Soil organic matter is used to extrapolate the toxicity and bioavailability of organic pollutants between different soils. However, it has been shown that other factors such as microbial activity are crucial. The aim of this study was to investigate if sterilization can reduce differences in the fate and bioavailability of organic pollutants between different soils. Three natural soils with increasing total organic carbon (TOC) content were collected and three artificial soils were prepared to obtain similar TOCs. Soils were sterilized and spiked with (14)C-pyrene and (14)C-lindane. Total (14)C radioactivity, HPCD extractability, and bioaccumulation in Eisenia fetida were measured over 56 days. When compared to non-sterile soils, differences between the natural and artificial soils and the influence of soil-contaminant contact time were generally reduced in the sterile soils (especially with middle TOC). The results indicate the possibility of using sterile soils as "the worst case scenario" in soil ecotoxicity studies.
- MeSH
- Hexachlorocyclohexane analysis metabolism MeSH
- Soil Pollutants analysis metabolism MeSH
- Environmental Monitoring MeSH
- Oligochaeta metabolism MeSH
- Soil MeSH
- Pyrenes analysis metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Artificial soil is an important standard medium and reference material for soil ecotoxicity bioassays. Recent studies have documented the significant variability of their basic properties among different laboratories. Our study investigated (i) the variability of ten artificial soils from different laboratories by means of the fate, extractability and bioavailability of phenanthrene and lindane, and (ii) the relationships of these results to soil properties and ageing. Soils were spiked with (14)C-phenanthrene and (14)C-lindane, and the total residues, fractions extractable by hydroxypropyl-β-cyclodextrin, and the fractions of phenanthrene mineralizable by bacteria were determined after 1, 14, 28 and 56 days. Significant temporal changes in total residues and extractable and mineralizable fractions were observed for phenanthrene, resulting in large differences between soils after 56 days. Phenanthrene mineralization by indigenous peat microorganisms was suggested as the main driver of that, outweighing the effects of organic matter. Lindane total residues and extractability displayed much smaller changes over time and smaller differences between soils related to organic matter. Roughly estimated, the variability between the artificial soils was comparable to natural soils. The implications of such variability for the results of toxicity tests and risk assessment decisions should be identified. We also suggested that the sterilization of artificial soils might reduce unwanted variability.
Lindane (γ-hexachlorocyclohexane) and its isomers (HCH) are some of the most common and most easily detected organochlorine pesticides in the environment. The widespread distribution of lindane is due to its use as an insecticide, accompanied by its persistence and bioaccumulation, whereas HCH were disposed of as waste in unmanaged landfills. Unfortunately, certain HCH (especially the most reactive ones: γ- and α-HCH) are harmful to the central nervous system and to reproductive and endocrine systems, therefore development of suitable remediation methods is needed to remove them from contaminated soil and water. This paper provides a short history of the use of lindane and a description of the properties of HCH, as well as their determination methods. The main focus of the paper, however, is a review of oxidative and reductive treatment methods. Although these methods of HCH remediation are popular, there are no review papers summarising their principles, history, advantages and disadvantages. Furthermore, recent advances in the chemical treatment of HCH are discussed and risks concerning these processes are given.
- MeSH
- Hexachlorocyclohexane MeSH
- Insecticides * MeSH
- Oxidation-Reduction MeSH
- Pesticides * MeSH
- Environmental Pollution MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
