- Email: [email protected]
Contamination of bovine (buffalo, Bubalus bubalis (L.)) milk from indoor use of DDT and HCH in malaria control programmes
The Science of the Total Environment, 86 (1989) 281-287 Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
281
CONTAMINATION OF BOVINE (BUFFALO, BUBALUS BUBALIS (L.)) M I L K F R O M I N D O O R U S E O F D D T A N D H C H I N M A L A R I A CONTROL PROGRAMMES
R.S. BATTU, P.P. SINGH, B.S. JOIA and R.L. KALRA Department of Entomology, Punjab Agricultural University, Ludhiana 141 004 (India) (Received December 2nd, 1988; accepted March 10th, 1989)
ABSTRACT
Samples of bovine (Buffalo, Bubalus bubalis (L.)) milk collected from randomly selected houses of Ludhiana and Sangrur districts of Punjab, India, where DDT and HCH, respectively, had been sprayed for the control of malaria, were analysed for insecticide residues between September 1985 and June 1986. The average concentration of DDT residues in samples from the DDT sprayed area were ~ 4-12 times higher than those in the corresponding samples from HCH sprayed areas. Mean levels of HCH residues in samples from the HCH sprayed area were greater than those in samples from DDT sprayed areas by factors of 2-11. Milk samples collected from four rural houses in each district before and after applications of DDT or HCH for mosquito control also showed that indoor use of these insecticides results in a substantial increase in residue levels. About 74% of the samples analysed contained DDT residues above the extraneous residue limit of 0.05mg kg -1 (whole milk basis). Estimated maximum daily intakes of DDT and fl-HCHthrough consumption of contaminated milk by 1-3-year-oldchildren exceeded their acceptable daily intakes by nearly three and five times, respectively.
INTRODUCTION
I n India, b o v i n e milk t o g e t h e r with its p r o d u c t s h a v e s h o w n a h i g h incidence of c o n t a m i n a t i o n w i t h residues of DDT a n d H C H ( K a l r a et al., 1983; K a l r a a n d Chawla, 1985). However, the s o u r c e s of the c o n t a m i n a t i o n are n o t c l e a r l y k n o w n . I n a d d i t i o n to a g r i c u l t u r a l usage, a s u b s t a n t i a l a m o u n t of DDT and H C H is used in public h e a l t h p r o g r a m m e s in I n d i a for the c o n t r o l of m a l a r i a (ICS, 1986). A q u e o u s s u s p e n s i o n s p r e p a r e d from 5 0 % w a t e r dispersible p o w d e r f o r m u l a t i o n s of e i t h e r D D T at a r a t e of 2 g m -2 or H C H at a r a t e of 3 g m -2 are s p r a y e d o n t o walls a n d ceilings of r u r a l houses, c a t t l e sheds and o t h e r dwellings. H o w e v e r , o n l y limited i n f o r m a t i o n is available on t h e i m p a c t of s u c h a n i n t e n s i v e use of t h e s e p e r s i s t e n t insecticides on t h e e n v i r o n m e n t (Farvar, 1979; K a p o o r et al., 1980; S i n g h et al., 1986). The p r e s e n t s t u d y was c o n d u c t e d in o r d e r to i n v e s t i g a t e the i m p a c t of the public h e a l t h use of DDT a n d H C H w i t h r e g a r d to c o n t a m i n a t i o n of b o v i n e milk.
0048-9697/89/$03.50
© 1989 Elsevier Science Publishers B.V.
282 MATERIALS AND METHODS
Sampling Two a d j o i n i n g districts of P u n j a b State, India, n a m e l y L u d h i a n a , w h i c h is s p r a y e d with DDT u n d e r the N a t i o n a l M a l a r i a E r a d i c a t i o n P r o g r a m m e , and S a n g r u r , w h e r e H C H is used for this purpose, were c h o s e n for this study. Two villages were selected in e a c h district of L u d h i a n a a n d S a n g r u r . E a c h village consisted of ~ 500 houses. The m a j o r i t y of the r u r a l h o u s e s in I n d i a are cons t r u c t e d in a w a y t h a t e a c h h o u s e h o l d has a c o v e r e d shed ( v e r a n d a h ) for k e e p i n g c a t t l e on one side a n d a dwelling u n i t on the o t h e r side, l e a v i n g an open space (compound) in b e t w e e n the two. In S t u d y I, the sites for r a n d o m s a m p l i n g were so selected in a village t h a t a gap of ~ 40 h o u s e s was m a i n t a i n e d in b e t w e e n a n y two h o u s e h o l d s sampled. Care was t a k e n to collect samples from all d i r e c t i o n s in different lanes of the village. At e a c h s a m p l i n g time, ~ 10 samples were collected from e a c h village (Table 1). The h o u s e h o l d s from w h e r e samples were t a k e n o n c e were excluded a t s u b s e q u e n t samplings. E n q u i r i e s s h o w e d t h a t the dwellings c o v e r e d in this s t u d y h a d been t r e a t e d with insecticides for m o s q u i t o c o n t r o l in v a r y i n g m a n n e r s . W h i l e t h e r e h a d been complete c o v e r a g e of some houses, o t h e r s were o n l y p a r t i a l l y t r e a t e d and some h a d n o t been s p r a y e d at all. In S t u d y II, samples were collected from four r u r a l h o u s e s in e a c h district at five i n t e r v a l s before a n d after insecticide a p p l i c a t i o n s for m o s q u i t o c o n t r o l (Table 2). The s p r a y i n g of DDT or H C H in these h o u s e s was in a c c o r d a n c e with the r e q u i r e m e n t s of the N a t i o n a l M a l a r i a E r a d i c a t i o n P r o g r a m m e a n d was e n s u r e d t h r o u g h p e r s o n a l supervision. F r o m e a c h house, ~ 250 ml of b o v i n e milk was collected in glass bottles i m m e d i a t e l y after e v e n i n g milking; 2 ml of s a t u r a t e d p o t a s s i u m d i c h r o m a t e
TABLE 1 DDT and HCH residues (mean _+ SD, mg kg -1, whole milk basis) found in bovine milk samples collected from DDT and HCH sprayed areas Period of sampling
Insecticide sprayed in the area
Number of samples analysed
Total DDT
Total HCH
September 1985
DDT HCH DDT HCH DDT HCH DDT HCH DDT HCH
19 22 20 20 20 20 20 22 21 22
0.33 0.06 0.59 0.05 0.35 0.09 0.32 0.06 0.22 0.05
0.02 0.22 0.03 0.20 0.03 0.23 0.02 0.18 0.04 0.08
November 1985 January 1986 March 1986 June 1986
+ 0.28 _+ 0.07 + 0.28 + 0.03 + 0.21 + 0.04 +_ 0.48 _+ 0.04 + 0.21 _+ 0.03
± 0.01 _+ 0.16 + 0.02 _+ 0.13 + 0.03 i 0.20 + 0.02 + 0.18 + 0.03 _+ 0.04
283 TABLE 2 Increase in levels of DDT and HCH residues (ragkg- ', whole milk basis) in bovine milk samples collected at different intervals from four rural houses before and after indoor application of DDT or HCH Sampling interval (days)
Total DDTa
Before spraying 1b
0.28 (0.14-0.49) 1.07 (0.11-2.60) 43 0.99 (0.58-1.31) 63b 1.35 (0.81-2.33) 91 0.49 (0.32-0.67) 159 0.57 (0.36-1.09) aMean and range of four samples. bSamples collected 1 day after DDT application. cSamples collected 1 day after HCH application.
Sampling interval (days)
Total HCHa
Before spraying 1c
0.09 (0.064). 14) 4.96 (0.24-10.62) 0.58 (0.39-1.02) 1.10 (0.58-1.80) 1.14 (0.74-1.46) 0.52 (0.33-0.69)
30 49° 77 145
s o l u t i o n c o n t a i n i n g 1% amyl a l c o h o l was added as a preservative. The samples were b r o u g h t to the l a b o r a t o r y a n d stored in a r e f r i g e r a t o r p e n d i n g analysis.
Analytical method S u b s a m p l e s (20 ml) of bovine milk were e x t r a c t e d with h e x a n e and a c e t o n e ( l : l , v / v ) a n d cleaned-up by t r e a t m e n t with c o n c e n t r a t e d s u l p h u r i c acid ( K a p o o r et al., 1981). The residues were estimated u s i n g a P a c k a r d B e c k e r GLC model 417 fitted w i t h a t r i t i u m s o u r c e e l e c t r o n - c a p t u r e d e t e c t o r and glass c o l u m n (1 m long and 2 mm i.d.) p a c k e d with 1.5% OV-17 + 1.95% OV-210 on Gas C h r o m Q. The identification of residues was confirmed by micro-alkali d e r i v a t i s a t i o n (EPA, 1980). The r e c o v e r y v a l u e s d e t e r m i n e d by spiking samples ( 0 . 0 5 m g k g -1) with c o m p o u n d s of i n t e r e s t were > 80%. The residue values r e p o r t e d h a v e n o t been c o r r e c t e d for recovery. RESULTS AND DISCUSSION F o r S t u d y I, all 206 b o v i n e milk samples collected from h o u s e s in the L u d h i a n a a n d S a n g r u r districts at v a r i o u s time i n t e r v a l s d u r i n g S e p t e m b e r 1985 to J u n e 1986 were c o n t a m i n a t e d with residues of b o t h DDT a n d HCH. T o t a l DDT residues c o n s t i t u t e : p , p ' - T D E (43%), p,p'-DDE (28%) and p,p'-DDT (28%). In a few samples collected d u r i n g September 1985, low levels of o,p'-DDT
284
and o,p'-TDE were also detected. Total HCH residues were chiefly represented by fl- (69%), followed by ~- (23%), ?- (6%) and 6- (2%) isomers in decreasing order of abundance. The invariable presence of DDT as well as HCH residues in all the samples could be due to use of these insecticides in agriculture and veterinary practice as well as the ubiquitous presence of these residues in the environment (Kalra and Chawla, 1985). In India, the present annual consumption of DDT and HCH is nearly 19 × 106 and 45 × 106kg, respectively (ICS, 1986). Of this, ~ 80% DDT and 40% HCH are employed for indoor spraying of rural houses and cattle sheds for mosquito control, while the remainder is used in agriculture. Furthermore, persistent organochlorine insecticides are known to be dispersed in various components of the environment via atmospheric transportation, resulting in detectable residues in substrates having no history of direct treatment (Woodwell et al., 1967; Spencer, 1975). The ubiquitous presence of residues of DDT and HCH in environments in India has been discussed by Kalra and Chawla (1981, 1985). Mean values of DDT residues in bovine milk samples from DDT sprayed areas were ~ 4-12 times higher than their corresponding levels in samples collected from HCH sprayed areas (Table 1). Similarly, mean values of HCH residues in bovine milk samples from HCH sprayed areas were ~ 2-11 times higher than their corresponding levels in samples collected from DDT sprayed areas. During this time, DDT residues in samples from the HCH sprayed district and HCH residues in samples from the DDT sprayed district remained at relatively lower levels (Fig. 1). ¢ DDT SPRAYED AREA e- . . . . -e HCH SPRAYED AREA
DDT Residues
0-6 0.5 T
0.~, 0.3
~
0.2
~
0.1
~
...1
~ u.l Q:
i
0
i
i
i
/
SEPT,
NOV.
JAN.
MAR.
JUNE
1985
1985
1986
1988
1986
0.4
HCH Residues 0.3 0.2 0.1 0
SEPT.
NOV.
J/~N,
MAR.
JLJNE
1985
1985
1986
1986
1986
--
SAMPLING PERIOD
Fig. 1. Median DDT and HCH residues in bovine milk samples collected during September 1985 to June 1986 from DDT and HCH sprayed areas.
0.36 0.04 0.12 0.01 0.01
2.28 0.06 0.17 0.01 0.01
1200 300 60 600 c
200 50 10 100 c
Child (10 kg)
Adult (60 kg)
Mean
Maximum
Acceptable daily i n t a k e b (~g individual- 1 day- 1)
Residue level (rag k g - 1)
90 10 30 2.5 2.5
Mean
Adult (60 kg)
570 15 40 2.5 2.5
Maximum
Estimated daily i n t a k e (~g)
aGopalan and Rao, 1980. bADI value for DDT as recommended by FAO (1986) and ADI value for HCH isomers as reported by Herbst (1982). CADI value not available.
DDT ~-HCH fl-HCH ~-HCH 5-HCH
Insecticide
108 12 36 2.5 3.0
Mean
Child (10 kg)
684 18 48 3.0 3.0
Maximum
Estimated daily intake of DDT and HCH isomers t h r o u g h consumption of bovine milk contaminated as a result of anti-malaria applications of these insecticides (assuming intake of bovine milk by adults and children to be 250 and 300 g, respectively, as recommended by the Indian Council of Medical Research) a
TABLE 3
O0
bD
286 Statistical t-test comparison of the residue levels observed in samples from different areas and collected at different time intervals showed that the concentration of DDT residues in milk from DDT sprayed areas was significantly higher at the 5% level of significance than their concentration in HCH sprayed areas throughout the study period (t = 2.34-5.09). Similarly, the concentration of HCH residues in milk from HCH sprayed areas was also significantly higher than their concentration in DDT sprayed areas (t = 3.66-4.23). During Study II, the average residue level of 0.28 mg kg-1 DDT found in milk before spraying increased to 1.07 mg kg-1, 1 day after spraying of the dwellings with DDT for malaria control (Table 2). Thereafter it again increased after a second application of DDT and persisted at a fairly high level even up to 96 days following the last application of the insecticide. Similarly, applications of HCH to houses for malaria control were also found to result in considerably higher residues in bovine milk obtained from milch cattle kept in these buildings. The increase in levels of DDT and HCH residues in bovine milk after treatment of dwellings with these insecticides could have arisen from consumption of contaminated feed by lactating animals. Battu et al. (1989) have reported the contamination of stored wheat straw and green fodder with levels as high as 86.1 and 5.4 mg kg-1 of DDT or 208.8 and 459.0mg kg 1 of HCH residues, respectively, through indoor application of these insecticides for mosquito control. About 74% of the bovine milk samples were found to contain DDT residues above the residue limit of 0.05 mg kg-1 (whole milk basis). For HCH residues no such limit is available (FAO, 1986). However, their levels in the majority of samples were also found to be quite high. Estimated daily intakes of DDT and HCH isomers following the consumption of contaminated bovine milk calculated from mean and maximum residue levels of DDT and HCH observed in randomly selected samples are given in Table 3. When estimated from maximum residue levels, daily intake for children exceeded the ADI value for DDT and fl-HCH, while it was contributing 50 and 66%, respectively, for adults. fl-HCH is known to possess the highest chronic mammalian toxicity of all isomers of HCH. This is of concern, particularly when a single food commodity seems to be responsible for considerable intakes of residues by Man. The results, therefore, emphasise the need for appropriate care and restriction in the application of these insecticides in order to regulate their residues in bovine milk in India and other countries using persistent organochlorine compounds for mosquito control. ACKNOWLEDGEMENT This study was financed, in part, by the Indian Council of Medical Research, New Delhi, under the project ¢'The Contribution of DDT and HCH Used in Public Health Programmes Towards the Contamination of the Environment".
287 REFERENCES Battu, R.S., P.P. Singh, B.S. Joia and R.L. Kalra, 1989. Contamination of stored food and feed commodities from indoor use of HCH and DDT in malaria control programmes. Sci. Total Environ., 78: 173-178. EPA, 1980. Confirmatory procedures, Section 12 D(1). In: R.R. Watts (Ed.), Analysis of Pesticide Residues in Human and Environmental Samples. U.S. Environmental Protection Agency, Research Triangle Park, NC. FAO, 1986. Codex Maximum Limits for Pesticide Residues. Food and Agricultural Organization, Rome, 2nd edn, Sect. 21-(iv). Farvar, M.T., 1979. Collection of h u m a n biological specimens in developing countries for monitoring organochlorine compounds. In: A. Berlin, A.H. Wolff and H. Hasegawa (Eds), The Use of Biological Specimens for the Assessment of Human Exposure to Environmental Pollutants. Nijhoff, The Hague, pp. 15~163. Gopalan, C. and B.S.N. Rao, 1980. Dietary allowances for Indians. National Institute of Nutrition, Hyderabad, 90 pp. Herbst, M., 1982. Unterschiede Zwischen Lindan und HCH und Ihre Bewertung. Lindan Workshop Hannover. Centre I n t e r n a t i o n a l d'Etudes du Lindane, Brussels. ICS, 1986. Demand patterns of pesticides during the seventh five-year plan. In: Indian Chemical Statistics 1986-7. Ministry of Industry, Government of India, New Delhi, pp. 136-139. Kalra, R.L. and R.P. Chawla, 1981. Monitoring of pesticide residues in the Indian environment. In: B.V. David (Ed,), Indian Pesticide Industry - - Facts and Figures. Vishvas Publications, Bombay, pp. 251-285. Kalra, R.L. and R.P. Chawla, 1985. Pesticidal contamination of foods in the year 2000 AD. Proc. Indian Natl Sci. Acad., P a r t B, 52: 188-204. Kalra, R.L., R.P. Chawla, M.L. Sharma, R.S. Battu and S.C. Gupta, 1983. Residues of DDT and HCH in b u t t e r and ghee in India, 1978-1981. Environ. Pollut., Ser. B, 6: 195~206. Kapoor, S.K., R.P. Chawla and R.L. Kalra, 1980. Contamination of bovine milk with DDT and HCH residues in relation to their usage in malaria control programmes. J. Environ. Sci. Health, 15: 545-557. Kapoor, S.K., R.P. Chawla and R.L. Kalra, 1981. A simplified method for determination of DDT and hexachlorocyclohexane residues in milk. J. Assoc. Off. Anal. Chem., 64: 14-15. Singh, P.P., R.S. Battu, B.S. Joia, R.P. Chawla and R.L. Kalra, 1986. Contribution of DDT and HCH in malaria control programmes towards the contamination of bovine milk. In: S.C. Goel (Ed.), Proc. Natl Symp. Pesticide Residues and Environmental Pollution. P.G. Department of Zoology, S.D. College, Muzaffarnagar, 1985, pp. 86-92. Spencer, W.F., 1975. Movement of DDT and its derivatives into the atmosphere. Residue Rev., 59: 91-117. Woodwell, G.M., C.F. Wuster and P.A. Isaccason, 1967. DDT residues in an east coast estuary: a case of biological concentration of persistent insecticide. Science, 156: 821-824.
281
CONTAMINATION OF BOVINE (BUFFALO, BUBALUS BUBALIS (L.)) M I L K F R O M I N D O O R U S E O F D D T A N D H C H I N M A L A R I A CONTROL PROGRAMMES
R.S. BATTU, P.P. SINGH, B.S. JOIA and R.L. KALRA Department of Entomology, Punjab Agricultural University, Ludhiana 141 004 (India) (Received December 2nd, 1988; accepted March 10th, 1989)
ABSTRACT
Samples of bovine (Buffalo, Bubalus bubalis (L.)) milk collected from randomly selected houses of Ludhiana and Sangrur districts of Punjab, India, where DDT and HCH, respectively, had been sprayed for the control of malaria, were analysed for insecticide residues between September 1985 and June 1986. The average concentration of DDT residues in samples from the DDT sprayed area were ~ 4-12 times higher than those in the corresponding samples from HCH sprayed areas. Mean levels of HCH residues in samples from the HCH sprayed area were greater than those in samples from DDT sprayed areas by factors of 2-11. Milk samples collected from four rural houses in each district before and after applications of DDT or HCH for mosquito control also showed that indoor use of these insecticides results in a substantial increase in residue levels. About 74% of the samples analysed contained DDT residues above the extraneous residue limit of 0.05mg kg -1 (whole milk basis). Estimated maximum daily intakes of DDT and fl-HCHthrough consumption of contaminated milk by 1-3-year-oldchildren exceeded their acceptable daily intakes by nearly three and five times, respectively.
INTRODUCTION
I n India, b o v i n e milk t o g e t h e r with its p r o d u c t s h a v e s h o w n a h i g h incidence of c o n t a m i n a t i o n w i t h residues of DDT a n d H C H ( K a l r a et al., 1983; K a l r a a n d Chawla, 1985). However, the s o u r c e s of the c o n t a m i n a t i o n are n o t c l e a r l y k n o w n . I n a d d i t i o n to a g r i c u l t u r a l usage, a s u b s t a n t i a l a m o u n t of DDT and H C H is used in public h e a l t h p r o g r a m m e s in I n d i a for the c o n t r o l of m a l a r i a (ICS, 1986). A q u e o u s s u s p e n s i o n s p r e p a r e d from 5 0 % w a t e r dispersible p o w d e r f o r m u l a t i o n s of e i t h e r D D T at a r a t e of 2 g m -2 or H C H at a r a t e of 3 g m -2 are s p r a y e d o n t o walls a n d ceilings of r u r a l houses, c a t t l e sheds and o t h e r dwellings. H o w e v e r , o n l y limited i n f o r m a t i o n is available on t h e i m p a c t of s u c h a n i n t e n s i v e use of t h e s e p e r s i s t e n t insecticides on t h e e n v i r o n m e n t (Farvar, 1979; K a p o o r et al., 1980; S i n g h et al., 1986). The p r e s e n t s t u d y was c o n d u c t e d in o r d e r to i n v e s t i g a t e the i m p a c t of the public h e a l t h use of DDT a n d H C H w i t h r e g a r d to c o n t a m i n a t i o n of b o v i n e milk.
0048-9697/89/$03.50
© 1989 Elsevier Science Publishers B.V.
282 MATERIALS AND METHODS
Sampling Two a d j o i n i n g districts of P u n j a b State, India, n a m e l y L u d h i a n a , w h i c h is s p r a y e d with DDT u n d e r the N a t i o n a l M a l a r i a E r a d i c a t i o n P r o g r a m m e , and S a n g r u r , w h e r e H C H is used for this purpose, were c h o s e n for this study. Two villages were selected in e a c h district of L u d h i a n a a n d S a n g r u r . E a c h village consisted of ~ 500 houses. The m a j o r i t y of the r u r a l h o u s e s in I n d i a are cons t r u c t e d in a w a y t h a t e a c h h o u s e h o l d has a c o v e r e d shed ( v e r a n d a h ) for k e e p i n g c a t t l e on one side a n d a dwelling u n i t on the o t h e r side, l e a v i n g an open space (compound) in b e t w e e n the two. In S t u d y I, the sites for r a n d o m s a m p l i n g were so selected in a village t h a t a gap of ~ 40 h o u s e s was m a i n t a i n e d in b e t w e e n a n y two h o u s e h o l d s sampled. Care was t a k e n to collect samples from all d i r e c t i o n s in different lanes of the village. At e a c h s a m p l i n g time, ~ 10 samples were collected from e a c h village (Table 1). The h o u s e h o l d s from w h e r e samples were t a k e n o n c e were excluded a t s u b s e q u e n t samplings. E n q u i r i e s s h o w e d t h a t the dwellings c o v e r e d in this s t u d y h a d been t r e a t e d with insecticides for m o s q u i t o c o n t r o l in v a r y i n g m a n n e r s . W h i l e t h e r e h a d been complete c o v e r a g e of some houses, o t h e r s were o n l y p a r t i a l l y t r e a t e d and some h a d n o t been s p r a y e d at all. In S t u d y II, samples were collected from four r u r a l h o u s e s in e a c h district at five i n t e r v a l s before a n d after insecticide a p p l i c a t i o n s for m o s q u i t o c o n t r o l (Table 2). The s p r a y i n g of DDT or H C H in these h o u s e s was in a c c o r d a n c e with the r e q u i r e m e n t s of the N a t i o n a l M a l a r i a E r a d i c a t i o n P r o g r a m m e a n d was e n s u r e d t h r o u g h p e r s o n a l supervision. F r o m e a c h house, ~ 250 ml of b o v i n e milk was collected in glass bottles i m m e d i a t e l y after e v e n i n g milking; 2 ml of s a t u r a t e d p o t a s s i u m d i c h r o m a t e
TABLE 1 DDT and HCH residues (mean _+ SD, mg kg -1, whole milk basis) found in bovine milk samples collected from DDT and HCH sprayed areas Period of sampling
Insecticide sprayed in the area
Number of samples analysed
Total DDT
Total HCH
September 1985
DDT HCH DDT HCH DDT HCH DDT HCH DDT HCH
19 22 20 20 20 20 20 22 21 22
0.33 0.06 0.59 0.05 0.35 0.09 0.32 0.06 0.22 0.05
0.02 0.22 0.03 0.20 0.03 0.23 0.02 0.18 0.04 0.08
November 1985 January 1986 March 1986 June 1986
+ 0.28 _+ 0.07 + 0.28 + 0.03 + 0.21 + 0.04 +_ 0.48 _+ 0.04 + 0.21 _+ 0.03
± 0.01 _+ 0.16 + 0.02 _+ 0.13 + 0.03 i 0.20 + 0.02 + 0.18 + 0.03 _+ 0.04
283 TABLE 2 Increase in levels of DDT and HCH residues (ragkg- ', whole milk basis) in bovine milk samples collected at different intervals from four rural houses before and after indoor application of DDT or HCH Sampling interval (days)
Total DDTa
Before spraying 1b
0.28 (0.14-0.49) 1.07 (0.11-2.60) 43 0.99 (0.58-1.31) 63b 1.35 (0.81-2.33) 91 0.49 (0.32-0.67) 159 0.57 (0.36-1.09) aMean and range of four samples. bSamples collected 1 day after DDT application. cSamples collected 1 day after HCH application.
Sampling interval (days)
Total HCHa
Before spraying 1c
0.09 (0.064). 14) 4.96 (0.24-10.62) 0.58 (0.39-1.02) 1.10 (0.58-1.80) 1.14 (0.74-1.46) 0.52 (0.33-0.69)
30 49° 77 145
s o l u t i o n c o n t a i n i n g 1% amyl a l c o h o l was added as a preservative. The samples were b r o u g h t to the l a b o r a t o r y a n d stored in a r e f r i g e r a t o r p e n d i n g analysis.
Analytical method S u b s a m p l e s (20 ml) of bovine milk were e x t r a c t e d with h e x a n e and a c e t o n e ( l : l , v / v ) a n d cleaned-up by t r e a t m e n t with c o n c e n t r a t e d s u l p h u r i c acid ( K a p o o r et al., 1981). The residues were estimated u s i n g a P a c k a r d B e c k e r GLC model 417 fitted w i t h a t r i t i u m s o u r c e e l e c t r o n - c a p t u r e d e t e c t o r and glass c o l u m n (1 m long and 2 mm i.d.) p a c k e d with 1.5% OV-17 + 1.95% OV-210 on Gas C h r o m Q. The identification of residues was confirmed by micro-alkali d e r i v a t i s a t i o n (EPA, 1980). The r e c o v e r y v a l u e s d e t e r m i n e d by spiking samples ( 0 . 0 5 m g k g -1) with c o m p o u n d s of i n t e r e s t were > 80%. The residue values r e p o r t e d h a v e n o t been c o r r e c t e d for recovery. RESULTS AND DISCUSSION F o r S t u d y I, all 206 b o v i n e milk samples collected from h o u s e s in the L u d h i a n a a n d S a n g r u r districts at v a r i o u s time i n t e r v a l s d u r i n g S e p t e m b e r 1985 to J u n e 1986 were c o n t a m i n a t e d with residues of b o t h DDT a n d HCH. T o t a l DDT residues c o n s t i t u t e : p , p ' - T D E (43%), p,p'-DDE (28%) and p,p'-DDT (28%). In a few samples collected d u r i n g September 1985, low levels of o,p'-DDT
284
and o,p'-TDE were also detected. Total HCH residues were chiefly represented by fl- (69%), followed by ~- (23%), ?- (6%) and 6- (2%) isomers in decreasing order of abundance. The invariable presence of DDT as well as HCH residues in all the samples could be due to use of these insecticides in agriculture and veterinary practice as well as the ubiquitous presence of these residues in the environment (Kalra and Chawla, 1985). In India, the present annual consumption of DDT and HCH is nearly 19 × 106 and 45 × 106kg, respectively (ICS, 1986). Of this, ~ 80% DDT and 40% HCH are employed for indoor spraying of rural houses and cattle sheds for mosquito control, while the remainder is used in agriculture. Furthermore, persistent organochlorine insecticides are known to be dispersed in various components of the environment via atmospheric transportation, resulting in detectable residues in substrates having no history of direct treatment (Woodwell et al., 1967; Spencer, 1975). The ubiquitous presence of residues of DDT and HCH in environments in India has been discussed by Kalra and Chawla (1981, 1985). Mean values of DDT residues in bovine milk samples from DDT sprayed areas were ~ 4-12 times higher than their corresponding levels in samples collected from HCH sprayed areas (Table 1). Similarly, mean values of HCH residues in bovine milk samples from HCH sprayed areas were ~ 2-11 times higher than their corresponding levels in samples collected from DDT sprayed areas. During this time, DDT residues in samples from the HCH sprayed district and HCH residues in samples from the DDT sprayed district remained at relatively lower levels (Fig. 1). ¢ DDT SPRAYED AREA e- . . . . -e HCH SPRAYED AREA
DDT Residues
0-6 0.5 T
0.~, 0.3
~
0.2
~
0.1
~
...1
~ u.l Q:
i
0
i
i
i
/
SEPT,
NOV.
JAN.
MAR.
JUNE
1985
1985
1986
1988
1986
0.4
HCH Residues 0.3 0.2 0.1 0
SEPT.
NOV.
J/~N,
MAR.
JLJNE
1985
1985
1986
1986
1986
--
SAMPLING PERIOD
Fig. 1. Median DDT and HCH residues in bovine milk samples collected during September 1985 to June 1986 from DDT and HCH sprayed areas.
0.36 0.04 0.12 0.01 0.01
2.28 0.06 0.17 0.01 0.01
1200 300 60 600 c
200 50 10 100 c
Child (10 kg)
Adult (60 kg)
Mean
Maximum
Acceptable daily i n t a k e b (~g individual- 1 day- 1)
Residue level (rag k g - 1)
90 10 30 2.5 2.5
Mean
Adult (60 kg)
570 15 40 2.5 2.5
Maximum
Estimated daily i n t a k e (~g)
aGopalan and Rao, 1980. bADI value for DDT as recommended by FAO (1986) and ADI value for HCH isomers as reported by Herbst (1982). CADI value not available.
DDT ~-HCH fl-HCH ~-HCH 5-HCH
Insecticide
108 12 36 2.5 3.0
Mean
Child (10 kg)
684 18 48 3.0 3.0
Maximum
Estimated daily intake of DDT and HCH isomers t h r o u g h consumption of bovine milk contaminated as a result of anti-malaria applications of these insecticides (assuming intake of bovine milk by adults and children to be 250 and 300 g, respectively, as recommended by the Indian Council of Medical Research) a
TABLE 3
O0
bD
286 Statistical t-test comparison of the residue levels observed in samples from different areas and collected at different time intervals showed that the concentration of DDT residues in milk from DDT sprayed areas was significantly higher at the 5% level of significance than their concentration in HCH sprayed areas throughout the study period (t = 2.34-5.09). Similarly, the concentration of HCH residues in milk from HCH sprayed areas was also significantly higher than their concentration in DDT sprayed areas (t = 3.66-4.23). During Study II, the average residue level of 0.28 mg kg-1 DDT found in milk before spraying increased to 1.07 mg kg-1, 1 day after spraying of the dwellings with DDT for malaria control (Table 2). Thereafter it again increased after a second application of DDT and persisted at a fairly high level even up to 96 days following the last application of the insecticide. Similarly, applications of HCH to houses for malaria control were also found to result in considerably higher residues in bovine milk obtained from milch cattle kept in these buildings. The increase in levels of DDT and HCH residues in bovine milk after treatment of dwellings with these insecticides could have arisen from consumption of contaminated feed by lactating animals. Battu et al. (1989) have reported the contamination of stored wheat straw and green fodder with levels as high as 86.1 and 5.4 mg kg-1 of DDT or 208.8 and 459.0mg kg 1 of HCH residues, respectively, through indoor application of these insecticides for mosquito control. About 74% of the bovine milk samples were found to contain DDT residues above the residue limit of 0.05 mg kg-1 (whole milk basis). For HCH residues no such limit is available (FAO, 1986). However, their levels in the majority of samples were also found to be quite high. Estimated daily intakes of DDT and HCH isomers following the consumption of contaminated bovine milk calculated from mean and maximum residue levels of DDT and HCH observed in randomly selected samples are given in Table 3. When estimated from maximum residue levels, daily intake for children exceeded the ADI value for DDT and fl-HCH, while it was contributing 50 and 66%, respectively, for adults. fl-HCH is known to possess the highest chronic mammalian toxicity of all isomers of HCH. This is of concern, particularly when a single food commodity seems to be responsible for considerable intakes of residues by Man. The results, therefore, emphasise the need for appropriate care and restriction in the application of these insecticides in order to regulate their residues in bovine milk in India and other countries using persistent organochlorine compounds for mosquito control. ACKNOWLEDGEMENT This study was financed, in part, by the Indian Council of Medical Research, New Delhi, under the project ¢'The Contribution of DDT and HCH Used in Public Health Programmes Towards the Contamination of the Environment".
287 REFERENCES Battu, R.S., P.P. Singh, B.S. Joia and R.L. Kalra, 1989. Contamination of stored food and feed commodities from indoor use of HCH and DDT in malaria control programmes. Sci. Total Environ., 78: 173-178. EPA, 1980. Confirmatory procedures, Section 12 D(1). In: R.R. Watts (Ed.), Analysis of Pesticide Residues in Human and Environmental Samples. U.S. Environmental Protection Agency, Research Triangle Park, NC. FAO, 1986. Codex Maximum Limits for Pesticide Residues. Food and Agricultural Organization, Rome, 2nd edn, Sect. 21-(iv). Farvar, M.T., 1979. Collection of h u m a n biological specimens in developing countries for monitoring organochlorine compounds. In: A. Berlin, A.H. Wolff and H. Hasegawa (Eds), The Use of Biological Specimens for the Assessment of Human Exposure to Environmental Pollutants. Nijhoff, The Hague, pp. 15~163. Gopalan, C. and B.S.N. Rao, 1980. Dietary allowances for Indians. National Institute of Nutrition, Hyderabad, 90 pp. Herbst, M., 1982. Unterschiede Zwischen Lindan und HCH und Ihre Bewertung. Lindan Workshop Hannover. Centre I n t e r n a t i o n a l d'Etudes du Lindane, Brussels. ICS, 1986. Demand patterns of pesticides during the seventh five-year plan. In: Indian Chemical Statistics 1986-7. Ministry of Industry, Government of India, New Delhi, pp. 136-139. Kalra, R.L. and R.P. Chawla, 1981. Monitoring of pesticide residues in the Indian environment. In: B.V. David (Ed,), Indian Pesticide Industry - - Facts and Figures. Vishvas Publications, Bombay, pp. 251-285. Kalra, R.L. and R.P. Chawla, 1985. Pesticidal contamination of foods in the year 2000 AD. Proc. Indian Natl Sci. Acad., P a r t B, 52: 188-204. Kalra, R.L., R.P. Chawla, M.L. Sharma, R.S. Battu and S.C. Gupta, 1983. Residues of DDT and HCH in b u t t e r and ghee in India, 1978-1981. Environ. Pollut., Ser. B, 6: 195~206. Kapoor, S.K., R.P. Chawla and R.L. Kalra, 1980. Contamination of bovine milk with DDT and HCH residues in relation to their usage in malaria control programmes. J. Environ. Sci. Health, 15: 545-557. Kapoor, S.K., R.P. Chawla and R.L. Kalra, 1981. A simplified method for determination of DDT and hexachlorocyclohexane residues in milk. J. Assoc. Off. Anal. Chem., 64: 14-15. Singh, P.P., R.S. Battu, B.S. Joia, R.P. Chawla and R.L. Kalra, 1986. Contribution of DDT and HCH in malaria control programmes towards the contamination of bovine milk. In: S.C. Goel (Ed.), Proc. Natl Symp. Pesticide Residues and Environmental Pollution. P.G. Department of Zoology, S.D. College, Muzaffarnagar, 1985, pp. 86-92. Spencer, W.F., 1975. Movement of DDT and its derivatives into the atmosphere. Residue Rev., 59: 91-117. Woodwell, G.M., C.F. Wuster and P.A. Isaccason, 1967. DDT residues in an east coast estuary: a case of biological concentration of persistent insecticide. Science, 156: 821-824.