Findings supporting the natural formation of trichloroacetic acid in soil

The concentrations of trichloroacetic acid (TCAA) in soil and of chlorinate d solvents in soil air from simultaneously taken samples from four sites ar e presented. The data show that there is a significant positive correlation between the concentrations of TCAA and chloroform - but not between TCAA a nd other chlorinated solvents - in soil. The calculated half-life of TCAA s hows that the contribution of decarboxylation to the chloroform concentrati on in soil is negligible. Since TCAA and chloroform were found to be formed from humic acids in the chloroperoxidase (CPO)-mediated reaction and CPO a ctivity has been detected in soil, the observed correlation between the con centrations of TCAA and chloroform provides novel support for the hypothesi s that TCAA is formed naturally in soil. (C) 1999 Elsevier Science Ltd. All rights reserved.