Assessment of organochlorine pesticides in serum and urine of children from a community affected with nodding syndrome in Kitgum District

Abstract

This study aimed at determining the concentrations of OCP residues in serum and urine of children from a community affected with nodding syndrome (NS) in Kitgum District, Northern Uganda. A total of 150 urine and 75 serum samples were collected from children aged 5 to 18 years from Tumangu village, Kitgum District, Northern Uganda. The samples were extracted using solid-phase extraction. The extracts were analysed for organochlorine pesticides (OCPs) using GC-MS/MS. The levels of ∑OCPs in all serum samples ranged from 12.78 to 30.56 ng/mL (mean 21.78 ±3.65 ng/mL). The levels of ∑OCPs in serum samples from nodding syndrome (NS) cases varied from 17.16 to 30.56 ng/mL (median 23.46 ng/mL). The concentrations in household controls (HC) and community controls (CC) were 14.44 to 29.72 ng/mL (median 20.35 ng/mL) and 12.78 to 27.19 ng/mL (median 20.71 ng/mL), respectively. Levels of ∑OCPs in all urine samples ranged from 0.26 to 7.69 ng/mL (mean 2.28 ± 1.21 ng/mL). Levels of ∑OCPs in urine samples from NS, HC, and CC varied from 0.26 to 6.15 ng/mL, 0.26 to 7.69 ng/mL, and 0.26 to 4.48 ng/mL, respectively. Correlation and linear regression analysis showed that potential markers for ∑HCHs, ∑CHLs, ∑endosulfan, and ∑DDTs accumulation in children were gamma-HCH, heptachlor-exo-epoxide, endosulfan-α and p,pʹ-DDD for NS, while those for the HC and CC were alpha-HCH, heptachlor, endosulfan-α and p,pʹ-DDE, respectively. However, more studies with larger datasets may be needed to confirm the observed trend. Furthermore, study results showed that there is no conclusive evidence to link NS onset in children to OCPs exposure.