from pristine waters. However, animals taken from the Ohio River and Lake Michigan, where contamination - comes from used show higher levels and more complex mixtures of these compounds than do fish taken from the Hudson River, which is contaminated by newly manufac- tured but contains low levels of PCB combustion products. Rappe and Buser have 'been studying the combustion products of chlorophenols, and chlori- nated diphenyl ethers and benzenes. All of these compounds can be con- verted to dihenzo- dioxins and dibenzofurans in high yield, they find. However, 2.3,7,8- TCDD, the most toxic of the diben- zodioxins, is a minor product of combustion under the conditions found in municipal incinerators; the most toxic of this class of com pounds, is the major isomer formed under these conditions. can yield chlorinated dibenzofurans as high as 25%, they find. Nevertheless, except for a few special cases, they do not see even the dibenzofurans as health hazards. They do recommend that rinated phenolic chemical wastes he Very carefully incinerated in evens that allow for high-temperature in- cineration and lo .g residence make sure that toxic produ; :9 destroyed. And halogenated :33- 51%. biphenyls, and diphenyl A "a should not be used as flam. dants because of the high 10.1.: .. .- a: their combustion products.