Congenital anomalies in Baghdad children born near US military burn-pits: A case-control study showing tungsten and chromium association with increased odds of disease

Increases in congenital anomalies were reported from Iraq post-2003. We investigated associations of residential proximity to two US military bases – Camp Victory and Base Falcon – and metal levels in hair samples of children with congenital anomalies (22 cases and 9 controls). We developed mixed effects logistic regression models with village as the random effect, congenital anomalies as the outcome and distance to the closest US base and hair metal levels (one at a time) as the exposure, controlling for child's age, sex, and paternal education. We explored the mediation of the association between proximity to the base and congenital anomalies by hair metal levels. Children with higher tungsten (W) in hair had marginally higher odds of congenital anomalies (OR=1.32, 95 %CI = (1.01,2.02), P=.10). One µg/kg increase in W was associated with 41 % higher odds of a congenital abnormality (95 %CI=(1.08,2.33), P=.04). But proximity to military bases didn't have any effect on congenital anomalies. Higher hair chromium (Cr) marginally increased the odds of congenital anomalies (OR=1.02, 95 %CI=(1.00,.05), P=.09). Children with one µg/kg higher concentration of Cr in hair had 3 % higher odds of having congenital anomalies (95 %CI=(1.01,1.07), P=.04). Analyses were conducted by Inductively Coupled Plasma Mass Spectrometry.