DDT and HCH residues in dairy milk samples collected from different geographical regions of India: a multicentre study.

Under a multicentre study conducted by the Indian
Council of Medical Research, 2205 samples of dairy
milk were collected from rural and urban areas of 12
states representing di� erent geographical regions of
India. These samples were analysed for residues of
DDT and di� erent isomers of HCH by gas± liquid
chromatography. Analytical quality assurance between
various participating laboratories was ensured through
analysis of check samples. The residues of DDT and
HCH were detected in more than 80% of samples
analysed. Concentrations of DDT residues, ¬-HCH,
­ -HCH, ®-HCH and ¯-HCH exceeded their maximum
residue limits prescribed by the Ministry of Health and
Family Welfare of the Indian Government in 37, 21, 42,
28 and 4% of the samples, respectively. Median values
of DDT and HCH found in dairy milk in India were
more than the corresponding values reported from most
other countries. The results showed signi® cant variations
in the incidence as well as level of these
contaminants in dairy milk from di� erent regions of
the country.