Pesticides in general terms are “Plant Protection Products”. Pesticides are used for economic reasons to maximize yields of good quality produce.Pesticides may be used deliberately by spraying, dusting the soil or cultivation and by fumigating the stored material to preempt the infestation.
On over enthusiasm of protection many use higher doses and also use it often than required. This leaves higher levels of pesticides residues in the produce. Toxic effect of Pesticides is very well known and therefore it is very imperative to monitor the pesticides residues in the material for consumption.Food and Agriculture Organization of WHO have established the permissible levels of pesticides.
A few examples of Classification of Pesticides are as follows:
1. Chlorinated Hydrocarbons: Aldrin, Benzen hexachloride (BHC), Chlordane, DDT, Endrin, Dieldrin,Heptachlor, Lindane etc
2. Chlorinated phenoxyalkanoic acid herbicides: 2, 4-D, 2, 4, 5-T
3. Organophosphourous based: Chlorthion, Carbophenothion, Dichlorvosvos, Ethion, Malathion, Parthion etc
4. Carbamate Insecticides: Carbaryl
5. Dithiocarbamate fungicides: Ferbam, Maneb, Thiram, Zineb, Ziram
6. Inorganic pesticides: Aluminum phosphide, Calcium arsenate, Lead arsenate
7. Pesticides of plant origin: Tobacco Leaf, Nicotine, Pyrethrum flower, Derris root, Reterioids etc
8. Miscellaneous: Bromopropylate, Chloropierin, Ethylene dibromide, Ethylene oxide, Methyl bromide
Longer retention of residues are found in case of chlorinated hydrocarbons, aldrin, BHC, chlordane, dieldrin,DDT and a few organophosphorus pesticides.
As the above mentioned pesticide may get decomposed, it is necessary to analyse for metabolites also.
Though it may be difficult at present to replace the synthetic pesticides but it appears that there is a need to have biodegradable pesticides which will not only protect the produce but will also be safe and harmless when consumed.
Pesticide Residues in Herbals