Effects of geography, age, and gender on Chinese children's soil ingestion rate

The soil/dust ingestion rate (SIR) is a crucial parameter for a human health risk assessment associated with contaminated soil. In addition, SIR levels may be influenced by demographic characteristics and geographic environments. The objectives of this study were to explore the effects of geography, age, and gender on Chinese children's SIR levels. We estimated SIRs for 210 children aged 2.5 to <12years from three cities of China. The results showed that the mean SIR level for children aged 2.5 to <6years (kindergarten age) was 60.8mg d(-1), significantly lower than that (91.6mg d(-1)) observed for children aged 6 to <12years (primary school age). There was no significant difference in mean SIR levels between females (78.0mg d(-1)) and males (69.2mg d(-1)). The mean SIR level (117.4mg d(-1)) for the children group in Lanzhou was significantly higher than that for the Wuhan children group (63.0mg d(-1)) and the Shenzhen children group (47.5mg d(-1)). However, there was an appreciable but not statistically significant difference in SIR levels between children groups in Wuhan and Shenzhen. Our study highlights the necessity of developing SIR values for children in different geographic locations and age stages.