Nghiên cứu phân tích, đánh giá tồn lượng hoá chất bảo vệ thực vật và tình trạng ô nhiễm môi trường ở một số tỉnh miền Trung

BO
GIAO
DUG VA DAO TAO
TRirdNG Dm HOC
T6NG HOP
HA
Ndl
Phung Thi Thanli
Tu
NGHIEN
CtrtJ PIIAN
TICH,
DANH
GIA
TON
LlTdNG
HOA CHAT BAO VE
THlTC
VAT
VA
TINH TRANG 6 NHIEM MOI TRlTdNG
6
MOT SO TINH MIEN TRUNG
Chuyen
nganh
: Hoa
hCru
ccf
Ma
so 01.04.02
LUAN

AN
PHO
TIFN
SI KHOA HOC
HOA
HOC
Ngudi
htfdng
ddn
khoo
hoc :
GS.
TS
: NGO
THI
THUAN
PGS.PTS
:
NGUYIN
DQC
HUE
HANOI.
1994
MUG
LUC
Trang
DAT VAN
DE 1
I. Phan tong quan tai lieu 3
1.1. Khai niem

chimg
ve HCBVTV 3
1.2. Phan
loai
HCBVTV 3
1.3. Tmh hinh san xuat va
sik
dung HCBVTV 5
1.4. Tac hai cua HCBVTV 7
1.5. Ton
lifdng
HCBVTV trong moi
tnl6ng
24
1.5.1.
Su
di chuyen cua HCBVTV trong moi
trifdng
24
1.5.2.
Van de ton
lifdug
HCBVTV trong nong san
28
1.5.3.
Phildng
phap phan tich ton
lUdng
HCBVTV
trong moi

trildng
29
n.
Phan
thilc
nghiem 39
2.1.
Lap doing
phudng
SKLM de xac dinh ton
lUdng
HCTS 39
2.1.1.
Thiet
bi,
dung cu, hoa chat 39
2.1.2. Lap dung
phiidng
phap phan tich 40
2.1.3.
Do thu hoi cua ton
liidng
HCTS trong cac
doi tildng
52
2.1
A.
Cach tinh ket qua 53
2.2.
Lap dung

phiidng
phap xac dinh warfarin trong phan rom 54
2.2.1.
Thiet
bi,
dung cu, hoa chat 55
2.2.2.
PhUdng
phap sinh hoc 55
2.2.3.
Phiidng
phap phan
tich
hoa hoc. 57
2.3.
Lap dung phUdng phap GC/ECD xac dinh HCTS. 62
.
2.3.1.
Thiet bi, dung cu, hoa chat 62
2.3.2. Phiidng phap phan tich 62
2.4.
LTng
dung 65
2.4.1.
Doi
tUdng
nghien
ciiu
66
2.4.2. Nghien

ciJu
tinh trang
6
nhiem moi
tru5ng
67
2.4.3.
Ton
liidng
HCTS bi cam
sik
dung va han che
sik
dung 79
2.4.4. Ket qua xac dinh ton
lUdng
HCTS
bkng phUdng
phap
GC/ECD 86
2.4.5.
Ton
liidng
HCTS trong
liidng thiic
87
2.4.6. Ton
lUdng
DDT tren dong vat 88
2.4.7.

Su
lam dung HCBVTV 88
2.4.8.
Xii ly
HCTS trong
nvfdc
89
2.4.9. Tac tai cua HCBVTV den
sufc
khoe
ngUcii
tiep xuc 90
ni.
Phan thao luan ket qua nghien
ciiu
95
3.1.
PhUdng phap phan tich. 95
3.2. Ton
lUdng
HCTS bi cam va han che sU dung d mien
Trxmg
102
3.3.
Danh gia
mtic
do 6 nhiem moi
trudng
d mien Trung 106
3.4.

Xik
ly HCTS trong
nUdc
111
3.5.
HCBVTV anh hu6ng den
siic
khoe cua
ngUdi
tiep xuc. 112
IV.
Phan ket
luan 115
Tai lieu tham khao
Phu
luc
DAT VAN
DE
Hien nay tren the gidi, hoa chat bao ve thUc vat (HCBVTV) ngay
cang dUdc dung rong rai trong nong nghiep de bao ve cay trong va bao
dam cung cap
lUdng
thUc,
thUc pham nuoi song con
ngUcJi
[ 1, 23]. Theo
To
chiic
Y te the gidi (TTYTTG), hang nam cac loai con trung va sau bo
pha hoai khoang 33 trieu tan

lUdng
thUc. So'
lUdng
nay c6 the nuoi
song 150 trieu
nguM
trong mot nam [ 38, 53 ].
6
nU6c ta HCBVTV
dUdc
diing
rong rai. Hang nam
lUdng
HCBVTV
svL
dung binh quan la
0,5 - 0,7 kg hoat chat / ha [24].
Nhd
diet dUdc con trung sau benh nen
san
lUdng lua
tang
10%,b6ng,
day, do tUdng, cam, che tang tii 17,6 - 70
% [ 5, 53 ]. Nam mUdi nam qua, viec dung HCBVTV mot
each
than
trong va c6 kiem soat la dieu can thiet de phat trien nen nong nghiep
hien dai va sit dung trong viec khong
che

cac benh do con trung truyen
[12,
19] va vi vay
Idi
ich cua HCBVTV da vUdt xa so v6i gia thanh
cua no [ 10,34 ]. Tuy nhien neu HCBVTV dUdc dung khong dung
each
hoac khong than trong se de doa nghiem trong den
stic
khoe con
ngUdi,
den nong nghiep va he sinh thai noi chung [ 27.34 ]. Hang nam
ty
le
nhiem doc va
ti
vong do hoa chat
trit
sau (HCTS) kha 16n [56,58].
Nhieu loai HCBVTV c6 kha nang ton
lUu lau
dai d moi
trUdng,
gay 6
nhiem dat, nU6c, khong khi, tac hai lau dai den
siic
khoe va
Ian
truyen
tii

the he nay sang the he khac [76, 81 ]. Hien nay sU quan ly
HCBVTV d
nUdc
ta chUa that chat che.
O
mien Trung, dat dai can coi,
sau benh
luon
de doa mua mang.
Dae
trUng cua khi hau mien Trung
la : nhiet do cao,
lUdng
mUa
Idn
va gio bao nhieu. Dieu do de dang cho
viec di dong nhanh cac ton
lUdng
HCBVTV vao khong khi, dat,
nU6c,
gay 6 nhiem moi
trU5ng
tren mot dien rong. Mac du nha
nU6c
da c6
lenh
cam dung diclodiphenyl tricloetan (DDT), hexacioxiclohexan
(HCH) va han che sU dung wofatox, monitor [75] nhUng cho den nay
nhan dan van quen dung wofatox va monitor. Su quan ly HCBVTV d
mien Trung cung con long

leo.
Do do viec nghien
ciiu
phan tich, danh
gia ton
lUdng
HCBVTV va tinh trang
6
nhiem moi
trUc^ng
d mien
Trung la dieu can thiet va c6 y
nghia.
Chung toi tien hanh nghien
ciiu
de tai nay nham muc dich :
- Lap
dilng
phUdng phap phan tich
s^c
ki
16p
mong (SKLM), sac
ki khi detectd cong ket dien tii
(GC/ECD)
va phUdng phap do quang
thich hdp de lam phUdng tien khao sat ton
lUdng
HCBVTV trong moi
trUcfng.

- Danh gia ton
lUdng
hoa chat
tri^
sau bi cam
sii
dung va han che
sii dung
ci
mot so' tinh mien Trung.
- Danh gia tinh trang 6 nhiem moi
trU6ng
do HCBVTV gay ra tai
cac cd
scl
san xuat, bao quan, sU dung va sau cac ddt bao
lut
d mien
Trung.
- De xuat mot so' bien phap giai quyet tinh trang 6 nhiem moi
trudng.
I.
PHAN TONG QUAN
TAI LIEU
1.1. Khai niem chung ve HCBVTV
HCBVTV la ten goi chung de chi cac hoa chat dung trong nong
nghiep, lam nghiep,
nh^m
muc dich diet sau benh, c6 dai, con trung va
dong vat gam nham de bao ve cay trong, cac

Idio lUdng
thUc hang hoa
[41, 61].
1.2. Phan loai HCBVTV
1.2.1.
Phan loai theo muc dich sit dung [21, 61]
*
Nhom cac chat
tru!
sau, trii nhen,
tri
con trung gay hai :
- Cac chat
trtT
sau nhom cd
clo
: DDT, HCH, endrin diendrin,
clodan
- Cac chat
trtf
sau nhom cd photpho : wofatox, diazinon,
malathion, monitor
- Cac hdp chat
cacbamat:
sevin, furadan, mipcin, bassa
- Cac hdp chat sinh hoc : piretroit, permetrin, dentametrin.
* Nhom cac chat trii nam,
trii
benh, trii vi sinh vat gay hai :
- Cac hdp chat

chiia
dong
- Cac hdp chat
chiia lUu
huynh
- Cac hdp chat chiia thuy ngan
- Mot
so'loai
khac
*
Nhom cac chat trii
c6
dai, lam rung la, kich
thich
sinh
trUdng
:
- Cac hdp chat cua phenol
- Cac hdp chat
ciia
phenoxi [2,4 diciophenoxyaxetic axit -2,4 - D]
- Cac dan xuat cua axit
alofic
[dalapon]
- Cac dan xuat cua cacbamat
[satxm,
eptam]]
- Triazin [simazin, atrazin, evik ]
* Nhom cac chat diet chuot va dong vat gam nham : phoszin va
warfarin

1.2.2. Pban loai tbeo nguon goe san xuat va eau true boa boe
1.2.2.1.
HCBVTVhvtu
ca[41,
83]
- Cac chat BVTV nhom cd photpho :
metyl
parathion
[114],
parathion [117] monocrotophot
[119],
diazinon
[122],
malathion
[128],
dimetoat
[142],
azodrin
[143].
- Cac chat BVTV nhom cd clo : DDT [89] andrin
[118],
HCH [125,
147],
cloran
[137],
heptaclo
[141],
2,4-D[123, 139].
- Cac chat trii sau thuy ngan
hUu

cd,ceresau,
granosan, felizan [114]
- Cac dan xuat cua hdp chat nitro [41]
- Cac dan xuat
ciia
ure [41]
- Cac dan xuat ciia axit cacbamic [61]
- Cac dan xuat cua axit propionic [41]
- Cac dan xuat cua axit xianhidric [41]
1.2.2.2. Cac chat
trvtsau
v6
ca:
[41, 61]
- Cac hdp chat ciia asen [131]
- Cac hdp chat ciia dong [61]
- Cac hdp chat cua
lUu
huynh [138]
- Cac hdp chat
v6
cd khac [114]
1.2.2.3. Cac chat trii sau nguon gob thiic vat la : cac
ancaloit,
thUc vat
CO
chiia nicotin, anabazin, piretroit [41, 121, 140]
1.2.3. Pban
loainbom
doe tbeo TCYTTG

[131,
132]
Bang
1:
Phan loai nhom doc theo TCYTTG
(LD50 mg/kg, chuot nha)
Phan nhom doc
la.
Doc manh
lb.
Doc
II.
Doc trung binh
III.
Doc it
IV.
Qua
mieng
The ran
5
5-50
50 - 500
500-2000
>2000
The long
20
20 - 200
200 - 2000
2000-3000
>3000

Qua da
The ran
10
10 - 100
100 1000
1000
The long
40
40-400
400-4000
4000
1.3. Tinh hinh san xuat va sik dung HCBVTV :
L3.1.
Tlnb
binb sin xuat va
svt
dung HCBVTV tren
tbegioi
Tii lau con
ngUdi
da biet
dtmg
mot so' san pham tU nhien
de
diet
truf
sau benh
nhu
cac hdp chat cua asen, cac hdp chat ciia flo, cac chat
CO

nguon go'c thUc vat va dau khoang [1, 61]. Tii nam 1849 - 1922 cac
san pham xong
Idioi
cua cac chat v6 cd va dau hoa cung dUdc
diing de
diet trii sau bo [38]. Tii sau naml923, cac hdp chat
trtt
sau tong hdp ra
ddi
[41]. Nhom HCTS dUdc diing sdm nhat la DDT, HCH. Tiep theo la
cac hdp chat endrin, diendrin. Cac hdp chat cd clo nay ton tai qua lau
trong moi trUdng va tich
luy
trong cd the dong vat, gay hai cho moi
trUdng
va con
ngudi.
Do do ngay nay nhieu nu6c da cam diing [36, 89,
90].
Nhom HCBVTV tong hdp phong
phii
va dUdc sU dung rong rai
nhat trong nong nghiep la nhom HCTS cd phot pho va cacbamat [61,
94].
Ngay nay cac nU6c tren the gidi dang khuyen khich dung cac
phUdng phap sinh hoc va cac phUdng phap phong trii tong hdp
de
bao
ve thUc vat, nham han che sU dung HCBVTV c6 hai cho moi
trUdng.

Tuy vay, hien nay HCBVTV van dUdc
sii
dung vdi khoi
lUdng
16n tren
the gidi.
U*6c
tinh hang nam cac
nU6c
tren the gidi diing khoang 1,25
ti tan nguyen chat HCBVTV [23]. Hien nay cd khoang 100.000 hdp
chat hoa hoc dUdc tong hdp va dUdc thi nghiem de lam HCBVTV [38].
Trong dd cd khoang 1.500 hdp chat dUdc xac dinh tinh nang, 500 hdp
chat dat tieu chuan quoc te, dUdc
dua
vao
sii
dung [56]. Rieng d My
cdl.200
HCTS da dUdc dang ky, 35.000 san pham thUdng mai dUdc ban
dudi
dang cac thUdng pham khac nhau [5]. Tuy cd
nhUng
y kien khac
nhau ve viec sii dung HCBVTV nhUng miic sU dung HCBVTV hang
nam tren the gidi van tang tren 10% [53]-
Nam 1985 My sU dung 486 trieu tan HCBVTV, rieng nganh
nong nghiep sU dung 464,22 trieu tan [38].
Indonexia
nam 1982

sii
dung 45.258 tan bao gdm 450 loai HCBVTV, chi phi cho HCBVTV phat
trien manh, ty le tang trung binh hang nam la 15-20% [84]. Malaixia
trong nam 1983 ban hdn 100 trieu do la My, trong dd thudc diet c6
chiem 80%, thudc diet con trung chiem 12% [84]. Nam 1981 Thai Lan
sii
dung khoang 35.000 tan HCBVTV, tri gia 130 trieu dd la My [84].
Tanzania cud'i nam 1981, cdng
ngliiep
ca phe diing khoang 6353 tan
HCBVTV [50, 71]. Columbia trong nam 1985 xuat khau 6693 tan
HCBVTV vdi tri gia 490.969 dd la My [82]
O cac nUdc phat trien, HCBVTV dUdc quan ly chat che
tit
khau
san xuat, dang ky xuat khau, bao quan, van chuyen,
sii
dung; cd nhieu
trung tam nghien
ciiu
sU ton
lUu ciia
HCBVTV trong moi trUdng va tac
hai cua
chiing
doi vdi con ngUdi [24, 50].
1.3.2.
Tinh binb sin xuat vasvt
dung
HCBVTV d Viet

Nam
Tii xa xUa, nhan dan ta da biet dung nicotin lay tii cay thudc la,
thudc lao va rotenon che tU mot sd' cay ho dau de
trii
sau hai rau va
cay an qua. Nhan dan Nam bo da diing dau
gasol
de phong trii ray nau
hai
Ilia d
cac tinh mien Tay. Tii nam 1957, DDT va
nhUng
hdp chat
tUdng tu dUdc diing rong rai
d
nUdc ta [41]. Tii nam 1963
d
mien
B^c
da diing nhieu wofatox, dipterex, malathion, Bi58 [61]. O mien Nam
nhan dan diing nhieu diazinon , monitor, orthene, azodrin [41]. Nudc
ta la mot nUdc ndng nghiep, khoang 13 trieu ho gia dinh gom 52 trieu
ngUdi lam viec trong
linh
vUc ndng nghiep [18, 43], do dd viec
sii
dung
HCBVTV ngay cang tang [51, 57]. Trong tong so HCBVTV dUdc
sii
dung, HCTS chiem 68%, HCTN chiem 24% va HCTC chiem 8% [43].

LUdng HCBVTV diing binh quan hang nam la 0,5 - 0,7 kg hoat chat/ha
[57].
Trong
Idii
dd d Nhat la 14,05 kg hoat chat/ha, d
Balan
la 0,94 kg
hoat chat/ha, d Hungari la 8,93 kg hoat chat/ha, d Thuy Dien la 4,93
kg hoat chat/ha, d My la 4,56 kg hoat chat /ha [38, 48].
HCBVTV dUdc
sii
dung d nUdc ta chu
yeii
tii nguon nhap khau.
Sd
lUdng
HCBVTV hang nam dUdc thong ke nhUng chua day du vi
hien nay cd nhieu ngudn nhap HCTS khong hdp phap. Theo so lieu
thong ke chUa day du :
nhUng
nam cua thap ky 80, hang nam
nude
ta
nhap tii 8-9 nghin tan va
nhUng
nam dau thap ky 90 nhap tii 20-24
nghin tan HCBVTV [38].
1.4. Tac hai cua HCBVTV.
1.4.1.
Tinb

hinh nbiem doc
HCBVTV.
1.4.1.1. Tinh hinh nhiSm doc HCBVTV tren
the
gidi.
So'
ngUdi bi
nhilm
doc HCBVTV ngay cang tang tren the gidi
[38].
Nam 1977, dUa vao bao cao cua 9 nUdc, TCYTTG [24] da Udc tinh
hang nam tren the gidi cd 20640 ngUdi chet vi HCBVTV. Nam 1981
TCYTTG Udc tinh rang toan cau cd 750000 ngUdi bi nhiem doc. Gan
day Uy ban
Idnh
te va xa hoi chau A va Thai Binh DUdng da cho biet
so'
ngUdi bi nhiem doc
len
den 2 trieu, trong dd sd'
tii
vong la 40000
ngudi [24]. Theo Rosenstock [36] d My cd khoang 3000 cdng
nhan bi nhiem doc hang nam. Nam 1987 cac tac gia dieu tra tai phong
kham cap
ciiu
va nhap vien d Nebraska thay ty le nhiem doc HCBVTV
la
1,35/1000
dan, trong dd

nhilm
doc HCTS nhom cd photpho chiem
25%
[50].
d
Indonexia tii 1974-1982 cd it nhat 1065 ngUdi bi nhiem doc
HCBVTV, trong dd cd 54 ngudi chet. Rieng mien dong Java nam 1980
cd 431 ngudi bi nhiem doc trong dd cd 17 ngUdi chet. Thii do Giacata
trong mot nam cd 165 ngUdi bi nhiem doc chiem ty le 1,99% trong tong
sd' benh nhan nhap vien [84].
6
Malaixia tii nam 1977-1981 cd 569
ngUdi bi chet, chii
yeii
la do paraquat, malathion va DDT. Tii thang
1/1981-6/1982 ti le
nhigm
doc paraquat la 46/100000 dan. Ti le chet do
paraquat 54,5% [84].
O
Srilanca tii nam 1975-1980 hang nam cd
khoang 13000 ngUdi bi
nhigm
doc HCBVTV, cd khoang 1000 ngUdi
chet [84].
U
Thai Lan Udc tinh hang nam cd it nhat 1000 ngUdi bi
nhidm
doc HCBVTV, khoang 100 ngUdi
tii

vong [84]. Theo Bary [76] va
Fest [83] khoang 10% cac trUdng hdp bi nhiem doc cap ciiu la do
HCBVTV, trong dd cd 50% la do nhdm cd photpho.
1.41.2
Tinh hinh nhiSm doc
HCBVTVd Viet
Nam
- Theo Le Dinh Cdng,
ci
Ben Tre tU nam 1986-1992 cd 1102 ngUdi
bi nhiem doc, cd 208 ngUdi chet [5].
6
Tien Giang tii nam 1986-1992 cd
3.167 ngudi bi
nhigm
doc HCBVTV, trong dd cd 333 ngUdi chet [60].
8
Theo Le Trung, tu: nam 1986-1991 sd ngUdi vao dieu tri d mot so benh
vien tinh thanh va benh vien Bach Mai la 3.019 ngUdi, trong dd sd'
ngitdi
tu tu
cliie'm
89,5%,
do nham
lin
la 3,8% va do nghe nghiep la
6,6%. Ty le
tii
vong do nhiem doc HCBVTV kha cao, trong dd HCTS cd
photpho chiem 10,4% [58].

1.4.2.
Tac
hai chung cua
HCBVTV.
HCBVTV it hay nhieu deu doc vdi cd
the
con ngUdi, gia cam, gia
siic
va moi trUdng song [12, 56, 76].
Mile
do nhiem doc phu thudc vao
titng
loai HCBVTV, lieu
lUdng,
dudng
xam nhap vao cd the va cd dia
cua tiing ngUdi tiep
xiic
[51, 92, 102].
Ngitdi ta thUdng bi tham
nliiem
HCBVTV qua 2 phUdng thiic :
tiep
xiic
nghe nghiep va tiep
xiic
mdi trUdng. Tiep xuc nghe nghiep,
dudng xam nhap chii yeu qua da va dudng ho hap. NgUdc
lai,
tiep

xiic
mdi trUdng
chii
yeu qua dUdng tieu hoa (vdi thiic an, nUdc udng bi
nhiem HCBVTV) [76, 78].
Mdi loai, mdi nhdm HCBVTV cd cd
che
tac hai
Ichac
nhau . Cd
the
tong quat cd
che
chung d hinh 1 va 2 [5]
^
''
Dat
-* 1
Khong khi
Sinh thai
s^
^ '
Nude
tl
lUc
a
n
^ '
Ngudi
Hinh 1 : Su

lUu
chuyen
ciia
HCBVTV trong mdi trUdng
Nhiem doc
Hau qua khac
I
Cap
tinh
r
Ban
cap
tinh
1
Man
tinh
Di
truyen
1
Di
tog
.
t
V
Sinh
bao
non
i
Mang
HCBVTV

^•
Doc
bao
thai
V
Doc
sinh
hoc
>•
Dot
bien
gien
Hinh 2 : Tac hai cua HCBVTV
i.
4.3.
Tac hai cua HCTS nhom cd clo.
HCTS nhdm cd clo la dan xuat clo ciia cac hidrocacbon da nhan,
cac
xicloparafin
cac tecpen va benzen : cacbon tetraclorua, DDT, HCH,
cloperin,
pentaclonitrobenzen
Cac chat nay cd clo trong phan
tii
nen
nen tac dung ciia chiing dd'i vdi cd
the
nhieu
liic
gid'ng nhau, chi khac

ve
miic
do doc tinh va bieu hien lam sang [31, 76, 78].
Dae
tinh chung
ciia cac loai HCTS cd clo la ben
vUng
d mdi trUdng ben ngoai, tac dung
manh vdi nhieu loai con triing gay hai, cd tinh tich luy rd ret va cd
kha nang gay nhiem doc cap tinh va man tinh cho ngUdi [15,42].
Chat doc gay ton thUdng nhieu cd quan va he thong khac nhau,
nhUng chu yeu la tac dong len he than kinh, gan, than, he thdng
tim mach va mau [54, 81]. Cd che tac dung doc cua HCTS cd clo
10
chua dUdc
kh^ng
dinh [38, 41]. Nhieu nghien ciiu cho thay cac chat
nay gay rdi loan cac he thdng enzim quan trong, do dd lam thay doi cac
qua trinh chuyen hoa, tang tinh trang thieu oxi
d
cac to
chiic
[76, 90,
104].
HCTS-cd clo cd
the
xam nhap vao cd
the
qua dUdng ho hap, tieu
hoa, da [53,

541.
Klii
chat doc xam nhap vao cd the
dii lUdng nhd
cung
gay nhiem doc man tinh vi nd tich luy trong cd the, dac biet la d to
chiic md [ 92, 104]. Da sd' HCTS - cd clo deu dao thai qua
sUa
va gay
doc dd'i vdi noi gid'ng [36, 118, 109]. Cac hdp chat DDT, diendrin,
andrin cd thdi gian ban huy sinh hoc dai [22, 28]. Chiing phai dUdc
xii
ly nghiem ngat vi chiing hen quan den mat can
hkng
sinh thai va
anh hudng tram trong den
siic
khoe con ngUdi [102, 103]. Tat ca cac
chat nay deu dUdc chiing minh la cac chat gay ung thU tren dong vat
[36,
137, 139, 144, 145, 147]
1.4.4.
Gidi
tliieu
mot so HCTS -
ccf
clo
tbiidng
dung
1.4.4.1. DDT,

Ci4HgCl5,
M=345,5[131
144]
- DDT cd ten la diclo diphenyl tricloetan. Nd con cd ten khac :
azotox [41], gesarol
[103],
neoxit
[144].
- DDT cd cdng thiic can tao :
H
*
l,l,l-triclo-2,2 - bis (p-clophenyl)etan
^^-Q-^-Q^'
*P,P-DDT
CClg
- DDT diet
dUdc
con
triing
rat
hflu
hieu,
ducic
tong hdp
tif
nam
1939 [38, 41]
- Co 2 loai dong phan o,p' - DDT va p, p' - DDT, nhUng loai c6 tac
dung keo dai va pho tac dung rong doi vdi con trung la p,
p'

- DDT [21]
11
- DDT cd dang tinh
thd
khong man, bay hdi d ap
lUc
1,5.10'^
mmHg tai
20^C,ndng chaydl09^GDDT
dd tan trong cac dung mdi hiiu
cd (hidrocacbon thdm va cac dan xuat halogen cua chiing, cac xeton,
cac este cua axit cacboxylic). DDT tan kem trong cac hidrocacbon mach
th^ng
va vong no.
6
nhiet do
27^C
DDT hoa tan trong nUdc vdi nong
do 0,001
mg/1
[38]. DDT ben
vttng
vdi tac dong cua nhiet do, dun sdi
vai gid van khdng bi phan huy. Trong mdi trUdng
Idem
bi phan huy
thanh DDE it doc hdn. O dieu kien tU nhien, tinh doc ciia DDT duy tri
dUdcl2nam[41,
144]
- DDT ky thuat, san pham thUdng mai, chiia khoang 70% dong

phan p, p' -DDT va mot
lUdng
nhd dong phan
o,p'
-DDT [38]. Trong
dieu kien tU
nliien
chi mot
lUdng
nhd DDT dUdc phan huy trong mdi
trUdng do chuyen hoa thanh cac san pham it hoat dong hdn nhU la
DDE, DDD,
DMC,
dicofol, clo benzylat, metoxiclo [81, 106].
a) DDE cd ten goi : 1,1 - diclo 2,2 - bis
(p-clophenyDetUen
ci_(
>-^^A_/"^i
V/
CCl,
^-^ '••
DDE
Hang nam sU phan huy DDT thanh DDE trong mdi trUdng chi
chiem vai phan tram [81, 103]
b) -DDD la mot chat ket tinh mau trang, ndng chay d
109^C,
ben
trong mdi trUdng. Nd chi bien hoa cham thanh
nhUng
hdp chat it hoat

dong
hdn
[106].
H * Diclodiphenyl dicloetan
^^~\^~^—
C^"
^^
* Tetraclodiphenyletan
CHCl2^—
*
TDF
*
Rotan
c) DMC la chat ket tinh cd mau, ndng chay d 70
^C,
DMC it ben
trong mdi trUdng hdn DDT va DDE [81, 106]
12
—
?^
—
CI—
^
/)~^^—C
y)~*^^
"^
4,4'-cUclometyLbenzhidrol
^^ CH3 ^-^ ^^
DCPC
^=

Dimit
•
d) - Dicofol cung dUdc chuyen hoa
tU
DDT trong to chiic
ciia
cd
the con triing. Nd la mot chat long nhdt mau
vang,
tan nhieu trong
nude
hdn DDT va it ben hdn DDT
[106].
OH
*
4,4'
diclo-triclometyl
- benz
hi drol
CI
—
<(
)>-(!:
— ^
)>—
CA '•^'-
Kentan
e) Clobenzylat cung la san pham phan huy
ciia
DDT. Nd khdng

doc vdi tat ca cac loai cdn triing, la chat ket tinh mau vang, ndng chay
d37OC[105]
*^^~'4 //~" ^-^""v y — ^'^ * Etyl
4,4'-diclobenzylat
c
O
^
OCH2CH3
D
San pham cudi
ciing
la metoxiclo. Metoxiclo it ben trong mdi
trUdng hdn DDT, nd chiu tac dung khii clo nhanh hdn
[106].
H
''l,l,l-triclo-2,2-bis(P-metoxiphenyl)etan
CH30-{^^H(^
*
DMDT
CCI3 '-''•
Metoxi - DDT
- DDT thudc nhdm doc loai II,
LD50
: 113 mg/kg [131, 132] ADI :
0,02 mg/kg
[131].
Nong do td'i da trong mdi trUdng lao dong la 1
mg/m^
trong khi quyen la
0_,05mg/m'^

[72].
- DDT
ditdc
dung de
trii"
cac loai cdn triing, sau hai khac nhau
vdi lieu 0,3 - 2 kg/ha (khdng tac hai len ve va chau chau). DDT
tru
sau
bap cai va mudi. Tac dung
trif
sau
ciia
DDT chu yeu la tac dong len he
13
than kinh. Nd bit cac
Id
tren mang te bao than kinh, ngan chan qua
trinh tham
hiit Na+
va lam mat tinh phan cUc cua te bao than kinh
dan den khdng dan truyen dUdc xung
lUdng.
Vi vay DDT dUdc xem nhU
la mot trong cac HCTS quan trong nhat va dUdc
sii
dung rong rai
trong ndng nghiep [41]. Do sU ton
lUu
lau dai trong mdi trUdng nen

ngay nay DDT da bi cam diing
[133].
Nudc ta van cdn mot sd ndi
sii
dung DDT do cac nguon budn lau dUa vao. Ndng dan
sii
dung DDT
trong khau
khii
trung dat, bao quan hat gidng [24, 61].
- DDT tich luy trong to chiic md cua ngUdi va dong vat, luan
chuyen trong cac ddi tUdng tU nhien
ciia
mdi trUdng (dat, nUdc, khdng
khi,
cay cd ) Vi vay mac du da cam sU dung, ngUdi ta van tim thay
DDT va cac san pham chuyen hoa ciia nd trong cac cd quan
phii
tang
cua con ngudi va dong vat [101,
106],
DDT va cac san pham chuyen
hoa cua nd dUdc thai qua
stfa
va nUdc tieu khoang 1% trong ngay. Khi
phan tich DDT d tre sd sinh nhan thay cd khoang 0,24 mg DDT trong 1
kg can nang
ciia
tre sd sinh do
bii sUa

me cd DDT [38]. Lieu chet dd'i
vdi ngudi theo dUdng tieu hoa la 20-30 g DDT d dang nguyen chat, neu
DDT d dang hoa tan trong dau thi chi can 14 g [38]. Theo
Biii
Thanh
Tam, neu udng nham thi lieu gay nhiem doc la 3-5 g
D13T
tinh khiet
[41].
1.4.4.2.2.
HCH - Hexacioxiclohexan,
CeHeClc,
M
=
290,8
- HCH cd ten goi : 1, 2, 3, 4, 5, 6 hexacioxiclohexan
- Cac ten khac : hexaclo, hexacloran,
lindan,
gamakan,
666
[124,
147].
H.Faraday tong hdp HCH
ti^
nam 1925, Vander Linden tim ra
cac dang dong phan cua HCH va chiing dUdc dimg lam HCBVTV
tii
nam
1935.
Cd 8 dong phan

ciia
HCH. NgUdi ta thUdng
sit
dung dong phan
a
14
than kinh. Nd bit cac
Id
tren mang te bao than kinh, ngan chan qua
trinh tham
hiit
Na"*"
va lam mat tinh phan cUc cua
te
bao than kinh
d^n
den khdng
dAn
truyen dUdc xung
lUdng.
Vi vay DDT
dUdc
xem nhu
la mot trong cac HCTS quan trong nhat va dUdc
sii
dung rong rai
trong ndng nghiep [41]. Do sU ton
lUu
lau dai trong mdi trUdng nen
ngay nay DDT da bi cam diing

[133].
Nudc ta van cdn mot so ndi
sii
dung DDT do cac ngudn budn lau dUa vao. Ndng dan sU dung DDT
trong khau khu triing dat, bao quan hat gid'ng [24, 61].
- DDT tich luy trong to chiic md cua ngUdi va dong vat, luan
chuyen trong cac ddi tUdng tU nhien cua mdi trUdng (dat,
nUdc,
khdng
khi,
cay cd ) Vi vay mac du da cam sii dung, ngUdi ta van tim thay
DDT va cac san pham chuyen hoa cua nd trong cac cd quan
phii
tang
ciia
con ngUdi va dong vat [101, 106]. DDT va cac san pham chuyen
hoa
ciia
nd dUdc thai qua siia va nUdc tieu khoang 1% trong ngay. Khi
phan tich DDT d tre sd sinh nhan thay cd khoang 0,24 mg DDT trong 1
kg can nang
ciia
tre sd sinh do
bii sUa
me cd DDT [38]. Lieu chet ddi
vdi ngudi theo dudng tieu hoa la 20-30 g DDT d dang nguyen chat, neu
DDT d dang hoa tan trong dau thi chi can 14 g [38]. Theo Bui Thanh
Tam, neu udng nham
tlii
lieu gay nhiem doc la 3-5 g DDT tinh khiet

[41].
1.4.4.2.2.
HCH - Hexacioxiclohexan,
CQHQCAQ,
M =
290,8
- HCH cd
ttin
goi : 1, 2, 3, 4, 5, 6 hexacioxiclohexan
- Cac ten khac : hexaclo, hexacloran, lindan, gamakan, 666
[124,
147].
H.Faraday tong hdp HCH tit nam 1925, Vander Linden tim ra
cac dang dong phan cua HCH va chiing dUdc dimg lam
tlCBVTV
tit nam
1935.
Cd 8 dong phan cua HCH. Ngudi ta thUdng
sii
dung dong phan a
14
p,
Y,
5-HCH
nhUng chi cd dong phan
y-HCH
lacd
dac tinh
trii"
sau rd ret.

Trong thanh phan HCH cd
tH
10-12%
chat boat hoa la dong phan y cd
70%
dong phan a, cdn lai la cac dong phan khac. Khi trong HCH ky
thuat cd chiia 99% la dong phan
y
- HCH, thi goi la Lindan
[124].
- HCH d dang tinh the mau
tr^ng,
mid
khd
ngiii.
HCH hoa tan
trong cac hidrocacbon chUa no va thdm, it tan trong cac dung mdi
liidrocacbon
mach
thing
va vdng no.
d
nhiet do phdng, HCH tan trong
nude
vdi ti le
lg/100
ml va trong etanol vdi ti le 6,4g/100 ml [38]. Diem
ndng chay cua HCH la
1120C
[114].

- HCH ben vdi anh sang, nhiet do, khdng khi va vdi cac axit
manh, phan huy thanh triclobenzen va
HCl
trong mdi trUdng kiem,
- Doc tinh hoa hoc :
LDQQ
qua mieng 88 mg/kg,
LD50
qua da 300
mg/kg, thudc nhdm doc loai II [124, 131].
- HCH la thudc trii sau cd hoat tinh cao, cd pho tac dung rong,
dUdc sii dung cho nhieu loai cay trong vi nd cd kha nang diet trit nhieu
loai sau hai : sau
due
than, bo canh
ciing
hai
liia,
ray nau. HCH ton
lUu
lau dai trong mdi trUdng nen da bi cam sU dung [133,
1471.
Lieu
cho phep trong mdi trUdng lao dong la 0,2
mg/m'^
khdng khi
[41|.
Tieu
chuan cua My gidi han 0,2-0,5 mg/kg dat. Mudn trong cac loai cay an
cu trong dat da xU

ly
HCH thi phai tien hanh sau thdi gian 4 nam [61].
HCH di vao cd
the
va tich luy trong cac to
chitc
md, gan than,
nao [76, 147]. NgUdi ta da dinh
lUdng
HCH trong to chiic md va mau
cua ngudi tiep
xiic
vdi HCH . Ket qua cho thay : d md
lUdng
a-HCH
nhieu gap 363 lan, y-HCH nhieu gap 124 lan, (3-HCH nhieu gap 83 lan
so vdi ndng do cac chat nay cd trong mau [38,
147].
(^iing
nhU DDT,
H(3H
va cac san
pham
chuyen hoa
ciia
nd dUdc thai qua
sUa
me. Ngay
15
ca

nhitng
ngitdi khdng tiep
xiic
vdi HCH, trong
sUa ciing
cd HCH
vi
nd
ton
lUu
trong thitc an va nUdc udng [25, 35]. Theo Le Trung [54],
Biii
Thanh Tam
[41]
Linda Rosens [37], bieu
liien lam
sang
ciia
nhiem doc
HCH giong nhu nhiem doc DDT, chi khac la bieu hien rd ret hdn. HCH
Cling gay nhiem doc cap tinh va man tinh, lam rdi loan mau va cd quan
tao man. HCH cdn cd tac hai tdi cac qua trinh chuyen hoa tao enzim d
gan va gay thoai hoa
tebao
gan [76, 92].
1.4.5. Tac hai chung cua HCBVTV nhom
cd
photpho
1.4.5.1. Dac tinh chung cua HCBVTV
nliom

ca photpho.
HCBVTV nhdm cd photpho dUdc diing rong rai va pho bien nhat
trong cac loai HCBVTV. Cac HCTS thudng dimg nhat la wofatox,
(metyl parathion), thiophot (parathion), diazinon (basudin),
metamidophot (tamaron, monitor), clorophot
((hphterex),
malathion
(cacbophot), systoc (mecatophot)
a. Tat ca HCBVTV nhdm cd photpho deu cd chung cdng thiic
[106,
136]
RO
0^(S)
\
//
P
(S)
O
day R la gd'c
ankyi,
X la gdc hiiu cd. Tuy theo oxi hay
lUu
huynh chiem vi tri 1 hoac 2 ma ngUdi ta phan ra may loai nhU sau :
-
Photphat:
P\ P\
RO OX
C2H5O
0^^^N02
Paraoxon

16
Thiophotphat
A
RO
OX
R'
^
//
s
Pv
RO'^
0-{^
V02
Dithiophophat
RQ .S
A
RO SX
^=
Metylparathion : R la CH3
^=
Parathion :R la
(^2^5
CHoO
S
^ \
II
P
/ !
CH3O S-CHCOOC2H5
CH2COOC2H5

CH30^
S
CHsO^
S-CH2CONHCH3
- Clophotphat
RO
(Flophotphat)
^'-
Malathion
Bi 58 (dimetoat)
RO CI
(F)
- Photphatdiamidat
R2N^
^O
R2N''
^
OX
b.
Ndi chung trong cac hdp chat cd photpho khi S thay the cho
O
thi hdp chat it doc hdn. TU nam 1938 den nay ngUdi ta da tdng hdp
dUdc 50.000 hdp chat cd photpho, cd 50 chat dUdc dung
lam
HCBVTV
[38,
56].
c. Ve boat tinh sinh hoc, cac hdp chat cd photpho deu rat doc ddi
vdi ngitdi va dong vat man ndng [98, 105, 106].
d. Tinh chat chung

cda
HCBVTV nhdm cd photpho [39, 92, 136]
f>(ft!
-^or
^
/
• — "-•'
";\.7"
"'.,.,:,
\.'l!i
17
••M*r
».^ '-
'
*•
- Cac hdp chat cd photpho deu cd ap suat hdi cao, de bay hdi, la
nhfing
chat doc dUdng ho hap. Chiing de hoa tan trong cac dung mdi
hiiu cd va dau md,
dl
bi phan huy nen
„
khd thu hdi dUdc chinh
pham ban dau.
*•
- Dac diem chung ve hoa hoc ciia cac hdp chat cd photpho la de
bi thuy phan.
RO.
RO
P(S)

RO
OX
(S)
+0H-
RO.
0(S)
HO P/
RO^
OX
(S)
II
HO
P
=
0 + XOH
RO^
(S)
Tac nhan thuy phan den gan chat phan
ling
va tan cdng vao
nguyen tii photpho. Budc (I) xay ra cham hdn,
budc
(II) xay ra nhanh,
tao thanh este ddn gian hdn
ciia
axit photphoric (day gd'c
hfitu
cd ra).
- Tinh chat quan trong thii hai la phan
ling

hoat hoa nhan
photpho. Phan
ling
xay
ra
thUdng tao thanh chat
lic
che enzim
cholinesteraza manh hdn, phan
Idn
chuyen nhdm
y
P=S thanh nhdm
\
p=o.
(C2H50)2 -
P
-
o/
\N02
+ O2 + H2O ^ (C2H50)2
-P
-0-(^
^ NO2 + H2SO4
Parathion
-a
Paraoxon
- Di ddi vdi phan
ling
hoat hoa la phan

uEng
phan huy. Cac hdp
chat cd photpho chuyen hoa thanh din xuat trung gian kem doc hdn la
chat
chinh
pham. Dac diem nay cd the tim thay d dimetoat (Bi 58)
[106].
CH3O.
^P
CHsO-^
Din
I;.''
CHgO^
*~
^
S-CH2CONHCH3 Phan huy
aetoat
(I) (90%)
(10%)
0
CHsO.^
CHsO"'^
S-CH2C00H
(HI)
r
CH30
S
CH2CONHCH3
Axit 0,0 -dimetyl dithiphotphoryl axetic
18

Axit 0,0 - dimetyl dithiphotphoryl axetic kem doc hdn dimetoat den
3.400 lan.
1.4.5.2. Dxidng xam nhap cua HCBVTV nhom
ca
photpho vao
ccf
the:
'^'
HCBVTV nhdm cd photpho xam nhap vao cd the qua dudng hd
hap,
tieu hoa, da. Su hap thu cac hdp chat cd photpho d niem mac
dudng tieu hoa dien ra rat nhanh, chi sau vai
phiit
da xuat hien cac
dau hieu nhiem doc [76, 81]. Qua trinh hap thu qua da cham hdn,
khoang sau 2 gid mdi bat dau cd cac dau hieu ciia sU iic
che
enzim
cholinesteraza,nhttng
dau hieu nay keo dai 2 ngay [38].
1.4.5.3. Chuyen hoa cua HCBVTV nhom
cd
photpho trong
ccf
the.
- HCBVTV nhdm cd photpho de tan trong
lipit.
Chiing dUdc hap
thu nhanh chdng vao man, cac dich the cua to chiic va dat dUdc ndng
do cao trong cac

synap
than
Idnh
trung Udng va ngoai vi [41, 76].
HCBVTV nhdm cd photpho va cac san pham chuyen hoa ciia nd tap
trimg
cao nhat d gan va dUdc thai trit theo dudng tiet nieu [1, 105].
- HCBVTV cd photpho cd the phan huy thanh
nhflng
chat it doc
hdn,
nhttng
chat nay cd the hoa tan trong nUdc va thai
tr^
qua dUdng
tiet nieu [1, 105]
- HCBVTVcd photpho chuyen thanh dang khac, doc hdn,
lic
che
enzim cholinesteraza manh hdn [38, 57]. Qua trinh oxy hoa cac hdp
chat cd photpho dUdc thUc hien d gan, tao nen axit thiophotphoric va
dithiophotphoric. Ngoai ra cdn cd qua trinh thuy phan nhd phan
ling
phophataza, cacboxylesteraza, cacboxylamindaza [76, 81, 83].
19
1.4.5.4.
Ccf
che nhiem doc
- HCBVTV cd photpho la nhiing chat doc ddi vdi nhieu enzim.
NhUng cd che nhiem doc chii yen la do iic che hoat dong cua enzim

cholinesteraza, gay tinh trang tich luy nhieu chat axetylcholin dan
den nhiing rdi loan nghiem trong qua trinh dan truyen d cac synap
than kinh va
hitng
phan qua
miic
do he thdng than kinh trung Udng.
Vi vay chiing dUdc goi la nhiing chat doc than
Idnh
[81, 106].
- Binh thudng enzim
chohnesteraza
tac dung vdi axetylcholin
Sau khi tac dung, enzim cholinesteraza dUdc hoi phuc nhd phan
ling
thuy phan ciia hdp chat cholinesteraza-axetyl hoa.
- Trong trUdng hdp nhiem doc HCBVTV- cd photpho thi enzim
cholinesteraza ket hdp vdi phan tii HCTS cd photpho tao thanh hdp
chat ben viing, khd thuy phan, ket qua la enzim cholinesteraza bi
iic
che
[1,41].
- HCBVTV-cd photpho dUdc dung de : chdng sau benh cho cac
loai cay cdng nghiep, cay an qua, rau,
liia
mau, diet cd dai, chdng nam,
lam rung la, diet trii rudi, mudi, bo chet [12, 22, 28].
L
4.6.
Gidi tbieu mot so

HCTS-eaphotpho
tbiidng diing :
1.4.6.1. Parathion [21, 117]
- Parathion cd cdng thiic tong quat: C10H14NO5PS, M
=
291,
26,
; ' • C2H5O
S
\r^
-
C2H5O 0(;^i>N02
Ten hoa hoc : 0,0 - Dietyl 0-p nitrophenyl
photphothioat:
20
Ten khac : Alkron, bladan, folidol, E 605,
etyl
parathion,
thiophot
Nam dang ky dau tien : 1948, Parathion la chat diet cdn triing
va sau bo. Parathion la chat long mau nau sam, miii gidng nhU
miu
tdi,
diem sdi : 157 -
162^0/
0,6 mm Hg, ap suat hdi la
3,2.10-**
mmHg d
30*^0.
Parathion de tan trong cac dung mdi hiiu cd va dau, it tan trong

nUdc[117].
- Cung nhu cac HCTS-cd phopho, parathion de bi thuy phan.
Tinh chat quan trong
thii
hai la phan
ling
hoat hoa nhan photpho,
phan ling xay ra thUdng tao thanh chat
tie che
enzim cholinestaraza
manh hdn. Trong cd
the
parathion chuyen hoa thanh paraoxon doc hdn
parathionlOOO lan [39, 56].
- Parathion thudc nhdm doc loai I. Hdp chat nay cUc ky doc vdi
dong vat cd
vii
[76], Parathion nhiem doc qua dUdng hd hap, da, tieu
hoa. Nd dUdc chiing minh cd tac hai man tinh nhU gay cac khoi u trong
thUdng than, chiing teo va thoai hoa vong mac va sU thoai hoa ciia day
than
Idnh
hdng. Cac tac gia da ket luan rang parathion la chat gay
khoi u loai C, cd kha nang gay ung thu tren ngUdi [98, 117]. LD50 la
13 mg/kg,
ADI:
0,005 mg/kg the trong [114, 132].
- Cac dac diem ve sinh ly va sinh hoa : Parathion la chat diet cdn
triing. Parathion tac dong len ngudi bang
each

gay
iic
che khdng hdi
phuc enzim cholinesteraza, gay tich luy axetylcholin. Su nhiem doc
lam giam chiic nang ciia he than
Idnh
trung Udng [81, 136].
1.4.6.2
Metylparathion,
CgHioNOsPS,
M
=
263,
2[138,
146]
Ten hoa hoc :
0,0-dimethyl
0,4-nitrophenyl-photphothioat
21