ANALYSIS OF PESTICIDE
RESIDUES
IN PENINSULAR
MALAYSIAN
WATERWAYS TAN GUAN HUAT,* GOH SWEE HOCK and K. VIJAYALETCHUMY Department of Chemistry. University of Malaya, 59100 Kuala Lumpur. Malaysia
(Received November 1990) Abstract. The use oforganochlorine pesticides has caused concern due to their effects on human health and the Malaysian aquatic ecosystem, particularly so in view of their persistent and bioaccumulative properties. Since the extent of organochlorine pesticide pollution in Malaysian waterways is unknown except for isolated instances, a systematic survey has now been carried out. Water samples from various rivers were extracted, cleaned up with Florisil and analysed for the individual organochlorine pesticides by gas chromatography (GC) with an electron capture detector (ECD). DDE, DDT and heptachlor were present in all the river water samples of the west coast of Peninsular Malaysia. Other organochlorine pesticides were also identified from the water samples. However, the levels of all these are still below criteria values for Malaysian aquatic life, indicating that organochlorine pesticide pollution is less of a problem than other organic or inorganic pollutants.
Introduction Pesticides have been found all over the world. In 1966, just a little over 20 years after its i n t r o d u c t i o n , D D T was f o u n d in seals in the A n t a r t i c ( G e o r g e et al., 1966). Public attention was first focussed on the use o f pesticides following the publication o f Silent Spring (Carson, 1962). The increasing usage a n d variety of organic chemicals in tropical a g r o b a s e d countries is placing a heavy pollution b u r d e n on the aquatic environment. The extensive use o f pesticides a n d herbicides have created concern over their effects on living aquatic resources. The lipophyllic nature and low chemical a n d biological d e g r a d a t i o n rate o f m a n y o f the organochlorine pesticides lead to the accumulation o f these c o m p o u n d s in biological tissue and subsequent magnification of concentrations in organisms progressing up the food chain. Chronic and subtle, yet i m p o r t a n t changes in the ecosystem have been attributed to the biomagnification phenomenon. In Malaysia, pesticides and herbicides m a y be responsible for some cases o f fish mortality attributed to u n k n o w n causes (Kanniah, 1983). Thus, a study of residue levels of these c o n t a m i n a n t s in M a l a y s i a n river waters is of great i m p o r t a n c e as large scale application o f pesticides in agricultural a n d forest areas have been practised in Malaysia in the past. B a c k g r o u n d levels need to be m o n i t o r e d since there are specific legislations covering pesticide levels for drinking a n d ambient water, for food products and in land being used for housing or growing crops ( G o b et al., 1986). C o n t a m i n a t i o n o f waterways can occur from surrounding terrain, precipitation from a t m o s p h e r e , accidental spills of pesticides in the watershed area or a cross connection in a * Author to whom correspondence should be addressed. Environmental Monitoring and Assessment 19: 469-479, 1991. 9 1991 Kluwer Academic Publishers. Printed in the Netherlands.
470
TAN
GUAN
HIJAT
ET AL.
distribution system. A study was carried out to estimate the extent of environmental contamination by organochlorine pesticides in Malaysian waters in the west coast of Penisular Malaysia; from Perlis to Johor. Monitoring of trace levels of these chlorinated pesticides was carried out in greater detail for the Klang River basin.
Experimental SELECTION OF WATER SAMPLES Two major groups of river water were collected - one in the Klang River basin for monitoring purposes, and the other in major river basins along the west coast of Malaysia for screening purposes. Sampling stations were selected to represent water outlets for domestic, agricultural and industrial use. All water samples were analysed to determine the residue levels of organochlorine pesticides. The grab sample technique was used whereby the water was fished out of the river and filled into amber bottles. Water samples were collected in duplicates and were acidified to p H 2 with sulfuric acid to eliminate biological activity in the water. APPARATUS (a) Shimadzu Gas Chromatograph G C 9A with electron capture detector (ECD); glass column (2m X 3mm I.D.)packed with G P 1.5% SP-2250/1.95% SP-2401 on 100/120 Supelcoport. (b) Rotary vacuum evaporator. (c) Glass chromatographic columns (15mm I.D.) fitted with teflon stopcocks and solvent reservoirs at the top. REAGENTS G C / H P L C grade solvents were used. The impurity levels of all solvents and reagents used did not exceed an acceptable blank when subjected to the complete procedure without the sample. (a) (b) (c) (d) (d) (f)
Freon, Trichlorotrifluoroethane, CC13CF3, from DuPont Hexane, from FSA Lab Supplies Diethyl ether, from B D H Petroleum ether, b.p.: 60-80 ~ from BDH Anhydrous sodium sulfate, from Fluka Florisil, from Sigma, 60-100 mesh activated at 450 ~ overnight in a large porcelain basin. After cooling, distilled water was added to make a 1.5% v / w water/Florisil and this Florisil was stirred for 3 hours before use.
LIQUID-LIQUIDEXTRACTION All glassware in this procedure was washed with the extraction solvent. 250 m L of the river water sample was extracted with 3X8mL of freon and the freon was distilled offbefore the
PESTICIDE RESIDUES IN M A L A Y S I A N W A T E R W A Y S
471
sample was cleaned up. FLORISIL COLUMN CHROMATOGRAPHY
Florisil column chromatography was used for fractionation of organochlorine pesticides from the water samples by elution with solvents of increasing polarity (Grob, 1985; Onuska, 1989; Thier et al., 1987; US-EPA 608, 1984). The chromatographic columns were slurry packed with 7 g Florisil and settled by tapping. Approximately 0.5 cm anhydrous sodium sulfate was placed at the top of the column to absorb any water in the sample or the solvent. The column was pre-eluted with 60 mL of petroleum ether. Just prior to the exposure of the sodium sulfate layer to the air, the washings from the vial containing the extracted sample was placed on the column and allowed to sink below the sodium sulfate. The sides of the column above the sodium sulfate layer were rinsed with petroleum ether and a total of 200 m L petroleum ether was poured into the column. The flow rate was adjusted to 5 m L per minute and the eluate was collected in a round bottom flask. The elution was done with five different solvent mixtures (Van Hall, 1985); (See Table I for eluting solvents and elution patterns). The eluates were then evaporated to dryness using a rotary evaporator and the residues were dissolved in 1 mL HPLC-grade hexane for gas chromatographic analysis. A N A L Y T I C A L PROCEDURES
The separation and quantification of the pesticide residues were performed with the Shimadzu G C 9A using a mixed phase column. The operating temperatures were: injector, 250 ~ oven temperature was maintained at 180 ~ for 13 minutes, then TABLE I Percentage of recovery and elution pattern of chlorinated pesticides. Recovery (%) Chlorinated pesticides
Amount added (#g)
BHC - c~ BHC - / 3 Lindane (3' - BHC) D D E (o, p') D D T (p, p') Heptachlor Endosulfan 1 Endosulfan II Endrin Dieldrin Aldrin
1.00 1.00 1.00 1.00 1.26 1.52 1.68 0.84 1.30 1.26 1.12
Fraction I
Fraction II
Fraction lII
94.0 98.0 96.0 95.0 85.0 88.0 93.0 93.0 105.0 98.0 96.0
No. of analyses 4 4 4 4 4 4 4 4 4 4 4
Fraction I: 6% diethyl ether in petroleum ether Fraction I1: 15% diethyl ether in petroleum ether Fraction II1: 50% diethyl ether in petroleum ether Two other eluting solvents: petroleum ether to separate PCBs from fraction I; diethyl ether to wash column of all organic contaminants.
472
TAN
GtJAN
HUA1
ET AL.
p r o g r a m m e d at 5 ~ to 190 ~ a n d held there for 11 minutes. Nitrogen was used as carrier gas at a flow rate o f 50 m L / m i n , the sample size was 2 #L. CONCENTRATION MEASUREMENT The direct c o m p a r i s o n technique (Van Hall, 1985; U S - E P A 608, 1984) using external standards was chosen for this study because the pesticides identified in the samples clearly matched k n o w n organochlorine pesticide standards on the basis o f their retention times. The concentration o f pesticide residues in the water sample was calculated using the formula (Van Hall, 1985; U S - E P A 608, 1984): #g/L=
A) 8 0 % of the samples from the west coast rivers. Endosulfan is another widely used agricultural pesticide. In the Sg. Perak samples (5 of them), one can observe an interesting trend from the results of the analysis (Figure 1). The level of D D E slowly decreases from 0.99 ppb to 0.27 ppb close to the estuary. This may be due to dilution from the tributaries as the river flows downstream. As for D D T , its level slowly decreases to a minimum at 14.40 km from the estuary and then increases again as the fiver approaches the estuary. The decreasing level can be explained
474
TAN GIJAN HUAT ETAL. TABLE IV Pesticide residue levels in the major river basins of the west coast of Peninsular Malaysia.
River
Distance
Residue level ng/L
from Linestuary dane (km) (,)
Sg. Perlis Sg. Kedah Sg. Kcdah Sg. Merbok Sg. Muda Sg. Perai Sg. Jejawi Sg. Kerian Sg. Kurau Sg. Sepetang Sg. Beruas Sg. Beruas Sg. Perak Sg. Perak Sg. Perak Sg. Perak Sg. Perak Sg. Bernam Sg. Tengi Sg. Selangor Sg. Buloh Sg. Mclaka Sg. Duyong Sg. Kcsang Sg. Muar Sg. Batu Pahat Sg. Mersing Sg. Mcrsing Sg. Ulu Scdili Sg. Sedili Bcsar Sg. Johor Sg. Pontian Sg. Semberong
6.76 38.47 17.22 20.12 12.88 15.29 20.44 16.96 47.52 2.24 28.32 9.12 3.20 5.92 14.40 32.00 39.70 17.60 6.76 63.43 39.45 18.52 7.25 49.27 22.06 20.77
0.05
/3-BHCAldrin Endo- Endo- Dielsulfan sulfan drin I II
0.73 0.22 0.32
0.02
0.23 0.06 0.15
Endrin DDE DDT Heptachlor
1.36 0.26 0.19
1.55
1.11
0.66
0.15 0.15
0.08 0.04
1.94 0.86 0.91
0.33
0.39
0.02 1.44 0.90
0.70
0.49
0.54 0.22
0.24
0.03
0.41
0.46
0.57 0.04
0.04
56.99 66.98 61.02 237.80 0.05
0.40 0.04 0.14 0.00 0.01 0.77 0.63
0.02 0.01 0.02 0.02
0.52
0.43 0.33 44.00 0.44 0.09 0.12 0.21 0.48
4.36 1.25 4.48 0.06 4.24 8.86 0.25 10.05 0.16 3.29 1.36 0.15 2.11 0.10 1.05 0.15 0.72 0.11 2.08 0.07
1.23 0.80 0.26 0.21 0.90 0.92 0.14 1.24 2.54 3.23 0.77 0.72
0.82 0.61 0.91 0.83 0.70 0.71 0.74 0.73 0.82 0.68 0.58 0.61 0.41 0.27 0.57 0.65 0.99 1.12 0.91 1.53 1.21 0.52 0.60 0.65 1.13 0.70 0.70 0.65 0.55 0.43 0.59 0.61 0.78
22.20 25.95 3.76 33.68 68.69 4.11 7.41 9.28 32.10 5.53 8.88 7.78 13.73 5.65
1.10 0.94 2.17 1.50 1.57 2.60 1.77 1.55 0.65 0.77 1.10 1.28 0.66 0.96 1.83 6.14 1.09 19.94 1.38 3.28 1.72 17.74 0.29 8.05 0.76 13.46 1.50 0.92 1.60 11.55 1.75 7.86 1.29 35.51 2.18 9.60 1.01 8.07 1.02 18.17 1.82 5.35 2.93 4.13 3.38 5.89 1.12 3.82 1.34 6.16
* Calculated amount includes a-BHC, which co-elutes with Lindane during G.C. analysis.
by m e a n s o f the d i l u t i o n c a u s e d b y the tributaries. T h e o r c h a r d s in the s u r r o u n d i n g area, especially the g u a v a faryns, m a y b e t h e c o n t r i b u t i n g f a c t o r to the i n c r e a s e in t h e D D T level as the river f l o w s d o w n s t r e a m . H o w e v e r , this t r e n d is yet t o b e c o n f i r m e d . F r o m T a b l e III, o n e c a n o b s e r v e t h e c h a n g i n g levels o f the r e s i d u e s in the f o u r s t a t i o n s o f t h e K l a n g R i v e r basin. T h e levels o f the residues are g e n e r a l l y low; n e v e r t h e l e s s , t h e y are still existent.
PESTICIDE
20
RESIDI_JES
IN MALAYSIAN
475
WATERWAYS
'
19
18
17 16 15
\ v
c
\
d
14 13
12 11 10 9
Ld n
8
7
Ld n,
5 4 3 2
0 T
o,
3.20
~
5.92 [3
ODE
Fig. 1.
,
14.40 DISTANCE: fROM [STUARY / + DDT
32.00
39.70
(krn) Hepfachlor
Some residue levels in Sg. Perak.
From the screening test done in the west coast rivers and the monitoring done in the Klang River basin, it can be concluded that the Malaysian rivers are not free from pesticide residue contaminants, though in most, but not all cases, the levels have not exceeded the criteria specified in Table V (Goh et al., 1986; Yap, 1987). Steps should be taken to monitor the levels in the more contimanited rivers like SG. Muda and Sg. Merbok. Though the residue levels of the west coast rivers have all been tabulated, it must be said TABLE V Criteria for some chlorinated pesticides in river water.* Criterion / n g / L Chlorinated pesticides
Livestock
Aquatic life
H u m a n health
Aldrin/Dieldrin BHC DDT/DDE Endosulfan Endrin Heptachlor Lindane
90.00 600.00 300.00 12000.00 90.00 60.00 600.00
8.00 130.00 4.00 10.00 14.00 60.00 380.00
20.00 2000.00 100.00 10000.00 60.00 50.00 2000.00
* Malaysian Interim Standards 1986 (Goh et al., 1986)
476
FAN
(ItIAN
]t[JAT
1~71 A I . .
t h a t t h e results are n o t yet c o m p r e h e n s i v e b e c a u s e this was o n l y a o n e - t i m e m o n i t o r i n g test. M o r e m o n i t o r i n g n e e d s to b e d o n e in these rivers as well as t h e K l a n g R i v e r b a s i n to o b s e r v e t h e t r e n d s a n d c o n f i r m t h e o r g a n i c c h e m i c a l p o l l u t i o n level o f t h e s e river basins.
References Carson, R.: 1962, Silent Spring, Houghton Mifflin, Boston. George, .l.L. and Frear, D. E. H.: 1966, .L Appl. Ecol., Suppl 3, 155-166. Goh, S. H., Lira. R. P. and Yap, S. Y.: 1986, Water QuaffO' Criteria and Standards For Malaysia, Vol. 4, pp. 59-148, Institute Of Advanced Studies, University of Malaya. Grob, R. L.: 1985, Modern Practice of Gas Chromatography, 2nd Ed., John Wiley and Sons, N.Y. Ka nniah, R.: 1983, 'Pesticide Abuse in Malaysia: Problems and Issues' in Proceedings of the Symposium on the Environment. Development and Natural Resource Crisis in Asia and the Pacific', Oct. 23, 1983, Penang, Malaysia, pp. 324-334. Kurtz, David A.: 1988, 'Pesticides Around The World', ChemistO, in Britain, 9, 6-8. Onuska, F. 1.: 1989..l. High Res. Chrom, 12, 4-11. Thier, H. P. and Zeumer, H. (Eds.): 1987, Manual of Pesticide Residue Analysis, Vol 1, VCH Press. Van Hall, C. E. (Ed.): 1985, Standard Methods for the Examination oj" Water and Waste Water, pp. 538-555, American Society for Testing and Materials. Yap, S. Y.: 1987, 'Water Quality Criteria for the Protection of Aquatic Life and its Users in Tropical Asian Reserwfirs', in Proceedings of A Workshop On Reservoir Fishery Management And Development In Asia, 23 28 Nov 1987, Kathmandu, Nepal, pp. 246. USEPA Test Method 608: 1984, Organochlorine PesticidesAndPCBs, EMSL-USEPA, Cincinnati, OH, U.S.A.
Appendix I. Major River basins of Peninsular Malaysia Basin No.
Name of River
Basin No.
Name of River
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Sg. Perlis Sg. Kedah Sg. Merbok Sg. Muda Sg. Prai Sg. Jejawi Sg. Kerian Sg. Kurau Sg. Sepetang Sg. Beruas Sg. Perak Sg. Bernam Sg. Tenggi Sg. Selangor Sg. Buloh Sg. Kelang Sg. Linggi
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Sg. Melaka Sg. Duyong Sg. Kesang Sg. Muar Sg. Pahat Sg. Johor Sg. Sedili Sg. Mersing Sg. Pontian Sg. Pahang. Sg. Kuantan Sg. Kemaman Sg. Kerteh Sg. Paka Sg. Dungun Sg. Trengganu Sg. Besut Sg. Kelantan
PESTICIDE
RESIDUES
\
IN MALAYSIAN
477
WATERWAYS
i
102 ~
104 ~
6~
Appendix I. Major river basins of Peninsular Malaysia.
478
TAN
A
GUAN
HUAT
ETAL.
or
Sampling Station
NG
BUKIT
\ SRI KEMBANGAN PORT KLANG
a
f
o
a
u
& |
Appendix 2. Sampling stations in the Klang River Basin.
PESTICIDE RESIDUES IN MALAYSIAN WATERWAYS 13
1. Lindane & a-BHC 2. /3-BHC 3. Aldrin 4. Heptachlor 5. Heptachlor epoxide 6. o,p'-DDE 7. Dieldrin 8. Endrin 9. Endosulfan 10. p,p'-DDT
Retention time/rain
1'o
~o
ab
Analytica column:
GP 1.5% SP-2250/1.95% SP-2401 on Supelcoport.
Carrier gas:
N 2 at 50 ml/min
Column Temperature:
180 ~ -13 rain 5~ 190 ~ -11 min
Detector:
Electron Capture
Injection volume:
2 ~L
-
Appendix 3: Gas chromatogram of pesticide standards.
479
RESIDUES
IN PENINSULAR
MALAYSIAN
WATERWAYS TAN GUAN HUAT,* GOH SWEE HOCK and K. VIJAYALETCHUMY Department of Chemistry. University of Malaya, 59100 Kuala Lumpur. Malaysia
(Received November 1990) Abstract. The use oforganochlorine pesticides has caused concern due to their effects on human health and the Malaysian aquatic ecosystem, particularly so in view of their persistent and bioaccumulative properties. Since the extent of organochlorine pesticide pollution in Malaysian waterways is unknown except for isolated instances, a systematic survey has now been carried out. Water samples from various rivers were extracted, cleaned up with Florisil and analysed for the individual organochlorine pesticides by gas chromatography (GC) with an electron capture detector (ECD). DDE, DDT and heptachlor were present in all the river water samples of the west coast of Peninsular Malaysia. Other organochlorine pesticides were also identified from the water samples. However, the levels of all these are still below criteria values for Malaysian aquatic life, indicating that organochlorine pesticide pollution is less of a problem than other organic or inorganic pollutants.
Introduction Pesticides have been found all over the world. In 1966, just a little over 20 years after its i n t r o d u c t i o n , D D T was f o u n d in seals in the A n t a r t i c ( G e o r g e et al., 1966). Public attention was first focussed on the use o f pesticides following the publication o f Silent Spring (Carson, 1962). The increasing usage a n d variety of organic chemicals in tropical a g r o b a s e d countries is placing a heavy pollution b u r d e n on the aquatic environment. The extensive use o f pesticides a n d herbicides have created concern over their effects on living aquatic resources. The lipophyllic nature and low chemical a n d biological d e g r a d a t i o n rate o f m a n y o f the organochlorine pesticides lead to the accumulation o f these c o m p o u n d s in biological tissue and subsequent magnification of concentrations in organisms progressing up the food chain. Chronic and subtle, yet i m p o r t a n t changes in the ecosystem have been attributed to the biomagnification phenomenon. In Malaysia, pesticides and herbicides m a y be responsible for some cases o f fish mortality attributed to u n k n o w n causes (Kanniah, 1983). Thus, a study of residue levels of these c o n t a m i n a n t s in M a l a y s i a n river waters is of great i m p o r t a n c e as large scale application o f pesticides in agricultural a n d forest areas have been practised in Malaysia in the past. B a c k g r o u n d levels need to be m o n i t o r e d since there are specific legislations covering pesticide levels for drinking a n d ambient water, for food products and in land being used for housing or growing crops ( G o b et al., 1986). C o n t a m i n a t i o n o f waterways can occur from surrounding terrain, precipitation from a t m o s p h e r e , accidental spills of pesticides in the watershed area or a cross connection in a * Author to whom correspondence should be addressed. Environmental Monitoring and Assessment 19: 469-479, 1991. 9 1991 Kluwer Academic Publishers. Printed in the Netherlands.
470
TAN
GUAN
HIJAT
ET AL.
distribution system. A study was carried out to estimate the extent of environmental contamination by organochlorine pesticides in Malaysian waters in the west coast of Penisular Malaysia; from Perlis to Johor. Monitoring of trace levels of these chlorinated pesticides was carried out in greater detail for the Klang River basin.
Experimental SELECTION OF WATER SAMPLES Two major groups of river water were collected - one in the Klang River basin for monitoring purposes, and the other in major river basins along the west coast of Malaysia for screening purposes. Sampling stations were selected to represent water outlets for domestic, agricultural and industrial use. All water samples were analysed to determine the residue levels of organochlorine pesticides. The grab sample technique was used whereby the water was fished out of the river and filled into amber bottles. Water samples were collected in duplicates and were acidified to p H 2 with sulfuric acid to eliminate biological activity in the water. APPARATUS (a) Shimadzu Gas Chromatograph G C 9A with electron capture detector (ECD); glass column (2m X 3mm I.D.)packed with G P 1.5% SP-2250/1.95% SP-2401 on 100/120 Supelcoport. (b) Rotary vacuum evaporator. (c) Glass chromatographic columns (15mm I.D.) fitted with teflon stopcocks and solvent reservoirs at the top. REAGENTS G C / H P L C grade solvents were used. The impurity levels of all solvents and reagents used did not exceed an acceptable blank when subjected to the complete procedure without the sample. (a) (b) (c) (d) (d) (f)
Freon, Trichlorotrifluoroethane, CC13CF3, from DuPont Hexane, from FSA Lab Supplies Diethyl ether, from B D H Petroleum ether, b.p.: 60-80 ~ from BDH Anhydrous sodium sulfate, from Fluka Florisil, from Sigma, 60-100 mesh activated at 450 ~ overnight in a large porcelain basin. After cooling, distilled water was added to make a 1.5% v / w water/Florisil and this Florisil was stirred for 3 hours before use.
LIQUID-LIQUIDEXTRACTION All glassware in this procedure was washed with the extraction solvent. 250 m L of the river water sample was extracted with 3X8mL of freon and the freon was distilled offbefore the
PESTICIDE RESIDUES IN M A L A Y S I A N W A T E R W A Y S
471
sample was cleaned up. FLORISIL COLUMN CHROMATOGRAPHY
Florisil column chromatography was used for fractionation of organochlorine pesticides from the water samples by elution with solvents of increasing polarity (Grob, 1985; Onuska, 1989; Thier et al., 1987; US-EPA 608, 1984). The chromatographic columns were slurry packed with 7 g Florisil and settled by tapping. Approximately 0.5 cm anhydrous sodium sulfate was placed at the top of the column to absorb any water in the sample or the solvent. The column was pre-eluted with 60 mL of petroleum ether. Just prior to the exposure of the sodium sulfate layer to the air, the washings from the vial containing the extracted sample was placed on the column and allowed to sink below the sodium sulfate. The sides of the column above the sodium sulfate layer were rinsed with petroleum ether and a total of 200 m L petroleum ether was poured into the column. The flow rate was adjusted to 5 m L per minute and the eluate was collected in a round bottom flask. The elution was done with five different solvent mixtures (Van Hall, 1985); (See Table I for eluting solvents and elution patterns). The eluates were then evaporated to dryness using a rotary evaporator and the residues were dissolved in 1 mL HPLC-grade hexane for gas chromatographic analysis. A N A L Y T I C A L PROCEDURES
The separation and quantification of the pesticide residues were performed with the Shimadzu G C 9A using a mixed phase column. The operating temperatures were: injector, 250 ~ oven temperature was maintained at 180 ~ for 13 minutes, then TABLE I Percentage of recovery and elution pattern of chlorinated pesticides. Recovery (%) Chlorinated pesticides
Amount added (#g)
BHC - c~ BHC - / 3 Lindane (3' - BHC) D D E (o, p') D D T (p, p') Heptachlor Endosulfan 1 Endosulfan II Endrin Dieldrin Aldrin
1.00 1.00 1.00 1.00 1.26 1.52 1.68 0.84 1.30 1.26 1.12
Fraction I
Fraction II
Fraction lII
94.0 98.0 96.0 95.0 85.0 88.0 93.0 93.0 105.0 98.0 96.0
No. of analyses 4 4 4 4 4 4 4 4 4 4 4
Fraction I: 6% diethyl ether in petroleum ether Fraction I1: 15% diethyl ether in petroleum ether Fraction II1: 50% diethyl ether in petroleum ether Two other eluting solvents: petroleum ether to separate PCBs from fraction I; diethyl ether to wash column of all organic contaminants.
472
TAN
GtJAN
HUA1
ET AL.
p r o g r a m m e d at 5 ~ to 190 ~ a n d held there for 11 minutes. Nitrogen was used as carrier gas at a flow rate o f 50 m L / m i n , the sample size was 2 #L. CONCENTRATION MEASUREMENT The direct c o m p a r i s o n technique (Van Hall, 1985; U S - E P A 608, 1984) using external standards was chosen for this study because the pesticides identified in the samples clearly matched k n o w n organochlorine pesticide standards on the basis o f their retention times. The concentration o f pesticide residues in the water sample was calculated using the formula (Van Hall, 1985; U S - E P A 608, 1984): #g/L=
A) 8 0 % of the samples from the west coast rivers. Endosulfan is another widely used agricultural pesticide. In the Sg. Perak samples (5 of them), one can observe an interesting trend from the results of the analysis (Figure 1). The level of D D E slowly decreases from 0.99 ppb to 0.27 ppb close to the estuary. This may be due to dilution from the tributaries as the river flows downstream. As for D D T , its level slowly decreases to a minimum at 14.40 km from the estuary and then increases again as the fiver approaches the estuary. The decreasing level can be explained
474
TAN GIJAN HUAT ETAL. TABLE IV Pesticide residue levels in the major river basins of the west coast of Peninsular Malaysia.
River
Distance
Residue level ng/L
from Linestuary dane (km) (,)
Sg. Perlis Sg. Kedah Sg. Kcdah Sg. Merbok Sg. Muda Sg. Perai Sg. Jejawi Sg. Kerian Sg. Kurau Sg. Sepetang Sg. Beruas Sg. Beruas Sg. Perak Sg. Perak Sg. Perak Sg. Perak Sg. Perak Sg. Bernam Sg. Tengi Sg. Selangor Sg. Buloh Sg. Mclaka Sg. Duyong Sg. Kcsang Sg. Muar Sg. Batu Pahat Sg. Mersing Sg. Mcrsing Sg. Ulu Scdili Sg. Sedili Bcsar Sg. Johor Sg. Pontian Sg. Semberong
6.76 38.47 17.22 20.12 12.88 15.29 20.44 16.96 47.52 2.24 28.32 9.12 3.20 5.92 14.40 32.00 39.70 17.60 6.76 63.43 39.45 18.52 7.25 49.27 22.06 20.77
0.05
/3-BHCAldrin Endo- Endo- Dielsulfan sulfan drin I II
0.73 0.22 0.32
0.02
0.23 0.06 0.15
Endrin DDE DDT Heptachlor
1.36 0.26 0.19
1.55
1.11
0.66
0.15 0.15
0.08 0.04
1.94 0.86 0.91
0.33
0.39
0.02 1.44 0.90
0.70
0.49
0.54 0.22
0.24
0.03
0.41
0.46
0.57 0.04
0.04
56.99 66.98 61.02 237.80 0.05
0.40 0.04 0.14 0.00 0.01 0.77 0.63
0.02 0.01 0.02 0.02
0.52
0.43 0.33 44.00 0.44 0.09 0.12 0.21 0.48
4.36 1.25 4.48 0.06 4.24 8.86 0.25 10.05 0.16 3.29 1.36 0.15 2.11 0.10 1.05 0.15 0.72 0.11 2.08 0.07
1.23 0.80 0.26 0.21 0.90 0.92 0.14 1.24 2.54 3.23 0.77 0.72
0.82 0.61 0.91 0.83 0.70 0.71 0.74 0.73 0.82 0.68 0.58 0.61 0.41 0.27 0.57 0.65 0.99 1.12 0.91 1.53 1.21 0.52 0.60 0.65 1.13 0.70 0.70 0.65 0.55 0.43 0.59 0.61 0.78
22.20 25.95 3.76 33.68 68.69 4.11 7.41 9.28 32.10 5.53 8.88 7.78 13.73 5.65
1.10 0.94 2.17 1.50 1.57 2.60 1.77 1.55 0.65 0.77 1.10 1.28 0.66 0.96 1.83 6.14 1.09 19.94 1.38 3.28 1.72 17.74 0.29 8.05 0.76 13.46 1.50 0.92 1.60 11.55 1.75 7.86 1.29 35.51 2.18 9.60 1.01 8.07 1.02 18.17 1.82 5.35 2.93 4.13 3.38 5.89 1.12 3.82 1.34 6.16
* Calculated amount includes a-BHC, which co-elutes with Lindane during G.C. analysis.
by m e a n s o f the d i l u t i o n c a u s e d b y the tributaries. T h e o r c h a r d s in the s u r r o u n d i n g area, especially the g u a v a faryns, m a y b e t h e c o n t r i b u t i n g f a c t o r to the i n c r e a s e in t h e D D T level as the river f l o w s d o w n s t r e a m . H o w e v e r , this t r e n d is yet t o b e c o n f i r m e d . F r o m T a b l e III, o n e c a n o b s e r v e t h e c h a n g i n g levels o f the r e s i d u e s in the f o u r s t a t i o n s o f t h e K l a n g R i v e r basin. T h e levels o f the residues are g e n e r a l l y low; n e v e r t h e l e s s , t h e y are still existent.
PESTICIDE
20
RESIDI_JES
IN MALAYSIAN
475
WATERWAYS
'
19
18
17 16 15
\ v
c
\
d
14 13
12 11 10 9
Ld n
8
7
Ld n,
5 4 3 2
0 T
o,
3.20
~
5.92 [3
ODE
Fig. 1.
,
14.40 DISTANCE: fROM [STUARY / + DDT
32.00
39.70
(krn) Hepfachlor
Some residue levels in Sg. Perak.
From the screening test done in the west coast rivers and the monitoring done in the Klang River basin, it can be concluded that the Malaysian rivers are not free from pesticide residue contaminants, though in most, but not all cases, the levels have not exceeded the criteria specified in Table V (Goh et al., 1986; Yap, 1987). Steps should be taken to monitor the levels in the more contimanited rivers like SG. Muda and Sg. Merbok. Though the residue levels of the west coast rivers have all been tabulated, it must be said TABLE V Criteria for some chlorinated pesticides in river water.* Criterion / n g / L Chlorinated pesticides
Livestock
Aquatic life
H u m a n health
Aldrin/Dieldrin BHC DDT/DDE Endosulfan Endrin Heptachlor Lindane
90.00 600.00 300.00 12000.00 90.00 60.00 600.00
8.00 130.00 4.00 10.00 14.00 60.00 380.00
20.00 2000.00 100.00 10000.00 60.00 50.00 2000.00
* Malaysian Interim Standards 1986 (Goh et al., 1986)
476
FAN
(ItIAN
]t[JAT
1~71 A I . .
t h a t t h e results are n o t yet c o m p r e h e n s i v e b e c a u s e this was o n l y a o n e - t i m e m o n i t o r i n g test. M o r e m o n i t o r i n g n e e d s to b e d o n e in these rivers as well as t h e K l a n g R i v e r b a s i n to o b s e r v e t h e t r e n d s a n d c o n f i r m t h e o r g a n i c c h e m i c a l p o l l u t i o n level o f t h e s e river basins.
References Carson, R.: 1962, Silent Spring, Houghton Mifflin, Boston. George, .l.L. and Frear, D. E. H.: 1966, .L Appl. Ecol., Suppl 3, 155-166. Goh, S. H., Lira. R. P. and Yap, S. Y.: 1986, Water QuaffO' Criteria and Standards For Malaysia, Vol. 4, pp. 59-148, Institute Of Advanced Studies, University of Malaya. Grob, R. L.: 1985, Modern Practice of Gas Chromatography, 2nd Ed., John Wiley and Sons, N.Y. Ka nniah, R.: 1983, 'Pesticide Abuse in Malaysia: Problems and Issues' in Proceedings of the Symposium on the Environment. Development and Natural Resource Crisis in Asia and the Pacific', Oct. 23, 1983, Penang, Malaysia, pp. 324-334. Kurtz, David A.: 1988, 'Pesticides Around The World', ChemistO, in Britain, 9, 6-8. Onuska, F. 1.: 1989..l. High Res. Chrom, 12, 4-11. Thier, H. P. and Zeumer, H. (Eds.): 1987, Manual of Pesticide Residue Analysis, Vol 1, VCH Press. Van Hall, C. E. (Ed.): 1985, Standard Methods for the Examination oj" Water and Waste Water, pp. 538-555, American Society for Testing and Materials. Yap, S. Y.: 1987, 'Water Quality Criteria for the Protection of Aquatic Life and its Users in Tropical Asian Reserwfirs', in Proceedings of A Workshop On Reservoir Fishery Management And Development In Asia, 23 28 Nov 1987, Kathmandu, Nepal, pp. 246. USEPA Test Method 608: 1984, Organochlorine PesticidesAndPCBs, EMSL-USEPA, Cincinnati, OH, U.S.A.
Appendix I. Major River basins of Peninsular Malaysia Basin No.
Name of River
Basin No.
Name of River
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Sg. Perlis Sg. Kedah Sg. Merbok Sg. Muda Sg. Prai Sg. Jejawi Sg. Kerian Sg. Kurau Sg. Sepetang Sg. Beruas Sg. Perak Sg. Bernam Sg. Tenggi Sg. Selangor Sg. Buloh Sg. Kelang Sg. Linggi
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Sg. Melaka Sg. Duyong Sg. Kesang Sg. Muar Sg. Pahat Sg. Johor Sg. Sedili Sg. Mersing Sg. Pontian Sg. Pahang. Sg. Kuantan Sg. Kemaman Sg. Kerteh Sg. Paka Sg. Dungun Sg. Trengganu Sg. Besut Sg. Kelantan
PESTICIDE
RESIDUES
\
IN MALAYSIAN
477
WATERWAYS
i
102 ~
104 ~
6~
Appendix I. Major river basins of Peninsular Malaysia.
478
TAN
A
GUAN
HUAT
ETAL.
or
Sampling Station
NG
BUKIT
\ SRI KEMBANGAN PORT KLANG
a
f
o
a
u
& |
Appendix 2. Sampling stations in the Klang River Basin.
PESTICIDE RESIDUES IN MALAYSIAN WATERWAYS 13
1. Lindane & a-BHC 2. /3-BHC 3. Aldrin 4. Heptachlor 5. Heptachlor epoxide 6. o,p'-DDE 7. Dieldrin 8. Endrin 9. Endosulfan 10. p,p'-DDT
Retention time/rain
1'o
~o
ab
Analytica column:
GP 1.5% SP-2250/1.95% SP-2401 on Supelcoport.
Carrier gas:
N 2 at 50 ml/min
Column Temperature:
180 ~ -13 rain 5~ 190 ~ -11 min
Detector:
Electron Capture
Injection volume:
2 ~L
-
Appendix 3: Gas chromatogram of pesticide standards.
479
