Contamination of liquid milk and butter with pesticide residues in the Ludhiana district of Punjab state, India

Abstract

An analysis of 92 samples of liquid milk from Ludhiana, India, during 1999–2001 revealed the presence of DDT in 6 (7.4%) samples and of these 2 samples were found to exceed the maximum residue limit (MRL) of DDT fixed at 0.05mgkg−1 (on a whole milk basis). HCH residues were detected in 49 (53.3%) samples and constituted only γ-HCH (lindane). The MRL of lindane is fixed at 0.01mgkg−1 (whole milk basis), and all 49 liquid milk samples exceeded this value. These results are indicative of contamination of bovine milk with pesticide residues as a result of the ban on the use of DDT and HCH in agriculture and public health programs. Similarly, analysis of 40 samples of butter showed the presence of DDT and HCH in 28 and 8 samples, respectively. However, none of the samples exceeded the MRL value of either DDT or any isomer of HCH. DDT residues comprised mainly p,p-DDE and p,p-TDE, whereas HCH residues were present as lindane in 6 samples, and 2 samples revealed the presence of β-HCH. The estimated daily intake of lindane through the consumption of contaminated liquid milk exceeded its acceptable daily intake value for children. Interestingly, none of the liquid milk or butter samples revealed the presence of any commonly used organophosphorus or synthetic pyrethroid insecticides at their detection limit of 0.01mgkg−1.