Document kmQYzQajmkd473xZVQ4ZpJonb

1. What is dioxin? The term "dioxin" has re c e n tly become a household word, as had asb esto s, PCB's and DDT during the la s t decade. A ctu ally , "dioxin" is a term commonly used as the abbreviation for 2,3,7,8-tetrachlorodibenzo-p-dioxin, a polycyclic chlorinated compound. Dioxin is an unwanted contaminant formed during sev eral chemical processes (such as 2,4,5-T production) and also during in cin eratio n of in d u stria l and municipal wastes. . 2. How did we get dioxin a t the N itro P lan t? Here at N itro 2,4,5-trichlorophenoxyacetic acid (2 ,4,5 -T ), a herbicide, and .its relate d interm ediates were produced from 1948 to 1969 in B uildings 34, 41, 51, and fin a lly 92, which was demolished in 1972. In March 1949, a v io len t reactio n and decomposition occurred which released vapors and a tarry residue into the atmosphere. I t is now b eliev ed th a t dioxin was formed during th is "explosion" and was also present in trace amounts in the 2,4,5-T product. 3. What is a p art per b illio n ? Dioxin has been found in the low p a rt p er b illio n (ppb) range in the s o il, from none d etected to 137 ppb. A ppb is a very sm all amount; the follow ing examples a l l rep resent one ppb - one inch in 16,000 m iles, on cent in $10,000,000 (ten m illion dollars) or one thousandths of an ounce of s a lt in 62,500 pounds of sugar. A n aly tical techniques continue to analyze lower and lower lev els of dioxin on down in to the p a rts per t r i l l i o n (ppt) range. One ppb equals 1,000 p p t. . Cl9487 . 2- A. What were the re s u lts of th e EPA's recen t te s tin g fo r dioxin? 5. Are we being exposed to dioxin now? Exposure to any chemical can occur through three routes; in h alatio n , ingestion and sk in absorptio n . Dioxin is a s o lid a t room tem perature and e s s e n tia lly has no vapor pressure (vapors are not given o ff). Since dioxin binds so tig h tly to s o il, inh alatio n would be lim ited to breathing in contaminated s o il which is unlikely because the so il is under several inches of gravel. Skin contact with or ingestion of contam inated s o il is s im ila rly u n lik e ly . Remember th a t due to .the very low levels of dioxin, an awfully lo t of d irt would have to be inhaled or contacted with before any h ealth hazard would be expected. 6. What are the h e a lth e ffe c ts o f exposure.to dioxin? Chloracne is the predominate health effect diagnoses in humans, and i f absent, other adverse health effects are not lik ely . Following occupational exposures, symptoms have been reported of fa tig u e , nerve response changes and liv e r to x ic ity . Follow-up surveys have shown th a t these e ffe c ts are rev ersib le,- except fo r possible permanent scarrin g from severe chloracne cases. Extensive dioxin studies have been performed on a v ariety of animals w ith atwide range of resu lts found. 3- - A ctually, anim al stu d ie s are the reason fo r much of the concern and confusion about the to x icity of dioxin. For example, a very minute amount of dioxin can k ill the guinea p ig , whereas 5,000 tim es more is necessary to k i l l a ham ster (however, s t i l l a sm all amount). Also, the cause of death or toxic effect often d iffers between animals making i t d iffic u lt to a n ticip ate what amount and what e ffe c t dioxin w ill have oh humans. 7. I recently heard of a study that linked dioxin to soft tissu e cancer. Is th at true? Soft tissu e sarcoma is a rare form of cancer th at attacks the so ft tissu e s; muscle, fa t, nerves or connective fib e rs. A study by The N ational In s titu te of O ccupational S afety & H ealth (NI.0SH) th a t has not been pub lish ed y e t has suggested th a t s o ft tis s u e sarcomas may be a re s u lt of dioxin exposure. Due to incom plete data and the small workforce involved here at N itro, i t is not s ta tis tic a lly possible to show any d iffe re n c e s between us and th e g en eral p o p u latio n . NIOSH is perform ing sim ilar studies with other work populations. to obtain a larg e r number of employees fo r s t a t i s t i c a l ev alu atio n . L ittle is known about s o ft tis su e sarcomas because they are so rare, but because of the d iffe re n t tissu e s involved, more than one cause is suggested. 8. How w ill dioxin a t the N itro P lan t a ffe c t my job? Now th a t d io x in has been found a t very low le v e ls in the s o il , only operatio n s th a t re q u ire excavation w ill re q u ire changes. As s ta te d in Q uestion 5, good work p ra ctic es w arrant the use o f some types of personal p ro te c tiv e equipment to m inim ize' sk in con tact and dust in h a la tio n during ground b reaking. An excavation procedure is being prepared to standardize protective equipment. 9. Is there any danger to the community from dioxin at the N itro Plant? Dioxin binds strongly to s o ils, especially clay, and is not soluble in w ater. Although i t remains fa irly long in the s o il, su n lig h t has been shown to rapidly degrade i t . For these reasons, the community is a t no ris k as the dioxin w ill stay in the lo catio n s where i t was buried. 5TW 3U2 ,, . .Cl9489 4- - 10. I'v e heard of dioxin a t Times Beach, M issouri; Midland, Michigan; and Seveso, Ita ly . What happened in those places? There have been several incidences of dioxin contamination in recent years and w ill undoubtably be more. In July of 1976, dioxin was released from a trichlorophenol plant in Seveso, Ita ly when a sa fe ty d isc on a re a c to r ru p tu red . An area of about one square m ile was contaminated w ith the s e ttlin g reacto r contents, p o te n tially exposing upwards of 37,000 people. There have been 134 confirmed chloracne cases as a re s u lt of th is release. Studies on the exposed groups continue, but to date there have been no Increases in deaths, cancers or other h ealth problems when compared to a non-exposed Ita lia n control group. Several incidences of dioxin contamination have also occured in M issouri. In 1971, w aste o il contam inated w ith dioxin was sprayed on horse arenas to keep dust down. Over 65 horses and o th e r anim als d ied and one g i r l developed an inflam ed and bleeding bladder, which returned to normal a fte r her exposure was stopped. The la te s t incid en t was in Times Beach, M issouri when contam inated s o il from sim ilar o il spraying a c tiv itie s on d irt roads and in la n d fill s o il was found to contain various le v e ls of d io x in . EPA was put under p re ssu re to a lle v ia te th e problem , and because the human h ea lth e ffe c ts b esides chloracne are not known, they decided to buy out the residents and evacuate the town. In Midland, Michigan the major concern is th at fish have been found.w ith low levels of dioxin and the exact source has not been id en tified . A suspected source of contamination are the in d u stria l and municipal incinerators in the area. CONFIDENTIAL SUBJECT TO PROTECTIVE ORDER. * 19490