Chat Doc Maud a Cam

8/8/2019 Chat Doc Maud a Cam

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Trng:i hc Quc TGing vin: Tin s Ng Quang nhH v tn sinh vin: o Mnh LinhM s sinh vin: BA070092

BI THU HOCH CHUYN THAMQUAN BO TNG

CHNG TCH CHIN TRANH


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Li m u:

D sng Si Gn gn 2 nm nhng va ri ti mi c dp i thmbo tng chng tch chin tranh. Ni y qu l ang lu gi v vn nhngt liu qu gi v mt thi gian kh, au thng m ho hng ca dn tc ta.Xem nhng bc nh, ti khng khi au. Ti c mi canh cnh mt cuhi:"Cng l con ngi vi nhau, sao ngi ta c th i vi ng loi mnhnh th?", v ti au, au ni au mt thi mt nc, mt thi kh nhcdi bn tay tn bo ca bn gic xm lc.Tht s, khi xem nhng tmnh, xem my chm, khng ai thot khi cm gic rn rn, lnh lnh

ngi.Nhng, vt ln trn tt nhng cm gic y vn l s cm gin. y thng c ngi nc ngoi n xem lm. Nhiu ngi xut xoa,

cht lng, lm du thnh, ci u...Qu tht, khng ai c th bng quangtrc nhng tm nh nh th.Ti n tng nht tm nh mt ngi cha gicng a con b nh hng cht c mu da cam. Trong chin tranh, ngita phi hy sinh nhiu cho T quc, y vy m sao khi t nc ho

bnh, h khng c hng cuc sng hnh phc ?Th mi bit d chin tranh qua i, nhng hu qu ca n vn li

khin cho bao nhiu ngi dn phi lao ao, nhng a tr s sinh hay nm

trong bng m no c ti tnh g m phi chu s phn nh th: d hnh ddng ngay t khi cn trong bng m, hay l sinh ra li b thiu nng tr tu,khng pht trin c nh ngi thng! Tht ti nghip, chng ch lnhng nn nhn ca chin tranh ch v mt l do duy nht: cha m chng lk ch ca ch M - Dim hay ch n thun l v ngi dn nm trongvng nghi ng ca chng, l nhng ngi ht th bu khng kh y chtc mu da cam.

Vy cht c mu da cam l g? quc M s dng khi no? Gyhu qu ra sao v lm sao gii quyt?... Vi mt bi thu hoch nho nhny em hy vng s gii p c phn no nhng cu hi trn v truyn ti

c nhng g m mnh c tn mt chng kin bo tng chng tchchin tranh.

TP H Ch Minh, ngy 25 thng 7 nm 2009

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o Mnh Linh

Mc lc:

Li m u: .......................................................................................................................... 2I.Mt s thng tin v cht c mu da cam: ........................................................................4

1 > Cht mu da cam l g .............................................................................................. 4Cht c mu da cam l mt cht dit c c sn xut vo nhng nm 1940. Cht ny c qun i M v ng minh s dng nhiu nht trong chin tranh Vit Nam lm tri rng v rng s vt nhm lm l ra cc con ng vn ti v cc cn c quns; ph hu ma mng ngn ta khng c lng thc d tr. Cc cht dit c c chatrong cc thng c dung tch 280 lt. phn bit cc cht khc nhau, cc thng cmang nhng ci bng mu nhn dng. Cc mu trong sc cu vng c dng nnchng ta c tn cc cht dit c. Tn cht c mu da cam i din cho tt c cc

cht dit c c s dng trong chin tranh Vit Nam

2 > Ti sao Cht Mu Da Cam li nguy him ?.......................................................................................................................................... 4

2.1 Dioxin l g? ...........................................................................................................4Dioxin hay TCDD (tetrachloro-dibenzo-para-dioxin) l mt tp cht cha trong2,4,5T - mt hp cht mch vng cha clo, c tc dng dit c v gy rng l. Chtda cam l mt hn hp 50/50 ca 2,4 D v 2,4,5T v v vy c cha dioxin. ............ 42.3. Ngun pht sinh Dioxin ........................................................................................ 52.4. Tnh cht ca Dioxin .............................................................................................52.5. c tnh ca Dioxin .............................................................................................. 6

II. Cuc chin tranh ho hc Vit Nam: ......................................................................... 111.Qu trnh nhim c Dioxin Vit Nam ....................................................................112. tch t dioxin ........................................................................................................14

III. Thng k v cc tc hi ca Dioxin ............................................................................. 151.1. nh hng n con ngi ......................................................................................151.2 Mt s hnh nh v tc hi ca Dioxin i vi con ngi ....................................... 182.1. nh hng n h sinh thi ...................................................................................213. Mt s hng x l Dioxin ........................................................................................24

3.1. Cc phng php phng chng v x l Dioxin ................................................243.2. Cc hot ng tiu c Dioxin ca Chnh ph ...................................................25

Li kt ................................................................................................................................27

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I.Mt s thng tin v cht c mu da cam:

1 > Cht mu da cam l g

Cht c mu da cam l mt cht dit c c sn xut vo nhng nm1940. Cht ny c qun i M v ng minh s dng nhiu nhttrong chin tranh Vit Nam lm tri rng v rng s vt nhm lml ra cc con ng vn ti v cc cn c qun s; ph hu ma mngngn ta khng c lng thc d tr. Cc cht dit c c cha trongcc thng c dung tch 280 lt. phn bit cc cht khc nhau, ccthng c mang nhng ci bng mu nhn dng. Cc mu trong sccu vng c dng nn chng ta c tn cc cht dit c. Tn cht cmu da cam i din cho tt c cc cht dit c c s dng trongchin tranh Vit Nam

2 > Ti sao Cht Mu Da Cam li nguy him ?

Hai phn ba cht dit c c s dng trong chin tranh Vit Nam trong c chtmudacam c cha a-xit 2,4,5-T. Th nhng axit ny khi c snxut ra t cc nh my cng nghip thng c cha mt lng ng k

Dioxin (TCDD) ln vo.

2.1 Dioxin l g?

Dioxin hay TCDD (tetrachloro-dibenzo-para-dioxin) l mt tp chtcha trong 2,4,5T - mt hp cht mch vng cha clo, c tc dngdit c v gy rng l. Cht da cam l mt hn hp 50/50 ca 2,4D v 2,4,5T v v vy c cha dioxin.

2.2 Cng thc cu to ca Dioxin

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Qui c x, y la so nguyen t Clo moi vong Benzen.Trong Clx, x co gia tr t 0-4, va y trong Cly co gia trt 1 - 4. Hay noi khac i, trong cong thc cau taocua Dioxin co the co t 1 en 8 nguyen t Cl.

Theo ly thuyet, co the co en 75 dang chat dioxinkhac nhau do v tr va so lng nguyen t Cl co mattrong cau tao nguyen t sap xep khac nhau. Chungbao gom: monoclor, 10 diclor, 14 triclor, 22 tetraclor, 10hexaclor, heptaclor va 1 octaclor-dibenzo-para-dioxin(TCDD) ma chung ta quen goi ladioxin.

2.3. Ngun pht sinh Dioxin

Dioxin ch yu pht sinh t cc ngun sau:

- Qui trnh ty trng giy v bt giy bng clo trong cc nh my sn xutgiy.- Qu trnh t cc loi cht thi, rc thi (sinh hot, y t, cng nghip,) ccha dn xut clo ca hp cht hu c vng thm, m cht ch yu hin nayl PCB (ha cht Polychlorinated Biphenyls) .- Qui trnh sn xut ho cht, thuc tr su v thuc tr c 2,4,5T to sn

phm ph l Dioxin .- Bnh phn ng ch to triclophenol b n gy ra nhim c sn phm phl dioxin.

2.4. Tnh cht ca Dioxin- Dioxin l cht c rn, rt bn vng trong mi trng, t b phn hu docc yu t bn ngoi nh nhit , m, tia cc tm v cc ho cht.- Dioxin hu nh khng tan trong nc (0.2g/l) v t tan trong dung mihu c.- Dioxin c th chu c nhit ln n 800-1000oC.- Dioxin hon ton khng b phn hu bi sinh hc do cc vi sinh vt thngthng.- Chu k bn phn hu ca dioxin t 3-5 nm v c kh nng ln ti 12 nm.

bn vng ca Dioxin c xc nh theo chu k bn hy (thi giandioxin t phn hy mt na khi lng). Nhng chu k bn hy ca Dioxintrong thc t cn c rt nhiu tranh ci: Theo D.Pautenbach (1992) v R.Puri (1989, 1990), trn lp t b mt,chu k bn hy ca Dioxin dao ng t 9-25 nm, cn cc lp t su hnl 25-100 nm.

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Theo Hi ngh quc t ti TPHCM (1983), l 5-7 nm, nhng thc t ctrng hp ngi b nhim c sau 35 nm cn pht hin thy dioxin.

2.5. c tnh ca Dioxin

2.5.1. Mt s nghin cu v tiuchun liu lng DioxinDioxin l 1 trong nhng ha cht cnht c bit n hin nay trongkhoa hc. Trong bn bo co ca CcBo v Mi trng Hoa K (EPA)nm 1994 miu t dioxin nh lmt mi tc nhn e do nguy himi vi sc kho cng ng. EPA

cng nhn dioxin l mt cht gy ungth cho con ngi.Thng 1 nm 2001, chng trnh chc Quc gia Hoa K chuyndioxin vo nhm "cc cht gy ungth cho con ngi".Vin Hn lm khoa hc M chpnhn c t nht 13 bnh lin quan ndioxin.Cui cng, trong mt nghin cukim nh nm 2003, cc nh khoa hc khng nh khng c mt liu lngno l an ton hoc c mt ngng dioxin no m di n th khng gyung th. Ngha l nu mt ngi phi nhim dioxin d lng nh nht th mang trong mnh him ha ung th.Dioxin l cht rt c, cho nn liu lng ti a cho php ca chng i vingi tip xc l rt nh.

T chc Y t th gii (WHO) quy nh liu cho php ca dioxin l: 1 - 4 ppt (phn nghn t gram) cho 1 kg trng lng c th trong mt

ngy m.Mt ngi c trng lng l 50 kg th liu cho php trong mt ngy mti a l 50-200 ppt.M cn nh gi dioxin c hi ln hn nn liu cho php ca c quan bov mi trng M (EPA) l 0,006 pg, < 160 ln so vi liu cho php ca Tchc Y t th gii.

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nh chp ti bo tng chng tchchin tranh
http://vi.wikipedia.org/w/index.php?title=C%E1%BB%A5c_B%E1%BA%A3o_v%E1%BB%87_M%C3%B4i_tr%C6%B0%E1%BB%9Dng_Hoa_K%E1%BB%B3&action=edithttp://vi.wikipedia.org/w/index.php?title=C%E1%BB%A5c_B%E1%BA%A3o_v%E1%BB%87_M%C3%B4i_tr%C6%B0%E1%BB%9Dng_Hoa_K%E1%BB%B3&action=edithttp://vi.wikipedia.org/wiki/1994http://vi.wikipedia.org/wiki/2001http://vi.wikipedia.org/wiki/2003http://vi.wikipedia.org/w/index.php?title=C%E1%BB%A5c_B%E1%BA%A3o_v%E1%BB%87_M%C3%B4i_tr%C6%B0%E1%BB%9Dng_Hoa_K%E1%BB%B3&action=edithttp://vi.wikipedia.org/w/index.php?title=C%E1%BB%A5c_B%E1%BA%A3o_v%E1%BB%87_M%C3%B4i_tr%C6%B0%E1%BB%9Dng_Hoa_K%E1%BB%B3&action=edithttp://vi.wikipedia.org/w/index.php?title=C%E1%BB%A5c_B%E1%BA%A3o_v%E1%BB%87_M%C3%B4i_tr%C6%B0%E1%BB%9Dng_Hoa_K%E1%BB%B3&action=edithttp://vi.wikipedia.org/wiki/1994http://vi.wikipedia.org/wiki/2001http://vi.wikipedia.org/wiki/2003


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2.5.2. C ch gy c ca DioxinC ch phn t ca dioxin tc ng ln cc t bo v c th ngi, ng vtvn ang cn nhiu tranh ci v chi tit.Thi gian bn phn hu ca dioxin trong c th ng vt l 7 nm hoc cth lu hn. Thng thng, dioxin gy c cho t bo thng qua mt th thchuyn bit cho cc hydratcarbon thm c tn l AhR(Aryl hydrocarbon

Receptor).Phc hp dioxin - th th s kt hp vi protein vn chuyn ArnT (AhRnuclear Translocator) xm nhp vo trong nhn t bo. Ti y dioxin sgy ng m mt s gene gii c quan trng ca t bo nh Cyp1A,Cyp1B,... ng thi, mt s th nghim trn chut cho thy dioxin lm tngnng cc gc ion t do trong t bo.iu ny, c th l lm ph hu cc cu trc t bo, ccprotein quan trngv, quan trng hn c, n c th gy t bin trn phn t DNA.

2.5.3. S liu v tc hi ca Dioxin ln con ngi v ng vt i vi con ngi:

Dioxin gy ra s phn chia t bo mtcch bt bnh thng trong c th, xy ra: phi, da, d dy, rut, gan, tu sng,..

Dioxin lm tng nguy c tiu ng, ung

th, bnh rm da, sinh con qui thai, hhm ch hoc thiu nng tr tu, d ttbm sinh v.v.

Bng 1: Mc nh hng n conngi ng vi tng nng Dioxin

Liu lng Tc hi

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Trch bng tng kt hi ngh v hu quchin tranh ha hc ln 2 ti H Ni(17-19/4/1986)
http://vi.wikipedia.org/w/index.php?title=AhR&action=edithttp://vi.wikipedia.org/w/index.php?title=ArnT&action=edithttp://vi.wikipedia.org/wiki/Chu%C3%A1%C2%BB%C2%99thttp://vi.wikipedia.org/wiki/Proteinhttp://vi.wikipedia.org/wiki/DNAhttp://vi.wikipedia.org/w/index.php?title=R%C3%A1m_da&action=edithttp://vi.wikipedia.org/w/index.php?title=Sinh_con_qu%C3%A1i_thai&action=edithttp://vi.wikipedia.org/w/index.php?title=Thi%E1%BB%83u_n%C4%83ng_tr%C3%AD_tu%E1%BB%87&action=edithttp://vi.wikipedia.org/w/index.php?title=AhR&action=edithttp://vi.wikipedia.org/w/index.php?title=ArnT&action=edithttp://vi.wikipedia.org/wiki/Chu%C3%A1%C2%BB%C2%99thttp://vi.wikipedia.org/wiki/Proteinhttp://vi.wikipedia.org/wiki/DNAhttp://vi.wikipedia.org/w/index.php?title=R%C3%A1m_da&action=edithttp://vi.wikipedia.org/w/index.php?title=Sinh_con_qu%C3%A1i_thai&action=edithttp://vi.wikipedia.org/w/index.php?title=Thi%E1%BB%83u_n%C4%83ng_tr%C3%AD_tu%E1%BB%87&action=edit


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0,3.10-3mg/g

Kch thch da, chng mt, au u,bun nn

1 g /g Ng c cp tnh nu a vo c th1 mg/g T vong nu a vo c th

Mt nguy c thc t l con ngi khng phn ng nhy vi hiu ng cpca dioxin nhng dioxin l mt cht gy qui thai (teratogen) v ri lonnhim sc th tim nng i vi con ngi hn l cc loi ng vt trong

phng th nghim.

V vy dioxin rt d gy ng c cho phi thai, d dng, khuyet tat v tcng vo gen di truyn, ngay nng b nhim rt thp.

Bng 2: Mc nh hng n con ngi ng vi tng nng Dioxin

Nng Dioxin Mc nh hng1 ppt Tc ng n thainghn

5 ppt C th gy ung th50-70 ppb C th cht ngi

Cc quan im nu trn cho thy hiu qu tc hi ca dioxin ph thuc vonng v thi gian, nu nng thp th thi gian di v ngc li.

i vi ng vt:

Cc nh khoa hc chng minh c rng kh b nhim dioxin s b bnhtng ng vi liu dioxin. V d: 71% kh nhim dioxin liu 25ppt b bnh trung bnh cho n nng. 42% kh th nghim ch nhim liu 5ppt xut hin bnh.

Bng 3:Liu Dioxin gy cht i vi kh (LD50) ca 1 s cht c

Chtc

Liu Dioxin(ppb)

Dioxin 70

Sarin 83Tabun 208

Liu cht 70 ppb i vi kh c ngha l 1 gram dioxin l 14 triu liu cht.

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Dioxin rt bn vng trong mi trng v con ngi, kt hp vi c trngtc hi ca dioxin c tnh cht cng hp, nn d nng thp hay caodioxin u c tc hi.i vi chut th dioxin l mt cht gy ung th rt mnh (ung th gan,

phoi,..)Qua nhiu th nghim nghin cu trn chut ngi ta cho bit trong cth chut, chu k bn hy ca dioxin khong 32 ngy. Liu gy ung th vt bin i vi chut l rt thp 0,1-0,3g/kg.c tnh dioxin gy ra r rtv khc nhau.

Bng 4:Liu lng LD50 g/kg trng lng c th (lng Dioxin gy cht 50% sV th nghim)

ng vt LD50 (g/kg trng lng cth)

Chut ci 0,6-0,2Chut ng 5050Heo 0,6Kh 70Th 115Mt s ng vtkhc

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Mc du 2,3,7,8-dioxin ch co mot ty le rat thaptrong chat oc da cam (khoang 2 phn trieu, tc latrong 1kg chat oc da cam co 2mg dioxin) khong gayt vong cho ngi nhng no gay oc tiem tang trongcon ngi khi b nhiem va se anh hng en isau.Ngi ta cung tnh rang, co 1kg TCDD th co the gietchet 1 trieu ngi. Cai nguy hiem nhat cua TCDD latac ong xau vao c che DNA di truyen gen, gay

quai thai va co the gay ung th.

2.5.4. Mt s cn bnh do Dioxin- Gay benh tren da: theo Herxheimer (1899), nhngcong nhan san xuat TCDD khi b nhiem oc th dacua ho noi mun trng ca, sau o dien bien nang

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dan, co the b en roi loet. Co the la dioxin a tantrong m cua chat nhn di da va tac ong chuyeu la cua Cl. Benh nhan nang hn co the teo ganroi chet.

- Gay benh tren mat: ngo oc cap tnh, o, phuket mac, viem mong mat, giac mac. Sau giai oancap tnh co the th phat suy nhc mat 81,3%nan nhan Viet Nam (GS Ton That Tung, 1977).- Gay xuat huyet: chay mau ng tieu hoa trensuc vat th nghiem va ca tren ngi.

- Ton thng gan: cac dauhieu lam sang va ch

tieu men gan a cho cacnha khoa hoc khang nhrang, gan la c quan bdioxin gay ton thng trcnhat, tham ch gay tvong.- Say thai, quai thai va roiloan nhiem sac the: ty lesay thai va quai thai

phu n va gia suc vungo nhiem rat cao (GS TonThat Tung, 1977). Say thaii kem vi nhiem sac the(J.G.Boue, 1976), gay quai thai, chet bao thai (Neubert,1977).- Gay ung th: GS Ton That Tung cho rang, dioxin latac nhan gay ung th,nhat la ung th gan

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Cc nh nghin cu cho rng c milin h gia vic John Ball, Jr. b

khuyt tt bm sinh vi vic cha cachu b nhim cht Dioxin( Ngun: BTCTCT)


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II. Cuc chin tranh ho hc Vit Nam:

1.Qu trnh nhim c Dioxin Vit NamVo thp k 70, chnh ph M

bt u s dng cc cht hohc trong cuc chin tranhVit Nam, vi mc ch phtquang rng rm v truy tmch n np ca Vietkong( ngi ca chnh ph BcVit Nam).

Ngy 13-1-1962, ba my bayC-123 ca khng lc M risn bay Tn Sn Nht khiu mt chin dch mi mangtn "Ranch Hand" Nhngchic C-123 y ri xung mt cht c m nhiu thp nin sau ch

ring ci tn ca n khng thi l ni kinh hong: cht c da cam!

Thc t l nhng cht c y, bao gm nhiu loi vi cc m mu khc nhau: cht mu hng (Agent Pink), cht mu xanh l cy (Agent Green), mu tm(Agent Purple), mu da cam (Agent Orange), mu trng (Agent White), vmu xanh da tri (Agent Blue). Mi loi ha cht mu c thnh phn hahc khc nhau, nhng ni chung phn ln chng u c thnh phn 2,4,5-T,tc c cha dioxin. V ngay khi bt u c ri chin dch u tin, n pht huy ngay tc dng, lm pht quang ton b mt din tch rng ln.

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My bay C123 ang phun ri cht da cam(Ngun: Bo tng chng tch chin tranh)


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Trc kt qu kh quan ca chin dch,trong thi gian 1961 - 1971, gn 80triu lt ha cht b ri xung rng ni v ng rung Vit Nam. Trongs ny cht c mu da cam l ch yu, ngoi ra cn cc cht mu trng, lc,lam v tm.

Bng: S lng ha cht qun i M dng trong chin tranh Vit Nam1961-1971

Ngun gc: Tp san Nature

c chtS lng(lt) T l %

Cam AgentOrange

49.268.937 64,0%

Tm AgentPurple

495.190 0,6%

Lc Agent Green 1.892.773 2,5%Trng AgentWhite

20.556.525 26,7%

Lam Agent Blue 4.741.381 6,2%Tng s 76.954.806 100,0%

Biu :T l % cc cht c ho hc trong chin tranh Vit Nam 1961 -1971

T l % cc cht c ho hc trongchin tranh

64.0%

26.7%

6.2%

2.5%0.6%

Cam Agent Orange Tm Agent Purple

Lc Agent Green Trng Agent White

Lam Agent Blue

Trong cc cht c chnh c s dng min Nam Vit Nam, cc cht dacam, cht xanh da tri v cht trng l cht c thc s, v chng cha cccht rt c hi

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Qua th nghim qun i M thy rng, cht c da cam c hiu qu nhttrong vic ph rng, cht trng c hiu qu trong ph hoi hoa mu, la, do cc cht ny c s dng nhiu nht.Din tch phun ri ca cc cht ny l 1,4 triu ha, ch yu l cc vng ninh Qung Tr, Tha Thin, Qung Nam, Ty Nguyn, ng Nam B, vngrng ngp mn t Cn Gi n C Mau.- Cht da cam (agent orange):

Hn hp ca 50% n-butyleste ca 2,4 dichlorophenoxy axetic acid(2,4-D) v 50% n-butyleste ca 2,4,5 trichlorophenoxy axetic (2,4,5-T). Cha cht dioxin - mt cht vo loi c nht m loi ngi

tng hp c. C tc dng lm rng l

cy trong thi gian t 3 6 tun sau

khi phun.- Cht xanh lam (agent blue):

Hon hp cua muoinatri cacodilate va dimethyl arsenicacid theo ty le 2,6:1.

C cha thnh phn rtc hi l cht arsenic (thch tn).- Cht trng (agent white, tordon101):

Cc mui tri-isopropanolamin ca 2,4-D v 4-amino-3, 5, 6-trichloropicolinic acidtheo ty le 3,8:1.

C cha tp cht hu c c hi v bn vng l cht hexaclorobenzen.

Trong cc cht c da cam, tm, xanh l cy u cha tp cht dioxin. Can lu y, ten goi chat trang, xanh, da cam

ch la quy c ch khong phai la mau thc scua cac chat o. Theo ly thuyet, cac chat nay,khong s dung e giet ngi ma chu yeu e dietcay. Ban chat hoa sinh cua no la co the phanhuy t 2 15 tuan sau khi phun, trong ieu kien nhieti am, t cac hp chat d thng trong 2,4,5-T la2,3,7,8-tetrachlorodibenzo-para-dioxin (TCDD).

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Cc thng cha cht khai quang cchuyn ln my bay ti sn bay qun s Nng


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T nm 1961-1971, My a s dung nhieu chat dacam: 64% tong lng chat diet c Viet Nam. octnh nguy hiem cua chat nay la khong nhng diet

cay, pha hoai toan bo he sinh thai, ma con anhhng en sc khoe con ngi, gay ra quai thai.Trong o, vai tro cua chat oc 2,3,7,8- tetraclodibenzo-para-dioxin (TCDD) ma ta quen goi dioxin vi ham lng0,05-6,0 mg/kg, co khi tap chat nay len en100mg/kg, rat nguy hiem cho con ngi.

2. tch t dioxinMi ha cht (cht mu da cam, mu tm, mu xanh, v.v...) c tch t

dioxin khc nhau.

Trc y, gii khng qun M ctnh rng lng dioxin dng trongton b chin dch Ranch Hand lkhong trn di 100 kg, v Vin Ykhoa c tnh l khong 167 kg.

Nhng da vo h s mi pht hin,cc nh nghin cu i hc Columbiac tnh s lng dioxin c sdng trong ton b chin dch RanchHand l 366 kg. Cc nh nghin cucho bit thm rng y ch l con sti thiu, v trong thc t, n c thnhiu hn th na.

L do cho nhng khc bit ny l vn xc nh tch t (concentration)ca dioxin trong cc loi ha cht.

Trc y, da vo cc mu(samples) t hi qun M, cc nhnghin cu thuc khng qun M ctnh tch t dioxin trung bnh l 1,77 phn triu (hay 1,77 particles permillion, vit tt: 1,77 ppm), nhng cc nh khoa hc thuc Vin Y khoa Mth c tnh l khong 13,25 ppm.

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Bn ca qun i M v cckhu vc b ri cht c Dioxin


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Tuy nhin, c hai c tnh ny u thp hn so vi thc t. S liu thnghim mi nht cho thy mc tch t trong ha cht mu tm l 45 ppm,trong ha cht mu da cam l 13 ppm. Do , cng vi s lng ha chtmi c pht hin, tng s lng dioxin cao hn trc rt nhiu.

III. Thng k v cc tc hi ca Dioxin

1.1. nh hng n con ngi

Tng s lng dioxin Vit Nam hng chu l vo khong 370kg, tronghn 80 triu gallon (1 gallon = 4,54 lt Anh) thuc dit c.Tng s din tch t ai b nh hng ha cht l 2,63 triuh ectares.

C gn 5 triu ngi Vit Nam chu nh hng c cht Dioxin. Trong khong 3 triu ngi b phi nhim cht c mu da cam.Trc y theo c tnh ca cc nh nghin cu thuc Vin y khoa, tng sdin tch khng qun M v Nam Vit Nam ri Dioxin l 1,5 triu ha. Nhngqua s dng h thng kim tra dn s thn p (Hamlet Evaluation System)do qun i M pht trin trong thi chin, cc nh nghin cu i hc

Columbia cho thy tng din tch b nh hng ha cht khai hoang l2.631.297 ha.

Trong s ny, c n 86% b ri 2 ln tr ln, khong 11% b ri hn 10 ln.Trong s din tch nh hng, c n 1.679.734 ha b nh hng dioxin, vtrong s b nh hng dioxin, c n 80% b ri 2 ln tr ln.

Bng 6.3.1.1.Din tch b nh hng ha cht khai hoang trong thi gian1961-1971

Ngun gc: Tp san Nature

S ln riDioxin

Din tch (ha) bnh hng do hacht

Din tch (ha) bnh hng dodioxin

1 368.556 343.426

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2 369.844 332.2493 361.862 275.7704 341.037 236.2325 272.709 153.192

6 216.724 119.1277 153.391 75.0628 138.610 51.3719 115.103 32.988

>=10 293.461 60.316Tng 2.631.297 1.679.734

Ngy 12/7/2006, ti cuc ta m v hu qu cht c ha hc/dioxin doM s dng trong chin tranh Vit Nam, TS-BS L K Sn, Chnh Vn

phng Ban ch o 33 (B Ti nguyn v Mi trng) cho bit:- Theo nghin cu mi y ca Hc vin Qun y thc hin i vi 47.893cu chin binh v gia nh th t l tr mc a d tt do nhim cht c hahc/dioxin kh cao (16,14%).- Nghin cu ny cn cho thy: T l con cc cu chin binh c tin s phi nhim dioxin b d tt bmsinh chim 2,95% T l chu ca cu chin binh c tin s phi nhim dioxin b d tt bmsinh chim 2,69%.

Ch trong gn 10 nm, qun i M ri xung min Nam Vit Namkhong 80 triu lt cht c ha hc, bao gm hn 20 loi cht c khcnhau, trong a s l cht c da cam - hn hp ca 2,4D v 2,4,5T. Vimt lng cc nh c mt phn t gram, dioxin c th gy ung th v tai

bin sinh sn ng vt thc nghim.Hin nay, Vit Nam c khong hn 3 triu ngi b phi nhim cht c hahc/dioxin, trong c hng trm ngn tr em b d tt bm sinh do cht cha hc ny.

Nghin cu mi y ca Hc vin Qun y, i hc Y H Ni v Vincng ngh sinh hc pht hin thy nhng ri lon v nhim sc th, bini gene cc nn nhn b nhim cht c ha hc, gy ra d tt bm sinh nn nhn cht c ha hc v h thng b a d tt trn mt c th. V thcc nn nhn b bnh rt nng v l gnh nng v th cht v tinh thn chochnh h v x hi.

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GS. Nguyn Ngc Phng v nhm nghin cu ca i hc Y dcthnh ph H Ch Minh cho bit: ngi b phi nhim dioxin c nguy csinh con b d tt cao gp 14 ln ngi khng b nh hng ca cht c ny.Hin nay, s tn lu ca dioxin cn rt cao ti mt s vng nng vn lkho tng, sn bay ca qun i M:

Bng 1.2.Lng Dioxin tn ng (g) 1 s sn bay trong nc ta

Sn bay Lng Dioxin tn ng(g)

Nng 850Bin Ha - ng

Nai

540

Ph Ct - Bnhnh

60

ty c nhng sn bay ny bng phng php chn lp c hc kt hpvi phng php ha sinh, d tnh kinh ph phi n hng trm t ng.Gnh nng ca hu qu chin tranh ha hc vn cn pha trc. Cc vngcn nhim nng cn c c lp v ty c.Bn cnh , cn t chc tt cc trung tm iu dng nn nhn cht cha hc, hng dn phc hi chc nng cho nn nhn ti cng ng, c

bit i vi gn 200.000 tr em b d tt bm sinh.

Thit hi v Dioxin Vit Nam nng n l th. Trong khi v nhim dioxin Seveso, , 1976 ch vi 30kg dioxin thi rami trng m tc hi ca n ko di hn 20 nm. Seveso, khi ri cht c c 2,5 tun c 700.000 ngi ditn khi cc vng gn nh my ho hc. Sau c 117 ngimc bnh v da ging nh bnh ni mn ngoi da (Chloracne

do thng xuyn tip xc vi cc hp cht hu c cha Clo);tc dng ca chng ging nhau: gy mn trng c cho thanhnin nhng ngy cng nghim trng, nhiu ph n b qui thai vng nhim phng x (Kilpatric , 1980).

Bnh ngh nghip dn l ra do nh hng ca TCDD trong sut qu trnhsn xut 2,4,5T v cc cht c ho hc khc, hoc cc cht n ho hc

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trichlorophenol Seveso trong nh my ch to c cht ho hc. Nu Vnhim TCDD s cht trong vng 33 ngy.

vng bc Tokyo c hng lot cc x nghip x l rc thi bng kh t,t l tr s sinh cht cao hn mc bnh thng t 40-70%. Hin Nht hmlng dioxin trong khng kh cao hn M 3 ln. Mc pht thi dioxin theotiu chun ca Nht Bn l 0,1 ppb/m3 (0,1 nanogam ~ 10-9g/m3). Tn gichung l polychlorinated dibenzo-p-dioxins (PCDDs).

1.2 Mt s hnh nh v tc hi ca Dioxin i vi con ngi

18

Nguyn Vn . Sinh nm 1979ti x H Sn, huyn TamDng , Tnh Vnh Phc(ngun: BTCTCT)

C 3 chu Nguyn T.H. (sinh nm 1975), NguynTh.H.(sinh nm 1979), Nguyn T.Q (sinh nm 1984)u b nh hng bi cht da cam( Ngun: BTCTCT*)


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19

u T H.N sinh nm 1997 tiNguyn Kh, huyn ng

Thnh Ph H Ni (NgunTCT)

BTCTCT :Bo tng chng tch chin tranh

Chu Nguyn Vn B sinh nm 1982 ti xHoi Ph, huyn Hoi Nhn, Tnh Bnhnh (Ngun :BTCTCT)

Cui nhng nm 90 nhng nh nghin cungi Canada ly cc mu t, nc, sinh vtv th m ch c cc bo thai b nh hn

Kt qu nghin cu ch ra cc vng b nhimc t l ioxin trong t vt qu mc cho

hp 13 ln, trong cc t bo c th ngi


20/28

20

Tr em d dng u, st mi

Ngun : BTCTCT

Cc nh khoa hc Nht so snh cc vng nhim cv khng b nhim, rt ra kt lun cc vngnhim c t l tr em sinh ra b nguy c mc chngh hm ch cao gp 3 ln so vi cc vng khc

hoc sinh ra b mc chng tha ngn


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2.1. nh hng n h sinh thi

Dng thuc dit c s lmthay i ln n thm thc

vt ca h sinh thi nngnghip. V nh hng cachng ng rung v ccvng ph cn, v cy 2 lmm rt nhy cm vi thuctr c trong gieo trng ngcc.Chat oc da cam lamot loai hoa chatdiet co lam cho:

- Cay coi b rung la,chet.- Gay ra hien tngxoi mon khi co cactran ma ln, at l cuon theo at troi xuong cacdong song lam cho nc b nhiem, dan en cacloai thuy sinh cung b nhim.- nh hng en chat lng dinh dng cua cu, quahat. Ham lng cha cac hp chat cha nit trong

hat b giam i ratnhieu.Cac nha khoa hoc chobiet, tong lng Nittrong hat lua sau 14ngay b rai thuoc la0,98%. Trong khi o,

21

T l mc cc bnh v chm phttrin tr tu cao gp 3 ln

Khu rng Dng Minh Chu trc v sau khi bri cht khai quang (Ngun : BTCTCT)


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cac hat lua cua vung khong b nhiem la 1-16%.Tong lng trong hat bap sau 3 ngay b rai thuoc la0,74%, con hat bap bnh thng la 1,14%

Vit Nam, trong chin tranh chng M, mt lng ln thuc tr c c s dng gy nhiu thm ha cho mi trng. D ch mt ln phunnhng cc thuc khai quang ny lm cht cc cy i mc nhit i, c

bit rng St: Mm, c, Vt ... Hay Du, Thao Lao v cc cy mc hCaesalpiniaceae cc rng vng ni (Westing, 1984). Cc dn xut ca acid

phenoxyacetic cng c i vi cc ng vt thy sinh.Thc t ton b rng cy ca Vit Nam b tri l v cht hng lot, nhngcnh rng ngp mn b ph hy hon ton, nhng cy lu nin qu him Vit Nam hon ton b tiu dit. i vi nhng vng rng b ri cht dacam/dioxin t 3 - 4 ln cy ci s b tiu dit hon ton, trong khi c vn

sng c bnh thng. phc hi nhng rng cy ny cn phi tri quamt thi gian di.Hn 30 nm qua, ddioxin l mt cht chm

phn hu v c thi gianbn phn hu di (thigian nng dioxin cnli 1/2 trong mi trng),di tc ng ca nh

nng mt tri, mal,...nng dioxin trongmi trng min Nam Vit

Nam gim xung mcbnh thng. Ch c tivng nng nh sn bay,kho tng cha cht cho hc ca qun i M -

Ngy trc y (sn bay Nng, Bin Ho, Ph Ct), nng cc cht dit c v dioxin vn cn

cao, thm ch gp hng trm n hng nghn ln nng cho php.Cn ti cc vng khc, khi nng dioxin gim di mc bnh thnghoc thm ch khng cn tm thy, nhng thit hi v mi trng, tnthng v sinh thi vn cn nguyn hoc c phc hi nhng rt chm.Song, dioxin l cht ho tan trong m v khng ho tan trong nc. Chnh vvy, dioxin khng thm thu theo cc vi mch ca thc vt xut hintrong cc sn phm lng thc v hoa qu. Theo TS. Olaf Paepke, mt nh

22

Rng c Cn Gi (thnh ph H Ch Minh) b phhy


23/28

phn tch dioxin ni ting trn th gii, trong hoa qu, go v c ph VitNam khng c dioxin.Ti cc vng nng, cc nghin cu gn y xc nh nng dioxin caotrong cc ng vt sng lp bn ca cc h ln cn. Th nn, ngi dn cc vng ny c khuyn co khng c n c, cua, c tr,... Vi ccsn phm thu hi sn khc, nht l cc loi hi sn nh bt bin v nuitrng ti cc vng khng phi l vng nng, c th khng nh khng cdioxin, c bit l dioxin c t 2,4,5T trong cc cht dit c m qun i M s dng trong chin tranh.V vy, khi ni rng nng dioxin trong mi trng Vit Nam gim nmc di bnh thng v nh th khng cn g bn v hu qu ca n lkhng ng. V cng khng ng khi ni rng nng dioxin cn cao timt s t vng nng s nh hng n cc sn phm nng nghip v thusn ca Vit Nam.

Cng c Stockholm v cc cht nhim hu c kh phn hy c ccnc k ngy 22/5/2001 ti Stockholm v bt u c hiu lc t ngy 17thng 5 nm 2004. Vit Nam ph chun Cng c Stockholm vo ngy22 thng 7 nm 2002, tr thnh thnh vin th 14 trong tng s 172 nc ktham gia Cng c tnh n nay. Cng c Stockholm ra i vi mc ch bo v sc kho con ngi v mi trng trc cc cht nhim hu ckh phn hy.

Cc cht nhim

hu c kh phn hyhay cc cht POPs lcc ho cht c hi,tn ti bn vngtrong mi trng, ckh nng pht tnrng, tch ly sinhhc trong cc h sinhthi trn cn v dinc, gy hy hi

nghim trng chosc khe con ngiv mi trng. Hinnay, Cng chng ti vic gimthiu v cui cng l

23

Tc hi ca cht c ny cn nh hng n cc vng nckhc nhau


24/28

loi tr 12 ho cht u tin (Aldrin, Chlordane, DDT, Dieldrin, Dioxin,Furan, Endrin, Heptachlor, HCB, Mirex, PCB, v Toxaphene).

T nhng nm 1950 ngi ta bit dioxin l sn phm ph ca cht phenolkh trng nh 2,4,5-T v y l mt trong nhng cht c hi nht conngi tng pht hin.Vo nm 2020 s loi b vic s dng PCB trong cc thit b, my mc;gim thiu lin tc lng pht thi cc cht nhim hu c kh phn hyhnh thnh khng ch nh (ha cht Dioxins v Furans).

3. Mt s hng x l Dioxin

3.1. Cc phng php phng chng v x l Dioxin

3.1.1. Phng chng nhim c c bn- Vi ngi: dung khan che mui tham nc ephong. Khi b dnh chat oc vao da, quan ao: dungxa phong tam giat. Neu an phai, can ra ruot.- Vi cay coi, hoa mau: ru bo, ti bo chat oc

ngay.- Vi at: ra bang nc nhieu lan, cay ai 20-30

ngay, sau o kiem tra lai roi mi gieo trong.

3.1.2. Phng php thanh lc c t

Phng php thanh lc c t trn con ngi c Hip hi V cuc sng vnn gio dc tt p hn (Able) gii thiu ti hi tho mi y H Ni m ra hy vng gip cc nn nhn cht c da cam/Dioxin Vit Nam c thty c c t khng khip ny ra khi c th.Hi tho do Ban khc phc hu qu cht c ha hc s dng trong chintranh i vi sc kho con ngi (Ban 10-80) thuc B Y t t chc, vi stham gia ca mt s nh khoa hc n t Anh, M, Australia.Phng php thanh lc c t ny do nh khoa hc L.Ron.Hubbard thchin t nhng nm 70 ca th k trc, nhm gim gnh nng ca cc cht

c hi nh cc cht PCB, kim loi nng v phng x i vi c th.Phng php ny ch n gin l kt hp gia tm hi hng ngy vi tp thdc v ung vitamin, khong cht, vin du b sung, qua , cht c cgii phng ra khi c th theo ng m hi.Phng php iu tr ny c p dng c hiu qu cho nhng nn nhn

b phi nhim cht phng x trong v n Chernobyl Ucraina; cng nhnphng chy, cha chy tip xc vi cc cht c hi ti v n Trung tm

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Thng mi th gii ca M ngy 11/9/2001, cho cc cu chin binh VngVnh v ang tch cc th nghim i vi cht c Dioxin.Hip hi Albe mun em phng php thanh lc c t ti Vit Nam nhmt n lc nhm gp tay xoa du ni au cho hn 4 triu nn nhn cht cda cam Vit Nam.Theo ng Trn Mnh Hng, Gim c Ban 10-80, phng php thanh lcc t ny c trin khai hiu qu nhiu nc trn th gii, Vit Namnn tm hiu p dng cho cc i tng ph hp. c bit, c th coi ynh mt bc t ph trong n lc xoa du ni au da cam.y l phng php khoa hc d p dng, t phi dng thuc v c trinvng. Nhng bi kch nh sinh con qui thai, d dng ca cc nn nhn chtc da cam s gim bt rt nhiu.

3.1.3. Phng php chn lp

Theo phng php chn lp tch cc, cc khu vc im nng s c oho cch ly vi vng xung quanh. Sau cc nh khoa hc s dng mt loivi sinh vt bn a c kh nng n ha cht c v thi ra cc cht khngc.Kt hp vi bin php vi sinh l bin php ha hc v to lp ph bentonite,mt loi khong ph bin Vit Nam. Lp ph bentonite ny, vi kh nngtrng n khi gp nc v tnh cht nh t st, khng cho php cht cthm thu ra ngoi mi trng trong khi vn to iu kin cho qu trnh sinhha phn hy cht c din ra bn trong.

Vic cn lm trc tin l phi c lp c cc im nng. u tin cnphi khoanh vng chnh xc cc khu vc b nhim dioxin, di di nhn dn(nu c) ra khi cc vng b nhim c.Tip theo, cn phi o mng, xy tng bao quanh hn ch s lan ta cacht c dioxin sang cc vng ln cn. Bn cnh c lp, ty c vng nng,cng cn nhanh chng xy dng tiu chun cho php hm lng dioxintrong t.

3.2. Cc hot ng tiu c Dioxin ca Chnh phCc im nng s c ty c t nay n nm 2010 gm khu vc sn bay Nng, sn bay Bin Ha v sn bay Ph Ct. Cc sn bay ny trc yc qun i M dng lm ni cha ha cht c/dioxin.

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Nng dioxin cc ni ny hin nay vn cao v rt cao, thm ch ln tihng nghn ppt (vit tt capart per trillion - phn nghn t), trong khi nng cho php trong t nng nghip M ch 1.000ppt.

im nng u tin c B T lnh ha hc kho st l sn bay Bin Ha,ng Nai. Sau khi hon thnh d tr kinh ph v trnh Chnh ph t kho stny, cng vic ty c s chnh thc tin hnh t cui nm nay hoc munnht l u sang nm.TS.BS L K Sn, Chnh Vn phng Ban Ch o 33 cho bit, nng dioxin ti sn bay Nng l cao nht (c mu ln n hng trm nghn

ppt), sau l sn bay Bin Ha v sn bay Ph Ct.Cc nh khoa hc Vit Nam nghin cu, pht hin nhng bin i v hthc vt, ng vt trn cn v di nc ti cc vng nng v vng ln cn.Kt qu cho thy, tnh hnh bnh tt v d tt bm sinh ti cc vng nng cao

hn so vi cc vng khc.Cng theo TS.BS Sn, ti cc vng nng, cc nghin cu gn y xcnh nng dioxin cao trong ng vt sng lp bn ca cc h ln cn.V th, nhn dn nhng vng ny c khuyn co khng n ln, trch,c, cua l ng vt sng trong lp bn ti cc h ny v khng n m ccgia cm nh g, vt v dioxin thng tch t trong cc m m ca cc ngvt ny.Theo VAVA (Hi nn nhn cht c da cam/Dioxin Vit Nam), trong thigian 10 nm (t 1961 - 1971), qun i M ri xung chin trng min

Nam Vit Nam 80 triu lt cht khai quang dit c, trong c gn 400 kgDioxin. Khong 4,8 triu ngi dn Vit Nam ang b phi nhim Dioxin,trong c khong 3 triu ngi l nn nhn cht c da cam.

Kt qu nghin cu ca i hc Columbia cn gp phn gii thch ti saohm lng dioxin trong mu ca c dn cc vng tng chu nh hng hacht khai hoang vn cn cao. Theo mt nghin cu c cng b khong 8nm trc y, hm lng dioxin trong c dn min Trung v Nam Vit

Nam (ni tng b xt ha cht) l 15 ppt (15 phn nghn t - part per trillion),cao hn so vi c dn min Bc Vit Nam (khng b xt ha cht trong thi

chin) khong 5 ln, v cao hn c dn M khong 3 ln.

Ngoi ra, c du hiu cho thy dioxin xm nhp vo su trong lng thu c, rt kh xc nh v phn tch, v trong thi gian 1982 - 1992, hmlng dioxin trong mu ca c dn min Trung khng gim.Thc t cht dit c c s dng rng ri M v cc nc chu u.Tuy nhin, cht dit c s dng trong chin tranh Vit Nam li c cha

26


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nhng thnh phn khng c "tinh khit", trong c cht dioxin, loi tpcht c hm lng nh nhng c nht. V vy cht dit c hy hoi mitrng, nh hng nng n n cht lng t ai, ph hy cy ci cng cngha l nhng cy nng nghip cng b hy dit. V khi , ngi dnthng khng ch b i ko di m cn chu s nhim c.

Li kt

Mt s tht hin nhin v ang lm au lng hng trm triu ngi clng tm Vit Nam v trn th gii l s vt v au n ca hng triunn nhn cht c da cam, trong c hng trm ngn tr em b d tt bm

sinh. Hng ngn gia nh c nn nhn ch sng vi thc ti y kh khn.Nhng tn tht v vt cht v tinh thn khng th ch tnh c bng tin.

T nm 1967, Tng thng M Johnson nhn c th phn khng cucchin tranh ha hc ny ca khong 5.000 nh khoa hc M, trong c 17ngi nhn gii Nobel. Tng thng Bill Clinton cng chnh thc thanhn hu qu ca cuc chin tranh ha hc ny i vi binh lnh M. Quchi New Zealand cng khai xin li cc cu binh ca h tham chin tiVit Nam v nhim cht c da cam. Hi ngh quc t ti Stockholm nm

2002 vi s tham gia ca gn 100 i biu n t 14 quc gia c nhngli ku gi khn thit n Lin Hip Quc v Chnh ph M hy gip VitNam khc phc hu qu chin tranh ha hc. Bn cnh , ti Paris, nhngngi yu chung cng l li tp hp vi nhau v thm mt ln ln tingmnh m ng h nn nhn cht c da cam kin cc cng ty ha cht M...

Qua cc Hi ngh quc t v Dioxin, c th d dng nhn thy t ncchng ta cn thng xuyn tham d nhng Hi ngh Quc t v Dioxin, cting ni trc cng lun quc t, nu r quan im, ch trng ca Chnh

ph v ku gi s ng tnh ng h ca cc nc v t chc, c nhn trn

th gii ng h Vit Nam khc phc hu qu cht c ha hc do M sdng trong chin tranh Vit Nam; ng thi hc hi cng ngh tin tintrn th gii nhm khc phc hu qu Vit Nam. Khi tham d Hi ngh,Vit Nam nn ch ng c mt bo co dn nhm hng d lun Hingh ng h mnh. Mt khc, chng ta cn tng cng cng tc bo mt ccti liu v Dioxin Vit Nam nhm phc v tt cho cng tc u tranh i

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trch nhim bi thng ca pha M trong vic s dng cht c ha hctrong chin tranh Vit Nam.

Cuc chin tranh ha hc Vit Nam i vo lch s nhn loi nh mtvt thng rt kh lnh. Vic lm th no c mt mi trng trong schhn v hn ch n mc ti thiu nhng ni au da cam l mt bi tonkh cha tm ra li gii khng nhng i vi cc nh Mi trng Vit Namm cn l ca ton dn tc.

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