[Development of lead benchmarks for soil based on human blood lead level in China]

Lead benchmarks for soil are mainly established based on blood lead concentration of children. This is because lead plays a dramatically negative role in children's cognitive development and intellectual performance and thus soil lead has been concerned as main lead exposure source for children. Based on the extensively collection of domestic available data, lead levels in air, drinking water are 0.12-1.0 microg x m(-3) and 2-10 microg x L(-1); ingestion of lead from food by children of 0-6 years old is 10-25 microg x d(-1); geometric mean of women blood lead 1concentration of child bearing age is 4.79 microg x dL(-1), with 1.48 GSD. Lead benchmarks for soil were calculated with the Integration Exposure Uptake Biokinetic Model (IEUBK) and the Adult Lead Model (ALM). The results showed the lead criteria values for residual land and commercial/industrial land was 282 mg x kg(-1) and 627 mg x kg(-1) respectively, which was slightly lower compared with U.S.A. and U.K. Parameters sensitivity analysis indicated that lead exposure scenario of children in China was significantly different from children in developed countries and children lead exposure level in China was obviously higher. Urgent work is required for the relationship studies between lead exposure scenario and blood lead level of children and establishment of risk assessment guideline of lead contaminated soil based on human blood lead level.