The relationship between organophosphate pesticide exposure and anthropometric outcomes among a cohort of children from four informal settlements in the Western Cape

Wallace, Hayley Marget

The relationship between organophosphate pesticide exposure and anthropometric outcomes among a cohort of children from four informal settlements in the Western Cape

Thesis / Dissertation

2026

Publisher

University of Cape Town

Department

Department of Public Health and Family Medicine

Faculty

Faculty of Health Sciences

Abstract

Objective: There is limited data on the association between pesticide exposure in children and anthropometric outcomes, particularly in non-agricultural communities and developing countries. This study investigated the association between organophosphate pesticide (OPP) exposure and anthropometric outcomes in primary schoolchildren from four informal settlements in Western Cape Province in South Africa. Methods: This study was a repeated cross-sectional study of 600 schoolchildren over a 12-month period. Measurements included urinary dialkyl phosphate (DAP) metabolites [diethylphosphate (DEP), dimethylphosphate (DMP), and dimethylthiophosphate (DMTP)] at baseline and DEP and DMP at follow-up. Individual level characteristics as well as anthropometric measurements [height, weight, and Body Mass Index (BMI)] were collected at both time points. Results: The mean age for all participants at baseline was 9.93 ± 0.90 years and mean ∑DAP at baseline was 41.78 ± 33.80 ng/ml. Mean changes in weight, height, and BMI from baseline to follow-up for all participants were 6.04 ± 5.29 kg, 6.83 ± 4.00 cm, and 1.05 ± 2.01 kg/m2, respectively. Eighty percent of participants measured below the 50th percentile in height-for-age at baseline, and 76.8% at follow-up. Although not all reached statistical significance, besides the association of the sum of DAP at follow-up (OR: 2.23, 95% CI: 1.09 – 4.57), all the other measures of urinary DAP were positively associated with low BMI-for-age (i.e., BMI values below two standard deviations of the WHO growth chart reference). Conclusion: Urinary OPP metabolite measurements and the prevalence of short stature among children in the study were high compared to other settings. The study found some evidence of decreased BMI-for age with increasing DAPs concentrations among the participating children. Large longitudinal studies with follow-up periods exceeding two years and incorporating pesticide biomonitoring at multiple time-points are recommended. Additionally, policy and intervention to reduce pesticide exposures in non-agricultural communities are recommended.