Whole blood cadmium levels and physical growth in children aged 0–6 years in China: A national cross-sectional study

Cadmium (Cd) is a toxic environmental pollutant that interferes with multiple physiological systems, particularly bone metabolism and endocrine disorders. Preschool-aged children undergo a critical period of growth and development that establishes lifelong health trajectories. Early-life Cd exposure may negatively influence children’s physical development. However, current evidence regarding the effects of blood cadmium levels (BCLs) on physical development in children remains limited. Further research is urgently needed to clarify the relationship between Cd exposure and growth outcomes in this population. To investigate the association between Cd exposure and physical growth indicators in children, including Z-scores for BMI-for-age (BMIZ), weight-for-age (WAZ), and height-for-age (HAZ), as well as nutrition status indicators, incorporating stunting, underweight, and overweight. We employed a multistage stratified cluster sampling method, recruiting over 30,000 children aged 0–6 years from 15 provinces across China. Venous blood samples were collected from all participants for Cd analysis, and structured questionnaires were administered alongside physical examinations. Multiple linear regression and restricted cubic splines were used to assess the associations between BCLs and growth indicators. P for trend was utilized to examine relationships between BCLs and nutrition status indicators (stunting, underweight, and overweight). Natural ln-transformed BCLs were negatively associated with HAZ (β = −0.107, 95% CI: −0.121 to −0.092), WAZ (β = −0.099, 95% CI: −0.112 to −0.086), and BMIZ (β = −0.055, −0.070 to −0.041) (all P < 0.001). Higher BCLs increased the risk of stunting (P for trend < 0.001) and underweight (P for trend = 0.036). Cd exposure is adversely associated with physical growth in young Chinese children, with particularly strong negative effects on linear growth. • Among the first nationwide studies of blood cadmium and child growth in China. • Blood cadmium inversely associated with height, weight, and BMI Z-scores. • Higher blood cadmium associated with increased risk of stunting and underweight.