Photodegradation by sunlight radiation is one of the most destructive pathways for pesticides after their application in the field. The generated photoproducts can exhibit various toxicological properties and affect non–target organisms. Sulcotrione is a herbicide believed to be a relatively non–toxic alternative to atrazine herbicides used on corn fields. Despite many tests required for placing plant protection products on the market, it still happens that transformation pathway and the toxicological profile of these compounds is not fully understood. The results presented in this article are complementary to the research performed by a research group from National Center for Scientific Research (CNRS) at the University of Blaise Pascal (Auvergne, France). Sulcotrione is one of main herbicides used to protect the maize plantations in the region of Auvergne (France), as well as in Poland. As part of the experiments, the distribution of sulcotrione under the influence of polychromatic radiation (fluorescent lamp, l > 295 nm, suitable for environmental tests) in aqueous solution of pH 6.5 was tested. The main products of these reactions were 1H–xanthene–1,9–dione–3,4–dihydro–6–methylsulfonyl (CP) and 2-chloro-4-methylsulfonyl-benzoic acid (CMBA), which are the result of intra-molecular cyclization and hydrolysis of sulcotrione, respectively. These products were quantified by using HPLC-diode array detector analysis. The studies clearly show an increase in toxicity towards tested organism (Vibrio fischeri bacteria) with the increase of irradiation time and appearance of the photoproducts. The results suggest that the observed increase in toxicity may be rather attributed to the occurrence of the same minor photoproducts than to the presence of the major photoproducts (CP and CMBA). Identification of the minor photoproducts could not be performed using the current instrumental equipment.
Diclofenac (2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid) is a non-steroidal anti-infl ammatory drug. Due to excessive use of diclofenac, this drug has been detected in surface water, ground water and drinking water. In our study, four fungal strain Trametes trogii, Aspergillus niger, Yarrowia lipolytica and Phanerochaete chrysosporium were investigated in terms of diclofenac degradation potential. Trametes trogii was found to be the most effi cient strain with 100% diclofenac degradation rate. Two hydroxylated diclofenac metabolites have been identifi ed in culture medium. Crude laccase from T. trogii almost completely removed diclofenac with 97% removal in 48 h. We suggest that the degradation of diclofenac depends on the cytochrome P450 enzyme system and laccase activity. After 24 h incubation decrease in toxicity of diclofenac was confi rmed by Microtox test.
The research aimed to use chemical, geochemical, and ecotoxicity indices to assess the heavy metals content in soils with different degrees of exposure to human pressure. The research was conducted in southern Poland, in the Malopolska (Little Poland) province. All metal contents exceeded geochemical background levels. The highest values of the Igeo index were found for cadmium and were 10.05 (grasslands), 9.31 (forest), and 5.54 (arable lands), indicating extreme soil pollution (class 6) with this metal. Mean integrated pollution index (IPI) values, depending on the kind of use, amounted to 3.4 for arable lands, 4.9 for forests, and 6.6 for grasslands. These values are indicative of a high level of soil pollution in arable lands and an extremely high level of soil pollution in grasslands and forests. Depending on the type of soil use, Vibrio fischeri luminescence inhibition was from -33 to 59% (arable lands), from -48 to 78% (grasslands), and from 0 to 88% (forest). Significantly the highest toxicity was found in soils collected from forest grounds.