Levels of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and organophosphorus pesticides (OPPs) in the blood were determined through LC/MS/MS and GC analysis methods.<h4>Results</h4>According to ELISA analysis, the PON1 level was significantly lower in the obesity group (102.8 ± 12.49 ng/mL) compared to the control group (134.8 ± 14.29 ng/mL) (<i>p</i> < 0.001). The gene discussed is PON1; the disease is obesity due to melanocortin 4 receptor deficiency.