Toxic effects of pollutants on the mineralization of substrates at low environmental concentrations in soils, subsoils and sediments

Abstract

A novel method is described to study the effect of toxicants on the mineralization of natural and xenobiotic substrates at low concentrations. The method is ecologically relevant because it uses the in situ microflora mineralizing substrates at environmental concentrations and it does not allow unnatural rapid growth. It is shown that this method can be more sensitive than traditional methods which monitor the mineralization of substrates at high concentrations. Compared to the established earthworm toxicity test the method is more sensitive for 2,3,4,5-tetrachlorophenol and pentachlorophenol and less sensitive for 3-chlorophenol. Moreover it is much faster and it can be used for soils, subsoils and aquatic sediments. The sensitivity for toxicants varies widely between different soils and different substrates, which means that a toxicant should have a relatively low concentration to prevent effects on any of the soils and mineralization processes which occur in the environment.<br>