C CHT HC VV SINH & AN TON NNG SN THC PHMPGS. TS. Dng Thanh LimB mn Dinh DngKhoa Chn nui Th YTrng i hc Nng Lm

Chng IGii thiu tng qut vcc cht c hi v s ng c TP

I. Khi nim v cht c v s ng cCht c (ting la-tinh potio, ting anh poisons hay cn gi l toxin) l nhng hp cht hu c hay v c c trong t nhin hay do con ngi tng hp ra, khi nhim vo c th gy ri lon cc qu trnh sinh l, sinh ha bnh thng, biu hin ra bng nhng triu chng, bnh tch c trng.

Ty theo loi cht c, mc nhim nng nh, ty theo c tnh ca loi, la tui, gii tnh v tnh trng sc khe ca c th m c th xut hin nhng triu chng ng c khc nhau, trng hp nng c th gy ra t vong, hoc triu chng nh, hoc sau mt thi gian lu di tch ly cht c mi c biu hin triu chng ng c.

Cc trng thi ng c- Ng c cp tnh l trng thi ng c sau khi nhim cht c mt thi gian ngn, xut hin nhng triu chng khc thng rt nghim trng, hoc c th gy ra t vong cho ngi hay ng vt b nhim c.

- Ng c tch ly (ng c trng din, ng c mn tnh) l trng thi nhim cht c vi liu lng thp, cha gy ra triu chng lin m phi tri qua mt thi gian di tch ly cht c trong c th n mt mc no lm bin i cc qu trnh sinh l, sinh ha mi pht sinh ra triu chng ng c.

- Gy ung th : i vi con ngi ngoi hai trng thi ng c trn ra cn c trng thi lu di hn, l trng thi gy ri lon hot ng ca t bo, lm t bin gen, bin i cu trc gen dn ti bnh bnh Ung th.

Cc yu t c nh hng n tnh trng ng c: 1.Liu lng cht c: - Liu an ton l liu khng c nh hng n sc khe hin ti cng nh lu di.-Liu gy ng c: Thng trong y hc v Th Y ngi ta ly liu LD50 (Lethal Dose).Liu c iu kin: L liu ch c php dng trong mt thi gian nht nh.

2.Yu t ging loi ng vt:Th nhai li nh c h vi sinh d c hot ng mnh nn n phn gii c mt s c t lm cho n bt c hi hn th n v.

3.La tui ca ng vt:Sc khng c t ca c th non v gi yu hn th trng thnh.

4.Tnh bit: Th mang thai, sinh sn hoc nui con th rt mn cm vi c t so vi th c. V d F2-Toxin

5.Tnh trng sc khe v ch dinh dng: Khi c th b bnh vim gan hoc vim thn th kh nng loi b c t ca c th rt km.

6.Khu phn n v ch dinh dng: Khu phn n thiu Cholin, methionine s gy ra thoi ha m gan lm s chng c t.

7.Trng thi vt l ca cht c: . Cht c trng thi ha tan trong nc th s gy ra triu chng ng c nhanh hn

II. Khi nim v nguy c v ri rotrong nghin cu cht cMi nguy, nguy c: Yu t sinh hc, ha hc, vt l hc, hoc tnh trng ca thc phm c tm nng gy nh hng xu cho sc khe con ngi.

Ri ro: L nhng nh hng c hi n chc nng c th, l hu qu ca cc mi nguy sinh hc, ha hc v vt l hc trong thc phm (FAO/WHO 1995).

Nhn dng nguy c v ri ro Gen di truynim cui gen khc nhau (gy t bin gen/clastogenicity) in vitro & in vivo; Sn lc theo kh nng gy ung thCp tnhThng nghin cu liu gy ng c cp tnh (LD50; ED50) K hn ngnLiu hng ngy lp li 14-28 ngy; nhn bit c quan ch b cht c tn cng, tnh cht ca nhng nh hng-mn tnhLiu hng ngy lp li 90 ngy; Tm p ng liu, v c s dng cho vic chn liu trong nghin cu mn tnh (MTD)Mn tnhLiu hng ngy lp li 2 nm trn loi gm nhm; s dng kim tra kh nng gy ung th; ngun NOAEL cho ADIKh nng SSLiu xy ra trc, trong v sau thi k sinh sn nghin cu nhng nh hng n s pht trin phi v bo thai

Nhng nghin cu khc c lin quan n nguy c v ri roTnh c hi vi khng th (Immunotoxicity)Tnh gy d ng (Allergy)Tnh khng chu ng (Intolerance)Tnh c hi thn kinh (Neurotoxicity) (cht c tc ng ln s pht trin hnh vi khng bnh thng)Nghin cu c bit (Special studies) v d nh: nghin cu c ch gy c, tnh c th ca loi i vi c t.

nh gi mi nguy v ri ro trong nghin cu cht cNhn dng mi nguy (Hazard Identification)Mt loi cht no gy ra nhng tc hi g cho c th?

c im ca mi nguy (Hazard Characterisation)Liu p ng ngng l bao nhiu?Liu an ton cho ngi nh th no? Bao nhiu?

c im ri ro (Risk Characterisation)C nhng ri ro g vi lng cht c n vo mc thp, cao?

nh gi lng n vo phi nhim (Exposure Intake Estimation)n lng cht c theo T hng ngy vo c th l bao nhiu?

PHNG PHP NH GI RI ROPhp ngoi suyliu thpRi ro lin ivi lng n vobit cnh giri ro s lngNOAEL* vYu t an tonLng n vo khng thy nh hng, v d: ADInh gi an ton* Mc nh hng c hi khng quan st c (No Observed Adverse Effect Level)

M hnh nh gian ton, nguy c v ri roDi 2 ln ngng an ton

Nghin cu nhng nh hng c bit:Kh nng gy ung th ca cc cht ph gia TP(Food and Feed Additives)Cht ngt nhn to Cyclamate dng lu ngy tch ly trong c th gy ra ung th gan, phi v gy nhng d dng bo thai ca ng vt th nghim. Cht chuyn ha trong c th ca cyclamate hnh thnh di-xyclohexylamin c hi hn c cyclamate.

Cht ngt saccharin gy ung th bng quang trn chut c th nghim. Khng thy tt c nh hng trong nghin cu th nghim c lin quan n bnh tt trn con ngiNghin cu c tnh ca cht ngt nhn to

Mc nh hng khng thy cNo Observed Effect Level (NOEL)NOEL l nng hay lng n ln nht t n iu m da trn nghin cu hoc quan st khng nhn thy c, nhng n lm bin i hnh thi hc, bin i dung lng chc nng, bin i sinh trng, pht trin hoc bin i tui th. V d thuc l lm gim tui th bao nhiu so vi tui th ch thc rt kh xc nh.

Mc tiu th hng ngy chp nhn (Acceptable Daily Intake)ADI: L s lng cht cho thm vo thc phm (food additive) da trn c s th trng (kg), vi lng n vo hng ngy trong sut cuc i m khng c bt c nguy c xu no n sc khe (JECFA) L nng hoc s lng cht ha hc c th tiu th hng ngy cho c cuc i c m bo, da trn c s ca tt c cc nhn t bit c khng c bt c mt tc hi no xy ra (JMPR)ARfD: L s lng ca cht ha hc c th tiu th trong tt c cc ba n hng ngy c bo m qua thc tin khng c bt c tc hi no.

PHN NG KHC BiT THEO LOIS THAY I KHC NHAU TRN NGIS dng nhng Factor khng m bo hoc m bo an tonFactor khng m bo hoc m bo an tan bng phng php ngoi suy.T nhng th nghim trn ng vt n th nghim trn ngi bnh thngv t ngi bnh thng n nhm ngi nhy cm trong qun th.1010Th trn cc loing vtTh trn ngitnh nguynTheo di trn ccth h cng ng123

S HP NHT CC T HP C CHT HC I VO NH GI RI RO I VI CC CHT PH GIA thc phm V CHT NHIM MI TRNG

Lethal Dose LD50/LC50LD/LC = 0LD/LC = 50 %LD: Lethal DoseLC: Lethal Concentrate

Phn chia cht c theo mc gy cNgun ti liu: Gary D. Osweiler, 1996.

n v o lng cc cht c hiNgun ti liu: Gary D. Osweiler, 1996.

n v o nng cc cht c c th hin sau y Cc n v o hm lng c t1 ppm (part per million) = 1.000 ppb (part per billion)1 ppb = 1.000 ppt (par per trillion)1 ppm = 1.000.000 ppt (par per trillion)C hai cch biu th nng : Hoc vic tt cc ch ci, hoc biu th nng trong 1 kg, g:1 ppm = 1 mg/kg = 1 g/g1 ppb = 1 g/kg = 1 ng/g1 ppt = 1 ng/kg = 1 pg/g

III. S phn chia cc cht c c hitheo ngun ly nhim vo thc phm1. Nhng cht c hi trong thc vt trn cn.2. Nhng cht c hi c ngun gc sinh vt bin.3. Nhng cht c hi trong nm cao cp.4. Nhng cht c hi trong vi nm.5. Nhng cht c hi trong ng vt sng trn cn.6. Nhng cht c hi sinh ra do thc phm bin cht.7. Nhng bnh do vi khun, virus, prion truyn qua T.8. Ng c thc phm do cc cht ph gia s dng trong ch bin thc phm.9. Ng c do nhim kim loi nng v cc loi nng dc s dng trong sn xut nng nghip nh: Thuc tr su, thuc dit c, thuc dit chut v nhng ha cht bo qun nng sn.

Phn loi ng c v nhim khun qua thc phmNg c do cht cNg c do VK gy bnhHa hcNhim c sinh hcThc vt ngVtVi sinh vtc t ng rutXm nhpSinh nha bo, tiptc truyn lyNi c t, ngoi c tVo c thB phn khc Cc t chc:ng rutNim mc, Gan, Cc t toNm v vi nmc tvi khunc t ng rut c t thn kinhRi lontrao i cht*

IV. S hp thu, phn tn v thi tit c t 1.1. Hp thu khuch tn th ng (Passive Diffusion):1.2. Hp thu lc qua mng t bo (Filtration): 1.3. Hp thu qua mng bng vt mang trung gian:1.4. Hp thu theo kiu nhn chm vo trong t bo, kiu thc bo (Endocytosis):1.S hp thu qua mng t bo:Macrophage

2. Cc c quan, t chc hp thu c t 2.1. Hp thu c t qua ng tiu ha Phn ln c t xm nhp vo thc phm, nc ung phn ln c hp thu vo c th qua h thng tiu ha. Nhng hp cht c hu c c tnh acid, ha tan c trong cht bo d hp thu d dy vi pH thp, ngc li hp cht kim hu c th hp thu rut tt hn d dy. 2.2. Hp th qua c quan h hp Nhng cht c hi d bay hi nh CO, SO2, NO2 hay nhng cht c bm trn cc ht bi, ht hi nc nh li ti bay l lng trong khng kh, khi ht phi chng c th hp thu qua lp t bo nim mc ng h hp. 2.3. Hp thu qua da C nhng cht, nht l cc loi thuc tr su ln hu c rt d dng hp thu qua da vo trong c th gy ra ng c.

3. S phn b cc cht c hi trong c th 3.1.Hng ro ngn cn:Hng ro mu no Hng ro nhau thai 3.2. Kh nng kt dnh v tch t c t S kt dnh c t (lu hay mau ty theo mi loa) S tch t c t (tan trong cht bo, tch t lu) 4. S bi thi c t ra ngoi:Cht c v gan b phn ng: oxyha kh, ester ha hay phn ng kha gc gy c ri theo dng mu n thn, n cc tuyn mt, m hi, i vi nhng cht d bay hi th ra phi bi thi ra ngoi.

Lm th no phng nga hot ng ca cc Xenobiotics trong c th?S phn b li (Redistribution) vt cht lKhi vo c th cc vt cht l chu tc ng phn b li ca c th, c th tn ti hoc b thi ra ngoi.S bi thi (Excretion) Trc tin l nhng hp cht tan trong nc, hp cht tan trong cht bo bi thi chm v n cn phi bin thnh cht tan trong nc mi thi ra c. V tr thi tit gan v thn.3) S trao i cht (Metabolism) bit c ch hot ng ca cc vt cht l, th phi xc nh c tnh hiu quan trng thng xuyn ca c th p ng chng li tnh c hi ca cc vt cht l. Gan, thn, phi, ng tiu ha, v cc c quan khc b tc ng.Lu : 1) v 2) ph thuc rt nhiu vo 3)

S trao i cht ca Xenobiotic Chuyn ha

Xenobiotics gy c hi c th nh th noMt s xenobiotics gy c hi bi s ph v chc nng t bo bnh thng nh:

Kt dnh v lm h hi proteins (Cu trc, enzyme)

Kt dnh v lm h hi DNA (t bin gen)

Kt dnh v lm h hi lipid mng t bo

Phn ng trong t bo vi oxygen hnh thnh cc gc t do free radicals lm h hi lipid, protein, v DNA

Mi quan h gia ng c thc phm v bnh truyn nhim Bnh truyn nhim l bnh pht sinh ngoi con ng truyn ly t ngun thc n ra, n cn c nhiu con ng truyn ly khc nh: hi th, tip xc qua da, truyn mu, vt trung gian mang trng chch bm

Bnh truyn nhim thng c st cao v c hin tng ly lan, c nh cao v c kt thc do c th sn sinh khng th v hiu ha mm bnh. Ng c thc phm do ha cht thng khng.

Ng c thc phm hay bnh pht sinh t thc phm (thut ng tin Anh Foodborne Illness) l ch truyn ly qua con ng thc n, nc ung m thi.

Tuy nhin gia bnh truyn nhim v ng c thc phm do vi khun, virus gy ra cng gn ging vi bnh truyn nhim, c th ly lan qua thc n nh bnh truyn nhim, v d nh dch tiu chy cp, dch t do vibrio cholera.

5. Khi b yu t mt th kh nng chng th kh nng chng yu t 2 s km i.

V. Tnh hnh ng c thc phm Vit nam1. Da theo ti liu iu tra cho thy: NTP do tc nhn vi sinh, tc nhn ha hc v s tn d khng sinh trong cc mu em kim nghim rt cao.2. Khng c phng xt nghim phn loi chnh xc tc nhn gy ng c, nn tng kt ng c cn kh chung chung.3. Thc t ng c thc phm ln hn rt nhiu so vi s thng k ly t sn xut i vi gia sc, t bnh vin i vi ngi.

Tnh hnh ng c thc phm Vit namhttp://vfa.gov.vn/YearStatisticsC.asp

Phn tch s v v nguyn nhn ng c thc phmnm 2008http://vfa.gov.vn/YearStatistics.asp

S yu km v h tng c s xt nghim v ngun lc cn bCha c c s labo vng c sc xt nghim c t v: -C qu nhiu c t, hm lng li qu thp, kh pht hin. -Vi sinh cng c nhiu loi, khng xc nh c loi, type.Qa trnh iu tra rt kh khn, v khng lu mu:- V hoc c hy mu trc khi on iu tra n.Khng c c quan chc nng v an ton thc phm: -Mc d c thnh lp, nhng lc lng cn qu mng.-An ton thc phm c tnh cht lin ngnh rt rng ln, nhng s kt hp rt lng lo, chng cho ln nhau.-X pht thiu nghim minh, mc cn qu nh khng rng e ngi vi phm, nng v ku ca trn bo ch.

Ng c vi khun trong nh n tp th ca Cng ty Kyunghim Vina, Bnh chnh 27/2/2003 Bo TN 17/4/03

Ng c vi khun trong nh n tp th ca mt s Cng ty, X nghip 5/7/2003 Bnh vin khngc ch chacc nn nhn, hphn ln l ccn cng nhntr, lao ng rtcng thng, n nh n tp th,b nhim c dovi khun c.

Ng c thc phm bp n tp th TP.HCM, 2004

Ng c thc phmdo bp n tp th 3 Cng tyNm 2005

Hnh nh ng c thc phm nm 2005Ng c do n c nc min TrungNgun: http://www.vtv.vn/vi-vn/VTV2/skcmn/2005/3/37172.vtv Ng c tp th do thc n nhim khun, Cp cu bnh vin Triu phhttp://www.vtv.vn/vi-vn/suckhoe/2005/4/50582.vtv

Ng c tp th trng hc u nm 2006Bo Thanh Nin 18/1/2006

Cng tc v sinh an ton thc phm c s ch bin thc nLink Video ClipNg c TP Th c 2009Ng c thc phm trng hocKim tra VSATTP

10 nguyn tc vng ch bin thc phm an tonNguyn tc 1. Chn thc phm an ton. Chn thc phm ti. rau, qu n sng phi c ngm v ra k bng nc sch. Qu nn gt v trc khi n. Thc phm ng lnh tan , ri lm ng li l km an ton. Nguyn tc 2. Nu chn k thc n. Nu chn k hon ton thc n, l bo m nhit trung tm thc phm phi t ti trn 70 C. Nguyn tc 3. n ngay sau khi nu. Hy n ngay sau khi va nu xong, v thc n cng lu th cng nguy him. Nguyn tc 4. Bo qun cn thn cc thc n nu chnh. Mun gi thc n qu 5 ting ng h, cn phi gi lin tc nng trn 60 C hoc lnh di 10 C. Thc n cho tr nh khng nn dng li. Nguyn tc 5. Nu li thc n tht k. Cc thc n chn dng li sau 5 ting, nht thit phi c un k li. Nguyn tc 6. Trnh nhim cho gia thc n chn v sng, vi b mt bn. Thc n c nu chnh c th b nhim mm bnh do tip xc trc tip vi thc n sng hoc gin tip vi cc b mt bn (nh dng chung dao, tht ch bin thc phm sng v chn). Nguyn tc 7. Ra tay sch trc khi ch bin thc n v sau mi ln gin on lm vic khc. Nu bn b nhim trng bn tay, hy bng k v kn vt thng nhim trng trc khi ch bin thc n. Nguyn tc 8. Gi sch cc b mt ch bin thc n. Do thc n d b nhim khun, bt k b mt no dng ch bin thc n cng phi c gi sch. Khn lau bt a cn phi c luc nc si v thay thng xuyn trc khi s dng li. Nguyn tc 9. Che y thc phm trnh cn trng v cc ng vt khc. Che y gi thc phm trong hp kn, chn, t knh, lng bn... l cch bo v tt nht. Khn dng che y thc n chn phi c git sch li. Nguyn tc 10. S dng ngun nc sch an ton. Nc sch l nc khng mu, mi, v l v khng cha mm bnh. hy un si trc khi lm ung. c bit cm thn vi ngun nc dng nu thc n cho tr nh.

10 nguyn tc vng an ton thc phm do FAO nghTiu chun an ton thc phm10 nguyn tc VSATTP gia nh