2012 EPA Research Progress Report
Protecting People from Arsenic and Lead in Soil
Toxics and human digestion may sound like a daunting pair, but EPA researchers have found a way to create a computer model of the digestive system and the way it absorbs arsenic to create a powerful science tool. This device is one of several innovative tools EPA researchers are developing to better estimate human exposure to arsenic and lead in soil.
Currently, mitigating the dangers of locations with contaminated soils means using heavy equipment to remove the entire top layer and hauling the soil to a landfill designed for hazardous material. Then the soil is treated and all the toxins are removed. This method, although effective, is expensive and inefficient because not all forms of soil contaminants are harmful to animals and humans, or “bioavailable” (can be absorbed into the bloodstream). Arsenic and lead are toxic only in this bioavailable form.
A team of EPA scientists looked at the way the digestive system takes in arsenic after exposure to develop an innovative and efficient way to determine the bioavailablility of arsenic and lead in soils. They used that model to make a tool that shows how much bioavailable arsenic is in soil. The tool can detect how much arsenic is actually toxic. The result is an effective way of protecting human health while guiding clean-up activities at Superfund and other contaminated sites.
Use of the tool, still in its testing stage, has led to significant cost savings at a number of regional Superfund site offices and could ultimately help EPA assess human exposure to soil contaminants in a much more cost effective way.