Th.S Trn Nguyn Vn Nhi

Vin Cng ngh Sinh hoc v Mi trng

i hc Nha Trang

C CHT HC

NI DUNG MN HC

CHNG I. TNG QUAN V C CHT HC

CHNG II. NG HC CA CHT C

CHNG III. C T SINH HC

CHNG IV. CHT C HA HC

CHNG V. C CHT KIM LOI NNG

CHNG VI. C T THC PHM

CHNG VII. NHIM C TRONG CNG NGHIP

DU M

CHNG VIII. NHIM C TRONG CNG NGHIP

CHT DO

TI LIU THAM KHO

TT Tn tc gi Tn ti liu Nm xut

bn Nh xut bn

a ch khai

thc ti liu

1 Nguyn Th

Thn

Cht c trong thc

phm

2007 i hc Y H

Ni.

Th vin trng

2 Hong Vn

Bnh

c cht hc cng

nghip v d phng

nhim c,

2002 Khoa hc v K

thut, H Ni.

Th vin trng

3 Phillip L.

Williams,

Robert C.

James,

Stephen M.

Roberts

Principles of

toxicology:

Environmental and

Industrial Applications

2000 Second edition,

Wiley-WCH

Publisher.

Th vin trng

4 L Huy B c hc mi trng c

bn

2008 i hc quc gia

tp.HCM

Th vin trng

CHNG I. MT S VN C BN

V C CHT HC

c cht hc l khoa hoc nghin cu v bn cht v c ch gy c ca cc

cht n c th sng hoc n nhng h thng sinh hc khc.

Mt s lnh vc nghin cu ca c cht hc - c cht hc m t: nh gi nguy c do phi nhim vi cht c hoc mi trng thng

qua cc kt qu thu c t cc xt nghim c tnh.

- c cht hc c ch: Gii thch c ch gy c, t c th d on nguy c v c s khoa

hc iu tr ng c.

- c cht hc lm sng: Nghin cu cc bnh do ng c, nhim c, cch chn on v iu

tr ng c, nhim c.

- c cht hc phn tch: Nghin cu cc phng php pht hin v th nghim cht c v

cc cht chuyn ho ca chng trong vt phm sinh hc v mi trng..

- c cht hc mi trng: Nghin cu s chuyn vn ca cht c v cc cht chuyn ho

ca chng trong mi trng, trong chui thc phm v tc dng c ca cc cht ny trn c th v

trn qun th.

- c cht hc cng nghip: Nghin cu v nh hng c hi ca mi trng lao ng cng

nghip i vi ngi v sc vt.

- c cht hc php y: Cc xt nghim c cht v khm lm sng cc trng hp ng c,

nhim c mang tnh php l.

Cc khi nim c bn

c tnh: tnh cht gy c ca cht c i vi c th sng

c lc: lng cht c trong nhng iu kin nht nh gy nh hng c hi hoc nhng bin i sinh hc c hi cho c th.

Liu lng p ng ca c th

c tnh

c lc

Cht c

* Cht c (toxicant, poison, toxic element)

Cht c l nhng cht gy nn hin tng ng c

(intoxication) cho con ngi, thc vt, ng vt.

Phn theo c tnh sinh hc

c cht (toxicant) ch vai tr tc nhn ha hc gy

c ca n.

c t (toxin) ch vai tr v bn cht sinh hc ca

cht c

c t

* c t (toxin): l cht c c tit ra t sinh vt.

V d:

c t do ng vt: nc rn, nc ong, nc kin,

c t do thc vt: cc alcaloid, cc glucoside,..

c t do vi khun: Clostridim Botulism..

c t do nm: Alflatoxin

c cht

Cht thi t cng nghip dc phm

Thuc tr su hu c

Hp cht phenol

Hp cht PCB (polychloro biphenyl)

Cht thi c ngun gc halogen

Cht c cyanua

Cht c phng x

Cc cht c kim loi nng

Phn theo bn cht

c bn cht (Natural Toxicity): C nhng cht c vi mt liu

lng rt nh cng gy c. V d: H2S, CH4, Pb, Hg, Cd, Be, Sn,

Cht c khng bn cht: t thn n khng l cht c nhng gy

nn cc hiu ng c khi n i vo mi trng thch hp no .

c liu lng (Dose Toxicity): C nhng cht mt liu lng

nh khng gy c thm ch cn l dinh dng. Nhng khi vt qu

mt liu lng nht nh i vi mt sinh vt trong mt thi k nht

nh s gy hiu ng c.

Phn loi theo tim nng hot tnh

Loi cc tc nhn gy c tim tng (Potential Toxicity): gm

tc nhn ha hc (t nhin, nhn to, hu c, v c), tc nhn vt

l (tc nhn c th, bc x, vi sng), tc nhn sinh hc (cc c t

ca nm, vi khun, thc vt, ng vt) c kh nng gy ng c

cho sinh vt nhng hin ti cha th hin. N ch biu hin c tnh

khi c iu kin mi trng thch hp.

Loi cc tc nhn gy c hot tnh (Actual Toxicity): cng

gm tt c nhng tc nhn gy c nh trn nhng ang dng

hot ng th hin c tnh, hin ti gy hi sinh vt.

Phn loi theo dng, th tn ti

Cc dng th hin ca tc nhn c c th l

khng kh, nc, thc phm, dc phm,

m phm v sn phm tiu th, qua tip xc

da.

Phn loi theo tnh nng

Dng cp tnh: Nguy cp, c th gy cht tc thi, ngn

hn, thng i vi liu cao hoc nng cao v s t ngi

b nh hng nh khi lm ha cht, thot cht thi c hi

ra khng kh.

Dng mn tnh: m tn ti trong c th sinh vt v qun

th, di hn, thng i vi liu lng v nng thp, xy

ra cho s ngi ng hn, hoc rt lu (thng i vi liu

lng v nng rt nh, nhiu ngi mc phi nh trng

hp nhim c thc phm, nhim kim loi nng hoc

nhim nc).

Phn loi theo tc ng ca cht c trn cc h c quan ca c th:

- Cc cht c tc ng trn h thn kinh: cafein, strychnin, cyanid, ch, hexachlorophen, thuc tr su

clo hu c...

- Cc cht c tc ng trn h tiu ho: asen, selen, canxi clorua, sulfat ng, mui thy ngn v c...

- Cc cht c tc ng trn gan, mt: tetraclorua carbon, phenol, aflatoxin, fumonisin, acetaminophen,

toluen, ng...

- Cc cht c tc ng trn thn: thuc khng sinh nhm aminoglycosid, oxytetracyclin, sulfonamid,

kim loi nng, ochratoxin...

- Cc cht c tc ng trn h h hp: carbon monoxid, kim loi nng, carbon dioxid, formaldehyd,

thuc tr su phospho hu c, fumonisin...

- Cc cht c tc ng trn h tim, mch: digitalis, digitoxin, cafein, cocain, monesin, amphetamin...

- Cc cht c tc ng trn h mu: aspirin, benzen, chloramphenicol, chlorpromazin, estrogen,

phenylbutazol, T2 mycotoxin (y l cc cht gy thiu mu).

- Cc cht c tc ng trn h sinh sn: testosteron, zearalenon, dicoumarol, corticosteroid, fumonisin,

ch, cadmi, selen...

- Cc cht c tc ng trn da: acid, base, formaldehyd, iodin, mui thy ngn, phenol, cc cht nhy

cm quang hc...

Liu lng c (dose)

LD50 (median lethal dose): liu lng gy cht 50% ng vt th nghim, n v mg/kg ng vt sng trn

cn.

LC50 (median lethal concentration): nng gy cht 50% ng vt th nghim, n v mg/l dung dch

ha cht; thng dng nh gi c tnh ca cht

c dng lng ha tan trong nc sng, sui hay nng

hi hoc bi trong mi trng khng kh nhim c th gy cht 50% s ng vt th nghim.

c tnh ca c cht

Nhm I : rt c, LD50 < 100 mg/kg.

Nhm II : c cao, LD50 = 100 - 300 mg/kg.

Nhm III : c va, LD50 = 300 - 1000 mg/kg.

Nhm IV : c t, LD50 > 1000 mg/kg.

PHN CHIA NHM C QUA MING

THEO QUY NH B NN&PTNN V CNTP NM 1995

Phn nhm

v k hiu

Biu tng

nhm c

LD50 mg/kg (qua

ming)

Th rn Th lng

I Rt c,

ch en trn bng

mu

u lu xng cho < 50 < 200

II c cao,

ch en trn bng

mu vng

Ch thp en 50-500 200-2000

III Nguy him,

ch en trn bng

mu xanh nc

bin

Vch en

khng lin tc > 500 > 2000

n v c cht

(TU Toxicity Units)

L i lng th hin lng c cht ca mu th vi sinh vt

th nghim. Mt n v tnh tng ng vi mu pha long git

cht 50% s lng sinh vt th nghim.

TU cng cao, EC50 cng thp th mi trng cng c hi.

Tc pht thi c cht (Toxicity Emission Rate) l

lng c cht, c t thi ra mi trng xung quanh trong thi

gian mt ngy

TER = TU/ngy = TU x Q (m3/ngy)

H s pht thi c cht (Toxicity Emission Factor

TEF): l lng c cht pht thi tnh trn mt tn cht thi rn

cc bi rc thi.

Hin tng ng c nhim c

Ng c l trng thi ri lon nhng hot ng sinh l bnh thng ca c

th do cht c gy ra.

Cht c c ch mt s phn ng sinh ho hc, c ch chc nng ca

enzym. T cht c c th c ch hoc kch thch qu lng cc hormon, h

thn kinh hoc cc chc phn khc ca t bo lm cho c th c nhng triu

chng, phn ng khc thng.

Ng c tnh cp tnh l nhng biu hin ng c xy ra rt sm

sau mt hoc vi ln c th tip xc vi cht c. Ty thuc vo

cht gy c, ng xm nhim cht c, biu hin ng c c

th xy ra 1- 2 pht hoc 30 pht n 60 pht sau khi c th hp

thu cht c v thng l di 24 gi. a s trng hp ng c

cp tnh chuyn sang dng cp tnh hoc mn tnh.

Ng c bn cp ( cp tnh)

Xy ra sau nhiu ngy, c khi sau 1- 2 tun. Sau khi iu tr, khi

nhanh nhng thng li nhng di chng th cp vi nhng

biu hin nng n hn.

V d ng c oxit carbon.

Ng c cp tnh c khi chuyn sang thnh dng mn tnh.

Ng c mn tnh

Ng c mn tnh ch xut hin sau nhiu ln phi nhim vi c

cht, c khi l hng thng, hng nm. V vy, nhng biu hin ca

nhim c thng l nhng thay i rt su sc v cu trc v chc

phn ca t bo, kh iu tr.

V d: tc dng gy ung th, gy t bin gen, gy qui thai, gy

c cho gan, thn, h thn kinh dn n suy gim chc nng khng

hi phc. Ng c mn tnh cng c th tr thnh cp tnh trong

nhng iu kin nht nh (ng c ch).

Nguyn l v c hc mi trng

Tnh c

Ngng c

Tnh bn vng ca c cht trong mi trng

Din bin v ng i ca c cht

Ngun pht sinh

Xm nhp

Gy c

Phn hy

o thi

Ngun pht sinh

Thin nhin:

- T hot ng ca ni la

- Chy rng

- Phn gii ym kh t nhin vng m ly, sng, ao, h

Nhn to: rt a dng

- Cng nghip

- Nng nghip

- Du lch, sinh hot, chin tranh

Cng nghip

Ngnh nhit in: thi ra bi, khi v hi nng, cc kh c hi, sn phm ca hot ng t nhin

liu ha thch (nh SOx, CO, CO2, N2O, NO2).

Ngnh vt liu xy dng: bi, kh SO2, CO, CO2, N2O, NO2...

Ngnh ha cht, phn bn: khi thi ln bi ha cht, c tnh n mn, nc thi acid (hoc kim),

trong nc thi ln nhiu cht l lng v d lng nhiu loi ha cht gy hi cho h sinh thi nh

toluene, cc dn xut gy ung th...

Khai thc v ch bin du m: sinh ra du r r, cn du, cht thi rn ca sn xut... Ta bit rng, du

m v sn phm chng ct du u gy c cho sinh vt v h sinh thi.

Ngnh dt nhum, giy, nha, cht ty ra: thi ra nhiu khi bi, kh c, nc thi c hi, cht thi

rn c hi.

Ngnh luyn kim, c kh: bi, cc kh giu SOx, NOx, CO, CO2, cc kim loi nng.

Ngnh ch bin thc phm: ch yu nc thi ra c hm lng cht hu c cao, to nn cc c t

trong mi trng.

Ngnh giao thng vn ti: cht thi do khi xng, du m, bi ch, bi t, tai nn, nht l tai nn trn

du...

Nng nghip

Do vic s dng thuc bo v thc vt nhm clo hu c

(DDT, DDD, lindane, thiodane, heptachlor...) v cc hp cht

polychlobiphenyl (PCB), dioxin... l cc cht kh tan trong nc

nhng c kh nng hp th v tch ly trong cc m m.

Hot ng du lch, sinh hot, ph rng,

chin tranh

V d: hu qu ca vic ri cht c khai quang, dit c

ca M trong chin tranh Vit Nam cn gy hi vi chc

nm sau.

Xm nhp

Tiu ha

H hp

ng da

Gy c

Cc cht gy c c chia thnh nm nhm:

Nhm 1: gy bng, kch thch da v nim mc. V d: nhm

acid, hi acid, kh NH3.

Nhm 2: kch thch ng h hp, nh Cl, NOx, HCl...

Nhm 3: cc cht gy ngt nh CO, CO2, kh CH4, C2H6 .

Nhm 4: cc cht tc dng ln h thn kinh, nh hydrocarbon, sulfurhydro, cc loi ru.

Nhm 5: gy c cho h thng c quan nh h to mu,

h tiu ha.

Phn hy Mot so oc chat co the b thuy phan hoac chuyen hoa di tac dung cua anh

sang t ngoai (phan ng quang hoa), tao chat co oc tnh kem hn.

Mot so loai thuoc bao ve thc vat co goc phot pho hu c de thuy phan nh

parathion, methylparathion, DDVP... kho gi c nong o cao trong moi

trng sau mot thi gian dai, nhat la khi moi trng nc co tnh kiem manh.

Thi gian ban huy cua chung ch 10 - 15 gi trong ieu kien pH trung tnh.

Nhieu chat hu c trong nc thai sinh hoat (chat beo, carbohydrate,

hydrocarbon...) de dang b oxy hoa e cho cac san pham khong oc hoac t

oc oi vi ong thc vat thuy sinh.

o thi

Hp th - Absorption

Phn phi - Distribution

Chuyn ha - Metabolism

o thi - Elimination

ADME

Lp lipid ca mng t bo

Chuyn ha v o thi hay tng tr?

Phn ng enzym ca c th : gan

M hi, nc bt, mt, nc tiu

Toxicokinetics is essentially the study of "how a

substance gets into the body and what happens to it in

the body". Four processes are involved in

toxicokinetics.

The disposition of a toxicant along with its biological reactivity are the factors that determine the severity of toxicity that results when a xenobiotic enters the body. Specific aspects of disposition of greatest importance are:

Duration and concentration of substance at the portal of entry

Rate and amount that can be absorbed

Distribution in the body and concentration at specific body sites

Efficiency of biotransformation and nature of the metabolites

The ability of the substance or it's metabolites to pass through cell membranes and come into contact with specific cell components (e.g., DNA).

The amount and duration of storage of the substance (or its metabolites) in body tissues

The rate and sites of excretion

Absorption. A highly-toxic substance, which is poorly absorbed, may be no more of a hazard than a substance of low toxicity that is highly absorbed.

Biotransformation. Two substances with equal toxicity and absorption may differ in hazard depending on the nature of their biotransformation. A substance biotransformed into a more toxic metabolite (bioactivated) is a greater hazard than a substance that is biotransformed into a less toxic metabolite (detoxified).

Mixtures represent a challenge because the response of one chemical might be altered by the presence of another chemical in the mixture.

A synergistic reaction between two chemicals occurs when both chemicals produce the toxicity of interest, and when combined, the presence of both chemicals causes a greater-than-additive effect in the anticipated response.

Potentiation describes that situation when a chemical that does not produce a specific toxicity nevertheless increases the toxicity caused by another chemical when both are present.

Antagonists are chemicals that diminish another chemicals measured effect.

1. Functionalboth chemicals affect the same physiologic function.

2. Chemicala chemical interaction between the two compounds affects the toxicity of one of the chemicals.

3. Dispositionalthe absorption, metabolism, distribution, or excretion of one of the chemicals is altered by the second chemical.

4. Receptor-mediatedwhen two chemicals bind to the same tissue receptor, the second chemical, which differs in activity, competes for the receptor and thereby alters the effect produced by the first chemical.

Bioaccumulation is the increase in concentration of a substance in living organisms as they take in contaminated air, water, or food.

As bigger animals eat smaller animals, the level of contamination in the food is added to the level of contamination already in their body.

Bioaccumulation is a problem in the north because of higher concentrations of toxic pollution.

Also, northern animals have a lot of fat to keep them warm, toxins accumulate mostly in fat

Bioaccumulation: increase in concentration of a pollutant from the

environment to the first organism in a food chain

Biomagnification: increase in concentration of a pollutant from one

link in a food chain to another

We are concerned about these phenomena because together they

mean that even small concentrations of chemicals in the environment

can find their way into organisms in high enough dosages to cause

problems. In order for biomagnification to occur, the pollutant must

be:

- Long-lived

- Mobile

- Soluble in fats

- Biologically active

If a pollutant is short-lived, it will be broken down before it can become dangerous. If it is not mobile, it will stay in one place and is unlikely to be taken up by organisms. If the pollutant is soluble in water it will be excreted by the organism. Pollutants that dissolve in fats, however, may be retained for a long time. It is traditional to measure the amount of pollutants in fatty tissues of organisms such as fish. In mammals, we often test the milk produced by females, since the milk has a lot of fat in it and because the very young are often more susceptible to damage from toxins (poisons). If a pollutant is not active biologically, it may biomagnify, but we really don't worry about it much, since it probably won't cause any problems.

Biomagnification (see diagram above) is the increase in pesticide as you move up a food chain. If the organism at the bottom has small amounts of pesticide, the predator that eats 100 of these will get 100 times the amount of pesticide in the individual organisms. The same will happen to the next predator so that the final consumer (often humans) will have huge amounts of pesticide.

A way of preventing bioaccumulation and biomagnification is to have pesticides that degrade and so they will not get stored in organisms.

DDT stands for dichloro, diphenyl trichloroethane. It is a chlorinated hydrocarbon, a class of chemicals which often fit the characteristics necessary for biomagnification. DDT has a half-life of 15 years, which means if you use 100 kg of DDT, it will break down as follows:

Year Amount Remaining

0 100 kg

15 50 kg

30 25 kg

45 12.5 kg

60 6.25 kg

75 3.13 kg

90 1.56 kg

105 0.78 kg

120 0.39 kg

If it does bioaccumulate and biomagnify, much of the DDT will be in the bodies of organisms. DDT actually has rather low toxicity to humans (but high toxicity to insects, hence its use as an insecticide).

Because it could be safely handled by humans, it was extensively used shortly after its discovery just before WW II. During the war, it was used to reduce mosquito populations and thus control malaria in areas where US troops were fighting (particularly in the tropics). It was also used on civilian populations in Europe, to prevent the spread of lice and the diseases they carried. Refugee populations and those living in destroyed cities would have otherwise faced epidemics of louse-born diseases.

After the war, DDT became popular not only to protect humans from insect-borne diseases, but to protect crops as well. As the first of the modern pesticides, it was overused, and soon led to the discovery of the phenomena of insect resistance to pesticides, bioaccumulation, and biomagnification.

The levels of DDT in tissues of various animals in the sound showed bioaccumulation factors of 800x, and biomagnification factors up to 31 times. When we look at the whole food chain, the overall magnification is over 200,000x!

Most prominent is the phenomenon of shell-thinning in birds, particularly carnivorous birds (raptors) - birds that eat other birds, birds that eat carrion (dead animals), and birds that eat fish.

Recently, some studies have shown effects on sex ratios in some species of birds, with the males becoming "feminized", presumably the result of compounds in the environment mimicing the female hormone estrogen.

Biotransformation is the process whereby a substance is

changed from one chemical to another (transformed) by a

chemical reaction within the body.

Toxicants that are lipophilic ('lipid-loving', dissolve easily in

lipids), non-polar, and of low molecular weight are readily

absorbed through the cell membranes of the skin,

gastrointestinal (GI) tract, and lung.

Lipophilic toxicants are hard for the body to eliminate and

can accumulate to hazardous levels. However, most

lipophilic toxicants can be transformed into hydrophilic

('water-loving', dissolve easily in water) metabolites that

are less likely to pass through membranes of critical cells.

The biotransformation process is not perfect. When biotransformation results in metabolites of lower toxicity, the process is known as detoxification.

In many cases, however, the metabolites are more toxic than the parent substance. This is known as bioactivation. Occasionally, biotransformation can produce an unusually reactive metabolite that may interact with cellular macromolecules (e.g., DNA). This can lead to very serious health effects, for example, cancer or birth defects. An example is the biotransformation of vinyl chloride to vinyl chloride epoxide, which covalently binds to DNA and RNA, a step leading to cancer of the liver.

Phase I biotransformation reactions are simple reactions as compared to Phase II reactions. In Phase I reactions, a small polar group (containing both positive and negative charges) is either exposed on the toxicant or added to the toxicant. The three main Phase I reactions are oxidation, reduction, and hydrolysis.

alcohol dehydrogenation

aldehyde dehydrogenation

alkyl/acyclic hydroxylation

aromatic hydroxylation

deamination

desulfuration

N-dealkylation

N-hydroxylation

N-oxidation

O-dealkylation

sulphoxidation

ALCOHOL DEHYDROGENATION

Aliphatic compounds are not readily oxidized or

metabolized unless there is an aromatic side

chain. For aromatic substituted compounds

initially get 10 & 20 alcohols:

The replacement of sulfur by oxygen results in

the activation of a number of insecticides, such

as Parathion, below, where the Paraoxon product

is the more active substance

Alkyl groups are hydroxylated adjacent to nitrogen

and rearrange to release an aldehyde as shown

below for the dealkylation of N,N-dimethyl-p-

nitrophenylcarbamate:

For sulfur compounds such as sulfides, thiols,

thioethers (shown), etc. get a common pattern

of oxidation to the sulfoxide and then further

oxidation to the sulfone

Alkyl groups are hydroxylated adjacent to

oxygen and rearrange to release an aldehyde

as shown below for the dealkylation of p-

Nitroanisole

azo reduction

dehalogenation

disulfide reduction

nitro reduction

N-oxide reduction

sulfoxide reduction

Esters and amides are commonly hydrolyzed:

An example is the hydrolysis of the anesthetic, procaine is

rapidly hydrolized by esterases in the plasma and by tissue

microsomal esterases:

The analogous amide, procainamide, is hydrolyzed more

slowly by amidases in the microsomal fraction of tissue. It is

not hydrolyzed at all in the plasma.

Toxicants that have undergone Phase I

biotransformation are converted to

metabolites that are sufficiently ionized, or

hydrophilic, to be either eliminated from the

body without further biotransformation or

converted to an intermediate metabolite

that is ready for Phase II biotransformation.

The intermediates from Phase I

transformations may be pharmacologically

more effective and in many cases more toxic

than the parent xenobiotic.

A xenobiotic that has undergone a Phase I

reaction is now a new intermediate

metabolite that contains a reactive chemical

group, e.g., hydroxyl (-OH), amino (-NH2),

and carboxyl (-COOH).

Many of these intermediate metabolites do

not possess sufficient hydrophilicity to

permit elimination from the body. These

metabolites must undergo additional

biotransformation as a Phase II reaction.

Phase II reactions are conjugation reactions, that is, a

molecule normally present in the body is added to the

reactive site of the Phase I metabolite. The result is a

conjugated metabolite that is more water-soluble than the

original xenobiotic or Phase I metabolite. Usually the Phase II

metabolite is quite hydrophilic and can be readily eliminated

from the body. The primary Phase II reactions are:

Glucuronide conjugation - most important reaction

Sulfate conjugation - important reaction

Acetylation

Amino acid conjugation

Glutathione conjugation

Methylation

Glucuronide conjugation is one of the most important and common Phase II reactions. Glucuronide conjugation usually decreases toxicity, although there are some notable exceptions, for example, the production of carcinogenic substances. The glucuronide conjugates are generally quite hydrophilic and are excreted by the kidney or bile, depending on the size of the conjugate.

Sulfate conjugation is another important Phase II reaction that occurs with many xenobiotics. In general, sulfation decreases the toxicity of xenobiotics. Unlike glucuronic acid conjugates that are often eliminated in the bile, the highly polar sulfate conjugates are readily secreted in the urine. In general, sulfation is a low-capacity pathway for xenobiotic conjugation. Often glucuronidation or sulfation can conjugate the same xenobiotics.

Biotransforming enzymes are widely distributed

throughout the body. However, the liver is the

primary biotransforming organ due to its large size

and high concentration of biotransforming enzymes.

The kidneys and lungs are next with 10-30% of the

liver's capacity.

A low capacity exists in the skin, intestines, testes,

and placenta.

Since the liver is the primary site for

biotransformation, it is also potentially quite

vulnerable to the toxic action of a xenobiotic that

is activated to a more toxic compound.

The relative effectiveness of biotransformation depends on several factors, including species, age, gender, genetic variability, nutrition, disease, exposure to other chemicals that can inhibit or induce enzymes, and dose levels.

Differences in species capability to biotransform specific chemicals are well known. Such differences are normally the basis for selective toxicity, used to develop chemicals effective as pesticides but relatively safe in humans.

For example, malathion in mammals is biotransformed by hydrolysis to relatively safe metabolites, but in insects, it is oxidized to malaoxon, which is lethal to insects.

Lungs can detoxify by removing gases (gas anesthetics are removed from the body by the lungs).

Skin can detoxify by reducing the penetration of toxic substances (toxins in water don't get in through the skin well; however, toxins in oils do penetrate easily).

Digestive System can detoxify by eliminating toxic foods, by either vomiting or diarrhea.

Kidneys detoxify by secreting toxins or filtering toxins out of the blood into urine.

Liver detoxifies by changing the chemical nature of many toxins.

1. Lungs - remove toxic gases and volatile

chemicals that can be breathed out of the body.

An example is the chemical, acetaldehyde,

which is created when the liver destroys alcohol.

Acetaldehyde is what you smell on the breath of

a person who has drunk a lot of alcohol. This gas

would be lethal if it were not removed from the

blood by way of the lungs.

Gas anesthetics are eliminated from the body

mostly by way of the lungs

2. Skin - some toxins can dissolve in sweat and be

removed from the body that way.

It is a common belief that stimulating sweat

with intense exercise or heat will help clean the

body of toxins. But there is not much medical

evidence that this is practical. And, excess

sweating can cause loss of water, which may be

more hazardous than the toxins.

3. Gastro-intestinal System - toxins that are

taken in by eating or drinking can be

eliminated in the feces.

This is particularly true in the case of "food

poisoning," where the body defends itself by

vomiting and diarrhea in order to remove the

toxins quickly.

There are two very vital organ systems that

have a direct role in detoxication. In fact,

detoxication is the main reason we have these

systems. They are:

1. The liver

2. The kidneys

All substances that are absorbed in the digestive tract enter the veins that drain the gut and are carried in this venous blood to the liver.

Think of the liver as the gatekeeper between the intestines and the general blood circulation. This is one of the few cases where venous blood comes INTO an organ.

The liver detoxifies numerous toxins. It also destroys drugs, such as alcohol, nicotine, and prescription medicines, because these things are not normal to the body.

Some medicines have the bad side effect of damaging liver cells. It is like a war between liver cells and the medicine, because the liver is programmed to destroy foreign chemicals and cannot know that medicines are supposed to be good for the body nor know which medicines may damage the liver cells in the process of destroying the drug.

The liver takes two steps:

If we examine the liver under a microscope,

we see rows of liver cells with small spaces

in between that act as a filter to remove

dead cells, microorganisms, and chemicals as

the blood flows slowly through the liver.

This filter includes cells that engulf ("eat")

the sludge that is left trapped in the filter.

There are two phases of detoxification in the liver:

Phase one includes an enzyme, cytochrome p-450, to detoxify the bad stuff. This means that the harmful chemical gets broken down into smaller parts that are not harmful to the body.

Phase two detoxification is when the Kuppfer cells add materials to the chemical to be broken down, and this new chemical is not harmful to the body. This addition of materials to a harmful substance is called conjugation.

Once phases one and two have been performed, the sludge is ready to be added back to the regular blood stream and secreted as waste, and it never harms the body. We have a wonderful, life-saving detoxification plant.

The first place that blood from the stomach and intestines goes is to the liver. But then the blood leaving the liver goes to the heart and is pumped directly to the kidneys. Kidneys regulate the balance of water and salts in the body, but they also have a very important role in detoxication.

With about 200 quarts being pumped through the kidneys every day, they do a big job for such a small organ! The main job is to take all of the blood in the body and clean it. This means:

Filtering blood to hold back the cells

Reabsorbing much of the filtered water and certain chemicals

Actively secreting certain chemicals that do not get eliminated by the filtering

Each kidney contains about one million microscopic units, called GLOMERULI, which work together to clean the blood.

GF = glomerulus filtering.

TR = tubular reabsorption.

TS = tubular secretion

Reabsorbed sugar, sodium, vitamins, nutrients, water

Secreted hydrogen ion, potassium, ammonia, drugs,

toxins

Blood is filtered, giving up much of the water and dissolved substances it contains. Then, much of the water and some of the dissolved substances are reabsorbed into blood. Finally, some dissolved substances in blood are actually secreted into the urine.

Summary of Chemical Changes of Filtered Blood:

Chng III. c t sinh hc

La chat oc do sinh vat tao ra, ac biet la cac vi sinh vat gay benh, co tac dung khang viem bang cach tao ra khang

th

Bactogein: la loai oc to dang tinh the do mot loai vi sinh vat bacillus thuringienes trong qua trnh song san sinh ra,

co tac dung giet sau hai.

oc to nam (mycotoxin): la chat oc do nam tao ra, thng co trong thc pham.

oc to vi khuan (bacterotoxin): la chat oc dang protein do vi khuan tiet ra e chong lai cac chung vi khuan khac trong

qua trnh au tranh sinh ton cua chung.

c t sinh hc

Ngoai oc to: la nhng oc to (toxinelement) do sinh vat gay ra, nhn chung chung la cac oc to protein, kem

chu nhiet (ngoai tr oc to anh hng ng ruot cua

vi sinh vat staphylococcus).

Noi oc to: la nhng oc to do phan vat lieu cua thanh te bao vi sinh. oc to chu yeu do lipid gay ton thng

bach cau va gay sot cho c the. oc to trong c the sinh

vat hoac do sinh vat tiet ra trong qua trnh song thng

c hnh thanh do nhieu nguyen nhan. ay ch

nghien cu cac dang oc to t san sinh trong qua trnh

song, t ve cua sinh vat vi moi trng song, qua trnh

sinh ly cua c the sinh vat tiet ra.

OC TO ONG VAT

oc to do ong vat tiet ra c chia lam bon nhom oc

chnh: oc to co tnh acid cao, oc to co tnh kiem, oc to

co ham lng vitamin cao, oc to protein oc.

Nha cc

Chat oc tap trung nhieu hai ben mat gom co: bufogin,

bufotagin, bufotoxin, bufotenin,

bufotionin.

Bufotoxin la mot chat dang tinh the, khong tan trong nc, este,

axeton, t tan trong ru, tan

trong pyridin, methyl.

Tht coc khong oc tham ch rat bo dng nhng da coc va toan

bo gan, ruot, trng eu rat oc,

gay ngo oc cho ngi an.

Coc oc cane toad

Tuyen tiet nha oc nam trong

nhng vet san sui tren da coc,

chu yeu la bufotoxin co tac dung

tren tim, lam tim ap cham lai va

ngng han.

Nha coc dnh vao da gay rop

da, l loet; neu e nha coc dnh

vao mat, mat se b sng au va

b ton thng, gay mu. Nguy

hiem hn la oi vi ban tay b

xay xat, thng ton, nha coc

dnh vao khien chat oc se i

thang vao trong mau, nguy hiem

kho lng va rat nhanh.

Coc ma

Cc ta Bombina maxima

Nc rn

Tren the gii hien nay con ton tai khoang 2700 loai

ran, trong o 15% la loai co noc oc, tap trung

vung nhiet i.

Viet Nam co khoang tren 100 loai, trong o 18 loai

ran oc song tren can va 13 loai ran oc song di

nc.

c tnh

- Nhng chat oc chnh cua noc rn gom co hai loai:

Chat oc vi he than kinh hay neurotoxin, theo Calmette (2000), chung huy hoai cac chc nang cua trung tam ho

hap va dan en cai chet do ngng ho hap. Con theo

Arthrus (1998) th, ngc lai, chat oc nay tac ong len

cac au mut c cua cac than kinh van ong va lam tang bo

nhay cam, no giet cac c ho hap bi s lam liet ngoai vi

ch khong phai bi liet trung khu.

Chat oc cua mau hay hemorrhazin, no lam ong, lam tan ra mau va pha huy cac thanh mach mau; ngoai ra, no

con tao ra nhng roi loan do viem tai cho.

Chat crotalotoxin (C34

H54

O21

)

co trong noc ran crotalus

adamanteus.

Chat ophiotoxin hay cobratoxin (C

17H

26O

10) la chat oc cua ran

ho mang naja tripudians, mau

trang hay vang nhat, tan trong

nc.

Ngoai ra, con co dang oc to ankaloid goi la monocrotalin

(C16

H23

O6N).

c ca nc rn

o oc cua ran luc Vipera ch bang 1/20 o oc cua noc ran ho mang.

o nhay cua tng loai ong vat khac nhau oi vi noc ran khong ty le vi trong lng cua chung. Theo Calmette (1908), 1 gram

noc ran ho giet chet 1250kg cho, 1400kg chuot, 2000kg tho

rng, 2500kg chuot cobay, 833kg chuot nhat, 20000kg nga.

Neu tng ng vi ngi cho la trung gian gia cho va nga,

Calmette chap nhan la 1 gam noc kho cua ran ho mang co the

lam chet 10000kg c the ngi hoac 166 167 ngi co trong lng trung bnh 60kg.

o oc cua noc cung thay oi cung mot loai ran oc, no nhay hn sau khi ran lot xac hoac sau khi nhn an keo dai.

S nghiem trong cua vet can d nhien ty le vi lng oc a truyen: mot con ran a can lien tiep nhieu lan se thai dan noc ra

va nhng vet can sau cung khong ang s.

Ran ho chua (ophiophagus gunther). - ac iem: than ln, dai tren 4m,

lng co mau vang luc hay nau, oi

khi co mau en ch hoac lng co

anh bac. Co kha nang banh co

ngang cao au ti 1,5m; co kha

nang phun noc.

- Phan bo: vung nhiet i am Viet

Nam, An o.

- Ni : ni am t quanh ho ao, bui

ram, trong hoc cay ln.

- Tap tnh: kiem an em; an ga, vt,

chuot hay cac loai ran khac.

- Gay hai: au, da b bam tm, ngat

th roi chet. Lieu gay chet: 12 mg

noc giet chet 1 ngi 50 - 60 kg.

Ran cap nia (bungarus candidus linne) - ac iem: ran ln, thng dai tren 1m, lng co nhng

khoang en hay nau xen ke vi nhng khoang trang, gia

song lng co hang vay hnh luc giac.

- Phan bo: khap ni.

- Ni : song trong hang bui ram quanh b ho, am,

song

- Thc an: an cac loai ran khac.

- Sinh san: e 6 - 10 trng/lan.

- Noc oc: crotalotoxin C34

H54

O21

; ophotoxin C17

H26

O10

;

monocrotalin C16

H23

O6N.

- Lam sang: khi b ran cap nia can luc au khong thay

au, thay te, cho can khong b sng, khong mau nhng tht

co giat, nhiem oc ti au co giat ti o, au bung roi ngat

th gay oc than kinh, xuat huyet va dan en t vong.

- Lieu gay chet: la loai ran oc nhat, 1,5 mg noc oc gay

chet ngi co trong lng 50 - 60 kg.

- Cach cu cha khi b ran can: rach vet can nan cho

chay mau, garo, dung huyet thanh.

Ran luc au en

(azemiops feae boulenger) - ac iem: ran oc nho, thng dai tren

0,5m, than mau en co vach ngang mau trang

hong, la loai ran hiem gap, cham chap.

- Phan bo: khap ni

- Ni : song trong nc, vung nui cao.

- Thc an: an cac loai thu nho, chuot,

chim - Sinh san: e 8 - 12 trng/lan, con me canh

gi cho ti khi n.

- Lam sang: khi b can thay au, pha huy

cac mo vet can xung quanh, huy hoai c tim,

than va phoi, gay oc mau la chu yeu.

- Lieu gay chet: 50 - 100 mg noc oc gay

chet ngi co trong lng 50 - 60 kg.

Gila monter

Gila monter loai than lan co oc duy nhat song trong sa mac tay

nam My, bac Mexico. No co cac

ranh nho trc rang mang noc

oc.

oc tnh

Tng ng noc ran. Nhiem oc

gay hai giong nh ran eo chuong

can.

Trieu chng

Buon non, sng tay vet thng,

xanh xao, ho hap kem, yeu dan.

ieu tr: giong nh ieu tr ran can.

oc to cua ong

Hach oc va ngoi ot co nhieu gai sac nhon nam pha sau cua bung ong. T ngoi ot co hai ranh thong vi hai tuyen khac nhau: mot

tuyen mang tnh acid va mot tuyen mang tnh kiem ro ret. Khi ch co

acid tiet vao ngoi ot th con vat b ong ot ch b te liet ch khong

nhc nhoi.

Nhng khi tan cong ke thu hung ac th noc cua ong gom dch tiet cua ca hai tuyen kiem va acid.

Noc ong la mot chat long sanh, khong mau, thanh phan hoa hoc rat phc tap, gom albumin, chat m, hp chat hu c phan t lng thap,

cac acid amine nh xystrine, lysine, arginine, glicocol, alanine,

methionine, acid nucleic, glutamic, treonine va chu yeu la Melitine.

Melitine ben vng trong moi trng acid manh vi nhiet o, nhng lai

tan trong kiem.

V vay, khi b ong chch, ngi ta boi voi vao giai oc. Melitine lam tan hong cau, co cac c trn, ha huyet ap, phong be mot oan than

kinh trung ng. Men hialurodinaza lam tan cac lien ket, tang lan

truyen noc. Men phot pholipaza phan huy texitin tao ra mot lisoxitin.

oc to cua ong Noc oc va mau sac s cua ong co moi lien quan vi nhau.

Ong co pheromone giong nh tn hieu cua ngi thoi ken lenh, co tac dung lam cho ca an vao t the san sang chien au.

vet ot, nhng con ong gian d con phun len mot chat co mui

chuoi. nh hng theo mui o, hang tram con ong khac lao

uoi theo nan nhan va ot them. Trong moi lieu noc ong co

cha khoang 10-6 gam isoamilaxetate u e trong vong 10

phut bao cho ca gia nh ong biet ni cua ten biet kch thu

ch. Mac du sau khi mat vu kh con ong se chet, khi nhan

c tn hieu bao ong, chung van voi va en cu tr.

Ong vo ve lai khac. Trc khi tan cong, chung phun len ke thu nhng giot noc oc co tron lan pheromone bao ong. Nhng

con ong cung an hung hang xong vao ot khong thng tiec

nan nhan.

Latrodetus Mactans

Song vung nhiet i, trong ong go, co,

nha hoang, bui ram.

Nguy hiem hn noc ran. Nhng khi tan

cong, no ch tiem vao mot lng rat t,

do o, no ch nguy hiem cho nhng tre

em di 15kg. Noc oc gay tac hai than

kinh.

au nhe, tai nht, cho can sng; sau o,

au vung ngc, bung, buon non, chay dai

va o mo hoi.

Bo cap

Song vung kho can, trong vn nha Brazin, chau Phi, Viet Nam.

Giong oc c goi la titytus bahiensis va T. serralatus. Nam

Phi, giong oc co ten androctonus

australis. Bo cap nc ta thng

thuoc chi buthiurus hay chi

heterometrus.

Anh hng len tim va he than kinh trung ng. Nga hi au. Neu

nang th co that co, bon chon, noi

gian, tang hoac ha huyet ap, loan

nhp tim. Trieu chng keo dai 24 -

48 gi, trieu chng than kinh co

the keo dai mot tuan.

Su bm ti Caterpiller l mt trong s

nhng loi nguy him nht. Cc u trng

sng bn trong mt chic ti mu nu, lm

bng la, chng chui ra vo ban m v

kim n trn nhng cy thn g.

Khi di chuyn gia cc loi cy, su bm

ti tr n i u n ui, to nn s di

chuyn c trng cho c h su bm ti.

Chng t v bng cch s dng nhng cht c.

Nhng ngi khng may mn chm vo

loi bm c th b chy mu c bn ngoi

cng nh trong ni tng bi l trong cht

c ca chng c cha mt cht chng ng

mu cc mnh. Nhng con su bm bo

v mnh bi tuyn nc c nm trn lng

ca chng. Mt ngi trng thnh c th

d dng b chy mu n cht nu b nh hng bi cht c ca chng.

Saddleback

Cc gai cng ca Su bm Saddleback c

t trong tuyn nc c cc mnh.

Nn nhn s b au nhi khi chm vo, vng b

nh hng lp tc sng to bun nn v pht ban

nng kh chu tuy nhin li rt kh pht hin.

i khi phi n c ngy tm ra nguyn nhn.

Nhng con su nguy him ny rt thch cy rm

bt v cy c.

Puss

Su bm Puss hoc sn len l su bm c nht M.

N s tit acid vi bt k k no tn cng n

bng nhng gai c trn c th, nhng cht

ny gy ra phn ng ha hc cc mnh vi da ngi.

Nhng con su bm Puss rt d b nhm ln

vi bng gn cho nn nhng ngi khng tinh s rt d b trng c.

Theo nghin cu, loi su ng s ny rt

thch nhng cy h cam qut, cy du, cy si v cc loi cy vn khc

Cinnibar

Su bm Cinnibar tit ra mt ha cht c v ng v chng s dng c v ngoi sc s c th phng nga bi nhng k sn mi. Chng c bao ph bi nhng si lng ngn c cha cht c gy kch ng khi tip xc vi da.

Cht c trong si lng c th dn n cc vn sc khe nghim trng ngi mc d thng thng ch gy pht ban.

Singing Rose

Nhng con su bm Singing Rose l mt trong nhng sinh vt c mu sc hp dn nht.

Cp sng di, c nhiu lng c t dc c th cng vi h thng cc gai nh l c th ca

loi su ny. Mc d cm gic ban u khi chm

phi chng l kh au n nhng mc nguy hi th khng phi qu ln.

Chng c th c tm thy trong qu to, si, h cy sung, cy th du v trn c bi hoa hng

Spiny Oak Slug

Cht c tuyn gai dc theo pha

sau v hai bn c kt ni vi cc

tuyn cht c.

Nn nhn au n khi b ng c.

Su bm Spiny Oak Slug sinh sng

trong g si v cy liu

Moth Bac M

Trong qu trnh sinh trng mu da ca n s chuyn t mu da cam sang mu xanh ti.

Nn nhn b ng c bi nhng si lng trn lng n do tit ra mt loi cht c

gy au n.

Su bm Moth sinh sng trn hoa hng

Hickory Tussock

Su bm Hickory hp th ha cht

t v t chnh nhng loi cy m

n n cht c sau cht c s

c tit ra t cc gai lng trn c th

ca n.

Ngay khi tip xc vi da ngi, chng

s gy ra cm gic nga v au n.

Nga v pht ban c th ko di n

vi ngy

Gypsy Moth

Nhng con su bm Gypsy Moth l loi c lng di vi mu sc sc s.

Mc d khng c thc s b coi l mt trong nhng loi c mnh

nht ca cc loi su nhng nhng

si lng ca chng vn c th gy

au n khi tip xc v dn n vim da nhng ngi nhy cm.

ong vat nhuyen the vo cng

Trai, so co the phat sinh oc to trong nhng thang nong

hoac trong mot moi trng ac biet.

oc to: dang hp chat N, tng t nh nha oc cura,

gay te c bap; t xay ra t vong.

Gay oc: gay te liet ho hap, nga moi, li, mat va mui.

Ca noc (tetrodon ocellatus)

- ac iem: than ngan, vay kem phat trien, rang bam vi nhau

thanh tam; ac biet, bung phnh to va nga bung len tri khi t ve.

Trong 60 loai co 30 loai co noc oc.

- Phan bo: vung bien nhiet i nh Viet Nam.

- oc to: tetrodotoxin, ciguatoxin tan trong chat beo; ciguaterin tan

trong nc va aminopehydroquinazolin (C11

H17

N3O

8). Nhng oc to

nay tap trung trong gan, ruot va c bung. ac biet tnh oc tang cao

trong mua e trng.

- Gay oc: len than kinh trung ng, gay te liet c the, ngng tre

tuan hoan va ho hap. Ngo oc do an ca xuat hien sau 2 - 24 gi. Nan

nhan te moi, te li, non ma, hon me. Ty le chet 60% sau 1 - 24 gi.

- Lieu gay chet: 4 mg/1kg c the.

- Cu cha: uong nc da.

T. Ocellatus (ca noc thu)

Ham lng oc to rat cao (700750g/gam)

T. Stellatus (ca noc mu)

Loai nay con non va con trng thanh khac nhau ro ret ve mau sac. Con trng thanh bung khong co om va tren toan

than day ac nhng iem en nho. ca con non va con

trng thanh toan than ay nhng vay nho. Vay lng co t

1112 vach mem, vay bung co 11 vach, than dai ti 5060cm.

Ham lng oc to rat cao (600650g/gam)

Lagocephalus Lunaris (ca noc gao)

Loai ca nay co nhng vay nho trai tren pham vi rong, au

mut tren va di cua vay uoi trang, than dai ti 3538cm, vay lng co 14 vach mem, vay bung co 1213 vach mem.

Ham lng oc to rat cao (600650g/gam)

T.Hispidus (ca noc vay hoa vang)

Cac om cua con non va con trng thanh hoan toan khac

nhau. Con non bung co nhieu song. Con trng thanh th bung

trang nh, con cac phan khac cua con non va con trng thanh

hoan toan giong nhau. Vay lng co 1011 vach mem vay bung co 1011 vach mem. Than dai ti 4850cm.

Ham lng oc to kha cao (300400g/gam).

Tetraodon patoca (ca noc mt)

ac iem cua loai ca nay

la lo mui co hnh ac biet.

Vay lng co 10 vach mem,

vay bung co 8 vach, than ca

dai ti 2022cm.

Ham lng oc to khong

cao (130 50g/gam), tap trung trong gan va trng.

T.Xanthopterrus (ca noc vang)

Loai ca nay co nhng ng soc trang tren nen xanh am, tat ca vay de nhan ra bi mau vang. lng va bung

co nhng vay nho mat o day. Vay lng co 1618 vach mem, vay bung co 1416 vach, than ca dai ti 100cm. Nong o c t khong cao (5075g/gam)

T. Oblungus (ca noc vang)

Khong co vay, ngoai da co ng rat manh. Da bung

nheo, vay lng co 9 vach mem, vay bung co 9 vach

mem, than dai ti 3840cm.

Loai ca nay t oc.

T. Lunaris (ca noc tro)

au mut tren va di uoi vay trang. Vay lng co t 1214 vach mem, vay bung co t 913 vach mem, than ca dai 3040cm, loai ca nay khong oc.

Dioden Halocanthus (ca noc nhm)

Than cua loai ca nay co nhng vay dai lng. Mot ac iem na la ham tren va ham di ch co mot rang.

Vay lng co 12 vach mem, vay bung co 12 vach mem.

Loai ca nay co the phnh bung nh qua bong. Loai ca

nay khong oc.

c t thc vt

- Alkaloid: oc to cha N, nh trong cay thuoc la, nam oc.

- Glucoside: San pham ket hp gia ng va goc OH. V du

nh chat ginosit trong cay bach qua (ginkgo bibola) va trong hat

hanh nhan ang (prunus armeniaca ansu).

- Saponin: trong mam xanh khoai tay, mot hp chat phc tap,

khi hoa tan trong nc noi bot trang.

- Protein oc: nh rilin trong hat thau dau.

- Crotein trong hat ba au (cron tiglium)

- Cac chat oc co the ch phan bo trong mot vai bo phan hay

ca toan cay; ngay trong mot bo phan lai phan bo khac nhau, co

the nhieu trong la hoac re hay canh. Ngay re co the nhieu

chop re, la co the la gia, trong mot la, co the, ch tap trung

chop la. Tuy nhien, trong hoa th t gap chat oc hn.

Day cam thao (aburus precatorius)

Ho Canh bm (papilonacae), day leo,

canh nho, than cha nhieu x, la xep

hnh long chim; hoa mau hong.

Trong hat cha chat protein oc goi la

abrin (C12

H14

N2O

2), kem oc hn rixin

trong hat thau dau va abralin

(C13

H14

O7) la mot chat dang tinh the.

Kim anh (rosalaevigata mich)

Thuoc ho hoa hong (rosacae), cay dai 10m, ng knh

than 2cm.

Than va canh co gai hng pha mat at.

Trong hat cha oc chat glucoside, 17,12% saupunozit

co tac dung manh len tuy song, than kinh va tim mach.

Mu u (calophyllum inophyllum)

Moc hoang, cung c trong cac tnh Quang Ninh,

Quang Bnh, Vnh Long, Bnh Dng.

Trong vo, vo cay, re cha nhieu oc chat xyanhydric va

saponin.

Cay cu au (cu san)

Ten khoa hoc: pachryrhizus erosces L, thuoc ho canh bm (papilionaceae).

Thanh phan hoa hoc: hoat chat tap trung gan cu trong hat, la.

Loai chat oc: Loai alkaloid co ten rotenon (C23

H22

O6),

tephrosin (C23

H22

O7) va pachyrhizon (C

20H

14O

7). Ty le rotenon trong

hat 0,56 - 1,01%. La oc vi cac loai nhai lai nhng khong oc vi

nga.

Lam sang: buon non, choang vang, te toan than, co the chet.

Thc te a co ngi an nham phan do toi (phan cng pha tren

cu), gay ngo oc. La oc vi ca va loai nhai lai. Hat oc vi sau va

ca.

Nhiet o nong chay phan huy cac chat nay t 232oC - 240

oC. Ty

le rotein trong hat 0,56 1,01%.

Cay la ngon (gelsenium gams benth)

Ho ma tien (loganiaceae), moc hoang rat nhieu vung nui pha Bac va Bac Trung Bo, vung rng Anh Sn, Ngha an, Con

Cuong (Nghe An).

V ang.

Cay la ngon (gelsenium gams benth)

Trong cay cha chat gelsemin (C20

H22

O2N

2) co oc tnh rat

manh, con kumin (C22

H22

ON2) khong oc lam. Ngoai ra,

no con cha mot so alkaloid khac nh kaumide

(C22

H24

O5N

2), cominin lam yeu c, c che ho hap.

Them vao o con co oc chat semoecvirin va sempecvin

co oc tnh rat manh. Nhieu hien tng i rng an nham

phai ch vai la ngon hay ai o muon t t ch can nhai va la

la cac chet en tc th...

Cay sui (antiraris toxicaria cesch)

Moc hoang nhieu mien nui Viet Nam, Trung Quoc,

Malaysia, An o. Ngi ta thng lay nha cay tam ten

san thu rng.

Trong nha ay cha chat oc lucozit la anfa antiarin va

beta antiarin, tac ong manh len tim. Anfa antiarin

(C29

H42

On4H

2O) la chat bot, phan ng trung tnh, tan

mot phan trong nc (27%), nhiet o 100oC, tan 70%

trong ru, nhiet o 85oC.

Thuoc la (nicotinia tabacumlin)

Mac du thuoc la la mot chat oc nhng the gii hien nay

van trong thuoc la la chu yeu e hut, lam thuoc th sau,

lam thuoc tr benh. Hoat chat chu yeu cua thuoc la la

nicotine, ham lng cha t 2%-10%.

Ben canh nicotine con co nornicitin, anabasin la ong

phan nicotin, ngoai ra con co nicotenlin, nicotilin,

myosmin. Ngi ln chet khi c the hap thu 15 - 20g

nicotine; tre con ch can vai gam cung chet bi v no lam

tang benh tim mach, ung th... Nha cua thuoc la boi len

da chuot gay ung th da.

Cay thuoc phien

(papaver somniferum)

ay thuoc loai oc chat gay nghien gay ao giac, lieu cao

co the gay ot t. Co cha acid meconic, acid tactric,

acid xitric, mocphin, nacotin papaverin

Trong qua chn cha alkaloid, lng morphine 0,5%;

nacotin = 0,018%, codein = 0,028%.

Thau dau (ricius communis)

Con goi la u u ta, thuoc ho thau dau (euphordiaceae). Thanh phan cua thau dau co

cac glyceride chung nh: stearin, panmitin,

rixinolein, acid rixinoleic (la mot acid co cong

thc CH3-(CH

2)

5-CH-CH

2-CH-(CH

2)

2-COOH).

Acid nay thuy phan manh. Chat rixin t le 3 -5

% trong hat la mot protein oc. Co the chiet

xuat rixin bang cach ngam nc muoi roi cho

ket tua bang amonsunphat; rixin khong tan

trong dau.

Theo Vallete va Salvanet (1936), tac dung tay cua thau dau la do acid rixinoleic c giai

phong trong ruot non. Chat rixin rat oc, lieu t

0,002mg se gay ra chet tho nang 1kg. Rixin b

nhiet o cao huy 115oC trong vong 1,5h.

Tnh oc: 3 gram kho dau giet chet con bo nang 100kg; ch tiem 0,03 mg vao cho, chet ngay.

Ca oc dc (datura melel)

Chat oc chu yeu trong cay nay la alkaloid. Ty le alkaloid

thay oi tuy theo bo phan va thi ky sinh trng cua cay,

trong la cha 0,1 - 0,5%, re cha 0,6 - 0,7%, hat t 0,1 -

0,5%, qua cha 0,12%, hoa t 0,25% - 0,6%. La, hoa, hat,

re co chat hyoxin hay scopolamin (C17

H21

NO4), ngoai ra

con co hyoxyamin va atropin (C17

H21

NO3).

Atropin lam c vong mat dan ra, gay dan ong t, nhan

cau dep lai, ap lc mat tang len, lam cho qua trnh tiet

nc bot, mo hoi, dch v, dch ruot dng lai. Lieu oc

atropin tac ong len nao lam say, ien, ho hap tang, sot, te

liet ...

Trong hoa ca co chat gay me scopolamin co hoat tnh sinh

ly cao tac ong len than kinh con ngi. au day than kinh

b chat scopolamin chiem gi, lam cho hoat ong dan

truyen be mat b c che.

Cay nap am

c t do nm mc tit ra

Nam moc la mot t ghep e ch nam noi chung. Nam moc

oc la nhng loai nam moc ban than no mang oc tnh do

tch luy hay do bien dng c the.

oc chat sinh ra t nam la micotoxin co trong thc an cua

con ngi va suc vat. Ngoai ra trong nam con cha:

alkaloid, tricotexin, alkatoxin. Co hai loai nam gay oc

nhat la: amanita muscaria va amanita palloides.

Nam amanita

Con co ten la nam bat moi, tan mau vang tham hoac o ti, nh co

cham trang hay vang rat ep. Nam nay

cha chat muscarin rat oc, lieu gay

chet ngi la 50mg, ngo oc thng

xay ra vai phut ti vai gi sau khi an.

Nam amanita muscaria cha atropine alkaloid va mot so chat khac co the gay

me, co giat va gay ao giac. Mot so loai

nam co cha alkaloid muscarine gay

anh hng nh kch thch ong giao

cam tren da va mach. Nhiem oc man

tnh thng khong xay ra.

Nam amanita palloides

Thng thay loai nam mau nau uc, rat thng gap va ngo oc xay ra sau mot thi

gian 5 - 15gi bang cac hoi chng: viem da

day, ruot rat au n, mat the dch kem

theo cac bieu hien cua cac thng ton noi

tang, gluco huyet giam thap.

Nam amanita phalloides cha polypeptides amanitin bien oi than nhiet va phalloidin

gay nguy hiem en te bao va c the. Gan,

than, nao bo va tim eu b anh hng.

Nhng loai nam khac nh loai nam

amanita cung nh gelerina co the gay

nhiem oc nhe. oc chat chu yeu gay anh

hng en mo te bao ngi va ong vat.

gelerina.

amanita phalloides amanita verna

amanita esculenta

Trieu chng ngo oc

Bieu hien chnh cua nhiem oc la non ma, kho th va

gay vang da.

Trieu chng khi an vao:

- Amanitin (amatoxin) (amanita phalloides, amanita verna,

amanita visora, amanita esculenta va loai gelerina) - sau

khi ngam va gay buon non d doi va non ma ra mau va

phan, au n yeu dan; gay to gan, vang da, yeu phoi, au

au, lang tr va suy nhc; co dau hieu chan thng nao,

hon me hay te liet. Ty le t vong khoang 50%. o trong 6 -

24 gi,

- Nam gyromitrin (monomethylhydrazine) (gyromitra va helvella) gay non ma, te liet, hon me, xuat huyet. Ty le t vong khoang 15 - 40%.

- Nam muscarine (inocybe va clitocybe)- non ma, teo tim, giam huyet ap, chay nc dai, co that con ngi, co that cuong phoi, chay nc mat. S loan

nhp tim co the xay ra. Ty le t vong khoang 5%.

- Nam antichonilergic (amanita muscaria, amanita pantherina, amanita cokeri, amanita crenulata va loai amanita solitaria). Trng hp nay gay rat

nhieu trieu chng khac nhau sau khi an vao bung 1-2 gi; bao gom: ong

kinh, me sang, chay nc dai, th kho khe, non ma, tieu chay, cham nhp

tim, m rong hay thu hep con ngi, rung c. Cac trng hp t vong thng

hiem xay ra.

- Loai kch thch ng ruot (boletus, cantharellus, clitocybe, clorophyllum, hebeloma, lactarius, lepiota, naematoloma, rhodophylus, russula va

tricholoma) gay buon non, non ma, tieu chay, loan nhp tim va gay kho chu

keo dai en 1 tuan. Cac trng hp t vong t khi xay ra.

- Nam disulfiram (coprinus)- gay non ma, tieu chay, loan nhp tim va tang nong o con trong nhieu ngay. Cac trng hp t vong hiem khi xay ra.

- Loai gay ao giac (psilicybe va panaeolus) dan ong t, mat ieu hoa, yeu dan, mat phng hng, au bung, sot, co giat. Cac trng hp t vong hiem

khi xay ra.

Phong chong: hau het cac loai nam dai thng rat nguy

hiem nen cach tot nhat la tranh dung.

ieu tr: loai bo thc an trong da day bang cach gay

non, tr nhng benh nhan a non roi. Sau khi non, dung

than hoat tnh 70% tinh chat e loai bo nhng chat oc

khong hap thu.

Nam aspergillus flavus va parasiticus

La nhng nam oc gay oc to ung th nh : aflatoxins.

Dang nam moc nay phat trien nhiet o 7,5 40oC, khi phat trien 3 ngay chung co the phat tan nhanh oc to bao

t khap ni trong gao, au phong, bap, lua m, thc an

gia suc...

Trong vang si nam hoac pha ngoai cac san pham trao

oi chat khac nhau cua si nam, cha cac chat: acid oxilic,

acid xitric. Cac chat oc hai oi vi cac vi sinh vat khac,

cac chat khang sinh... Khi b nam moc tan cong, mam hat

giong de b h do oc to nam gay ra. Ngoai ra, nam moc

con phan huy tao ra cac protein la, gay d ng...

aspergillu

s

parasiticu

s aspergillus

flavus

c t vi sinh vt

Viem ai trang do vi khuan

Nguyen nhan la do cac loai shiga, flexner, salmonella,

Escherichia (E.coli), tu cau, lien cau va mot so loai vi

khuan khac.

Cac vi khuan co trong ai trang co tac dung len men,

a en snh hi va cac acid hu c va lam thoi ra, tao

nen amonia, phenol, indol,...

Lien cau khuan

Gay ra benh thap khp cap (bouillaud), benh pho bien nc ta.

Lien cau khuan tiet ra oc to streptolysin, streptokinaza, streptodornaza...,

S phoi hp oc to lien cau vi cac thanh phan trong mau, lam xuat hien khang the ac hieu ma phan ng la nguyen nhan cua s viem

nhiem tim, khp.

Rieng oi vi van tim, do trong cau truc co mot phan tng t mot khang nguyen lien cau; v vay, khang the streptolysin khi phan

ng vi lien cau khuan cung phan ng vi van tim, gay nen nhng

ton thng ngay cang nang, ke ca sau nay khi khong con nhiem lien

cau khuan na.

Trieu chng:

Sot 38 - 40oC sau 2 tuan viem hong, mach nhanh, c the met moi, gay, xanh xao, bieng an, chay mau cam; loan nhp tim; viem khp:

cac khp au, sng o.

Vi khuan thng han

Salmonella gay benh thng han va salmonella para A va

B gay benh pho thng han. ay la nhng trc khuan co

long, di ong, gram am, co khang nguyen long, than,

dung vao viec chuan oan huyet thanh vidal va felix va

khang nguyen e phat hien ngi ang nhiem khuan.

Vi khuan xam nhap vao, sinh san ruot, lam sot keo dai,

li b, roi loan tieu hoa va tieng tim m. Lay qua ng

ruot, gian tiep qua nc hoac thc an nhiem khuan va co

the lay t ngi nhiem benh. Trc khuan theo phan ra

ngoai va ton tai rat lau.

Vi khuan clostridium botulinum

La mot dang trc khuan k kh, sinh san bang bao t

phat trien tot nhiet o t 34 50oC, co at, nc, nhat la thc pham co o acid thap.

oc to la nhng protein co phan t lng ln, thuoc

vao loai oc to manh nhat. Ch can 28,3 gram co the

giet 200 trieu ngi, nhng, oc to nay de b phan

hy khi nhiet o cao, no se b phan huy sau khi un

soi.

Vi khuan staphylococcus aureus

La loai cau khuan hieu kh, thng ky sinh tren da,

khoang mui, toc ngi. Khi xam nhap vao thc pham tao

ra oc to protein co phan t lng thap, goi la oc to

ng ruot, gay non ma, tieu chay. oc to nay chu

nhiet, un soi khong pha huy, nan nhan khong chet

nhng rat au n do cac phan ng cc ky d doi.

Vi khuan vibrio cholerae

Gay dch benh rong ln, la mot vi sinh dang trc khuan

hnh dau phay, chung thng phat trien tot tren moi

trng kiem tnh va chuyen ong linh hoat bang long

roi; san sinh ra oc to ruot va noi oc to trong ng tieu

hoa, kch thch nghiem trong mang nhay va lam suy yeu

bm natri cua te bao ong vat, gay benh tieu chay.

Vi khuan vibrio parahaemolicus

La sinh vat a man, phat trien trong moi trng co o

muoi t 4 - 8%o, nhiet o chu ng t 15oC - 40

oC,

vi pH t 5 - 9,6. Vi sinh vat oc to co kha nang gay

tan huyet mau ngi.

Thng gap chung trong cac loai nhuyen the, giap xac

bien va ca moi trng nc ngot.

Dch benh manh vao mua he khi nhiet o am hn gay

ra cac benh au bung, non, tieu chay, au au ....

CHNG IV. CHT C HA HC

THUC DIT C

Chat oc da cam (agent orange): la hon hp cua 50% n butyleste cua 2,4 dichlorophenoxy axetic acid (2,4D) va 50% nbutyleste cua 2,4,5 trichlorophenoxy axetic (2,4,5T).

Chat oc o ta (agent purple): la hon hp 50% nbutyleste cua 2,4D, 30% nbutyleste cua 2,4,5T va 20% isobutyleste cua 2,4,5T

Chat oc xanh lam (agent blue): la cac acid cacodylic

Chat trang (agent white, tordon 101): la cac muoi triisopropanolamin cua 2,4D va picloram.

OC CHAT DUNG MOI

Tat ca cac dung moi hu c eu co mot ac tnh chung

la nhanh chong hap thu trong phoi va khi b nhiem cac

oc chat dung moi th chung lam can tr qua trnh trao

oi chat cua c the.

Co nhieu loai dung moi hu c gay oc cap tnh va

man tnh cho ngi va ong vat khi tiep xuc trc tiep

vi chung.

BENZENE

Benzene la mot loai dung moi hoa tan c rat nhieu chat

nh m, cao su, vecni, da, si, vai, len Trong cong nghiep hoa hoc, benzene c s dung trong qua trnh tong hp.

* Tnh chat

Benzene la mot hydrocarbon thm, co cong thc C6H

6

c chiet t than a hoac dau mo.

Benzene la mot chat long khong mau, de bay hi, co mui.

Nong chay nhiet o 5,48oC, soi 80

oC. nhiet o bnh

thng, benzene nhe hn nc, d = 0,87g. Hi benzene nang

hn khong kh, 1 lt hi benzene ieu kien tieu chuan nang

3,25g. Khi benzene hon hp vi khong kh ty le 1,4 6% co kha nang gay no.

BENZEN

* Tac hai

Benzene hap thu thong qua phoi va qua da. Khi tiep xuc lieu

cao gay oc cap tnh, suy giam than kinh trung ng, gay chong

mat, nhc au, ngop th va dan en roi loan tieu hoa nh kem an,

xung huyet niem mac mieng, non, roi loan huyet hoc, thieu mau.

Khi ngng tiep xuc vi benzene benh van b keo dai do benzene

tch luy trong cac mo m, tuy xng gay ra benh bach cau. Neu b

nhiem man tnh th gay xao tron ng da day, ruot, nhiem sac the

bach cau, gay xao tron DNA di truyen.

Hp chat cua benzene phc tap khi chuyen hoa thanh sinh hoc,

benzene de dang ket hp vi protein hoac nucleic acid trong c

the.

* Lieu lng gay oc:

10 15g hap thu trong c the, gay t vong cho ngi va ong vat.

TOLUENE

* Tnh chat

Toluene (methylbenzene) co cong thc C6H

5CH

3 la chat

long, nhiet o soi 110,6oC, ap suat bay hi 31

oC la 40 mmHg,

co ty trong nho hn nc d = 0,8, t bay hi hn so vi

benzene, hoa tan nhieu chat, c s dung lam dung moi thay

the. Toluene la mot loai dung moi de bat chay.

Toluene c ng dung rong rai trong cong nghiep nh

san xuat sn, nha thong, keo. Toluene c coi nh la mot

loai dung moi trong san xuat cao su, trang phim kem. ay

cung la nguyen lieu tho cho cac phan ng tong hp hu c.

TOLUENE

* Tac hai

Khi ht phai, toluene hap thu vao phoi, con khi tiep xuc tren da th toluene

i qua ng da; v toluene co tnh tan tot trong m nen no i qua da, tan mot

phan trong lp m di da va tch tu lai tai cac mo m, anh hng en he than

kinh va nao. Khi b nhiem toluene nang th khong co thuoc giai oc va dan en

cai chet.

* Nhiem cap tnh

Khi b nhiem tren 100 mg/kg toluene, gay ra hien tng hoa mat, choang

vang, au au, co giat va co kha nang dan en hon me. Toluene khong tac ong

en he than kinh ngoai bien va di s tiep xuc toluene bnh thng th chung

cung khong gay nguy hiem cho bo nao.

* Nhiem man tnh

Ht phai kh toluene thng xuyen se co nhng trieu trng nhc au, chan

an, xanh xao, thieu mau, tuan hoan mau khong bnh thng. Neu phai lam viec

lien tuc trong tnh trang tiep xuc vi toluene se dan en tnh trang than th, mat

tr nh va de xuc ong.

XYLENE

* Tnh chat

Xylene cung la mot loai dung moi hu c. Nhn chung,

xylene t oc hn va t c s dung hn so vi toluene.

Xylene c s dung trong san xuat sn, vecni va tong

hp cac thuoc nhuom; xylene cung c them vao chat ot

nh la chat phu gia.

Xylene c ng dung nhieu trong phong th nghiem

e tong hp paraffin.

XYLENE

* Tac hai

Khi ht phai hi xylene th t 60 65% c gi lai trong phoi, gay ton thng cho phoi. Khi tiep xuc vi

xylene th no c hap thu qua da va ao thai qua nc

tieu. Qua trnh chuyen hoa sinh hoc cua xylene cung giong

nh toluene: khi c the b nhiem xylene th xylene se

chuyen hoa thanh methylhippuric acid va dau hieu nay tm

thay trong nc tieu.

Ngi ta cha phat hien nhiem man tnh bi xylene.

Tuy nhien khi tiep xuc vi xylene xut hin v ngot trong

mieng va gay bt rt kho chu, ong thi b mac chng

viem da.

CARBON TETRACHLORIDE

* Tnh chat

Cong thc CCl4, nhiet o soi 77,2

oC, ap suat bay hi 20

oC la

91 mmHg. Carbon tetrachloride phan huy thanh phosgene (COCl2)

va hydrochloric acid di tac dung nhiet. CCl4 c s dung nh la

mot dung moi va cac chat trung gian trong cac qua trnh cong

nghiep.

* Tac hai

CCl4 lam suy giam va ton thng hau het cac te bao trong c

the, nh he thong than kinh trung ng, gan va cac mach mau. Tnh

nhiem oc xuat hien dan en suy nhc cac c quan noi bao, c tim

co the b suy yeu va chung gay loan nhp tim, tam that; xuat hien

anh hng cac chat oc en tat ca cac bo phan. Suy thoai than,

phoi co the dan en suy thoai m. Mang trong mach mau co the b ton thng. Bieu hien chnh khi b nhiem oc carbon tetrachloride

la hon me, vang da.

CARBON TETRACHLORIDE

* Nhiem oc cap tnh

Do ht phai va do nhiem oc qua da vi lieu lng ln. Lieu gay oc cho

ngi ln la 2 5 ml, gii han tiep xuc la 5 ppm. Khi b ngo oc, nan nhan b au bung, buon non, oi ma chong mat, mach b cham hoac bat thng ha

huyet ap. Neu tnh lai, benh nhan co cac trieu trng nh buon non, bieng an...

khoang mot hai tuan sau o co bieu hien ton hai en gan, vang da; ton hai ve

than, tang can ot ngot nang dan en hon me.

* Nhiem oc man tnh

Khi nhiem oc nong o thap do tiep xuc thng xuyen vi CCl4 th

benh nhan co cac trieu chng nh met moi, bieng an, non ma thng xuyen,

bung kho chu co cam giac luc nao cung nh buon non, mat khong nhn ro,

mat tr nh va mat kha nang nhan biet mau, viem da

TETRACHLOROETHANE

* Tnh chat

Nhiet o soi: 121oC, ap suat bay hi 20

oC la 15 mmHg.

Tetrachloroethylene la loai dung moi hu c c s dung nh

dung moi lam sach kho.

Tetrachloroethane c s dung nh la mot chat trung gian e san

xuat tetrachloro ethylene va trichloro ethylene. Tetrachloroethane

c s dung rong rai. Tuy nhien, ay la mot loai dung moi cc oc

nen hien nay no a c thay the bang cac dung moi khac.

* Qua trnh hap thu tetrachloroethane

Khi ht phai hoac tiep xuc loai dung moi nay, no c hap thu qua

phoi va da; sau o, no c bai tiet ra ngoai nhng qua trnh bai tiet

dien ra cham. Qua trnh hap thu chat nay vao c the dien ra phc tap.

TETRACHLOROETHANE

* Tac hai

Tetrachloroethane la loai dung moi oc nhat cua nhom

chlorine hydrocarbon. Tetrachloroethane co mui giong nh mui

cua chloroform nhng kha nang gay me cua no cao hn gap hai

hay ba lan chloroform.

Tetrachloroethane gay ra hai hoi chng ac biet, o la

nhiem oc he than kinh va tac ong trc tiep va manh me len

gan. Tiep xuc vi loai dung moi nay khien nn nhan de b rung

mnh, chong mat va au au. Neu tiep xuc nong o ln hn th

co trieu chng au gan va ket qua b vang da, co the dan en cai

chet.

Gii han tiep xuc la 50 ppm; lieu lng gay oc la 230 ppm

TRICHLOROETHYLENE

* Tnh chat: nhiet o soi 88oC, ap suat bay hi nhiet

o 20oC la 60 mmHg. Trichloroethylene phan huy thanh

dichloroethylene, phosgene va carbon monoxide ket hp

vi cac chat kiem nh voi, soa.

Trichloroethylene c s dung nh la mot chat dung

moi cong nghiep nh chat lam sach tng, quan ao, tham

hoac s dung e gay me hoac lam giam au nhng rat nguy

hiem.

* Tac hai: lam suy nhc he than kinh trung ng,

phoi, tim, gay ra chng loan nhp tim, tam that cap tnh Gii han tiep xuc la 50 ppm. Lieu lng gay hai oi vi

ngi ln qua ng tieu hoa va ho hap la 5ml.

METHYLENE CHLORIDE

(DICHLORMETHANE)

a) Tnh chat

Methylene chloride la loai dung moi bay hi manh, c s dung trong san

xuat phim cellulose acetate va cung la mot thanh phan cua sn.

b) Qua trnh hap thu cua methylene chloride

Methylene chloride hap thu qua phoi va co the hap thu qua da. Khi i vao c

the, methylene chloride chuyen oi thanh CO2, qua giai oan trung gian la carbon

monoxide ket hp vi hemoglobin tao thanh carboxyhemoglobin. Sau khi b ngo

oc methylene chloride khoang 150 ppm th no se tao ra san pham tng ng

carborxyhemoglobin va 35 ppm carbon monoxide trong cung mot thi gian. Trong

ca hai trng hp, carboxyhemoglobin tang len khoang 5%. Nhng ngi nghien

thuoc la, khi b nhiem methylene chloride th lng carboxyhemoglobin se cao hn

ngi khong hut thuoc la.

c) Tac hai

Methylene chloride co tnh chat gay me. Tiep xuc khoang 300 ppm th ngi

trong tnh trang buon ngu; khi tiep xuc vi lieu cao hn th ngi tiep xuc se b mat

tr nh. Ngi ta a kham pha ra rang, khi tiep xuc lau dai vi methylene chloride

th ngi tiep xuc de b benh ve tim.

CARBON DISULFIDE

Carbon disulfide la mot loai dung moi hoa tan cao su va c s

dung trong san xuat si t nhan tao va lam chat trung gian e san

xuat phot pho.

* Qua trnh hap thu cua CS2

Con ng b nhiem CS2 la do ht phai hi CS

2 bay hi, no i

qua phoi chiem en 7090%, nhng cung xay ra khi chat nay hap thu qua da. Carbon disulfide ket hp vi cac amino acid, cac chat

tieu hoa va cac protein trong mau va trong cac mo. Qua trnh oxy

hoa tao ra CO2 va giai phong ra goc sulfur, ket hp vi men

cytochrome P450. Ket qua cua qua trnh la tao ra goc oxygen t do va oxygen t do nay se pha huy men cytochrome.

* Tac hai

Carbon disulfide lam cho mat tr nh, gay roi loan tam than, gay

tc gian mot cach vo c ma khong t kiem che c, mat ngu, anh

hng en he tuan hoan mau, gay benh tim.

OC CHAT DANG ION

Clorur

Clorur la mot trong cac ion co mat trong nc va nc

thai.

Nguon nc co nong o Cl cao co kha nang gay r set

ng ong va neu nc co ham lng Cl qua ln, tc la o

man cua nc qua ln se gay tac hai en cay trong.

Trong nc cap neu Cl qua nhieu se gay mui kho chu

va gay hai cho sinh vat va ngi s dung nc.

Cl = 35,5 g/l se gay tac hai en cay trong, cay co kha

nang chet nhng vung b nhiem man.

SULFATE

Neu trong nc co SO4

2 th nc co v chua va nhng

loai nc nh vay co kha nang b nhiem phen hoac b

nhiem sulfate t cac mo thach cao, ni khai thac quang co

cha lu huynh hoac do nc thai cong nghiep, nc phen.

Khi trong nc co cha nhom ion SO4

2 th se lam cho

pH cua nc giam xuong, do tao ra H2SO

4. Neu pH thap se

lam cho cac sinh vat song trong nc co nguy c b chet.

Tren at trong trot, cay cung kho trng thanh.

Ham lng sulfate co trong nc se gay ra hien tng

an mon kim loai nh r set ng ong va lam h hai cac

cong trnh xay dng.

CYANUR

Ion CN c che cac men cha kim loai Fe, Cu tao

thanh phc chat gia kim loai cua men vi goc CN

can tr qua trnh van chuyen cac chat trong c the va

ho hap te bao b c che.

Neu nong o CN khong u gay chet th no tach ra

khoi cac men chuyen thanh ion SCN khong oc va

c thai ra bi than.

OC CHAT DANG PHAN T

Cac hoa chat oc dang phan t nh O3, Cl

2, F

2,

Br2, I

2, NH

3

Nhng chat nay thng dang kh cho nen khi b

nhiem chung c hap thu qua ng ho hap va

gay tac hai phoi, gay c che tuan hoan nao, gay

kho th va nhieu khi benh nhan chet do suy ho

hap nang.

FLO

* Tnh chat

Neu so sanh flor vi cac nguyen to khac trong nhom halogen th flor hoat ong hoa hoc manh nhat.

Flor nam trong cac mo quang va hoa tan trong cac mach nc ngam. Nc b nhiem flor gay nguy hai cho con ngi va cac loai

thuy sinh.

Flor la mot nguyen to co hoat tnh hoa hoc cc manh; chung tng tac hau het vi cac n chat, tac dung manh vi kim loai

tao thanh muoi va thoat nhiet ln.

Acid HF la mot loai acid manh va co tnh chat an mon thuy tinh khi chung ket hp vi SiO

2.

Khi F dang hp chat CFC se co kha nang bay len t mat at qua cac tang kh quyen va en tang Bnh Lu (khoang 27 30 km), gay hai tang O

3.

FLO

* Tac hai

Neu ham lng flor qua ln se gay benh muc

xng, viem tuy, viem chan rang, nt men rang co

the dan en cai chet. Hi HF rat oc, khi ri vao da

gay bong nang va rat au n.

Lieu gay chet ngi cua NaF vao khoang 5 g. Lieu

lng cho phep trong kem anh rang la F < 1000

mg/kg.

Gii han trong nc < 0,5 mg/l theo TCVN (1985);

con Phap, F < 0,3 mg/l.

Neu ham lng flor trong nc ln hn 5 mg/l se

lam cho men rang b nt, rang b bien dang.

CLO

* Tnh chat

Chlor la chat kh co mau vang luc, co mui ac biet gay ngat th.

Khi nong o 5 ppm th phat hien c ra mui. Ty trong ln hn khong

kh d = 2,49, de hoa long; tan trong nc, de tan trong dung moi hu c.

Chlor de b hap phu vi than hoat tnh. Chlor la chat oxy hoa manh.

* Tac hai

Chlor gay bong da, nguy hiem nhat la bong mat, gay kch thch cac

niem mac, ng ho hap va mat. Khi b nhiem oc lieu lng cao, benh

nhan suy ho hap nang dan en ngat hoac dan en cai chet bat ng; ht kh

chlor vao phoi lam cho phoi b phu. Khi nhiem oc lieu lng thap th gay

kch thch niem mac, gay chay nc mat, ho va co that phe quan.

1000 ppm, chlor gay ngat th va dan en cai chet nhanh.

nong o 10ppm gay phu phoi, viem phe quan.

nong o 1ppm, benh nhan co the chu ng keo dai c.

BROM

* Tnh chat:

Brom trang thai long, mau o nau, co mui hac.

Brom la chat oc co khoi lng rieng la 3,1 g/cm3,

nhiet o soi la 58oC.

* Tac hai:

Khi ht phai kh brom, nhiem oc co trieu chng bieu

hien giong nh khi b nhiem oc kh chlor vi bieu

hien cao nhat la gay phu phoi cap tnh, bieu hien nhe

gay bong da, ho va kho th

IOT

c s dung nhieu dang con e sat trung, dung dch lugol (5% iot t do) e cha benh tuyen giap.

Tinh the mau o ta lap lanh, de boc hi khi e

ngoai khong kh t do.

Lieu gay chet: khoang 2g tinh the iot cho ngi ln. Khi b nhiem oc bang ng mieng, niem mac

mieng, thc quan, da day, b bong nang; nan nhan

non, anh hng en tim mach, giay dua va t vong.

Niem mac mieng co mau nau ac biet.

OC CHAT

HALOGEN HOA

* Nhom halogen hydrocarbon

* Nhom halogen vong thm

o ben vng cua thuoc clo hu c trong moi

trng song theo th t nh sau:

Aldrin > Dieldrin > Heptacloepoxid > HCH >

DDT> Clodan > Lindan > Endrin > Heptaclo >

Toxaphen > Methoxyclo.

DICHLORO DIPHENYL

TRICHLORETHANE (DDT)

Tnh chat: DDT co cong thc C14

H9Cl

15, dang bot trang hay

xam nhat, tan rat t trong nc, tan nhieu trong cac dung moi. Nhiet

o nong chay la 108,5oC 109oC. Ap suat hi 20oC la 1,5.107

mmHg.

DDT b kh chlor e bien thanh DDD (diclorodiphenyl

dichloroethane hoac co ten thng mai la rhothane), ay la mot chat

diet con trung.

Tiep theo DDD b kh chlor va hydro bien oi thanh DDE, la

san pham cua DDT va chat DDE ton tr lau hn, ben hn va thng

co nong o cao hn DDT va DDD trong moi trng.

Nh kha nang phan huy cua cac sinh vat ma t DDT se chuyen

thanh DDD va DDE. Ngi ta che ra loai thuoc nay lam thuoc diet

tr nhen. Ngi ta cung tm thay chung co trong m cua loai hai cau.

Nh vay, ay cung la loai nguy hiem v chung khong b ao thai ma

tch luy trong cac mo m.

DICHLORO DIPHENYL

TRICHLORETHANE (DDT)

Degradation of DDT to form DDE (by elimination of HCl, left) and DDD (by reductive dechlorination, right)

DICHLORO DIPHENYL

TRICHLORETHANE (DDT)

Tac hai: gay ton thng en he than kinh, lam yeu c va co giat, cac tai bien ben ngoai thng gap la

ban o, phu ne, da o.

Ngi tiep xuc vi DDT lau dai vi nong o thap

cung gay nhiem oc nh run, bien oi cac to chc

gan va bien oi nhe than.

Lieu gay oc oi vi ngi la 30g. DDT c tch

luy qua chuoi thc an. Khoang cach an toan gia

nong o diet c con trung va lieu gay oc cho

ngi la 0,4 g/kg.

HEXACHLOROXYCLOHEXAN

Tnh chat: cong thc C6H

6Cl

6 (666) la mot loai bot

mau trang, khong tan trong nc; tan trong con,

benzene Nhiet o nong chay la 112,5oC, ap suat hi 20

oC la 9,4.10

6 mmHg. No co 8 ong phan, trong o 7

ong phan khong oc, rieng ong phan la gay oc.

Tac hai: 666 tac ong do tiep xuc qua tieu hoa hoac ho hap, lam thuoc tieu diet con trung. So vi DDT th

666 t oc hn, lieu lng gay oc nghiem trong oi vi

ngi ln t 20 30g. Khi b nhiem oc 666 thng gay roi loan tieu hoa, au au chong mat, suy nhc c

the.

METHYL BROMIDE (CH3BR),

METHYL CHLORIDE (CH3CL),

METHYL IODIDE (CH3I)

Tnh chat: la chat kh, boc hi cao nhiet o thng. Chung c s dung trong ky nghe lam lanh, trong tong hp hoa hoc.

Methyl bromide c s dung trong cu hoa.

Tac hai: Methyl iodide co the hoa tan m. Methyl chloride va methyl iodide xam nhap vao te bao, chung b thuy phan tao

thanh cac methol va halogenion.

Nhng phat hien benh la s xung huyet cua gan, than, phoi vi

nhng thay oi trong cac te bao, viem cuong phoi. Nhng chat

nay gay nguy hai hau het en cac te bao.

Gii han tiep xuc: 5 ppm oi vi methyl bromide, 50 ppm oi vi methyl chloride va 2 ppm cho methyl iodide.

HP CHT HALOGEN VNG THM

Trong cong nghiep, nhat la cong nghiep che bien

thuy san, thuoc tr sau, san xuat giay, mc in mot lng ln chat thai c sinh ra la nhng hp chat

halogen vong thm nh PCP (polychlorophenol), PCPP

(polychlorpp), PCB (polychlorobiphenyl), PCBz

(polychlorobenzene)...

ay la nhng chat co oc tnh cao, anh hng en

sc khoe con ngi va moi trng.

HP CHT HALOGEN VNG THM

Tac hai

ac tnh phan cc cua cac chat thm halogen hoa lam cho

chung co the at en nong o cao trong moi trng long va

phan bo ong eu trong cac te bao.

Cac benzene halogen hoa nh bromobenzene, p dichlorobenzene (PDP), hexachlorobenzene (HCB) eu co

tnh a m cao. Do vay, trc khi b loai thai chung a i vao

cac qua trnh bien dng. Cac hp chat nay gay hai cho gan

than va he than kinh.

Cac chat bien dng gom nhng phenol halogen hoa co hoat

tnh sinh hoc gay ra bien d va ac biet, hau het chung eu

gay ung th.

Chng V. c cht kim loi nng

More Sources of heavy metal exposure

Aluminum Cookware

Mercury Amalgam Fillings

Drinking Water

Lead in the pipes in our

home

Air Pollution

Tobacco Smoke

Fish and Seafood

Pesticides

Medications

Cosmetics

Fertilizers

Heavy Traffic

Anti-Perspirants

Heavy Metals are all around you and are

detrimental to your

Health

You are being

exposed to heavy

metals and these are

some of the

symptoms of heavy

metal poisoning

CADMIUM (Cd)

Nguon goc phat sinh:

- Lam lp xi ma bao ve cho thep

- Trong nhng hp kim khac nhau

- Trong chat mau (cho cac chat nha, lp men va o gom).

- Tao chat lam chac cho chat deo PVC.

- Trong te bao pin kho NiCd.

- Trong vu kh quan dung

- Trong nhng hp chat khac nh: chat ban dan, bo phan

kiem soat lo phan ng hat nhan.

Nguon o nhiem Cd chnh

- Phan bon

- S khai thac mo va tinh luyen Cd va Zn.

- S o nhiem kh quyen t nhng khu cong nghiep va

luyen kim.

- Viec xa thai cac chat thai co cha Cd (thieu huy nhng

vat nha va pin).

- Bun thai (Nc bun cong ranh).

- Cac tro bui hoa thach.

- Khoi thuoc la

- n uong

Anh hng cua Cd en thc vat

Nhiem oc Cd bieu th benh vang la, s heo va tnh

trang ngng phat trien cay trong.

S tch luy Cd trong cay trong: cu cai > au nanh > cai

xoang > rau nhp > ngo > ca rot > au > lua m > cu cai

trang > ca chua > b > cai bap > cu cai ng > lua vung

cao.

Cadmium ket hp vi chat albumin trong mau gan (hnh thanh mot phc chat vi metallothionein (MT), MT tach

cadmium ra khoi te bao gan va hoat ong nh la mot tac

nhan giai oc. T gan co s phong thch cham cadmiumMT mau c tham qua tieu cau va tiep tuc c hap thu tr

lai bi cac te bao co hnh ong.

Vi nong o tiep xuc cadmium thap bang con ng an uong, cadmium dng nh di chuyen en MT trong mang nhay

ruot non, ni ma no co the b tach ra trong nhieu ngay. Sau

khi c a va trong mau, hp chat cadmiumMT di chuyen trc tiep en than. Khi vao trong c the, cadmium

c ao thai ra ngoai rat cham vao ac biet la trong than

phai mat phan na thi gian e ao thai ra ngoai so vi thi

gian ao thai la 10 30 nam.

Anh hng cua Cd en con ngi

Benh ung th tuyen tien liet va benh tang huyet ap nhng ngi cong nhan co bieu hien ham lng cadmium ln do ht

vao, mac du ho khong b hap thu cadmium t thc an.

Neu ham lng Cd trong than len en 200mg/kg khoi lng ti th se gay roi loan chc nang than dan en Nhiem oc than.

Nhiem oc gan.

Mau

He thong mien dch

Xng

Ch (Pb)

NGUON PHAT SINH CH

Ham lng trung bnh cua ch trong mot so khoang chat

Transport of lead in the environment; concentrations are given in parentheses.

Reproduced with the permission of Nelson Thornes Ltd from Environmental

Chemistry 3rd Edition ISBN No 0 7514 04837 first published in 1998.

Nguon gay o nhiem

+ Cong nghiep khai khoang va luyen kim: ay la nguon phat thai

ch ln nhat trong cong nghiep. Khong ch rieng nganh khai thac

va tinh che ch ma ca nganh khai thac va tinh che nhieu kim loai

khac cung phat sinh cac chat thai cha ch. Nhng dong thai cha

ch trong loai hnh cong nghiep nay bao gom:

- Chat thai ran khu khai thac va tuyen quang

- Nc thai khu vc mo, khu tuyen quang, luyen quang

- Khoi thai lo luyen quang.

Chat thai, chu yeu la nc thai va chat thai ran cua cac nganh

cong nghiep co s dung ch nh: cong nghiep che tao ac quy, san

xuat sn, an dc, bot mau,...

Nguon gay o nhiem

Cong nghiep

Nong nghiep

Quan s

Giao thong

Thng mai

Cuoc song hang ngay

Kha nang phan huy

Ch khong b phan huy trong moi trng, ch chuyen hoa

t dang hp chat nay sang dang hp chat khac va c

van chuyen gia cac thanh phan trong moi trng theo

mot chu trnh khep kn.

Nguon goc ch trong moi trng khong kh

+ ong at, nui la

+ Gio cuon bui ch t at

+ Kh thai cong nghiep

+ Khoi thai giao thong

Qua

trnh

van

chuyen

cua

ch

trong

moi

trng

Ch trong moi trng nc

Qua trnh phong hoa vo trai at;

Qua trnh xoi mon;

Qua trnh tiep nhan cac dong thai cha ch t hoat ong

cua con ngi;

Qua trnh lang ong ch t kh quuyen;

Qua trnh hoa tan, ra troi cac hp chat ch t at.

Ch trong moi trng at

Ch trong cac khoang chat t nhien, ien hnh la PbS;

Chat thai ran cha ch t cac hoat ong cua con ngi

nh khai khoang, chon lap rac o th,...;

Lang ong ch t kh quyen;

Ket tua va sa lang cac hp chat cua ch t thuy quyen.

ng lay nhiem

Ch xam nhap vao c the con ngi va ong vat thong

qua nhng con ng chnh sau: ho hap, an uong va hap

thu qua da.

Lc o mo ta qua trnh

hap thu, phan

bo va ao

thai ch trong

c the ngi

oc tnh

- 1000 mg: t vong.

- 10 mg1 lan/ngay: gay nhiem oc nang trong vai tuan.

- 1mg/ngay: sau nhieu ngay co the gay nhiem oc man tnh.

Nguon ch trong moi trng song t nc uong, thc an,

khoi bui vao c the hang ngay co the t 0,1 0,5 mg.

Cac muoi ch co lieu oc oi vi ngi ln la:

- Ch acetat: 1 g.

- Ch cacbonat: 2 4 g.

- Ch tetraetyl: nho giot 1/10 ml tren da chuot cong se gay chet

trong vong 1824 gi.

Tac hai

Arsen (As) As la nguyen to hnh thanh t nhien trong vo trai at. As nguyen

chat la kim loai mau xam, nhng dang nay t ton tai trong thien

nhien.

Ngi ta thng tm thay As ton tai di dang hp chat vi mot hay mot so nguyen to khac