Proceedings of the Asia regional workshop on the

Pesticide residues in food are regulated under <strong>the</strong> Food Act B.E. 2522 (1979). The
extraneous residue limits (ERLs) and maximum residue limit (MRLs) <strong>of</strong> certain pesticides were
determined. Residues <strong>of</strong> pesticides o<strong>the</strong>r than mentioned in <strong>the</strong> Food Act shall be conformed to
Codex MRLs. The Pesticide Residues Research Sub-Division, Office <strong>of</strong> Agricultural Production
Science Research and Development is responsible for pesticide residues research and monitoring. In
<strong>the</strong> year 2003, this Office analyzed 23 525 samples <strong>of</strong> food crop and found pesticides residue in
4 885 samples (20.76 percent). Out <strong>of</strong> this, residues exceeded MRLs in 1 007 samples (4.28 percent)
and 3 878 samples (16.48 percent) did not exceed MRLs. Pesticides residues <strong>of</strong>ten found on food
crops were:
● cypermethrin 0-8.48 ppm
● chlorpyrifos 0-11.5 ppm
● methamidophos 0.003-18 ppm
● endosulfan 0.004-5.63 ppm
● triazophos 0.01-5.24 ppm
● ethion 0.004-46 ppm
● parathion-methyl 0.003-4.45 ppm
● methidathion 0.01-5.51 ppm
● monocrotophos 0.01-1.09 ppm
● carbendazim 0.002-5.09 ppm
Environmental information
Impact <strong>of</strong> Pesticide Use Sub-Division, Office <strong>of</strong> Agricultural Production Science Research
and Development is responsible for monitoring pesticide contamination in <strong>the</strong> environment. Samples
were collected for analysis <strong>of</strong> pesticide residues. In <strong>the</strong> year 2003, number <strong>of</strong> samples taken from
water, soil and sediment were 1964, 560 and 1304, respectively. It was found that <strong>the</strong> most severe
cases were in orange orchards in Fang and Chaiprakarn districts <strong>of</strong> Chiang Mai province, pesticide
residues in water samples were as follows:
Table 1. Type and quantity <strong>of</strong> pesticide residues found in water resources <strong>of</strong> Fang and
Chaiprakarn district, Chiang Mai Province (2004)
Type <strong>of</strong> pesticide
No. <strong>of</strong> sample
Total found
Percent
Range <strong>of</strong> residues
(µg/l)
98 89 90.8 0.001-2.19
Organochlorines (87) (88.8) (0.001-0.7)
● endosulfan 82 83.7 0.002-0.7
● DDT & metabolites 59 60.2 0.002-0.164
● aldrin & dieldrin 25 25.5 0.001-0.14
● lindane 4 4.1 0.002-0.003
● dic<strong>of</strong>ol 3 3.1 0.004-0.011
Carbamates (23) (23.5) (0.018-0.269)
● metalaxyl 11 11.2 0.026-0.178
● metolcarb 5 5.1 0.018-0.269
● carb<strong>of</strong>uran 4 4.1 0.027-0.128
● fenobucarb
Pyrethroids
3 3.1 0.018-0.162
● cypermethrin
Quaternary N Compound
4 4.1 0.01-2.19
● paraquat 1 1.0 0.533
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