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With the rapid economic development, China is experiencing increased land contamination and lead poisoning problem in recent years, which is no longer restricted to isolated incidents and locations. There is an urgent need to remediate the lead contaminated soils to protect the publics health. However, contaminated land remediation and determination of remediation target value has been neglected for years. In order to accommodate uncertainties within the conservative point estimation of remediation target value for lead contaminated soils, Monte Carlo simulation technique is integrated into the traditional calculation model from a probabilistic perspective. Risk-based remediation target values for lead contaminated soils of different land use types (including school/hospital, residential, business and industrial use) are developed preliminarily. Furthermore, this study highlights the necessity to determine the remediation target value on the basis of actual (i.e. site-specific) risks to humans and, besides, actual risks due to contaminant migration.

As the biggest producer and the second largest consumer of lead in the world, China is facing serious conflict between rapid economic development and environmental deterioration caused by lead pollution. Our analysis results show that lead poisoning accidents increased sharply since 2005, and there is growing concern that children remain at risk from lead exposure. Accordingly, sustainable resource management and pollution control of lead is of great significance. As the first step, substance flow analysis (abbreviated as SFA) models of lead flows in both economic subsystem and environmental subsystem are established by using top-down approach in this study. Then the situation of production, consumption and emission of lead resources can be revealed. This study provides the most detailed depiction of lead flows within a regional level, and it is essentially important for the future analysis and management of lead resource. Furthermore, environmental simulation models, risk assessment models, Crystalball software and GIS tool are proposed to be integrated on the same platform to recognize the pollution situation, corresponding population risk and major exposure pathways in the study region. This new perspective extends the traditional method of substance flow analysis of lead, not only important for the improvement of lead resource efficiency, but also supporting the pollution prevention policy making.

Using magnetic resonance imaging (MRI), the present study was undertaken to investigate the therapeutic effect of acute administration of human bone marrow stromal cells (hMSCs) on traumatic brain injury (TBI) and to measure the temporal profile of angiogenesis after the injury with or without cell intervention. Male Wistar rats (300 to 350 g, n = 18) subjected to controlled cortical impact TBI were intravenously injected with 1 mL of saline ( n = 9) or hMSCs in suspension ( n = 9, 3 × 106 hMSCs) 6 hours after TBI. In-vivo MRI acquisitions of T2-weighted imaging, cerebral blood flow (CBF), three-dimensional (3D) gradient echo imaging, and blood-to-brain transfer constant (Ki) of contrast agent were performed on all animals 2 days after injury and weekly for 6 weeks. Sensorimotor function and spatial learning were evaluated. Volumetric changes in the trauma-induced brain lesion and the lateral ventricles were tracked and quantified using T2 maps, and hemodynamic alteration and blood–brain barrier permeability were monitored by CBF and Ki, respectively. Our data show that transplantation of hMSCs 6 hours after TBI leads to reduced cerebral atrophy, early and enhanced cerebral tissue perfusion and improved functional outcome compared with controls. The hMSC treatment increases angiogenesis in the injured brain, which may promote neurologic recovery after TBI.

Cell therapy promotes brain remodeling and improves functional recovery after various central nervous system disorders, including traumatic brain injury (TBI). We tested the hypothesis that treatment of TBI with intravenous administration of human marrow stromal cells (hMSCs) provides therapeutic benefit in modifying hemodynamic and structural abnormalities, which are detectable by in vivo MRI. hMSCs were labeled with superparamagnetic iron oxide (SPIO) nanoparticles. Male Wistar rats (300-350 g, n=18) subjected to controlled cortical impact TBI were intravenously injected with 1 mL of saline (n=9) or hMSCs in suspension (n=9, approximately 3 × 10(6) SPIO-labeled hMSCs) 5 days post-TBI. In vivo MRI measurements consisting of cerebral blood flow (CBF), T2-weighted imaging, and 3D gradient echo imaging were performed for all animals 2 days post-TBI and weekly for 6 weeks. Functional outcome was evaluated with modified neurological severity score and Morris water maze test. Cell engraftment was detected in vivo by 3D MRI and confirmed by double staining. Ventricle and lesion volumetric alterations were measured using T2 maps, and hemodynamic abnormality was tracked by MRI CBF measurements. Our data demonstrate that treatment with hMSCs following TBI diminishes hemodynamic abnormalities by early restoration and preservation of CBF in the brain regions adjacent to and remote from the impact site, and reduces generalized cerebral atrophy, all of which may contribute to the observed improvement of functional outcome.