Review on the pesticide residue works in Nepal. Sunil Aryal Senior Scientist Entomology Division Nepal Agricultural Research Council Khumaltar

Transcription

1 Review on the pesticide residue works in Nepal. Sunil Aryal Senior Scientist Entomology Division Nepal Agricultural Research Council Khumaltar

2 Content Introduction Methodology Residues in vegetables, Residues in soil and water and Residues in food articles and others. Conclusion

3 INTRODUCTION Use of chemical pesticides is common practice to manage insect pests Organophosphate and synthetic pyrethroids groups are major Vegetable crops receives chemical pesticides more than other crops Farmers apply chemical pesticides at high dose and frequency, cocktail spray Harvested product may still have considerable amount of pesticide that is deterrent to the human health Harmful effect on the environment, human and livestock - on the basis of qualitative information

4 Methodology Review of research paper, workshop proceedings, annual reports, dissertation etc. Review was mainly focused on residue monitoring and residue research work on pesticides in Nepal.

5 Pesticide residue in vegetables and fruits

6 NARC started performing pesticide residue investigations, on vegetables since 1998 Residue in fresh cabbage collected from Bhaktapur - none of the samples showed residue of toxic chemicals. However, sensitivity of gas chromatograph was 1 or > 1 ppm Entomology Division, 1998

7 contd Pesticides residues level (ppm) in tomato fruit (2004/05) Pesticides Pesticides residues level in tomato fruit (in ppm) 1 st day 3 rd day 7 th day 15 th day Dimethoate * Chlorpyrifos * Monocrotophos * Methyl # parathion Control N.D <0.01 N.D <0.01 N.D <0.01 N.D <0.01 ND- Not Dectected Source - Annual Technical Report, 2004/05 * Higher than ADI, # Higher than MRL

8 Mean value of pesticide residues lavel (ppm) in Cauliflower (2006/07) Pesticides Pesticides Residues Level (in ppm) in tomato fruit 1 st day 3 rd day 7 th day 15 th day Malathion 35% EC Cypermethrin * Fenvelerate * Dimethoate * Control N.D N.D N.D N.D Higher than ADI, # Higher than MRL Source (Paneru et al, 2010)

9 Mean Value of Pesticide Residues level (ppm) in Cauliflower 2008/09 Mean Value of Pesticides Residues Level in Cauliflower (in ppm) (n = 3) Treatments Dichlorovos (Nuvan 76%) Endosulfan (Thiodane 35% EC) 1st Day 3rd Day 7th Day 15th Day 25th Day NA * Fenvalerate (Fen-fen 10% EC) # * Cypermethrin (Super NA * Killer 10% EC) Control NA ND ND ND ND ND: Not Detected, NA: Not Analysed * Higher than ADI, # Higher than MRL source-paneru et al, 2011

10 Manandhar (2006) reproduced the pesticide residue statistics of vegetable crops (collected from Kavrplanchowk, Chitwan, Bara and Nuwakot districts in Nepal in 2004) obtained in Pesticide Registration and Management Division (PRMD), Plant Protection Directorate, Department of Agriculture Residues of pesticides ranged from to 1.64 ppm; Maximum residue was of mancozeb (1.64 ppm) followed by cypermethrin (0.84 ppm) in tomatoes from Kavre. The mancozeb residue in potato from Chitwan district was 0.16 ppm.

11 Chloropyrifos residues on spinach from Thimi- of mg/kg Metalaxyl on cucumber from Chattradeurali, Dhading mg/kg Cypermethrin on tomato from Dhading Besi- at rate of 0.84 mg/kg Author further reported Carbendazim on Apple Kalimati mg/gm Diphenylamine on apple- Asan, Kathmandu - of mg/kg and Ethion - Citrus fruit - Asan, Kathmandu-at the rate of mg/kg. Giri (2010)

12 17 potato samples analysed for POP, only four samples showed some residual pesticide levels above the detection limits only four samples showed some residual pesticide levels above the detection limits (D.L. = less than mg / kg) Residual DDT contents obtained for potato sample from Bhaktapur, Bode-5) and Indian bengali variety were mg / kg and mg / kg respectively ( 2005)

13 Dhakal (2010) investigated 100 samples of fruits, 20 samples each of apple, banana, grape, mango and orange. Among them only 12% samples were found contaminated with the POP chemicals, Organophosphate, organochlorine and pyrethroids contaminated percentage of fruits were 5%, 4%, and 3%, respectively.

14 Rawal, et. al., (2012) analyzed dichlorvos and methyl paration in 30 winter and summer vegetables Dichlorvous (ppm) was found in Cauliflower Cabbage Broad bean Elephant ear plant Garlic green Lettuce Spinach Spring onion turnip 0.03 Methyl parathion (ppm) was found in Cauliflower Broad bean Chilly Elephant ear plant 0.113

15 Pesticide residue in soil and water

16 Less than 1.0 ppm γ-bhc existed in water and fish of Phewa, Rupa and Begnas lakes of Pokhara, Kaski district (Entomology Division, 1998). Altogether, six composite soils out of 16 samples three from Kathmandu, one from Kavre and two from Bhaktapur) showed some indications of Lindane at detection level (0.001 to ppm) far below the US EPA (1999) standard values for DDT (0.053 ppm) and Lindane/BHC (0.023 ppm) ( 2005).

17 Total of 25 sample analyzed for POP residues (soil-21, water-4) Soil 13 samples α BHC 7 samples γ BHC Maximum level of γ BHC ppm Maximum level of α BHC ppm Aldrin in one sample Water α, γ, and δ isomers of pesticide was detected in 2 nd, 3 rd and 1 st sample respectively The residual levels of BHC remained within the WHO guideline for drinking water in all the analyzed water samples. Manandhar, 2002

18 Residue in food articles and others

19 Joshi (1989) reported the DDT residues from 527 samples of rice, wheat and milk during a period of six years from 1981 to 1986 Among the total 166 rice sample tested- percentage of samples above the MRL (0.01mg/kg) was ranging from 90% (in 1983) to 29% (in 1986) Out of 66 milk samples tested from the year 1981 to samples contained higher amount of DDT above MRL i.e mg/kg Out of 55 samples of pulses, maize, oils and oil seeds and fruits analyzed for pesticide residue- 13% of the fruits samples exceeded the WHO/FAO limit (1 ppm). However 69% of the fruits were contaminated with DDT more than 0.1 ppm

20 Contd.. One thousand and thirty four samples analyzed during (12% residue) Malathion (3.9%), BHC (3.1%), Methyl parathion (2.8%), DDT (1.8%) and Parathion (0.3%). highest level of contamination in root vegetables (11.9%) followed by leaf vegetables (10.9%) (Koirala et al., 2007). Nepalese tea was below the MRLs for 16 types of pesticides established by CODEX, India, Japan and EU countries (Koirala et al., 2008) Ethion residue was found at the level of 0.27 mg/kg in medium quality tea. Endosulfan residue at 0.57 mg/kg and cypermethrin residue at 0.55 mg/kg found in best quality tea and organic tea, respectively (Giri, 2010)

21 Analysis of 50 human serum samples each from Ludhiana and Nepal revealed - pesticide residues occurred with a frequency of 96 and 94 per cent, respectively. The levels were higher in Nepali population (Shrestha and Aulakh, 2010). Shrestha et al., (2011) conducted residue analysis on blood sample of school children residing adjacent to the warehouse containing pesticides since DDT-0.079, mg/l endosulphan mg/l chlorpyrifos0.245 mg/l Atreya et. al., (2012) studied the Ache activity on the blood of the farmers due to the exposure to organophosphate and found the the activity was reduced significantly but not enough t claim clinical symptoms

22 Rapid bioassay of pesticide residue It is an acetylchoninesterase (AChE) test used for detecting two categories of neurotoxin insecticides, organophosphate and carbamate Assay procedures were adopted as designed by Pesticide Research Laboratory, Applied Zoology Division, Taiwan Agricultural Research Council (TARI), Taichung, Taiwan. Out of 130 green tea leaves samples analyzed % (108) samples - < 35% AChE 13.85% (18) sample showed AChE inhibition between 35 to 45%. Three % (4) of the sample-the inhibition of AChE above 45% Out of 9 vegetable sample analyzed from Kathmandu, six sample - <35% 3 sample -between 35 to 45%. (Ento. Div. 2013) Official residue monitoring system in vegetable and fruits adopted by Govt. of Nepal

23 Conclusion Research indicated that even with application of recommended doses, certain pesticide still persists above ADI even after certain interval of time Residue analysis work for monitoring and research is not carried out on regular basis Residue analysis should be carried out in agricultural crop to establish Good Agriculture Practice (GAP) Qualitative as well as quantitative analysis should be carried out to know the status of pesticide residue in marketable agricultural commodity regularly Different work of pesticide residues such as dissipation study, monitoring on marketable agriculture produce, quality control of imported pesticides should well be delegated among the organizations and their role should be clearly defined

24 Thank you