To compare the levels of organochlorine pesticide (OCP) residues in sera and bone marrow of children with malignant and non-malignant hematological disorders (HDs) with those in healthy controls.

This case–control study was conducted among children aged ≤ 12 years with malignant and non-malignant HDs and non-anemic healthy controls. Children with gross congenital malformations, neurodevelopmental disorders, and chronic systemic diseases were excluded. OCPs were estimated in sera and bone marrow aspirate using gas–liquid chromatography/63Ni electron capture detection.

Thirty children, each, with malignant HDs, non-malignant HDs, and controls, were included. The median (Q1, Q3) serum total OCPs (ng/mL) were significantly higher in children with malignant and non-malignant HDs compared to controls [38.67 (33.64, 42.51); 32.72 (17.26, 41.60); and 14.11 (12.82, 16.40)]; levels were significantly higher in the malignant versus non-malignant HD group. The median (Q1, Q3) serum levels of total hexachlorocyclohexane [3.30 (2.23, 4.28) vs. 2.16 (1.31, 3.31) ng/mL] and β-hexachlorocyclohexane [0.98 (0.67, 1.68) vs. 0.54 (0.10, 0.77) ng/mL] levels were significantly higher in children with non-malignant HDs compared to malignant HD, respectively. The median (Q1, Q3) total bone marrow OCPs (ng/mL) were significantly higher in the malignant HD group [23.53 (20.83, 26.91)] compared to the non-malignant HD group [17.41 (0, 25.63)]; bone marrow endosulfan II (ng/mL) was significantly higher in the non-malignant HD group [1.56 (0.56, 3.89)] compared to malignant HD group [0.45 (0.35, 1.72)].

Children with HDs had significantly higher OCP residues in sera compared to controls. The cumulative OCP residues in sera and bone marrow were significantly higher in children with malignant versus non-malignant HDs.