Heavy metals such as arsenic and lead are well known for their harmfulness to human health, and are commonly present in nature. Care must be taken to ensure that contamination is not spread when soil is dug up in one place and transported to another. Accordingly, Kajima always works with its customers to check for naturally occurring pollutants before transporting soil that may be contaminated.

Kajima conducts geotechnical and environmental surveys on all company-owned land and undertakes field investigations before land transactions and earth works. If pollution is discovered, the pollutants are removed and the matter is publicly disclosed. In the one geotechnical and environmental survey conducted in 2008, no pollution was found.