Effect of 2,4,6-Trinitrotoluene and Its Metabolites on Human Monocytes

A lucigenin-dependent chemiluminescence (CL) assay was developed in which primary human monocytes were used as test cells. 2,4,6-Trinitrotoluene (TNT) and a number of its metabolites were subjected to this test system. A dose-dependent inhibition of CL was observed for most compounds. The following EC 50 values were determined: TNT = 8 μg/mL; 2,4-DANT = 5 μg/mL; 4-ADNT = 38 μg/mL; 2-ADNT = >50 μg/mL; 4-acetyl-2,6-DNT= 50 μg/mL, and 2-acetyl-4,6-DNT = >50 μg/mL. The CL assay was also applied to aqueous extracts of TNT-contaminated soil before and after bioremediation and to soil extracts free of any nitroaromatics. Extracts of non-contaminated soil reduced the CL by about 60%, whereas an extract of contaminated soil was 100% suppressive. Leachates of bioremediated soil caused a similar response as compost free of any nitroaromatics. The results demonstrate the usefulness of a primary human monocyte culture system for testing environmentally toxic compounds.