Risk assessment of toxic heavy metals containing in soil by Geo-environmental Risk Assessment System (GERAS-1) in Japan

The exposure rates, the distribution of exposure paths and the risk level of inorganic arsenic and lead containing in soil and groundwater in Japan have been evaluated by using originally developed risk assessment model (GERAS-1). The exposure rates of the children were higher than those of the adults, because much of the soil was ingested during this age. The major exposure paths of selenium were groundwater intake and crops intake. In case of arsenic and mercury, those were the direct ingestion of soil and groundwater intake. On the other hand, human was mainly exposed to lead and cadmium from the direct ingestion of soil, which indicate that arsenic, mercury and selenium easily migrate and transport to groundwater in comparison with lead and cadmium. The exposure rates and risks were not so much high for people living in the general environment by the estimation using the Monte Carlo simulation. Since the total lifetime exposure rates were not in 10% of TDI, Japanese soil environment criteria for arsenic, cadmium and selenium had a high risk for human by our risk assessment model.