Concurrent Assessment on Blood Lead in Young Children and Toy Lead in Shanghai

Since toys are potential sources of lead contamination for young children, we aim to explore potential correlations between blood-lead-levels (BLLs) of young children and toy-lead contamination using two concurrent investigations. In investigation-1, a total of 2249 children under 7 years old were studied using stratified-cluster-sampling in 6 districts of Shanghai, parents completed questionnaires and children’s whole-blood was collected, and then BLLs were measured using tungsten-atomizer-absorption-spectrophotometer. In investigation-2, a total of 288 toys made of different materials (plastic, wooden, metals, and stuffed cloth) were collected in 6 great supermarkets/toy-stores and toy-lead-levels were measured by a portable X-ray-fluorescence instrument. The geometric-mean of BLLs was 2.02 μg/dL. Adjusting for related confounders, playing with plastic toys was a significant risk factor ( β = 0.067, P < 0.05) for BLL-increment. Plastic toys accounted for the highest proportion (154/288, 53.47%) and had the highest rates exceeding toy-lead-standards (the over-standard rates of ≥ 300/600 mg/kg, plastic toys: 3.90%/1.30%; other toys: 0.00%/0.00%). Children’s BLLs in the three (Pudong-suburban, Xuhui, and Yangpu) districts and toy-lead over-standard rates in the neighboring stores were compared, the highest BLLs and over-standard rates were both found in Pudong-suburban district and similar BLLs and over-standard rates were observed between Yangpu and Xuhui districts (Pudong-suburban vs. Xuhui vs. Yangpu: 2.07 vs. 1.55 vs. 1.50 μg/dL for the medians of BLLs, P < 0.001; 1.67% vs. 0.00% vs. 0.00% for the over-standard rates of ≥ 600 mg/kg). This study raised the possibility that lead contamination in toys (especially in low social-economic-status areas) might be associated with BLLs in young children. Lead contamination from plastic toys needs cautions for preventing children from lead exposure.