Abstract: ObjectiveTo investigate the possible effects of environmental lead and cadmium co-exposure on intelligence and psychomotor function of children.MethodsA town near an industrialized area in southern China was selected as the exposed area, and an adjacent town on the windward side as the control area. Stratified by age, children aged 9–11 years at the town level primary school were selected as the subjects of the survey from both areas. Combined Raven’s Test in China Revision 2 (CRT-C2) was applied to test children’s intelligence and Jinyi Psychomotor test Battery (JPB) was used to test their psychomotor function. Simultaneously lead and cadmium contents in blood were analyzed by ICP-MS.ResultsA total of 530 pupils aged 9-11 years were surveyed, including 266 living in the exposed area and 264 in the control area. The geometric means of lead and cadmium in blood of children in the exposed area were 65.89 μg/L and 1.93 μg/L, and those in the control area were 37.21 μg/L and 1.07 μg/L, respectively (all P<0.01). The IQ scores of the children in the exposed area and control area were (103.38±10.76) and (106.23±12.84), respectively (P<0.01). The scores of number scratching, numeral connection, and target tracking of the children in the exposed area were significantly lower than those in the control area (all P<0.01). Multivariate linear regression analysis showed that blood lead was negatively correlated with IQ score (β=-4.16，P<0.01), numbers scratching(β=-0.96，P<0.05), numeral connection(β=-1.54，P<0.01), and target tracking(β=-11.85，P<0.01); but blood cadmium was only negatively related with target tracking (β=-31.21，P<0.01). There were no significant interactions between blood lead and cadmium on IQ and five psychomotor function tests (all P＞0.05).ConclusionEnvironmental lead and cadmium exposures could impact children's neurological development separately, but the effect of lead and cadmium co-exposure on children's neurological development was not observed.