Levels of select organophosphates in human colostrum and mature milk samples in rural region of Faizabad district, Uttar Pradesh, India

Introduction: Human colostrum and mature milk samples from rural mothers were separately screened for organophosphate pesticides (OPPs). The samples were assessed for the pollution load they are transmitting to the nursing infant to determine potential toxicity. The role of colostrum for toxicity monitoring was assessed in comparison to mature milk as it is the very first infant food. Materials and methods: The pesticides were quantified using a Gas Chromatograph equipped with Electron Capture Detector (GC-ECD) and the results were further validated on GC linked with Mass Spectrophotometer (GC-MS) and Fourier transform infrared (FTIR). Results: A total of 33 samples were analyzed out of 40 samples collected. These samples were from 33 mothers. Out of these, 25 were colostrum samples and 8 were mature milk samples. Frequency percentage (N%) of organophosphates analyzed was highest for ethion (23.1% or 6/26) in colostrum and chlorpyrifos (50% or 4/8) in mature milk samples. Frequency percentage in colostrum was 19.2% (5/26) for chlorpyrifos and 3.8% (1/26) for dimethoate; 25.0% (2/8) mature milk samples carried dimethoate and 12.5% (1/8) carried ethion. Mean OPPs in colostrum: dimethoate (85.888 ng/g fat) > ethion (48.000 ng/g fat) > chlorpyrifos (4.003 ng/g fat); and mature milk: ethion (744.925 ng/g fat) > chlorpyrifos (37.274 ng/g fat) > dimethoate (26.752 ng/g fat). MS data revealed the presence of methyl parathion, which was not quantitated. None of the samples exceeded acceptable daily intake standards set by Joint Meeting on Pesticide Residues (JMPR). The study will pave way for further analysis on pesticide toxicology.