suc khoe moi truong

5/28/2018 Suc Khoe Moi Truong

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TRNH THTHANH

SC KHEMI TRNG

NH XUT BN I HC QUC GIA H NI


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NH XUT BN GIO DC QUC GIA H N16 Hng Chui - Hai B Trng - H Ni

in thoi: (04) 7685236; (04) 9715012. Fax: (04) 9714899E.mau: [email protected]

* * *

Chu trch nhim xut bn:Gim c: PHNG QUC BO

Tng bin tp: PHM THNH HNG

Chu trch nhim ni dung:

Hi ng nghim thu gio trnh :.Trng HKHTN - i hc Quc gia H Ni

Nhn xt: GS. MAI NH YNPGS TS: TRN CM VN

Bin tp: MAI ANH

Trnh by ba:. QUC TON


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MC LC

Chng 1..................................................................................... 1Mt svn chung v .............................................................. 1sc khomi trng ................................................................... 1

1.1 Mt skhi nim c lin quan .......................................... 1

1.2 Mt sngun chnh to ra cht c ..................................51.3 Phn loi cht c ........................................................... 16

Chng 2................................................................................... 31Cc hnh thc tc ng v nh hng....................................... 31ca cht c ti cthcon ngi ............................................. 31

2.1 Con ng xm nhp ca cht c .................................312.2 Qu trnh xm nhp cht c .......................................... 342.3 Sbin i cc cht c trong cthcon ngi ............ 472.4 Mt syu tchnh gy nh hng ti c.................... 50tnh ca c cht ...................................................................50

Chng 3................................................................................... 58

nh hng ca c cht v mi trng n sc khocon ngi................................................................................................... 583.1 nh hng ca cht c ti cc bphn cthcon ngi............................................................................................... 583.2 nh hng ca nng v thi gian tc ng ca chtc ti cthcon ngi........................................................ 623.3 nh hng phi hp ca cht c ti cthcon ngi.643.4 Cc loi nh hng c hi ca thuc BVTV ti sc khocon ngi .............................................................................. 673.5 Cc hnh thc thhin tnh c ca c cht i vi cthcon ngi......................................................................... 70

3.6 nh hng ca mt scht c ti sc khocon ngi 743.7. nh hng ca mi trng ti sc khocon ngi...134Chng 4................................................................................. 151Mi trng v iu kin lm vic ........................................... 151vi sc khongi lao ng................................................... 151


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4.1 Khi nim chung vtc hi nghnghip ...................... 1514.2 Phn loi cc tc hi nghnghip ................................. 1534.3 Cc bin php qun l tc hi nghnghip trong lao ng.............................................................................................. 155

Chng 5................................................................................. 157Mt sv dvbnh do mi trng nhim v ng vt gy ra

i vi cthcon ngi v cch cu cha khi bngc..... 1575.1 Bnh do cthngi btc ng bi cc yu tvt l 1575.2 Bnh do cthngi bnh hng mi trng khog kh,nc nhim....................................................................... 1595.3. Cc bnh o mt sloi ng vt lm ly truyn........ 176Cc bin php kim sot: vsinh cbn (ly i ca chngthc n, nc v ni ). Bo qun rc thch hp (cho vo ti)v kim sot rc (lm sch rc). Bo qun thc n hp l. Sdng thuc tiu dit chng.................................................. 2065.4 Cc bnh ly truyn qua htiu ho ca ng vt........ 2065.5 Cc bnh i km vi thc phm bnhim khun.......... 233

5.6 Sc khov sphng x .............................................. 2625.7 Cc cch bo qun thc phm v dng.................... 2795.8 Nguyn tc chung vxl nhim c.......................... 3035.9. Cch cu cha khi bngc......................................304

TI LIU THAM KHO....................................................... 309


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Chng 1Mt svn chung vsc khomi trng

1.1 Mt skhi nim c lin quan

n sc khomi trngMi trng sng ca con ngi

Mi trng sng ca con ngi l phn khng gian m conngi tc ng, s dng v b n lm nh hng(UNESCO,1967). Mi trng sng ca con ngi bao gm tt

ccc nhn ttnhin, x hi bao quanh v c nh hng tisc kho ca con ngi. Ni mt cch khc mi trng l tphp cc thnh phn vt cht (t nhin v nhn to) v x hixung quanh con ngi. Cc thnh phn tnhin ca mi trngl cc yu thu sinh (cc loi ng thc vt v cc vi sinh vt)v yu tv sinh (t, nc, khng kh). Cc thnh phn nhnto l tt ccc vt thhu hnh do con ngi to nn (nh ca,ng x, cu cng...). Cn cc thnh phn x hi l stng hocc quan hcon ngi vi nhau, c nh hng ti stn ti v

pht trin ca mi c nhn v ton thcng ng x hi.Cht lng mi trng c nh hng rt ln n sc kho

ca con ngi v n bchi phi khng nhng bi iu kin tnhin m cn bi iu kin kinh tx hi. Ti thnh phv cc


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khu cng nghip vi mt dn s cao, tp trung nhiu loihnh sn xut cng nghip nn cht lng mi trng c nguycbsuy gim do tc ng ca bi, kh thi v nc b nhim. nng thn, cht thi chn nui, d lng thuc bo v thcvt, phn bn l nguyn nhn chnh lm suy gim cht lng

mi trng sng. Cht thi chn nui gy mi hi thi l mitrng sng thun li ca cc loi sinh vt nh: rui, nhng cthtruyn bnh cho con ngi.

Bo vmi trng sng l cc hot ng nhm hn chvphng nga nhng yu tbt li ca tnhin v x l cht nhim do cc hot ng ca cn ngi to ra, ng thi iuchnh v to nn mi trng sng tin nghi v bn vng cho hnngi.

Sc khoSc kho l mt trng thi hon ton thoi mi v thcht,

tinh thn v x hi. Mi iu kin v hin tng ca mitrng bn trong hay bn ngoi u tc ng nht nh n sckho. C sc kho tc l c s thch ng ca c th vi mitrng, ngc li bnh tt l biu thskhng thch ng. Nhvy, sc khol mt tiu chun ca sthch ng ca cthconngi v cng l mt tiu chun ca mi trng.

Trng thi sc kho ca mt c nhn, ca cng ng phnnh phn no hin trng cht lng nc, khng kh, thc n,

nh , tin nghi sinh hotSc khokhng chc bo m bi cuc sng vt cht m

cn quy nh bi i sng tinh thn (bn cht Vn ho v x hica con ngi).


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Sc khoca cng ng hay sc khoca x hi l sc khochung, hiu ton din l mt h thng c t chc gia conngi, quan hv tc ng ln nhau trong mt mi trng husinh v v sinh vi mt mi trng x hi bao gm kinh t, vnho, chnh tr, tn gio.

Mc ch cui cng ca cc bin php bo vmi trng lto iu kin thun li cho con ngi trong lao ng v sinhhot, m bo mt cuc sng lnh mnh vthcht v tinh thn.

iu kin lao ngiu kin lao ng c hiu l tng th cc yu t v t

nhin, x hi, kinh t, kthut c hiu thng qua cc cng cv phng tin lao ng, i tng lao ng, qu trnh cng

ngh, mi trng lao ng v s sp xp, b tr chng trongkhng gian v thi gian, s tc ng qua li ca chng trongmi quan hvi ngi lao ng ti ch lm vic, to nn mtiu kin nht nh cho con ngi trong qu trnh lao ng. Tnhtrng tm l ca ngi trong khi lao ng ti chlm vic cngc coi nh mt yu t gn lin vi iu kin lao ng[Nguyn An Lng v nnk, 2001].

Trng thi mang cht c l trng thi cht c xm nhp vo trong cthdn dn

v c pht hin thy trong mu, nc tiu, tc... c hm lng

trn mc bnh thng nhng cha c triu chng g thhin gybnh cho cn ngi.

Bnh nghnghip


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Bnh ngh nghip l hin trng bnh l mang tnh cht ctrng ngh nghip hoc lin quan n nghnghip m nguynnhn sinh bnh do tc hi thng xuyn v ko di ca iu kinlao ng xu. Cng c th ni rng l s suy yu dn sckho, gy nn bnh tt cho ngi lao ng do tc ng ca cc

yu tc hi pht sinh trong sn xut ln cthngi lao ng[nguyn An Lng v nnk, 2001].

Thuc bo vthc vtTheo T chc nng lng th gii FAO (1986) nh ngha

thuc bo vthc vt (thuc BVTV) l bt kmt cht hay mthp cht c tc dng dphng, tiu dit hoc kim sot cc loisu bgy hi, cc vector gy bnh cho ngi v ng vt, cc

loi cn trng c hi trong qu trnh chbin, dtr, xut khu,tip thlng thc, sn phm nng nghip, gv cc sn phmca g, thc n gia sc hoc c tc dng phng chng cc loicn trng, k sinh trung trong hoc ngoi cthca gia sc.nh ngha ny cng bao gm cc hp cht dng kch thchstng trng ca cy ci, cht hn chrng, kh l, tc ngi vi cy t quhoc hn chvic qunon brng v cc chtc tc dng thc y nhanh hoc lm chm trong qu trnh boqun v xut khu hoa qu.

Ngoi khi nim trn, Hi ng Codex ti chu u (1984)a ra nh ngha thuc BVTV cn bao gm cc loi phn bn,

cc cht tng trng cho cy trng, ng vt, thuc trvi sinhvt gy bnh, phgia v cc loi thuc th y.

Cht nguy him


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Cht nguy him l nhng cht khi xm nhp vo cthgynn cc bin i sinh l; sinh ho, ph vthcn bng sinh hcgy ri lon chc nng sng bnh thng dn ti trng thi bnhl ca cc cquan, hthng v ton bcth.

Cc cht nguy him c mt trong 4 c trng sau: phn ng,

bc chy, n mn v c hi.Cht phn ng l cht khng bn vng c iu kin thngthng. N c thgy nhay to ra khi, hi, kh c hi khitip xc vi nc hoc khng kh.

Cht d chy l cht db chy gy chy ln v trong thigian di. V dnhxng, cc cht lng dbay hi, dung mi.Hi ca chng d bt la chy nhit thp (nhit bnghoc di 600c).

Cht n mn l cc cht lng c pH thp hn 2 hoc lnhn 12,5 mang tnh n mn kim loi.

Cht c hi l cc cht c tnh c hi hoc gy nguy hicho ngi qua ng tiu ho, h hp hay tip xc qua da.

Liu lng

Liu lng l n v ho cht s dng/trng lng c thsng (v d. mg/trng lng c th, ml/trng lng c th...)hoc n vho cht sdng/in tch bmt cthbtip xc(v d: ml/din tch da, ml/dn tch da...).

1.2 Mt sngun chnh to ra cht c

1.2.1 Ngun cht thi cng nghip:

a. Ngnh ho cht v sn phm ho cht


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Ngnh cng nghip ho cht rt a dng, bao gm nhiu loihnh cng nghip sn xut ra cc sn phm lin quan n hocht. Cc loi hnh cng nghip phbin gm:

Ho cht v ccbnPhn bn ho hc

Ngnh sn, vecniCao su nha v sn phm trn cscao su v nhaCht ty ra v mphmAc quy v pin

Thuc trsuKh cng nghip

A xt sulphuricNguyn liu sn xut axit sunfuric l SO2.TSO2squa

giai on oxy ho chuyn thnh SO3, hp th vi nc schuyn thnh H2SO4. Nhvy, phng trnh tng qut ca ccphn ng ho hc nhsau:

SO2+ O2-> SO3

SO3+ H2O -> H2SO4

Cch thc sn xut SO2thng sdng lu hunh nguyn thoc t qung pyrit (qung pyrit l qung cha sulfua st). Qutrnh t S hay sunfua st (pyrit) c tin hnh trong l vinhit cao. Lu hunh trong qu trnh chy chuyn ho thnhSO2, mt lng nhH2S. Shnh thnh trong mi trng khca qu trnh tinh chSO2.

Cc cht SO2, SO3.Cc Oxit nitV H2S l nhng cht c ctrng cho ngnh cng nghip sn xut axit sunfuric gy tc ngn vng nim mc cua h thng h hp v h thng tiu ho.Cc cht ny lun l nguy ci vi cng nhn lm vic trongcc xng sn xut axit sulphuric v chng lun tn ti hm


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lng cao. Nng SO2 khong 0,06 mg/l c th dn nngc nng cho con ngi. Hin ti, ngi ta quy nh nngSO2ti a ti xng sn xut SO2l 20 mg/ms vi SO3nngti a cho php l 2 mg/m3. Nng ti a cho php ca H2Sti phn xng lm vic l 10 mg/m3

Trong x thi l pyrit lun c cha asen v asen lun tn ti

ng hnh trong qung st. Khi boxi ho nhit cao, asencng chuyn ho thnh oxit v sau thnh mui. Hm lngasen trong xthi tl t pyrit vo khong 0,15%. sn xut1 tn H2SO4c, c tnh lng xthan thi ra tvic t pyritkhong t1,3 n 1,4 tn. iu c ngha lng asen thi ratheo x s vo khong 2 kg asen (nguyn t). Lng asen nybay hi khi thi xnng trong khu vc l t hoc ra tri hocpht tn vo mi trng khng kh khu vc xung quanh didng bi xpyrit. c tnh khong trn 70% lng asen ny

phn tn vo mi trng di dng hi, bi x hay xm nhpvo nc v t o bra tri.Tng tPb, Zn. cng c nhiu trong xpyrit. Sn xut 1 tn

axit sto ra trong xkhong trn 5 kg ch, 10 kg km. Ch vkm cng l kim loi d bay hi, n c th tc ng trc tipn khu vc sn xut v sc khoca ngi lao ng:

Ngnh sn xut xt v clo in phn:Phng trnh ho hc cbn trong qu trnh in phn NaCl

sn xut xt v chl:2NaCl + 2H2O -> Cl2+ H2+ 2NaOH

Kh ch v hi HCI (sn phm trung gian) u l nhng khcc c Nng Clo khong 0,001 n 0,006 mu khng kh c thgy ngc nng. Nu nng Clo trong khng kh l


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0,1 n 0 2 mg/l c thgy ra tvong sau mt ginhim. HClcng c khnng tng ttuy thp hn, gy ra nhng phn ngi vi hthng h hp. Nng HCl ti a cho php i vikhu vc lm vic l 10 mg/m3.

Bn cnh cc cht c nu trn, aming cng c sdng

trong ngnh sn xut xt v do in phn. Aming c sdngdi dng ba lm cc mng ngn trong bin phn do bn ho hc cao. Trong qu trnh sn xut, ngi ta phi thngxuyn thay th mng. Mng aming c thi ra khng th sdng vo mc ch sn xut no khc v nu khng c binphp qun l cht thi hp l, cc si bi aming rt mn ny sbay vo mi trng gy ra ngun nhim aming trc tip chongi lao ng trong phn xng sn xut.

Khi c c xt tsn phm sau in phn t c cm th trng yu cu (ln hn 30% hoc n xt rn), NaOHc thbay hi vo khng kh vi lng ng knu hthng cc l h. Hi xt v xt lng u c thgy bng cho da, hthng h hp cng nhmt ca ngi lao ng nu khng ctrang bbo h. Nng ti a hi xt cho php dng sol l0,5 mg/m3.

Ngnh sn xut phn ln v phn mPhn ln c hai dng l phn supephotphat (mono) v phn

ln thu nhit. Nguyn liu ch yu sn xut phn ln l

qung apatit.Qung apatit l qung cha hn hp mui phc ca photphat

v florua ca canxi c cng thc ho hc chung l[(PO4)3F,Cl,OH]Ca5.


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Qu trnh phn ng to ra phn supephotphat chnh l qutrnh chuyn ho phospho dng khng tan sang dng ho tanCa(H2PO4)2cy ci c thhp thc. chuyn ho, ngita sdng H2SO4hoc H3PO4.Tuy nhin, do trong thnh phnqung apatit c CaF2 nn qu trnh phn hu qung bng axit

lun hnh thnh hp cht ca flo di dng HF, SiF4 hayH2SiF6.Phn ln thu nhit hay phn ln nung chy cng l phn

photpho c sn xut tqung apatit nhng qu trnh chuynho qung photphat c tin hnh bng qu trnh phn hunhit cao vi cc cht tr chy l secpantinMgO.Mg(OH)2SiO2.H2O. V mt S qung cha Mg, Ca vSiO2khc, th ddolomit MgCO3.CaCO3. Cng thc ca phn

ln nung chy l (Ca,Mg)P2O5.(Ca,Mg)O.P2OSiO2. Qu trnhnung chy cc hn hp qung nhit khong 14000C -15000C l ngun chnh to ra HF v cc hp cht khc nhSiF4, H2SiF6cdng kh v ng nc thi..

Flo nguyn tl mt cht kh rt c, gy ph humt, da vhh hp. Tip xc lu di vi kh flo c thgy ra cc bnh vxng v rng. c tnh ca flo rt cao vi gi tr LC50 l0,2mg/l. Mt khc, nhit cao c tnh ca flo c th tngln.

HF cng c thgy ra nhng tc ng tng tnh F2. nng khong 0,2mg/l l. Cc knguy him i vi hh hp

mc d nhim vi thi gian rt ngn. Nhim HF c thdn bph hucc tbo phi v phqun. Do p sut hi ca HF l

rt ln (122.900 kPa) nn c thni HF cc knguy him quang h hp ca cng nhn khi sn xut phn ln bng apatit


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c bit l khi phn huqung apatit bng axit trong hm , dokhng m bo thong kh v m cao sdn n khnngnhim HF nhit cao.

sn xut phn m, ngi ta sdng nguyn liu chnh lthan antraxit thng qua giai on tng hp NH3v sau tng

hp urea tNH3v Co2.Nguyn liu sn xut NH3l H2v N2. N2c ly tkhngkh, cn H2 c sinh ra t vic kh ho than bng hi nc.Hn hp kh than t bao gm Co, CO2v H2v cc tp chtkhc t cng ngh kh ho. c bit l nhng tp cht hnhthnh do qu trnh chy khi kh ho than nh: Xianua, phenol,H2S. V cc hp Cht PAHs.

Xianua c hnh thnh trong qu trnh chy ym kh kt hp

vi hydrocarbon mch vng hnh thnh cc Xianua thm nhBenzyl Xianua l hp cht rt c khi nhim c dng kh cthb chong vng, au u v nn ma rt nhanh, khi nhimc bng con ng tip xc n cn c thgy bng cho da vmt. Nhim Xianua vi hm lng khong 2 mg/kg thtrng c thgy tvong. Kh HCN c thgy tvong cho ngi mc 100 - 200mg/m3khng kh.

Ngnh sn xut sn v vecni.Chng loi cng nh lng ho cht sdng trong pha ch

sn kh nhiu v phc tp nh: cc loi bt mu, cc loi dung

mi, cc cht phgia v cc loi nha gc:- Cc loi nha gc: Alkylresine, acryhc resine, epoxy,

uretan

- Cc loi bt mu: oxit Titan, oxit st, km cromat...


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- Cc dung mi: xylen, toluen, butyl acetat

- Cc cht ph gia nh: cht chng lng, chng to bt,chng mc, to nm, dit khun,

- Cc cht n: CaCO3Talc, BaSO4Trong cng nghsn xut sn, ngi lao ng c nhiu nguy

ctip xc vi cc loi ho cht dng:Hi dung mi ngay nhit thng (chyu l dung mihu c).

Cc ht phn tn c kch thc cc nhphn tn trong mitrng lao ng.

b. Ngnh mkim loi v ckh

Ngnh min sdng kh nhiu ho cht dng mui kimloi c c tnh cao nh Cro3, CdCl2, MnCl2, ZnCl2, NaCN.Nc thi tkhu min v x l bmt ni chung c cha

cc kim loi c hi nhCr, Ni, Zn, Cd v mt sc tkhcnhCN; du khong vi axit hay kim cao, c bit khi cccsmkhng c sphn dng thi mtt, kh HCN sto rakhi hai dng thi Xianua v axit bho ln v HCN sbay vokhng kh tc ng trc tip n ngi lao ng. HCN c thgy ngc nng v cht sau khi nhim mt vi pht do khHCN rt linh ng. Cht thi cha kim loi nng tc ng chyu n ngi lao ng thng qua vic tip xc vi dung dchc mui kim loi qua da.

Ngnh m crom thng thng c tin hnh nhit khong trn 40oc v hi dung dch axit cromic c nng cao(thng ln hn 200 g/l) s tc ng n h thng h hp cacng nhn. Crom thuc nhm cht c thn kinh v gy ung th


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Crom dng Cr6+l dng c thgy ung thphi. Khi dngCrO3hi ho cht ny gy bng nghim trng cho h thng hhp ca ngi bthm nhim

Hn in l qu trnh nung chy kim loi v cc cht trdunghn m thnh phn bao gm nhiu oxit kim loi nhZn, Mn, Pb,

Cr v cc oxit kim loi ny do nhit cao ca qu trnh hn spht tn v tc ng trc tip n h h hp ca ngi cngnhn hn.

c.Ngnh dt nhum

Ngnh dt nhum s dng ho cht ch yu cng onnhum si v vi. Cc ho cht thc hin nhng chc nng khcnhau nh:

- X l bmt vi si nhm tng khnng hp thmu vgimu.

Ty trng si vi. :Trgip cho qu trnh khuch tn cht mu vo trong cc l

xp ca si v vi.Nhum v in hoa.Cc nhm mang mu thng thng l cc nhm: Nitrozo (-

NO), nhm nitro (-NO2) nhm azo (-N=N-), nhm etylen (

)C=C


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cht c ththot ra mi trng khi cng on c tin hnh nhit cao.

d. Ngnh sn xut giyTrong cng nghbt giy, ngun pht thi ho cht chyu

tkhu ty bt bng ch, dioxit clo, hypoclorit, oxy gi. y lnhng cht oxy ho v c khnng r rcao nhit ca qutrnh ty (xp x1000C)

e. Ngnh vt liu xy dngNgnh vt liu xy dng ca Vit Nam ch yu c nhng

nhm sn phm ng quan tm vho cht nh: svsinh vtrang tr, chyu sdng nguyn liu l SiO2v felspat c

nghin rt nhl ngun pht tn bi phi; vt hn to mu rt adng v chyu l mu v c, th doxit ca Zn, Zr, Se, Fbcng l ngun pht tn cc oxit kim loi vo khng kh trongqu trnh phun men ln sn phm trc khi nung.

g. Ngnh chbin lng thc, thc phmNgnh chbin thc phm sdng nhiu loi ho cht. Cc

loi ho cht chyu c dng lm ho cht ty mu, ty mi,chng i thiu, p lnh, ch bin mi, v, to mu v nhngcng vic khc. Khng chc cc loi ho cht c nhNaClO,H2O2, NH3c ng chbin thc phm m cn rt nhiu

ho cht thng thng khc c sdng phbin nh thuctm (KMnO4)dng ty mu min dong, hn the dng ch

bin cc loi bn, bnh ph, gi; dim tiu (lu hunh) dng sy v bo qun thc phm kh, Nam benzoiat dng chng nm


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mc, i thiu, phm mu dng nhum thc phm Bng 1 trnh by mt s v d v cc ngun sn xut cng

nghip to ra cht thi c nh hng bt li ti sc kho conngi.

1.2.2 Ngun cht thi nng nghip

Mt trong nhng loi cht thi nng nghip gy nhim mitrng nghim trng l d lng thuc BVTV. Thuc BVTVgm cc nhm chnh: do hu c, photpho hu c, nhmcacbamat, nhm pyrethroid v cc nhm trdch bnh khc.

Nhm cc hp cht chhu cgm DDT v cc dn xut can, cc hp cht hexachlorid, benzen, nhm cc hp chtxyclodien...Trong cu trc phn t ca nhm ny lun tn tinguyn tC1 lin kt trc tip vi nguyn tC v trong phn tc thc cc nguyn tN, S.

- Nhm cc hp cht ln hu c l nhng hp chthydrocacbon cha mt hoc nhiu nguyn t photpho, khngbn trong hsinh hc, chng dho tan trong nc v dhydroho, bao gm cc hp cht dng photphat, cc hp chtphotphorothionat, cc hp cht photphonitrothionat...

Bng 1Cc cht nhim cng nghip in hnh

cht nhim

Ngun thi Tinh c

SO2v bi Cc l t sdng than, du Ph huhh hpNOx Cc l t sdng than, du Ph huhh hpCO Cc lo t sdng than, du Gy ngc v ngtAming Cc ngnh cng nghip khc nhau Gy ung thphi


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Hydrocacbon Cc hot ng cng nghip: luyncc ho du....

Gy ung thphi, cbit lcc cht PAHs

Dung mihu c

Cc ngnh cng nghip: sn xutsn, dt nhum, ho du...

H thn kinh, h hhp htun hon

Cloroeste Ho cht Hh hpNaphtvlamin Dt nhum Tit liu

As, Cd, Hg,Pb Cc l t rc, luyn kim, sn xutpin, acquy, thuc BVTV, ho cht

Hh hp, hbi tit,c bit l As. Cd gyung th. Pb gy mtcn bng h tht kinhvn ng, Thu ngngy c thn kinh

Crom Ma in, mu, sn Hh hpNiken Luyn kim, ma in Hh hp

Nhm cc hp cht cacbamat bao gm cc hp cht c cng

thc R1-NH-COO-R2cc hp cht ny c hot tnh sinh hc gntng tcc hp cht photpho hu c.

Nhm cc hp cht pyrethroid tng hp: cc hp cht ny ctnh c cao i vi cn trng, nhng li c tnh c thp vicc loi ng vt c v. Cu trc phn tca chng gm c Cl,O, N v mt hoc nhiu nhn thm ni vi nhau bng nguyn t

oxy.

1.2.3 Ngun cht thi bnh vin.

Hu ht cc cht thi tqu trnh khm cha bnh c phnloi l cht thi c hi v mang tnh c th. Cht thi bnhvin hay cht thi y tbao gm cc loi chnh sau:.

Ph thi cha cc vi sinh vt gy bnh pht thi t cc caphu thut, t qu trnh xt nghim, hot ng khm cha


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bnh...Ph thi b nhim bn: Cc dng sau khi bnh nhn s

dng, cc dng ca y bc ssau phu thut, tqu trnh laura sn nh, bn cn no vt tcc hthng cng rnh, tiutrkhm cha bnh v vsinh cng cng..

- Phthi c bit: L cc loi cht thi c hi nhcc kimloi nng, cht phng x, cht c, dc phm qu hn sdng,kho thuc v ho cht .

Nhvy, cht thi bnh vin c thnh phn rt a dng. yl ngun gy nhim, truyn nhim dch bnh cho con ngi,gy nhim mi trng t, nc v khng kh:

1.3 Phn loi cht c

1.3.1 Phn loi theo trng thi vt l

Cn ctheo trng thi tn ti cht c c chia lm 3 dng:dng kh, dng rn, dng lng. Cc cht gy nhim dng c thphn thnh ,2 dng phbin: dng kh v dng phn t

Cc cht nhim dng kh

Kh SO2: Kh ny c coi l cht nhim quan trng nhttrong hoxit lu hunh. Tnh cht kh SO2 l kh khng mu,khng chy, hng v cay, c nh hng ti sc khocon ngiv ng vt c bit l cquan h hp.

- Sunfua Hydro (H2S): L kh c, khng mu v c mitrng thi. Cht kh ny c khnng lm gim s sinh trngca thc vt, vi con ngi n tc ng n hthn kinh v no,nng thp gy nhc u, mi mt, nng cao gy hn


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m hoc tvong.- Cacbon monoxit (CO): l kh khng mu, khng mi,

khng v; tc ng mnh n hhhp ca con ngi. Nhtipxc qua ng h hp vi nng khong 250 ppm sdn titvong.

- Florua hydro (HF): Kh ny c tc ng ph hoi cy xanh,lm hn chsinh trng v rng hoa qu. i vi ngi, kh nygy vim da, ph hucu trc xng v nu tip xc lu di sdn ti cc bnh vthn.

- Oxit Nit(NOx): Trong nhm kh ny, chc NO v NO2ctc ng mnh i vi ngi v ng vt, c bit l NO2. Vinng NO2 l 100 ppm, ch vi pht tip xc c th gy tvong. Nng NO2khong 0,06 ppm c thgy tn thng

trm trng cho phi.- Cacbondioxit (CO2):Chyu nm tng i lu ca kh

quyn, l mng chn bc xnhit t tri t vo v tr, l khchyu gy nn hiu ng nh knh.

Cc cht nhim dng phn t

- Cc sol kh v bi l lng: Cc soi kh trong kh quyn lnhng phn t nhim nhb trong mi trng khng kh, lmgim tm nhn, ngoi ra cn n mn kim loi v lm suy gimcht lng nh ca, cc cng trnh kin trc, vn ho nghthut,thit bmy mc (c bit l lm hng cc mi hn in). Cc

sol kh v bi ny u c thtc ng n hh hp tuthucvo tnh cht ca chng.

- Bi ch: Hi v bi ch c pht thi ch yu t ccphng tin giao thng dng xng pha ch. Ht phi hi hoc bi


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ch tu theo nng thm nhim s b mc bnh thiu mu,hng cu gim v gy ri lon thn.

-Bi l xi mng: Bi pht sinh tl xi mng v my nghinclinke gy tc hi i vi ngi, ng v thc vt.

- Bi gy d ng: C nhiu loi bi kh do sn xut cng

nghip thi ra v cc bi phn hoa ca mt sloi hoa cc tcng gy d ng i vi ngi. Tuy nhin, cc cht nhimnhn to c khnng phi nhim dng cao hn cc bi phnhoa tnhin.

1.3.2 Phn loi theo tnh cht tc dng

Phn loi theo tnh cht tc dng ca cht c ln cthgmhai nhm: nhm cht c c tc dng chung v nhm cht cc tc dng hthng.

Nhm cht c c tc dng chung

Nhm cht c c tc dng kch thchCht kch thch gm cc cht tc dng chyu ng h hp

trn: cc aldehyt, bi kim, amoniac, sunfur. Cc cht kchthch cng h hp trn nh: brom, clo, xianua...Cht kch thch tbo gm:

Cht gy ngt: cht gy ngt n thun l cc cht tr, lmlong p sut ring phn ca oxy trong khng kh nh: CO, CO2,

CH4, N2, cht gy ngt ho hc ngn cn mu vn chuyn oxyn cc tchc nhCo gy bnh thiu mu.Cht gy m v gy t: etylen, etyl-ete, xe ton...Cht gy tc dng dng: isoxianat hu c


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Cht c tc dng gy ung th: amin, thungn, PAHsCht gy t bin trn: cht phng x...

1.3.3 Phn loi cht c theo mc

tc dng sinh hc

Hi nghcc chuyn gia ca OMS/BIT (1969) nghphnloi sinh hc ca cht c cng nghip. Vic phn loi ny davo 4 mc tc ng ca cht c.

Loi A: tip xc khng nguy him - tip xc khng gy nhhng ti sc kho.

Loi B: tip xc c thgy tc hi n sc khonhng c thhi phc c.

Loi C: tip xc c thgy bnh nhng hi phc c.

Loi D: tip xc c th gy bnh khng hi phc hoc tvong.

Sphn loi ny ph hp vi thi gian.tip xc 8 h/ngy. V5 ngy/tun. Tuy nhin, vic phn loi ny khng ph hp i

vi nhng cht gy ung thhoc t bin trn.

1.3.4 Phn loi thuc BVTV

Thuc BVTV l nhm cht cha nhiu loi hot cht c hi.Cc ho cht bo v thc vt rt a dng v thnh phn, v

tc dng i vi cy trng v cch s dng. V vy, c nhiucch phn loi chng.

Mi cch phn loi c da theo cc tiu ch khc nhau,thng thng ngi ta phn loi theo: mc ch sdng, thnh


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phn, ngun gc sn xut, tnh c, cc phng php sdng,tnh bn vng ca chng trong tnhin...

Phn loi theo ngun gc sn xut v cu trc ho hc.Tutheo ngun gc sn xut v cu trc ha hc m cc cht

trsu c phn thnh 3 nhm.

Cc cht trsu hu cgmCc ho cht bo v thc vt nhm photpho hu c: Metyl-parathion, Parathion, Monocrotophot, Dazion, Malathion,

Dimetoal, Azodzin...

Cc ho cht bo vthc vt nhm do hu c: DDT, Aldrin,HCH, Chlordan, Heptaclo, 2,4-D...

Cc cht tr su thu ngn hu c: Ceresau, Granosan,Falizan...

Cc dn xut ca hp cht nitroCc dn xut ca ureCc dn xut ca axit cacbamicCc dn xut ca axit propionicCc dn xut ca axit xialhydic

Cc cht trsu v cbao gm- Cc hp cht ca ng- Cc hp cht ca asen- Cc hp cht ca lu hunh- Cc hp cht v ckhc

Cc cht tr su ngun gc thc vt: Cc alcaloit, thc vt

c cha nicotin, anabazin, pyrethroid...

Phn loi theo i tng phng tr

Tutheo i tng phng trm cc thuc BVTV c chia


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thnh cc nhm sau y:Thuc tr su l nhm thuc dng dit tr cc loi cn

trng gy hi cho cy trng v nng sn gm cc nhm sau: Cccht tr su nhm do hu c: DDT, HCH, aldrin, ieldin,chlodan...

Cc cht trsu nhm photpho hu c: Wofatox, diazinon,malathion, monitor...

Cc hp cht Cachamat: servin, furadan, mipxin, bassa... Cc hp cht sinh hc: pyrethroid, permetrin, deltametrin...

- Thuc tr nhn l nhm thuc dng phng tr nhngng vt gy hi cho cy trng thuc lp nhn (Acarna). Phnln thuc trsu t hoc khng c tc dng dit nhn.

- Thuc trng vt gm nhm: C tnh c cao i vi hu

ht cc ng vt c v, c dng chyu lm bc trchut(thuc dit chut). Loi thuc ny i khi cn c dng trchim v cc sc vt hoang di gy hi ma mng. Nhm nygm: Phoszin, Warfarin,Brodifacoum...

- Thuc trnm: C nhiu loi vi sinh vt gy bnh cho cytrng nhnm, vi khun, xkhun... Thuc trnm c tc dngbo vcy trng v ht ging, ngn nga nm bnh xm nhpv gy hi hoc c tc dng tiu dit nm bnh. Nhiu loi thuctrnm cng c tc dng phng tri vi nhiu loi vi khungy bnh cho cy trng. Nhm cc cht trnm, trbnh, trvisinh vt gy hi bao gm:

Cc hp cht cha ng Cc hp cht cha lu hunh Cc hp cht cha thungn


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Mt sloi khc- Thuc tr c di: Dng tiu dit nhng thc vt

hoang di trn nhng cnh ng, trong vn cy, trong knhmng, xung quanh nh ...C nhng thuc dit cc bit chiu lc cao i vi cy bi, cy thn gc gi l thuc dit

cy thn g.. Mt sloi dit cc tnh c cao i vi thc vtc dng chyu phun ln mt sloi cy trng nhbng,u tng trc khi thu hoch v chng c tc dng lm rng l

v kh cy. Nhm cc cht trcdi v lm rng l:

Cc hp cht phenolCc hp cht ca phenoxiCc dn xut ca axit afolic (dalapon)Cc dn xut ca cachamat (satun, eptam)Triazin (simazin, atrazin, evik...)Thuc bo qun lm sn v kh trng kho: Chuyn khtrng trong cc kho ging v kho nng sn, lm sn, trong cc

khoang chuyn chnng, lm sn ca x lan v tu thu. ikhi thuc ny c dng tr su bnh trong cc nh knhtrng cy hoc tr su bnh, cdi trong t. Nhm ny gm:Cypermerthrin, Deltamethrin, Fenitrothion...

Phn loi theo bn vng

Cc thuc BVTV c bn vng rt khc nhau, nhiu chtc thtn dtrong mi trng t, nc, khng kh v trong c

thng vt, thc vt trong mt thi gian di. Do vy cc hocht c ny c thgy nhng tc ng trc tip hoc gin tipn sc khocon ngi. Da vo bn ca chng, c thspxp chng vo cc nhm sau:


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Nhm cht khng bn vng:Nhm ny gm nhm photphohu cv cacbamat. Cc hp cht nhm ny c bn vngko di trong vng t1-12 tun.

Nhm cht bn vng: Cc hp cht nhm ny c bnvng trong thi gian t2 - 5 nm. Thuc nhm ny c thk

n thuc trsu bcm sdng Vit Nam l DDT, 666(HCH)...

Bng 2Phn loi thuc BVTV theo c tnh

LD50cho chut(mg/kg trng lng cth)Loi Nhm Qua ung Qua da

cht rn cht lng Cht rn Cht lng

IA Rt c (rt

nguy him)

- 5 < 20 - 10 40

IB c cao (nguyhi cao)

5 - 50 20 - 200 10 - 100 40 - 400

II c va (nguyhi va phi)

50 - 500 200 - 2.000 100 -1.000

400 -4.000

III t c (nguy hinh)

500 - 2.000 2.000 -3.000

> 1.000 > 4.000

IV Khng c > 2.000 >3.000

Ngun: M. Ruchirawat and R.C. Shank: EnvironmentalToxicology, Vol.2, 1996.

Phn loi theo c tnh

T chc Y t th gii (WHO) a ra bng phn loi thuc


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BVTV theo c hi i vi cc sinh vt cn c trn gi trLD50v LC50.Trong , LD50 l nng gy cht 50% c thth nghim, c th l chut hoc th, c tnh bng mg/kgtrng lng (Lb50 (per oarl) qua ng tiu ha c th khcLD50 (dermal hoc cutant) qua da). LC50 (lethal concentration

50) l nng gy cht trung bnh ca thuc xng hi c tnhbng m hot cht/m3 khng kh. Bng 2 trnh by phn loithuc BVTV theo c tnh ca n, trong , c tnh ca thucBVTV dng rn cao gp 4 ln c tnh ca thuc BVTV dnglng.

WHO (1990) v Uban Chu u (1984) phn loi thucBVTV theo mc nguy him c trnh by trong bng 3.

Bng 3Phn loi thuc BVTV theo mc nguy him i vi ngi

LD50(mg/kg trng lng cth)

Mc nguy him Ung Di da

Rn Lng Rn Lng

IA Ti nguy him 4000

Trn y l mt s cch phn loi thuc BVTV, tuy nhinphn loi theo i tng phng tr c s dng ph bin


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Vit Nam v c trnh by bng 4.

Bng 4Phn loi thuc bo v thc vt

Nhm chnh Nhm ph V d

I. Thuc tr

Cc cht v c Botanical (chit xuttthc vt)

Calcium arenate, Aluminiumphosphide, Cht nicotine.pyrethin rotenone

Du hydrocarbon Du cy chanh. chi cy(mcma ng) dit bgy

Clo hu c Aldrin, BHC. DDT. heptachlortoxaphene.

Hp cht pht phohu c

Cc cht huc Ngm qua r Arinphos, methmyl, dicglorvosparathion, methyl prathion

Khng ngm qua r Demeton methyl, dimethoate.monocrotophos, phosphamidon

Carbarmates

Khng ngm qua r Carbaryl, methomyl, propoxur,aldicarb, carbofuran

Pyrethroids tng hp Allethrin, bioresmethnn,permethrin

Vi sinh vt Bacillus thunngiensis

Vi sinh vt Vi rt virus polyhedralCht dit subnh khccht st khuttrong ho hc

Apholate, metepa, tepa


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Pheromones(cha t hp dnsinh dc v urt ng hp)Thuc trrp Deet, dimethyl phthalate. ethyl

hexenediot

Ni tit t cuasu bnh vcc ni tit tphng theo(iu chnh spht tri n cuasu bnh)

Juvennoids (Hocmoniuvenile v hocmonphng theo)Moulting inhibitors

Farnesol, Methoprene

Diflubenzuron, ecdysone

II. Thuc chiu dit ksinh vt

Clo hu c Chlobenzilate. dicofol,

tetradifonKhng ditnm Cyhexatin

Dit nm Hp cht dinitro vcc cht khc

Binapacryl, dinocap

chinomethionate

III. Thuc trnm

V c Dithocarbarmates Bordeaux hn hp, ng oxychloride, sulfur

Phthalimides Hpcht dinitro

Mancozeb. metiram,

propineb,thiram, zineb


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Hu c Thungn hu c captafol, captan, folpet,binapacryl, hp cht thu ngnhu c

Cc loi khc Fentin (acetate and hydroxide)Chinomethionate,

chlorothalonil, dichlofluonid,dichlone, diclran, dodine,

dyrene, glyodin

X l bng ho cht(khng sinh)

Blasticidin, cyclohexamidedasugamycin, streptomycin

Morpholine Dodemorph, tridemorph

Thuc ditnm qua r

Cc hp chtFormylamino

Chooraniformethan, triforine

Cc loi khc Ethirimol, carboxin dioxide,benomyl, tiabendazole,

thiophanate- methyl

IV.Cc chtxng hi

Halogenated

hydrocarbon

Chloropicrin, methyl bromie.

Khtrng t Methyl sothiocyanate Daxzomet, metham

Cc loi khc Carbon disulfide, formaldehydeHun khi t

giun trn

Halogenated

hydrocarbon

DD, dichloropropene, ethylene

dibromideV.Cht dit cV c Sodium arsenite, sodium

chlorate


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Hu c Phenolics Bromofenoxim, dinocsebacetate, nitrofen, PCP

Phenoxyaxits(hormon dlt cdi)

2,4D, 2,4,5-T

Carbarmates

Asuam, barba, bendiocarb,

carbetamde, chlorpropham,

phenmedipham, propham,

triallale.

Substituted ureas Diuron, fluometuron, linuron

metobromuron, monolinuronHalogenatedaliphatics

Dalaponl TCA.

Triazines Ametryn, atrazine,

methoprotryne, simazine,terbutryn

Diazines Bromacil, lenacil, pyrazon

Hp cht quaternaryammonium

Bipyidyls Diquat, paraquatPyrazolium DifenzoquatBenzoic axits Chlorfenprop methyl, dicamba

2,3,6- TBA Arsenicals Cacodylic axit,

DSMA,MSMA

Dinitroanilines Nitralin, profluralin. trifluralin


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Benzonitriles Bromoxynil, chlorthiamidichlobenil, ioxynil

Amides and anilides Benzoylprop-ethyl, diphenamid,

propachlor, propanil

Cc loi khc Aminotriazole. flurecol.

Glyphosate, picloramVI: cc chtlm rng lcht cy

Hp cht quaternaryammonium

(bipyidyls)

Diquat, paraquat

Phenolics Cacodylic axit, dinoseb. DNOC,

PCPVII:cc chtiu ho sinhtrng

Cht c ch

sinh trng(c ch ngnhn)

Hp cht quatemaryammonium

Gibberellic axitChlormequat

Kch thch

m chi vlm gim nychi bn

Carbarmates Chlorpropham, propham

Ethylene generators EthephonGieo ht trngcy lm quchn, n hoa

v kch thchsinh nha

cc loi khc Dimas, glyphosine.naphthaleneacetic axit

Lm rng qu Cycloheximide


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VIII: Thucdit chutCc cht xnghi (xng hiv dit chut)

Aluminium phosphide, calcium

cyanide, chloropicrin, methyl

bromideHydroxy coumarins coumaetralyl, ifenacoum,

wafarin

Cc cht

chngng mu lndandiones Chloro hacinone. phenyl-methyl pyrozolone, pindone

Cc loi khc Arsenicals "arse nious oxide", sodiumarsenite

Thioureas Antu, promurit

Ngun gc t thcvt

Red squill, strychnine

Cc loi khc Norbormide sodium,fluoroacetate, vitamin D

(calciferol), zinc phosphideIX Thuc ditc sn

Loi thuc t thcvt

Endod

di nc Tho cht sufat ng, niclosamide, sodiumpentachlorophenate, trifenmorph

trong t Carbarmates Aminocarb, vethiocarbmexacarbate

Cc loi khc Metaldehyde

Ngun: Gunn v Stevens , 1976


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Chng 2Cc hnh thc tc ng v nh hngca cht c ti cthcon ngi

2.1 Con ng xm nhp ca cht cvo cthcon ngi:Qu trnh xm nhp ca cht c trong cthcon ngi bao

gm qu trnh hp th, qu trnh phn b, vn chuyn sinh hcv bi tit. Con ng hp th, phn bv bi tit cc cht ctrong cthcon ngi c m thnh 1. Tt ccc qu trnhny c quan hqua li v tc ng tng hvi nhau.

Cthcon ngi c ngn cch vi mi trng bn ngoibi 3 loi mng chnh: Da, biu m ca htiu ha v biu m

ca hh hp.Da, phi v thc qun l nhng cquan c vch ngn chnhphn cch cthvi mi trng c cha mt lng ln cc chtho hc. Khi gy nh hng c hi n mt hoc mt vi bphn cthth cc cht c phi i qua cc ngn ny trc. Trmt scht huhoi m nhaxit, baz, mui, oxit...Cc chtho hc chyu c hp thqua mt trong 3 vch ngn nyvo mch mu v c truyn i trong cth. Cquan c mnghp thcc cht c ny thng c gi l cquan mc tiuhay m mc tiu. Mt loi ho cht c thc mt hoc c nhiucquan mc tiu v ngc li nhiu cht ha hc c cng mtcquan mc tiu V d: benzen c nh hng n htun honv cacbon tetraclorua c nh hng n gan. Ch v thungnchai u gy nh hng n h thn kinh trung ng, hbi


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tit v h tun hon. Cht c xm nhp vo c thcon ngitheo 3 ng: ng h hp, tip xc v tiu ho.

Xm nhp qua ng h hp

Phi ngi c bmt tip xc vi khng kh l 90m2, trong 70m2 l bmt tip xc ca ph nang. Ngoi ra n cn c

mng li mao mch vi bmt l 140 m2, qu trnh vn chuynmu qua phi nhanh v nhiu to iu kin thun li ch cccht c trong khng kh c hp th qua ph nang vo maomch. Ty theo bn cht ca cht c phn ng trn ngh hp gy tn thng nhkch thch, vim nhim, ph n, ginph nang, x phi... Hi cc dung mi hu c c ng knh

phn tnhhn 5m c hp thu nhanh qua phi.

Xm nhp qua ng tip xc

Xm nhp qua ng tip xc l con ng cht c tip xcqua da, qua mt, qua nim mc mi... C hai ng hp thquada l qua tbo da v qua cc tuyn ca da. Qua tbo l ngcbn. C nhiu yu tnh hng n shp thcht c quada: cu trc ho hc, tnh cht vt l ca cht c, nhit mi

trng, vng gii phu da khc nhau... Cc vt thng v vttry da c thto iu kin thun li cho vic xm nhp qua da.Cc yu t nh hng ti s xm nhp thuc BVTV qua dac trnh by bng 5.

Bng 5Cc yu tnh hng ti sxm nhp thuc BVTV


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Yu tnh hng V dc im ca da - Ccc vt thng v vt try da

- m ca da- V tr trn c th (v d nh s xm nhp

thng xy ra qua mt v mi)- Tch trng mch mu

Cc yu tmi trng - Nhit - m

c i m ca thucBVTV

- axit- Trng thi tn ti (rn, lng, kh)- Nng hot cht

Hnh 1Con ng hp th, phn bv bi tit ca cc cht c trong


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cth

Xm nhp qua ng tiu ho

Cht c khi hp th qua ng tiu ho th tnh c sbgim do tc ng ca ch ddy (c tnh axit) v dch ty (ctnh kim).

2.2 Qu trnh xm nhp cht c

trong cthngiKhi cht c xm nhp vo cth, cht c theo mu i n

Cc cquan. Do chc nng ca cc bphn v tnh cht c,cc cht c tutrng hp nm li t hay nhiu.

Mi cht c u c tnh c khc nhau nn vic xm nhpca chng vo cc bphn cng khng ging nhau. Cc thucm v thuc ngtan trong tng hu cnn tan c trong mdo n ng li cc tbo thn kinh, gan v thn. Vic tch

lucc cht c trong cthchyu do tnh cht ho hc cachng quyt nh. V d florua khng tan hay cc hp chtflorophotphat canxi nm ng li xng v rng, cc kim loinng, tc dng vi cc nhm theo (-SH) nm trong tbo sng(mng tay, tc...).

C nhiu tbo c khnng gicht c li nhgan gilicc kim loi nng. Trong mu, vic phn phi cng khc. V dnhng, thungn nm trong huyt tng, ch nm trong cchuyt cu. Cc huyt sc tc nhiu cht mnn n cng gi

li cc loi thuc ng, cc dung mi.Hiu bit vsphn bcc cht c trong cthl rt quan

trng. V d: asen v kim loi nng tp trung thn v ccmng chn tay, tc; thu ngn v cadimi thn; quanh v


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bacbiturat hng cu; DDT v cc cht trsu nhm halogen cc tbo dtrm; benzen tu... l nhng cn cgip taxc nh c mu i din phn tch.

Do phn ng l ho ca cht c vi cc h thng c quantng ng m c sphn bc bit cho tng cht:

Cht c c tnh in ly c dtrtrong mt stchc vcquan khc nhau nhch, bari, flo tp trung trong xng, bc,vng da hoc lng ng gan, thn di dng phc cht.

Cc cht khng in ly loi dung mi hu c tan trong mtp trung trong cc tchc giu mnhthn kinh.

Cc cht khng in ly v khng ho tan trong cc cht boni chung thm vo t chc km hn v ph thuc vo kch.thc phn tv nng cht c.

2.2.1 Shp th

a. Mng tbo

Cc cht c thng i qua rt nhiu tbo nhbiu m da,mng tbo mng ca phi hay ca rut non v cc tbo ca

cc c quan hay m mc tiu. Cc mng sinh cht bao phquanh cc tbo ny kh ging nhau. dy ca mng tbokhong 7-9 nm.

Con ng xm nhp ch yu ca cc cht c l qua da,phi v htiu ho: Mt scht c thtc ng trc tip ln b

mt ngoi ca mng plasma, chng lin kt vi protein c bitca mng v phn ng vi th th ca mng ny lm cho cchp cht ni sinh vn chuyn tmng plasma n vi cquanca tbo nhht nhn v gy ra hiu ng sinh hc.


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Hu ht cc cht c c hp thqua cc tbo biu b, ngtit mhi v lchn lng nhng lchn lng chim nhhn1% tng sbmt da nn chc mt st cht c i qua ngny.

Mt cht c c th chuyn qua mng bi mt trong 2 quy

trnh tng qut sau:Qu trnh vn chuyn b ng m t bo khng cnng lng.

Qu trnh vn chuyn c trng m t bo cung cpnng lng cho schuyn di cc cht c qua mng tbo.

Phn ln cc cht c chuyn qua mng tbo thng quaqu trnh khuch tn n gin. Cc phn tnha nc (cho titrng lng phn t khong 600 danton) thm thu qua mng,trong khi cc phn tknc khuch tn qua cht bo camng. Cc phn t a nc nh hn chuyn qua mng bngcch khuch tn. V d: etanol c hp thnhanh tddy vnhanh chng c chuyn i khp c th bng s khuch tnn gin tmu vo tt ccc m.

b. Svn chuyn c bit

C mt lng ln cc cht ho hc chuyn qua mng mkhng thgii thch thng qua skhuch tn hay qu trnh lc.Mt scc cht ho hc tan trong cht bo c thkhuch tnqua mng. gii thch cho nhng hin tng ny, ngi ta gi

nh c mt hthng vn chuyn c bit. Chng c nhim vvn chuyn qua mng tbo nhiu cht dinh dng nhng,amino; cc axit nucleic v mt vi hp cht khc. Sdi chuynl c bit quan trng loi cc cht dsinh ho tcth.


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Phi cng c thgp phn vo schuyn ho sinh hc hayloi cc cht ho hc trc khi i vo htun hon, mc d vaitr ca n t c xc nh r nhrut v gan. Hin tngloi bcc cht ho hc trc khi i vo htun hon c coinhstin o thi.

c. Shp thca cc cht c vo phiPhi ngi c din tch bmt ca phnang 70 m2, khong

cch tbiu m ca nang phi ti mch mu l 10m. Cc kh

tan trong nc sbho tan trong cc dch nhy ca cc ng hhp v c thtch t gy ra shhi khu vc, cc kh tantrong mkhuch tn qua mng phnang vi tc ph thucvo h s phn b m/nc v tan ca cc kh trong mu.Cc ht sol khi c hp thtutheo kch thc ca ht v tnhcht ng hc ca chng... Cc ht nh hn lm thng chui

vo cc phnang. Khong mt na sht bi sbloi ra trongmt ngy tuvo bn cht ca cht c. Cc ht cn li sbtip tc loi btrong thi gian tip theo. Cc ht kh tan nht s li lu nht. Cc ht tan c nm trong phnang skhuchtn trc tip vo mu i qua phi, cc ht khng tan s thmnhp vo cc kv vo mu qua hthng bch cu.

Phi thng hp th cht c dng kh (cacbon oxit, nitdioxit v sunfua dioxit) v dng hi.

Khi cht kh vo phi cc phn t kh s khuch tn t ti

phi vo trng mu v ho tan. Ngoi trmt scht kh c cci lc c bit vi mt scu tc sn trong cth(v dgncacbon oxit vo hemoglobin). S hp th cht kh thng clin quan n qu trnh ho tan vt l n gin. Kt qu l cc


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phn tkhi phn bgia hai pha kh v mu theo kiu hp th,hoc gia mu v cc m theo kiu phn b. Ti im cn bngtlnng ca cht ho hc trong mu v pha kh l mt hngs. Tlho tan c gi l hsphn bmu - kh. Hng sny c trng cho mi kh khc nhau. V vy, nng kh c

ht vo cao hn (c ngha l cao hn p sut ring phn) th sc nng cao trong mu nhng tlny skhng thay i chon khi t trng thi bo ho. V d: clorofom c tsho tantrong pha mu/kh cao (15) v etylen thp (0,14). Mu mang ccphn tkh ho tan n cc bphn cn li ca cth. Trongmi m cc phn t kh c chuyn tmu vo cc m chon khi t c scn bng xc nh bi hsphn btmvo mu.

d. Shp thcc cht c qua lp sng biu b, daLp sng biu b: L lp ngoi cng ca da, n gm cc t

bo phng, khng nhn, sng ho cha keratin (protein si).Cc tbo ny bao ly nhau to thnh mng bn vng v dodai, cc si keratin c bao phtrong mt lp mmng.

Lp biu b l vt tr ngi hn ch tc ca s hp ph.Cc cht c phn cc khuch tn qua bmt pha ngoi ca ccsi keratin ca lp sng hydrat ho. Cc cht c khng phncc sbho tan v khuch tn qua lp lipit khng thm ncgia cc si protein. Tc ca skhuch tn lin quan ti sho tan trong mv tlnghch vi trng lng phn t.

Trc khi i vo h tun hon cht c phi i qua mt slp tbo. Tc vn chuyn ny phthuc vo dy ca lp

da, dng mu hiu qu, schuyn cch gia cc k, cc tbobch cu. S hp th cng nhanh th nng trong mu cng


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cao, sphn bv p sut khuch tn a cc cht c ti cc tbo qua da khc nhau cc bphn cth.

Vng hp thcc cht tan trong ml:1.Lng di bn chn 7. Da u2. Mp bn chn 8. Nch

3. Gan bn tay 9. Trn4. Pha trc cnh tay 10. Quai hm5. Lng 11.Hc tai6. Bng 12. BuDa ca con ngi thng tip xc vi nhiu cht c. Song

da c tnh cht t b thm thu. V vy, n chnh l mt vchngn tt ngn cch cc cht c tmi trng. Tuy nhin,mt vi cht ho hc c thhp thc qua da vi mt lng

va gy nh hng n con ngi. V d: cht kh gy ch thn kinh nhsarin ddng hp thqua da. Cng nhvy,cacbon tetraclorua c thbhp thqua da n mt lng valm tn thng gan. Pha u tin ca shp thxuyn dal qu trnh khuch tn dsinh ho qua vch ngn gii hn (lpsng). Hu ht cc cht c truyn qua lp sng bng skhuchtn bng. Pha thhai ca shp thxuyn da l skhuchtn cht c qua lp di ca biu b (lp sng, bo t) v chnb. Cc lp ny su bn trong lp sng. Khc vi lp sng, cclp ny c cha nhiu l xp khng chn lc, mi trngkhuch tn nc. Cc cht c i qua lp ny do skhuch tn

v i vo h tun hon thng qua cc tnh mch v mao qunbch huyt trong da. Cc dung mi nh sunfoxit thc y vica cc cht c qua da v sunfoxit lm tng kh nng thmthu qua vch ngn ca da hay lp sng.


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e. Shp thcc cht c qua htiu hoQu trnh ny c th xy ra t ming n trc trng, ni

chung cc hp cht sc hp th trong rut ti ni c nngcao nht v dng dho tan trong mnht. Cc cht c cchc nng dinh dng v in ly sbvn chuyn rt tt vo

mu. Lng cht tn ti dng khng ion ho ph thuc vohng s phn ly ca cht o v gi tr pH ca dung dch, miquan h ny c biu din bng phng trnh Henderson -Hasselbach cho axit yu:.

Trong bazl cht nhn H+v axit l cht cho H+.

Tc hp thMt trong nhng yu tchi phi shp thl tc hp th.Mc c hi lin quan ti nng ca cht c ti vtr

xy ra phn ng.Trong hu ht cc trng hp shp thxy ra nhqu trnh

khuch tn thng, tc hp thc biu din theo hmmhoc ng hc bc mt.

Trong :

Mo- Nng ban u ca cht c ti vtr hp th.M - Nng ca cht c ti vtr hp ththi im t.Kat- Hng stc hp thbng 0,639-tl/2t1/2- thi gian bn hp th, khi M/MO=1/2.


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V dnng ca cht c trong ddy sxc nh tc hp thcht c tddy vo mu, khi nng trong ddygim th tc hp thvo mu cng gim.

Hu ht tc hp thcc cht c ph thuc nng cachng trong mu v phthuc schuyn ho trao i cht thnh

cc cht tan trong nc (tc l ng hc bc mt). Vi cc chtc c liu lng cao th cc enzym trao i cht c thbboho nn tc trao i cht l hng s, nu cht c tan trongmth sthi btrc tip skh khn, tc ca qu trnh nysl bc khng (l mt hng s, khng phthuc vo nng trong mu) cho n khi nng cht c nhhn mc bo ho.

2.2.2 Sphn b

Sau khi vo trong mu (kcqua hp thhay qua tnh mch)cht c c phn b vo c th. T l phn b vo cc c

quan hay cc m c xc nh bi tc dng mu v tc khuch tn ra khi mao qun, i vo cc tbo ca cc cquanhay m ring bit. Ni chung, pha u tin ca s phn b bnh hng bi tc dng mu, trong khi sphn bc xcnh bi i lc.

2.2.3 Vn chuyn sinh hc - Protein huyt tng

Protein huyt tng c lin kt vi cht dsinh ho hoc mts hp cht sinh l khc ca c th thc hin chc nng vn

chuyn sinh hc. Transferrin, - globin rt quan trng trongqu trnh vn chuyn st trong c th. Cc protein vn chuyncc kim loi khc trong huyt tng nh ceruloplasmin vn

chuyn hu ht ng. - lipoprotein v lipoprotein ng vai


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tr rt quan trng trong qu trnh vn chuyn cc hp cht hotan trong cht bo, nh cc vitamin, cholesterol v hoocmonsteroit hoc cc cht dho khc. Cc hp cht c tnh cht bazthng lin kt axit glycoprotein. Phn ln cc cht dsinh hob gi bi cc protein huyt tng thng gn vi atbumin.

Albumin l loi protein nhiu nht trong huyt tng v ngvai tr nh lu gi v vn chuyn cc hp cht ni v ngoisinh.

2.2.4 Qu trnh bi tit

Qu trnh bi tit vcbn cng gng nhqua trnh hp th,vn chuyn ho cht qua mng sinh hc, n ph thuc vogradient nng , cht c schuyn tni c nng cao n

ni c nng thp.Cc cht tan trong nc c thc loi bnhanh chng qua

thn v nc tiu hoc qua gan v mt.C mt s qu trnh c bit c tha cc cht.tan trong

nc vt qua mng lipit, v dsbi tit dch mt bi gan. Cccht trong mbthi.bchm hn vo hthng thi ca cthnhnc tiu v dch mt, v vy cc lng cht ny c gili trong cthlu hn.

Lng cht tan trong mc lc khi mu bng thn sb

ti hp thvo mu trc khi nc tiu i ra khi thn. Cc chtc c o thi ra ngoi cthqua thn, ng tiu ho, da...So thi ny phthuc vo tnh cht l ho ca cht . Thnl ng o thi chnh cc cht c. Cc ng o thi cht


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c cthcn c thc hin qua hi th(o thi mt slncht c di dng kh, hi). Cht c cn c o thi qua dav sa m.

Gan v thn c khnng lu gimt lng ln cc cht hohc. Nhn chung, bphn ny l ni tp trung lng cht c

cao hn cc bphn khc. Mc du cchvn chuyn cc chtc tmu vo gan v thn lun c lin quan ti svn chuynvo m. Trong lnh vc y hc, ng o thi cht c l cscho vic chn on v iu trbnh.

Thn l cquan quan trng cho sbi tit cc cht i sinhha, do c nhiu cht ho hc c loi b so vi cc tuynkhc. Cc cht c c chuyn i ttun hon thn bng conng chuyn ho sinh hc, sbi tit v s tch lua dng

trong cth. Sphn btng i ca quy trnh ny vi sbitit phthuc vo tnh cht ho hc ca cc cht c. Thn ngvai tr chnh, l ni loi tr phn ln cc cht c, nhng cquan khc cng c thng vai tr quan trng loi mt scccht c. V d: sloi trcc cht bay hi nhcacbonmonoxitqua phi hoc bi tit ch qua mt. Mc d gan l cquan nhybn nht trong vic chuyn ho cc cht c, cc c quan haycc m khc (enzim huyt tng, thn, phi, rut non...) c thgp phn vo qu trnh chuyn ho sinh hc. S chuyn hosinh hc thng l bc u tin trc khi bi tit rt nhiu chtc ho tan trong cht bo v v thc hp thli tthn sau

khi lc qua tiu cu. Sau khi cht c tri qua qu trnh chuynho sinh hc, cc dng trao i cht ca chng c a vo

mt (v ddng trao i cht ca DDT) hay a vo thn (v ddng trao i cht ca thuc trsu cphotpho).


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Khnng tn lu ca cc cht trong cthphthuc vo cim ho hc, cu trc phn t v tnh cht vt l ca chng.Mt scht thng tp trung cc tchc mnh: Chlordane,DDT, PCBS (polyclorbiphenyls).

Protein ca plasma c thlin kt vi ng v km. Cn chi

c khnng tch ng trong xng.Mc d vy, nhiu cht dsinh ho c chuyn ho sinh hcthnh cc sn phm ho tan nhiu trong nc trc i chng bitit qua nc tiu. Tuyn quan trng th hai bi tit mt slng ln cc cht dsinh ha l cc tuyn rut v tip theo lphi. Tt c cc con ng o thi trong c th u c khnng loi bc cc cht dsinh ho, v vy cc cht c cthc tm thy trong mhi, nc mt, sa...

a. sbi tit qua nc tiu

Thn nhn khong 25% sn phm carciac v khong 20% snphm trn c lc tiu cu. Cc mao qun ca tiu cu c cclrt ln (70nm). Do vy, cc hp cht c trng lng phn tn khong 60.000 dalton s c lc tiu cu (v d: ccprotein nhhn albumin). Mc lin kt protein huyt tngnh hng n tc lc v hn hp protein- cht dsinh ho lqu ln qua c cc lca tiu cu. Cht c lc tiucu c thnm trong ng lumen v c bi tit qua nc tiu.

Cc cht c cng c thc bi tit t huyt tng vo

nc tiu bi skhuch tn bng qua ng: Qu trnh ny clc ngha thyu v qu trnh lc nhanh hn nhiu sbi titkhuch tn bng qua cc ng, gy nn sti hp thti mtgradien nng ph hp chkhng phi l bi tit..


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Cc cht c c thc bi tit qua nc tiu. C hai qutrnh bi tit qua ng c bit mt lvi cc anion hu c(axit) v hai l vi cc cation hu c(baz). P- aminohippurat ldng nguyn mu cho h thng chuyn ho axit hu cv n-metylniotinamit cho qu trnh chuyn ho cc bazhu c.

b. Sbi tit cht cn

Sbi tit cht cn cng l con ng chnh loi bcc chtdsinh ho trong cth. Sbi tit cc cht c qua phn l mtqu trnh phc tp cha c nghin cu y nhsbi titqua nc tiu.

Cht thi rn (phn) l thc n khng tiu ho c bao gm:mt phn cht dinh dng tha v cc cht d sinh ho ctrong thc phm. Nhn chung, y l cc cht khng c cthngi hp th.

Sbi tit qua ng mt ng vai tr quan trng nht cho bitit cc cht dsinh ho v cc sn phm chuyn ho ca chng.Gan c chc nng loi b cc cht c trong mu sau khi hpthqua ng ddy - rut non, v mu tddy, rut non quagan trc khi ti htun hon. Gan c thtch cc cht dsinhho trong mu v do vy c thngn chn sphn bca chngn cc bphn ca cth...

Cc cht o thi qua mt thng chia thnh 3 nhm theo tl nng ca chng trong mt v huyt tng. Cc c cht

nhm A c t l mt/huyt tng gn 1, bao gm Na, K,glucoza, Hg, Ta, Ce, Co. Cc c cht nhm B c t l >1(thng gia 10 v 1000), bao gm cc axit mt, pylirubin,sunobrom phtalein, Pb, As, Mn v nhiu cht dsinh ho khc.


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Cc ccht nhm C c tl< 1, bao gm: imulin, albumin, Zn,Fe, Au, Cr.

c Sbi tit trong rut

Ngi ta thy rng mt s cht ho hc (digitoxin,dinitrobenzamit, hexaclobenzen, ochratoxin A...) c thi qua

phn khng qua qu trnh bi tit mt. Nhng th nghim ccng vt tht ng mt v tch ng mt cho thy c rt nhiucht ho hc c chuyn trc tip tmu vo rut v ra phn.

d. Sbi tit qua hi th

Cc ccht tn ti pha kh ti nhit cthc loi bchyu qua phi. Cc cht lng dbay hi nm cn bng vipha kh ca chng trong ti phi cng c thc loi bquaphi. Lng cht lng c loi bqua phi tlvi chnh p

sut hi cua n.e. Sbi tit qua tuyn sa

Vic nghin cu qu trnh bi tit cc cht c qua tuyn sal rt quan trng v: (l) mt cht c c thc vn chuyn quasa ca ngi mtruyn vo trong a tr; (2) mt cht c cthqua cc sn phm sa i vo cthngi sdng. Cc chtc i vo trong tuyn sa bi skhuch tn n gin. Cc chtdsinh ho ho tan trong cht bo khuch tn cng vi cht botrong huyt tng ti tuyn v v c thi ra qua tuyn sa khicho con b. Mt shp cht nhDDT v PCBS, polybrom... c tm thy trong sa.


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2.3 Sbin i cc cht c trong cthcon ngiQu trnh bin i cht ca cc cht ngoi sinh (cc cht c

hi trong mi trng) xy ra ch yu gan, thn, da, phi vmt cquan khc. Qu trnh trao i cht thng lm cho chngtrnn phn cc.v d tan trong nc hn. Nu khng c qua

trnh ny th khi dng mt liu thuc an thn thiopetal phi saumt trm nm vi c o thng khi cthv loi dc phmny tan tt trong m, khng thloi thi ddng c.

Qu trnh trao i cht c chia thnh hai giai on. Ccphn ng pha I thng lm cho cht c tr thnh hot nghn, pha II c thgn cc nhm tan trong nc vo nhm htrqu trnh bi tit bng thn v gan.

Cc phn ngho hc xy ra trong qu trnh bin i cht

gm:Ph I: xi ho (cho in ttmt nguyn ttrong phn t) ,

kh (nhn thm in t vo mt nguyn t trong phn t) vthuphn (kt hp vi nc v bgy phn t).

Pha II: lin hp (kt hp cc cht tan trong nc vo phnt).

Qu trnh xi ho v kh thng lm cho phn t tr nnhot ho hn v nhvy tnh c scao hn.

Qu trnh trao i cht pha IQu trnh xi ho : hu ht cc phn ng xi ho cc cht

ngoi sinh tan trong mc tin hnh bi cc enzym v s

dng mt nguyn t oxy t oxy nguyn t nn gi lmonxygenaza, ngoi ra enzym ny cn c cc tn khc nh

"oxydaza chc nng hn hp", "micro somalhydroxylaza",hydroxylaza hydrocacbon thm a vng' v "cytochrome P450".


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Tn chung cho c nhm enzym ny l 'monooxygenazacytochrom P450, l mt nhm rt nhiu izozyme oxy ho:

Mt v d cho s oxy ho l vic thay th nguyn t luhunh trong thiopental bng oxy nguyn t to thnhpentobarbital, sau l loi bkhi nhnh to ra sn phm

tan trong nc c th loi bbng thn qua nc tiu. tanca Thiopental trong mcao gp 3 ln so vi tan trong ncnn n rt ddng bhp thvo m kcno. Gan v thn ckhnng loi bsufua tthiopental v to thnh pentobarbital,hp cht ny tan trong nc nhiu hn thiopental 60 ln nnc loi bdn vo nc tiu Gan v thn c thoxy ho vloi bphn mch nhnh hydrocacbon lm cho n cng d tantrong nc hn. Nhvy qu trnh trao i cht ca thuc xy

ra thun li lm gim nh hng c hi n cth.Vi loi thuc trsu parathion cng xy ra phn ng tng

t. Tuy nhin sn phm trao i cht oxy ho-paraxon l mtcht c thn kinh mnh. Cch trao i cht ca parathion gan lm cho parathion dtan trong nc hn th li to ra mtsn phm hot ng hn v ph hu mt enzym quan trngtrong hthn kinh.

Fomaldehyt l mt sn phm hot ho ca methanol v n ckh nng gy c thn kinh: S to thnh fomaldehyt tmethanol ngi nhim c methanol c thc ngn chnbng cch cho ung ethanol, lc enzym alcnhol

dehydrogenaza sc p lc cao vi ethanol cn thn sbi titmethanol ra nc tiu, kt qu l c th s loi b methanol

trc khi n b trao i cht thnh cc sn phm trung gian cc tnh.


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Tuy nhin cc sn phm trao i cht pha I qua phn ngoxy ho, khv thuphn vn cha c tan trong nc loi bnhanh qua gan v thn. Trong cc trng hp cc snphm trao i cht cn phi i qua pha II.

Qu trnh trao i cht pha II - slin hp

Cc phn ng pha II mang tnh lin hp, mt cht nisinh tan trong nc c gn vo cht ngoi sinh, cc phn nglin hp to ra cc glucuronide, ethereal syfate, axit mecapturicthng qua s lin hp vi gulathon, axit amin, cc amin acetyl ho, methyl ho.

Cc sn phm lin hp rt quan trng trong phn ng gii cGan v cc m khc trong cthcha sn rt nhiu cc tc nhnto phn ng lin hp nu nhu cu l qu ln vt qu khnngcung cp th cc sn phm s tdo tng tc vi cc phn t

trong t bo nh nc, axit, nucleic, protein... l mt cchgii thch cho gi trngng trong c hi, mt lng nhchtc sc loi bkhi c thmt cch an ton cn nu liulng cht c vt qu mc ngng th cc cht c sctch lutrong tbo do qu trnh loi bkhng nhanh.

Khnng trao i cht con ngi phthuc nhiu vo yut di truyn. Cc dng enzym khc nhau c tnh cht trao icht khc nhau v l mt l do ti sao mi ngi li c png khc nhau i vi cng mt loi cht c. Hin tng ny

cng gii thch skhc nhau vnhy cm vi cng mt loithuc mi ngi.

Cc cht c khi xm nhp vo c th gy ra cc ri lonchc nng, tri li cthcng lm cho cc cht c bbin i,


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thay i c tnh theo chiu hng tng hoc gim. V dnhcc cht c v ckhng cn thln na m kt hp vi mthnh cc anbuminat c c gim i.

2.4 Mt syu tchnh gy nh hng ti c

tnh ca c cht

p ng sinh hc i vi mt ho cht c thbnh hngbi nhiu yu t. l bn cht ho hc ca ho cht, cc tnhcht ho l, iu kin tip xc nh liu lng, con ng tipxc, thi gian tip xc, loi, ging, gii tnh, tui, trng thi sckhoca i tng, tnh trng dinh dng v bnh tt, sngc mt ca ho cht khc trong c thv mi trng, s thch

nghi chng chu mn cm ca tng c thMt syu tchnh c thnh hng ti sp ng vi c

cht c tm tt bng 6.

Bn cht ca cht c

Bn cht ca ho cht (cc tnh cht ho hc v vt l) squyt nh hoi tnh sinh hc ca chng. Cc cht kh dbhpthti ng h hp, phi v si vo mu gy nn cc p ngti chnhozn hoc p ng cho cton thn nhcc kh gym, hi v cc ht sol kh, th hp chng c thkt hp vinc to thnh cc cht hot ho v gy p ng ti ch, v d:

hi fomaldehyt, SO2, NOX"' Cc ht bi lng ng trong phnang v hn chstrao i kh v d: bi cacbon, bi silic... Cccht ho hc hoc vi khun c thhp ph ln bmt cc htbi ri vo cthgy p ng ti chhoc ton thn.


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Bn cht ho hc ca ho cht quyt nh ththlin kt vbn cht lin kt. V d: steroid chlin kt vi ththsteroid,setrogen chlin kt vi ththsetrogen, l sc hiu calin kt.

Cc tnh cht ho l v tan trong mca cht c squyt

nh tc v phm vi di chuyn qua mng v nng ti ccvtr ca cth. Cc cht tan c trong mthm qua mng dhn cc cht tan trong nc. Mc ln ho cng nh hngti schuyn ng v snh vca ho cht bao gm qu trnhhp th, phn b, bin i sinh hc, bi tit cng nhng hcca cc qu trnh . Trong qu trnh bin i sinh hc, c ththng chuyn i cc ui tan trong mthnh dng dbloib.

Bng 6Mt syu tchnh nh hng ti sp ng ca cthvi

c cht

Mi trng Tc nhn i tng chu tc ng

Nhit Vt l Ging, loi

m Ho hc Gii tnh

p sut kh quyn nhim Tui

nh sng. S lu thng Tnh trng sc kho

Ting n. iu kin tip xc Trng thi dinh dng/sc

khochndi ngy Liu/nng Bnh tt

Sma trong nm Thi gian Cth

Khnng p ng

iu kin xung Con ng mn cm


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Quanh( nh ca v Tnh thch nghi, chng chuSinh) S c mt ca ho

cht khc qua muCi thin di truyn

Cc iu kin tip xc

Cc iu kin tip xc vi cht c bao gm liu lng, conng, nng tip xc v thi gian tip xc. Liu lng sinhhc hoc nng ca ho cht ti vtr tip xc squyt nhmc ca s p ng, c ngha l "liu lng quyt nh.Con ng tip xc cng l yu t rt quan trng. V d: ccng vt tip xc vi Methylenchloride qua ng h hp ssinh ra cc khi u cn qua ng tiu ho methylenchloride thli khng sinh u. Thi gian tip xc cng c nh hng ti khnng phi nhim ca cht c, n gm khong thi gian tip xc

v thi im tip xc. Trong mt strng hp , thi gian tipxc ngn thng gycc tc hi c thkhcphc cn s tipxc lu di sgy ra tc hi khng thkhc phc. V dnhimc alcohol ngn hn gy ra smt khnng lc mgan, cnsnhim c alcohol lu di sgy ra xgan. Sp ng cnc xc nh bi mc lin kt vi cth. Liu lng hocnng cng ln th s th th tham gia cng ln, lin kt sbn hn, p ng snhiu v lu hn.

Con ng tip xc cng nh hng ti sp ng v n xc

nh tnh cht ca cht c tc ng vo cth. Thng thngho cht i qua htiu ho, da, phi. Nu nc i qua da hocming th khng c tc hi nhng nc vo phi li c thgytvong. V d: thuc trsu cphotpho c thbhp ththeo


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nhiu cch nhtip xc qua da, xm nhp qua ng tiu ha.Cn vitamim D liu cao sgy hi khi ung nhng khng gyhi nu tip xc vi da. Nhiu cht c c th b hp thu quaming c bit l khi tip xc vi li. Nhng cng c mt scht bph hubi axit trong ddy, mt skhc li c hp

thnhanh trong d dy nh ru. Ngoi ra, shp th cn bnh hng bi sc mt ca cht dinh dng (loi v slng)trong h tiu ho, s chuyn ng ca ng tiu ho, tnh trngbnh tt v vi khun .

Cc cht tan trong mkhi tc ng ln da c thbhp thv gy nn cc hiu ng ton thn nhng cng c th khngthm qua da m ch gy tn thng ti ch. Nu da b tnthng th sxm nhp ca ho cht sddng hn.

S hp th cc cht qua h h hp ph thuc vo cc tnhcht ho l ca chng, nhkch cht, tan trong nc, nhpv su khi ht th. V dngi lm vic tip xc vi bi g,bi hu cniken, du ct gt hoc crom c thblot v thngrch mi, ung thmi v ni l ni lc cc vt liu ny. Ccht khng tan c th gy kch thch cho h h hp v d biaming, bi than, silic chng gy xnang phi thm ch gy ngth. Nu cc ht bi mang ho cht v vi khun thm nhp vohtiu ho th chng sgy tn thng cho bmt htiu ho.

Tnh trng cthkhi tip xc c cht

iu kin ca cthv tnh trng bnh tt c nh hng tiphn ng vi ho cht. Chn protein v vitamim c thbo v c th chng li cc cht c nh CCl4 s thiu htVitamim c th ko di thi gian tc ng ca ho cht nu


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vitamim tham gia qu trnh nh vho cht. Cc bnh gan, phiskch thch cc tc hi ca cht c ln gan v phi. Cc bnhvthn snh hng ti sbi tit ho cht v ko di tc ngca chng trong cth.

Tui

Nhng ngi trchu nh hng cht c t hn ngi gi.Nhn xt ny khng ng i vi tr em. Vi b phn nh

no v tusng ang pht trin mnh, do chng rt nhy cmvi cc cht c, c bit l cht c tc dng trn trung ngthn kinh (mocphin, bacbiturat) v ngi ta cng ra cc liulng theo cc tc gisau y (bng 7).

Bng 7Liu c ca Nobecourt xut cho trem

1 thng tui 1/10 liu ngi ln

T2 n 7 thng 2/ 10 u ngi ln

T8 thng n 5 tui 3/10 liu ngi ln

T6 tui n 10 tui 4/10 liu ngi ln

T11 n 12 tui 5/10 liu ngi ln

T13 n 14 tui. 6/10 liu ngi ln

Gn y A. Augsberger c nghcc cng thc nhsau:

Liu trem: (4 x tui + 20)% liu ngi ln,

v dtrem 5 tui th dng 40% liu ngi ln.

Tnh trng cth

Cht c ung khi i tc dng khc vi khi n, khi ln vi


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thc n, cht c gim c tnh. Khi lao ng chn tay v tr cnhiu cng gy tc dng tng t. Khi c thai tc dng mnh vadhn. Cho nn vi phnc thai, nn trnh lm vic nhngni tip xc vi cht c. Ngoi ra, trng thi bnh tt ca ccbphn chu nh hng ln ca cht c. Nu au thn th cc

cht c c o thi chm, c tnh tng. Nhng ngi augan mt kh nng chng c. Cc tuyn thn yu th cc chtc thm nhp c d ng; Nhng ngi thng xuyn sdng cc cht kch thch nhru th khng cn nhy cm vicc cht c tc dng c chnhthuc phin , cloral... khng gytc hi vi nhng ngi vim phi

Sc mt ca cc cht trong cthhoc trong mi trngkhi xy ra stip xc

Stng tc cho gy tc ng tloi ho cht ny sang loi

ho cht khc sto ra mt mi trng tip xc phc tp hn vmt nh tnh v nh lng. S tip xc v p ng c th lng thi hoc ni tip.

S tng tc ln nhau ca cc ho cht gy nn s thay ip ng vmt nh tnh v nh lng so vi p ng ring lca c thvi tng ho cht. Vic tip xc vi nhiu loi hocht c thl ln lt hoc cng mt lc u lm thay i ctnh, c thl tng ln hay gim i.

Stng tc cho c thc phn loi thnh tng tc cho

sinh hc hoc ha hc. Cc tng tc cho sinh hc gm nhhng ca mt loi ho cht ln snh vv hot tnh ththca loi ho cht khc. Cc tng tc cho ho hc gm ccphn ng gia cc loi ho cht to nn cc cht c hot tnh


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hay mt hot tnh. Cc yu tnh hng ti hiu quca phnng cho gm vtr tng tc, mi quan hliu lng p ngmi quan htm thi, tnh cht ho l, trng thi ca chth.

Cc tng tc cho ho hc c thxut hin bn ngoi cthtrong khng kh (s to thnh axt Sunfuric t S02 v nc),

trong nc (s to thnh Trihalomethal taxit humc v chlor,trong thc phm (shp thu ca vi lng vo thc phm). Cctng tc ho hc c thxut hin trong cthv lin quan tisnh vsinh hc (bao gm hp th, phn b, chuyn ho sinhhc, bi tit, ng hc) v hot tnh ca c th. Cc tng tccho xut hin bn trong c th c th lin kt vi shp thcc cht tham gia tng tc v tc nhn l ho (nh pk, pKa,kch cht, kch cphn t, lin kt).

Sto phc, shp thcnh tranh cc vtr vn chuyn quamng, mc hon thin ca bmt hp th, svn chuyn cccht tham gia phn ng c lin quan ti cc yu tho l, slin kt protein v cc i phn t, lu lng dng mu. Cc qutrnh sau cng b nh hng ca nhiu yu t qu trnh vnchuyn sinh hc ca cc cht ng phn ng s bi tit, hottnh thth...

Mc cng tc ng gy c ph thuc vo mi quan htm thi gia cc tip xc, khnng gy c stng ln vi tns tip xc. Nu cc tip xc l ng thi th cc tc ng hpthvn chuyn, phn b, chuyn ha sinh hc, bi tit l quan

trng. Nu stip xc l ktip nhau, th thi gian bn husinhhc, lin kt i phn t th th v tc hi phc l quan

trng.Sthch nghi, chng chu c coi l sp ng i vi mt


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ho cht sau khi tip xc vi mt liu lng di ngng. Cscho schng chu l vic to ra cc enzym thch hp tham giavo schuyn ho sinh hc ca ho cht. V d: mt sngin asen vi mt liu lng nhasen hng tun nng cao sckho(Asen c tc dng git cc k sinh trng ng rut) trong

nhiu nm s c khnng chu c 400mg Asen, y l liugy cht thng thng. Sthch nghi tng tcng c to ravi nicotin, cafe, ru...

Sc th ca tng c th:

Vi cng mt liu ho cht sgy ra mc phn ng khcnhau cc i tng tip xc, l skhc bit mang tnh ditruyn, n nh hng n snh vsinh hc ca ho cht. Vdnhng ngi bbnh bch tng da thng mng v nhy cmhn vi nh sng t ngoi, nhng ngi thiu ht enzym

Arylhydrocarbon hydroxylaza s khng b ung th v cc chthydrocarbon thm a vng khng th b hydroxy ho tothnh cc khi u. iu ny c thgii thch ti sao mt snginghin thuc l li khng bung th.

Cc yu tmi trng

Cc yu tmi trng c thnh hng ti p ng i vimt sho cht: c thl nhit , m, p sut, thnh phnkh quyn, nh sng, bc x, iu kin sinh sng, ting n, cc

yu tx hi v ma trong nm.


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Chng 3nh hng ca c cht v mi trngn sc khocon ngi

3.1 nh hng ca cht c ti cc bphn cthcon ngiCht c sau khi xm nhp bng cc cch khc nhau s

phn bvo cc bphn ca cth. Cht c c thnm li mt vi b phn ty theo tnh cht l ho ca n v cc iukin xm nhp vo cc bphn v slm ri lon schuyn hoca c th. Sau y l mt snh hng chnh ca cht c ticc bphn cthcon ngi:

nh hng ca cht c ti mu

Mu gm c cc thnh phn: huyt tng, hng cu, bchcu, tiu cu cc thnh phn trn. y u bcht c tc ng.

Huyt tng: Cc thuc m ton thn (clorofoc, te) slmgim pH, dtrkim v tng kali ca huyt tng. Loi nc rnColubride lm mt khnng ng mu, tri li loi Viperide lmtng khnng .

Hng cu: slng hng cu tng ln trong cc ca ngcgy ph phi (do, photgen, cloropicrin), mu c li do huyttng tot ra nhiu. Hng cu b ph hu trong ng c ch,

bnh quang tuyn X, benzen hoc cc dn xut qun nhn thm.i vi trng hp ngc saponoside v asenua hydro, hngcu bvv huhuyt sc tthot ra ngoi huyt tng.

Khi oxit cacbon (COx.) lin kt vi huyt sc t thnhcacboxylhemoglobin lm cho huyt sc tkhng cn khnng


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vn chuyn oxy dn n c th thiu xy hoc cht ngt. Cccht c loi dn xut nitnhn thm (nitrobenzen), anilin, ccnitrit, clorat c khnng oxy ho st (II) ca huyt sc tthnhst (III) chuyn hemoglobin thnh methemoglobin khng lmc nhim vvn chuyn oxy v c thdn n cht v ngt

Di nh hng ca cht c, mt vi thnh phn mi sxut hin. V d: trong ng c ch xt nghim s thy chtcopropocphirin, trong trng hp bngc bi cc axit mnhsthy cht hematopocphirin.

Bch cu: s bch cu c th thay i di nh hng cacht c Bch cu s gim trong ng c bi benzen, gy rathiu mu. Tiu cu: slng tiu cu c thht200.000 hoc400.000 xung cn vi vn trong ngc benzen...

nh hng ca cht c ti b my tiu ho

Cc cht c khi vo c thbng ng tiu ha gy phnng nn ma. cng l phn ng u tin ca cth; nhngbn cht l tc dng ca cht c trn h thnkinh gy co dnmnh ca m honh,

Cc cht c n da, bazhay axit gy cc tn thng cho ngtiu ho nhiu t tu theo mc c. Ch gy kh tiu, thungn gy vim ming.

nh hng ca cht c ti gan.

Gan l mt bphn nm ng tcc ng tiu ho. Ttnhmch ca, bn cnh cc cht do chuyn ho thc n cung cp,n nhn c cc cht c vo trong cc t bo gan. Mt khc,ng mch gan a mu vo gan v vn chuyn khp cc


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bphn. Do cc cht lthtun hon u c tc dng tigan. C thni khng c ngc no m khng c tn thng gan. S cng bin chuyn thnh s trong nghin ru kinhnin, thoi ho m trong ngc photpho, asen hay cc nm,vng da trong ngc asenua hydro.

nh hng ca cht c ti tim v mch muCc cht trtim, nu dng qu liu u gy c, c cht lm

tng nhp tim (tatycardie) trn 80 nhp pht nhcafe, thuc l vnicotin, ru, adrenalin, amphetamin...

C loi lm gim nhp tim (bradycardie) nhdigltalin eserin,ch trong ngc trng din.

Mt vi loi nh hng n co dn mch mu. V d nhacetycolin lm dn mch mu, tri li ergot seigle lm co.

nh hng ca cht c ti thn

Cc chc phn ca thn u bcht c lm nh hng. Vd nh thu ngn gy tng ur v anbumin trong nc tiu,ging nh ch, cadimi. Axit oxalic, cantharide gy i ra mu.

Cc dung mi hu cc chgy vim thn. Vic phn tch muv nc tiu scho nhiu thng tin vtnh trng ngc.

nh hng ca cht c ti hthn kinh

a scc cht c u tc dng t nhiu ti hthn kinh. Tutheo tc dng ca chng ngi ta chia chng thnh cht cthuc no, thuc hnh tu, thuc tu hoc cht c dy thnkinh cm gic dy thn kinh vn ng hoc ca hgiao cm.

Ta ly v d nh cc thuc m ton thn (te, clorofoc) tcdng n no, sau n giai on tusng tt cphn xu mt


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ht. Cui cng ti hnh tukhi gy ngng thKhi cht c tc dng vo no: c cc kch thch gy mt ng

hoc co git ng kinh (picrotoxin, cafein).Tiu no: ri lon ng tc v mt cn i (ru).Hnh tu: cc cht kch thch hnh tu (CO2) tc dng ch

yu vo tm th, lm co cng cc c th. Cc loi t lit hnhtunguy him hn (thuc m, mocphin) gy ngng th.Tu: tu ng vai tr chuyn cc phn x. Trong ng c

strycnin, gy ra mt skch thch qu mc cc nron tusng,tt ccc kch thch trung tm v ngoi vi u gy ra cc co gitton thn.

Hgiao cm: Hgiao cm gm c hai h: giao cm v phgiao cm. Cc cht nhadrenalin, ephedrin tc dng vo hgiao

cm gy ra gin ng t, tim p mnh, co mch, gin c phqun. Cc cht nhaserin, acetycolin tc dng vo hph giaocm gy co ng t, tim p chm, tng bi tit.

nh hng ca cht c ti hh hp

Cc cht c bay hi sxm nhp vo cthqua ng hhp, do n c thgy cc tn thng ti chhay ton thncc cht c c thgy ho km theo chy nc mi, nc bt.

V dvi cc hi c, hi ngt. Tc dng kch thch xy ra trn biu m phi do ph hoc bng.

Do h hp, cht c theo khng kh vo phi (ngi ta ht

chng 11 - 12 m3

khng kh trong 24 gi) ngm vo mu v gyngc. Tc dng ti ch thhin ngay trn nhp thgy nntrng thi kh thv ngt.

Mt scht tc dng vo khnng cung cp xy ca tbo


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vn chuyn xy cho cthnhCO, HCN c thgy tnh trngcht v ngt th.

3.2 nh hng ca nng v thi gian tc ng ca chtc ti cthcon ngi

Liu lng l n v ho cht s dng/trng lng c th

sng hoc n vho cht s dng/din tch bmt c th btip xc.Khi tip nhn mt liu cht gy c nht nh, cthsng b

kch thch v c p ng khc nhau. Sp ng cng cbiu hin nhl mt hiu ng. Liu dng - p ng l mt biuthc lin quan cht ch, c biu din bng mt ng congtng ng nh hnh 2. Theo hnh 2 khi c th tip nhn mtlng nhcht no cha tc ng, cthkhng gy png g, nu tng n mt ngng no cthbt u p ng,liu dng cng tng, cthcng p ng. n ngng m png cthl cc i th ng p ng skhng i, cthblit hon ton hoc cht.

Tnh c ca c cht chyu ph thuc vo liu lng, cngha l khi cththu nhn nhiu lng cht th tnh p ngc cng ln. Khi nim ny c hiu l liu lng - p ng.

Nng ca ho cht ti vtr tc ng tlvi liu lng.Trong cng mt liu vi hai hay nhiu loi ho cht c thlmcho nng ca chng khc i nhiu ti bphn btc ng. Skhc nhau ny lin quan n skhc bit ca qu trnh nhim

c. Tc ng ca bt cmt cht c no cng u phthucch yu vo nng ca n ti v tr tc ng. Nng cng

cao th hiu lc ph hoi cng ln. Nng ca mt cht c tivtr tc ng l mt hm sca:


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Mc tip xc i vi cht c, mc ny cng lin quanti cch thc th nghim a vo (tip xc) v shp thvo cth.

Sphn bca cht c trong cth.Strao i cht hoc chuyn ho sinh hc ca cht c.

Tip xc vi cht c nng cao trong thi gian ngn dgy nhim c cp tnh.

Tip xc vi cht c nng thp trong thi gian di dgynhim c mn tnh.

C hai loi tc dng chnh

Cht gy c nng : Mc gy c ca nhm ny l phthuc vo lng xm nhp vo cthdi liu gy tvong,


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thuc dn dn bphn gii, bi tit ra ngoi cth. Thuc nhmny l cc hp cht pyrethoid, nhiu hp cht ln hu c,cacbamat, cc hp cht c ngun gc sinh vt...

Cht gy nhim c tch lu: L cc hp cht chhu c, cchp cht cha thungn, asen v ch... c khnng tch lulu

trong c th v gy nhng bin i sinh l c hi cho c thsng.

3.3 nh hng phi hp ca cht c ti cthcon ngiTrong mi trng sn xut, khi c nhiu cht c cng tn ti

th tnh c sthay i, c thtc dng tng cng hoc gim inh hng ca mt ho cht ln hot ng ca mt ho chtkhc gi l mi tng tc (tc dng phi hp). Phn ng thuc c thmang tnh khuch i c (tnh cng: cht A +cht B : c tng gp 2 ln), thm ch nhiu trng hpkhuch i c ln gp bi (cht A + cht B = c tnggp 5 ln) v thng khng thdbo c. Bn cnh , phnng cn c thmang tnh tiu c (cht A + cht B < 1 ln c hoc cng c thc trng hp tiu c hon ton).

Khi 2 hoc 3 thuc BVTV c sdng ng thi, chng cthtng tc vi nhau v trthnh hoc l c hn (ng dnghoc ng khnng v dnhlindane v heptachlro) hoc t chn (i lp nhau). Stng tc ca nht trong chn hngngy vi thuc BVTV cha nhm quan thhai c thto ra ccnitrosamine c c tnh cao hn, gy bin dhoc gy ung th.

Ho cht hoc bt kmt loi cht no khi vo cthu quaqu trnh hp th, phn bv o thi. Trong qu trnh hp th,

cc loi ho cht si vo bmt cth, ri t i vo mu,tmu cc cht c bhp thv chuyn ng vo tbo. Ti


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y, mng tbo ng vai tr quan trng l sngn hoc schophp cc cht c i qua v khi xm nhp chng stn cngcc vtr nh, gy cc phn ng sinh hc ca cth.

Nhng cquan chnh ca c thc cc tbo xung yu cc cht c tn cng gy ngc l:

Gan v cc tbo chc nng ganHthn kinhHh hp-phiHbi tit-thnMtDa

Mi mt loi ho cht u tm c a im tn cng ca ntrong cquan ni tng ca cth. Do stng tc ho hc, sinh

hc v mi trng trong cc cquan ni tng, cc loi ho chtgy ra hai hiu ng chnh:

Hiu ng tch cc, c li: Hiu ng ny trgip cho cc tbo hot ng tt hn, gip ti sinh v phc hi nhanh chngcc tbo btn thng do bnh tt, sn sinh ra tbo mi. ychnh l cc loi dc liu, thuc Ty y v ng y v angc sdng. Hng nm, cc loi ho cht ny c sdngn hng triu tn. Ngy cng c nhiu cng trnh nghin cu,pht minh, gii thng khoa hc cho lnh vc ny v thc snhcc c tnh ny m loi ngi c cu sng v tn tinhhin nay. Thm vo l cc loi cht khc hoc mt s

cht c khi liu lng xm nhp di ngng.Hiu ng tiu cc, c hi: y l mt tri ca vic sdng

cc loi dc phm. Khi sdng hp l theo quy nh, n c tcdng tt nhng nu lm dng n hoc sdng nhm ln cng


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dng, khng theo chdn sgy tn hi ln n sc kho, nmi trng sng. Ngun chyu gy nn cc hiu ng tiu cc,c hi l cc cht c. Chng c phn loi theo tnh c vc xp thnh nhm cht c bng A, bng B v bng C (theotnh c gim dn). Sxm nhp ca thuc BVTV chyu qua

da v mt, do ht thhoc n ung. Trong mt gii hn no ,cc thuc BVTV tan trong m, thuc BVTV tan trong nc, hpth vo c th qua phn da tip xc. S xm nhp ca thucBVTV qua ng tiu ha c th xy ra do n thc phm bnhim hoc s dng cc cha thc phm b nhim. Tay bnhim thuc BVTV cng c thdn n sxm nhp ca thucBVTV khi ht thuc l.

i vi cc thuc BVTV c c tnh cao nhng li dchuyn

ho hoc loi trth mi nguy him chnh lin quan ti tip xccp tnh trong mt thi gian ngn. i vi cc thuc BVTV cc tnh thp hn nhng c khnng tch ng li trong cthth mt nguy him chnh li lin quan ti vic tip xc trong mtthi gian di, thm ch vi cnhng liu lng tng i nh.

Cc thuc BVTV c thloi trnhanh nhng li gy ra ccnh hng sinh hc bn vng cng c mi nguy him lin quanti vic tip xc trong mt thi gian di v liu thp. Cc nhhng c hi c thxut hin khng chdo bn cht hot ho vcht trn m cn do cc dung mi, cc cht mang, cc chtchuyn thsa v cc thnh phn khc trong thnh phm thuc.

Cc nh hng c cp tnh rt dnhn bit, trong khi , ccnh hng do tip xc trong mt thi gian di vi liu thp gy

ra thng kh phn bit.i vi hu ht cc loi thuc BVTV, mi quan hgia liu -


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p ng c xc nh v cc nh hng ca thuc BVTV cthpht hin c nhphn tch cc thay i nhv sinh hotrc khi xut hin cc nh hng ti sc kho trn lm sng.Cng c thc ngng m khng thquan st thy nh hngno (mc nh hng khng thquan st c). Tuy nhin, i

vi cc loi thuc BVTV nghi ng gy ung th th vic phthin sm cc nh hng phv xy dng mc nh hng khngquan st c c thl khng thch hp.

3.4 Cc loi nh hng c hi ca thuc BVTV ti sckhocon ngi

Chc mt st nhm hp cht xc nh c cchgyc trn ng vt c v. V dnh, cc cch c xc nhr i vi thuc tr su cphotpho v cacbamat, chai nhmu c ch men cholinesterase, cn nitrophenol va cc phenolkhchcao hn c chqu trnh phosphorin oxidase. Cc thucdit nm thu ngn hu c cng c c ch gy c r rng.Ngoi cc nh hng c lit k trong cc bng 8, 9, 10 diy th tip xc cc bcao c thgy ra bng ho cht v nngnht l bng mt do ho cht. Tchc nghin cu ung thquct (IARC) nh gi kh nng gy ng th ca nhiu thucBVTV.

Theo khnng gy ung thcho ngi, hai loi thuc BVTVethylene dibromid v ethylene oxide l cht c kh nng gyng thcho ngi. 14 loi thuc BVTV in hnh c phn

loi theo kh nng gy ung th l: amitrole, aramite,clordecone, chlorophenol, thuc dit c chlorophenoxy,. DDT,

1-3 - dichloropropene, hexachlorobenzen, hexachlorocyclo -

hexanes, mirex, nitrofen, sodium orthophenylphenate, sulfallate


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v toxaphene (IARC, 1998).

Bn cnh cc loi nh hng c hi nu trn cn c tcng ti sinh sn v cc nh hng khc.

c nhiu nghin cu cho rng cht dibromochloropropangy ra bnh v sinh cho nam gii, chlordecone, thiram v ziram.

benomyl gy nh hng xu ti khnng sinh sn ca ngii.Bng 8Cc nh hng ho sinh do mt sthuc BVTV gy ra

nhhng

Cchv cc yu tnguyn nhn

Gimmen

Gim men microsom (gip qu trnh oxy ho kh) trong ganrt r cc ng vt thc nghim v nhng ngi ciu trcc thuc nht nh hoc tip xc vi thuc BVTV c

Cloc chmen

Dithiocarbarmat c ch kh nng oxi ho kh ca ccmicrosom ca gan (v d oxi ho kh aldehyde). Khnng c chmencholinesterase trong mu ca thuc trsu cpht pho v carbamat khng chtrong cc trnghp nhim c m cn cc cng nhn tip xc vi cchp cht c ny. Nhim c cp tnh trn lm sng cthsxut hin khi hot tnh ca men cholinesterasebc chti 50% hoc nhiu hn v mc c chti 30%


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c nghl mc nguy him (WHO). Sc chmencholinesterase tch luc thxy ra ngay sau khi tip xcvi liu khng gy ra cc du hiu hoc triu chng trn lmsng. Liu ngng gim thp hn c thgy nhim c lmsng.

Cc nh hng xu khc i vi sc kho con ngi dothuc BVTV gy ra:

c nhn mt do tip xc vi diquat

Tng sinh tbo trong phi do tip xc vi paraquatnh hng ln hthng min dch do dicofol, cc hp chthu cv trichlorofom

Qu trnh photpho ho kh khng ng b dodinitrophenol, dinitrocresol..

Bng 9

Cc nh hng ca thuc bo vthc vt i vi da..

nh hng Cc yu tnguyn nhn

Vim da tip xc Paraquat captafol. 2.4-D v mancozeb

Phn ng dng v pht ban (danhy cm)

Barban, benomyl, DDT, lindane,zineb, malathion

Phn ng d ng nhy cm nhsng

HCB. Benomyl, zineb

Mn trng c Thuc BVTV c Clo nhHexachlorobenzene,pentachlorophenol, 2,4,5 - T, v c thdo nhim dioxin hoc dibenzofurans c khclo


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Tn thng do nt phng, sosu, rng tc vnh vin v teo da

Hexachlorobenzene

Bng 10Cc nh hng ca thuc BVTV i vi thn kinh

nh hng Cc yu tnguyn nhnNhim c thn kinh chm Mt scc hp cht cphotpho v d

nhleptophos

Thay i hnh vi. Cc thuc trsu cphotpho.

Tn thng h thng thn kinhtrung ng.

Thuc tr su c photpho, c clo vcc thuc dit nm thngn hu c

Vim dy thn kinh ngoi vi Thuc dit c Chlorophenoxy, thuctrsu pyrethroids v cphotpho.

3.5 Cc hnh thc thhin tnh c ca c cht i vi cthcon ngi

Tnh c ca cc cht c thhin di cc hnh thc: vt l,ho hc, sinh l, sinh ho hc v hnh thc kt hp nhngphng thc trn.

L hc

Nhng cht c nh dung mi hoc nh tng c th gykh da, vim da, bong vy sau mt thi gian tip xc ko di.nh hng ny do lm mt lp m da, cng c thdo lm bin

tnh Keratin hoc tn thng lp ngn nc pha di da.Cc axit hoc kim dng hi kh v dng lng gy kch

thch mt, ming v hng.Khi cht c xm nhp qua ng h hp, tiu ho c thgy


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kch thch, c th dn ti vim hng, gy vim teo ng hhp. ng tiu ho c thgy bun nn, vo su hn c thgy ri lon nhu rut v i tin.

Cc cht phng x c th lm thay i v tr v b gy cclin kt ca nhim sc th.

Ho hcTnh c thhin qua hnh thc ho hc bao gm:Skt hp trc tip gia cht c v mt thnh phn no

ca c th. V d: nhim c oxit ccbon (CO), CO skt hpnhanh chng vi hemoglobin (Hb) to thnhcacboxylhemoglobin lm Hb khng cn kh nng vn chuynoxy. Skt hp gin tip l sgii phng cc cht c ca cthnhhistamin gy tn thng, thm ch gy tvong cho conngi.

- Skt hp gia kim loi vi mt thnh phn ca tchc cth.

V d : borate gn vi nguyn t cc bon cnh nhm chchydroxyl lm cho chc nng bnh thng ca c thbngngtr.

- Tc ng n enzym hu ht cc cchgy c l do stcng lm thay i cc hot ng bnh thng ca h thngenzym.

+ Cht c c thlm thay i hot tnh ca enzym bng s

kt hp trc tip gia cht c vi nhm hot ng hoc kimloi hot ng trong cu trc ca enzym, lm c chhot ngca enzym. Th d: ch, thungn kt hp vi gc-SH, Xianuakt hp vi st ca enzym Cytocromoxydase lm enzym mt


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hot tnh c ch cnh tranh: Mt c ch gy c th hai tcng ln enzym l s cnh tranh ca cht c. vi nhng snphm chuyn ho bnh thng hay nhng coenzym cn thit chohot ng ca enzym. Th d cht sunfanilamid c cu trctng tnh. vitamin nhm B.

S tng hp mt sn phm c mi t cht c xm nhpvo cth. Cht mi tng hp gy c bng cch tc ng voqu trnh chuyn ho bnh thng. Th dcht natri fluoroacetat,sau khi c hp thu vo cth, di stc ng ca enzym vsc mt ca axit chc sc chuyn ho thnh fluorocitrat.Cht fluorocitrat l cht c thcp c khnng lm cho h hpca tbo ngng li.

+ Enzym gy c: Mt cchgy c khc xy ra khi chtc c to ra tenzym. l c tca nc rn, nc ong, vikhun.

+ Enzym cm ng: Hu ht trong cc cch trn, enzymu gim hot tnh, nhng trong mt siu kin no spng c th l kch thch hot ng chuyn ho. Nhng enzymcm ng l nhng enzym lm stng hp sinh l tng thm slng men do p ng vi mt tc nhn gy cm ng.

Cchthn kinh thdch

Tuyn thng thn trung tm thn kinh cao cp l nhng bphn bcht c tc ng mn tnh. Nghin cu cchny c

t lu trong nhim c i vi tetracloruacacbon hocsunfuacacbon c stham gia ca tuyn thng thn, tuyn ynv tuyn di i.

Hiu bit cc cchtc dng sinh ho, sinh l thn kinh th


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dch. Bn cnh tm quan trng trong l thuyt cn c gi trthct. Shiu bit cc ri lon sinh ho mc tbo hoc phn tcho ta kh nng xc nh cc ri lon sm ca tnh trng sckho, pht hin bnh giai on tn thng sinh ho v c khnng hi phc.

Cchmin dchL kt quca vic to ra mi khng nguyn mi do skt

hp ca cht c vi nhng thnh phn ca c th, thng lprotein. Cchny l csca mn cm da do tip xc vimt scht hu cnhchloroni trobenzoic. Mt v dkhc ltoluen disoganate v cc isocyanate thm, nhng cht ny quang thkt hp vi protein gy mn cm ng h hp.

Triu chng lm sng nhim bnh

Nhim c cp tnh

Thi kbnh l thi gian tkhi hp thu cht c n lcxut hin triu chng u tin. Tr mt s axit, kim c tcdng kch thch trc tip ngay, khng c bnh. Thi gian bnh tuthuc vo s lng hoc nng cht c. Tip theon thi ktin bnh l, xut hin triu chng khng r rt vkhng in hnh, bnh nhn chthy kh chu, mt mi v nhcu. Thi kny rt ngn nn dbsao lng, nhng nu ta akp thi bnh nhn ra ngoi v xl ngay strnh c hu qusau ny. Sau n thi kpht bnh vi triu chng r rt hncc giai on trc.

Nhim c mn tnh


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Do mt lng nhcht c tc ng trong mt thi gian digy bnh cho cth.

Triu chng khi pht rt nh, khng r rt, khng nhhng nhiu n hiu sut lao ng, v vy, dlm ngi ta saolng v khng pht hin kp thi. Bnh vn bv pht.

Nhim c bn cp tnh nm gia hai loi trnTrong sn xut cn ch trng chai loi ngun c cp tnh

v mn tnh. Do nhim c cp tnh nh hng ngay n laong c thgy tvong, ngc li nhim c mn tnh li ctnh cht rng v nghim trng. C nhng cht c c biu hinlm sng khc nhau trong nhim c cp tnh v mn tnh nhphotpho trong nhim c mn tnh li gy tn thng xnghm.

3.6 nh hng ca mt scht c ti sc khocon ngi

3.6.1 Nhm kim loi

Ch

Ngun gy nhim ch

Ch l kim loi c mu xm xanh, thng tn ti dng hotr +2 (Pb2+). Ngun pht thi ch nhn to ch yu l do qutrnh khai khong, nu qung thng l qung PbS, chto pin,cht do tng hp, sn, ha cht v khi bi ca ng c...

Ch c sdng sn xut c qui ch, hn... Cc hp chthu c ch nh tetraethyl ch c s dng rng ri lm chtchng kch nv cht lm trn trong xng. Tuy vy, hin naymt s nc khng cn dng loi xng cha ch. Phn ln


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lng ch c trong nc ung l do ng dn nc l hp kimch, cc vt dng hn bng ch trong ngnh xy dng. Lng chho tan tvt liu ca h thng dn nc c ch tuthuc ccyu. tnhpH, nhit cng ca nc v thi gian nc lutrong ng. Nc mm c tnh axit th c khnng ho tan ch

cao.Ti cc thln, phng tin giao thng chyu l xe myv t sdng loi xng A-83, A- 92 c cha ch. Ti mt sim nt giao thng H Ni c nng ch gp t1,2 n 1,5ln so vi tiu chun cho php (0,005 mg/m3). Ngun pht thich t khi bi ng c vo khng kh l mt trong nhngnguyn nhn lm tng nhim ti cc thuvc gn ng giaothng. Trong sng ngi, ch chyu tn ti dng rn llng,

chim > 83%, cn li dng trao i ln, dng PbOH+, PbCl-vto phc vi humic, fuvic. Ch hp phmn tnh trn bn: 58% dng rn; 10% dng phc vi cht hu c; cn li dngkhng tan, keo. Ch pht thi ra mi trng gp pH trung tnh rtdkt ta to Pb2O(OH)2, pb(OH)2.

Hm lng Pb trong nc ngt khong 0,06 - 120 g/l, trong

nc bin khong 0,03 - 13 g/l.

Cng nghip sn xut ch hng nm thi vo mi trng330.000 tn Pb2+. S pht tn ch do con ngi gy ra trn450.000 tn/nm.

Ch c sdng sn xut ng ng, kim loi tm, giy

kim loi, sn xut sn, c quy t, cc hp cht ch ankin.Nhng ngun ny bao gm ch trong sn ca ca cc nh ,trong khng kh do qu trnh t chy cc hp cht ca ch,trong cc ng choc trong sn xut ca mt s ngnh cng


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nghip.

Con ng xm nhp, o thi ch cthngi

Ch l nguyn tkhng thit yu vi cthsng. N l chtc thn kinh v xm nhp vo cthcon ngi bng nhiu conng khc nhau: h hp, n ung, tip xc qua da...Ch l kim

loi thng dng trong mi trng v l cht c c khnng tchttrong cthca ng vt c v. Trem hp thlng ch lnhn ngi trng thnh. Ch tn ti trong khng kh dng rn,bi hoc cc ht ch dioxit hoc dng hi, c bit alkyl chthot ra tnhin liu ca cc ng ct trong. Shp thchtrong phi phthuc vo nng khi tip xc ngoi ra cn phthuc vo mt tyu tkhc nhdng tn ti ca ch (rn hayhi), kch thc, phn b ca cc ht bi ch. Ch c th xmnhp vo cthcon ngi qua thc n, nc ung v ht thk

cqua da, tuy nhin con ng xm nhp chyu l tthc n.Lng hp thu qua phi cng ng k. Tu thuc vo loi

ho cht v kch thc ca ht, khong 40% lng ch ht quaphi c hp th.

Cc hp cht hu c, kcankin ch v sterat ch u chp thqua da. Sau khi c hp thqua da, ch c dn vot bo mu. Gn 10% ca nng ch trong mu nm tronghuyt tng.

Tt ccc m mm u cha ch nhng xng th cha nhiu

nht, hn 90% lng ch tch lutrong cthxng v rng.Ch thay thcho canxi nm trong tinh thhydroxi apatit v khi trong xng th lng ch n nh mc d c s trao icht gia ton bxng v huyt tng. Ch v ct khi i qua


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c vch ngn ngn mu no nhng ch hu cthng i cqua vch ngn ny. Ch hu ht c o thi qua thn nhngmt lng nhc o thi qua mt, qua mhi v qua sa.

Ch v c hp thu qua ng rut tng i t, chkhong10% ca lng ch i vo c thqua n ung. Tc hp th

tuthuc vo nng cc kim loi khc trong ng rut, cbit l nng canxi v st. Lng ch hp th thay i theonng cc kim loi canxi v st c trong ng rut.

Tnh c ca ch i vi cthcon ngi

Ch c c tnh cao i vi sc khocon ngi v ng vt.S thm nhim ch qua nhau thai ngi xy ra rt sm t tunth 20 ca thai k v tip din sut k mang thai. Tr em cmc hp th ch gp 4-5 ln ngi ln. Mt khc thi gian bnsinh hc ch trem cng lu hn nhiu so vi ngi ln. Ch

tch ng xng. Trem t6 tui trxung v phnc thail nhng i tng mn cm vi nhng nh hng nguy hi nsc khoo ch gy ra.

Ch cng km hm chuyn ho canxi bng cch trc tip hocgin tip thng qua km hm schuyn ho vitamin D. Ch gyc ch thng thn kinh trung ng v thn kinh ngoi bin.Ch tc dng ln hthng enzym, c bit l enzym vn chuynhydro. Khi bnhim c, ngi bnh c mt sri lon cth,trong chyu l ri lon bphn to huyt (tuxng). Tu

theo mc nhim c c th gy ra nhng tai bin nhaubng ch, ng vin en Burton li, au khp, vin thn, caohuyt p vnh vin, lit, tai bin no, nu bnng c thdn titvong. Tc dng ho sinh chyu ca ch gy nh hng n

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