Heavy metal exposure has adverse effects on the growth and development of preschool children

The purpose of this study was to investigate the associations between levels of lead (Pb), cadmium (Cd), chromium (Cr), and manganese (Mn) in the PM2.5 and blood and physical growth, and development parameters including birth length and weight, height, weight, body mass index (BMI), head circumference, and chest circumference in preschool children from Guiyu (e-waste exposure area) and Haojiang (the reference area). A total of 470 preschool children from Guiyu and Haojiang located in southeast coast of China were recruited and required to undergo physical examination and blood tests during the study period. Birth length and weight were obtained by birth records and questionnaire. Pb and Cd in both PM2.5 and blood were significantly higher in Guiyu than Haojiang. Remarkably, the children of Guiyu had significantly lower birth weight and length, BMI, and chest circumference when compare to their peers from the reference area (all p value <0.05). Spearman correlation analyses showed that blood Pb was negatively correlated with height (r=-0.130, p<0.001), weight (r=-0.169, p<0.001), BMI (r=-0.100, p<0.05), head circumference (r=-0.095, p<0.05), and chest circumference (r=-0.112, p<0.05). After adjustment for the potential confounders in further linear regression analyses, blood Pb was negatively associated with height (=-0.066, p<0.05), weight (=-0.119, p<0.001), head circumference (=-0.123, p<0.01), and chest circumference (=-0.104, p<0.05), respectively. No significant association between blood Cd, Cr, or Mn was found with any of our developmental outcomes. Taken together, lead exposure limits or delays the growth and development of preschool children.