Blood cadmium levels and its associated factors in middle school children in Kuwait

Cadmium (Cd), a toxic heavy metal, is associated with several adverse health consequences. In Kuwait, the presence of heavy petrochemical industry, heavy traffic burden, and high prevalence of smoking makes environmental Cd exposure more likely. Due to its cumulative nature in the body, children and adolescents are particularly vulnerable to the chronic effects of Cd. However, data on Cd exposure of adolescents is scarce. This study aimed to estimate the prevalence of Cd toxicity and its associated factors in a nationally representative sample of adolescents.

Adolescents (N = 1385; 673 boys and 712 girls; age, 11-16 years) were selected from middle schools from all six governorates of Kuwait using stratified multistage cluster random sampling. Data were collected through a self-administered questionnaire from parents and face-to-face interviews with adolescents. Blood Cd levels were determined by Inductively Coupled Plasma Mass Spectrometry.

Geometric mean (95% confidence interval) blood Cd level was 1.22 (1.15, 1.30) µg/L; 1.26 (1.14, 1.38) µg/L in boys and 1.19 (1.11, 1.29) µg/L in girls (P < 0.001). 22% of boys and 3.2% of girls had elevated blood Cd levels (≥5 µg/L; χ² = 115.13; P < 0.001). In the multivariable logistic regression, sex, governorate, father income, and blood levels of manganese, selenium, and zinc were significant predictors of Cd levels ≥5 µg/L.

A significant proportion of adolescents, particularly boys, in Kuwait have blood Cd levels ≥5 µg/L. Due to the long half-life of Cd in the body and chronic adverse health consequences, public health measures are needed to limit exposure to this toxic environmental pollutant.