Endocrine modulation, inhibition of ovarian development and hepatic alterations in rainbow trout exposed to polluted river water

Under laboratory conditions, female rainbow trout were exposed to graded concentrations of water from the River Lambro, a polluted tributary of the River Po, and to the effluent of a large wastewater treatment plant which flows into the River Lambro. In field exposures, trout were held in cages in the River Po upstream and downstream from the confluence of the River Lambro. After 10-day (laboratory) and 30-day (laboratory and field) exposures, trout were examined for several chemical, biochemical and histological endpoints. The results indicated that exposure to complex mixtures of chemicals, including estrogen receptor agonists, aryl-hydrocarbon receptor agonists, and probably antiandrogens, had occurred. Exposure altered the plasma levels of 17β-estradiol and testosterone, and some treatments also enhanced the activity of hepatic ethoxyresorufin O-deethylase. Gonadal histology showed varying levels of degenerative processes characterised by oocyte atresia, haemorrhages, melano-macrophage centres (MMCs), and oogonia proliferation. Liver histology showed less severe effects.     

QSAR trout toxicity models on aromatic pesticides

The pesticides originally designed to kill target organisms are dangerous for many other wild species. Since they are applied directly to the environment, they can easily reach the water basins and the topsoil. A dataset of 125 aromatic pesticides with well-expressed aquatic toxicity towards trout was subjected to quantitative structure activity relationships (QSAR) analysis aimed to establish the relationship between their molecular structure and biological activity. A literature data for LC50 concentration killing 50% of fish was used. In addition to the standard 2D-QSAR analysis, a comparative molecular field analysis (CoMFA) analysis considering the electrostatic and steric properties of the molecules was also performed. The CoMFA analysis helped the recognition of the steric interactions as playing an important role for aquatic toxicity. In addition, the transport properties and the stability of the compounds studied were also identified as important for their biological activity.     

A comparison of DEMETRA individual QSARs with an index for evaluation of uncertainty

Quantitative structure-activity relationships (QSARs) urgently need to be applied in regulatory programs. Many QSAR models can predict the effect of a wide range of substances to different endpoints, particularly in the case of ecotoxicity, but it is difficult to choose the most appropriate model on the basis of the requirements of the application. During the EC-funded project DEMETRA (www.demetra-tox.net) a huge number of QSAR models have been developed for the prediction of different ecotoxicological endpoints. DEMETRA individual models on rainbow trout LC50 after 96 h, water flea LC50 after 48 h and honey bee LD50 after 48 h have been used as a QSAR database to test the advantages of a new index for evaluating model uncertainty. This index takes into consideration the number of outliers (weighted on the total number of compounds) and their root mean square error. Application on the DEMETRA QSAR database indicated that the index can identify the models with the best performance with regard to outliers, and can be used, together with other classical statistical measures (e.g., the squared correlation coefficient), to support the evaluation of QSAR models.     

Food contamination control in European new Member States and associated candidate countries: Data collected within the SAFEFOODNET project

This paper reports the results obtained from the data collected within the European Commission funded project SAFEFOODNET regarding the state of the art in the control of chemical food contaminants in twelve European New Member States and one Associated Candidate Country (Turkey). Information has been gathered on institutions involved in food chemical contamination control, types of contaminants and matrices analyzed, procedures for data quality assurance, purposes of the analyses and accessibility of data in the participant countries. The resulting picture points out the general availability of adequate capabilities for the analysis of food contaminants in the laboratories in charge of control and the performance of the analysis of a large variety of chemicals (persistent organic pollutants, polycyclic aromatic hydrocarbons, pesticides, mycotoxins, heavy metals, radionuclides) in almost each country with few exceptions (dioxins in Bulgaria, Turkey, Latvia, persistent organic pollutants in Lithuania and Malta, polycyclic aromatic hydrocarbons in Malta). The application of validated analytical methods and the process of laboratory accreditation are partially fulfilled within the investigated countries, but still forthcoming for some countries, as in Romania, Turkey and Malta. Information collected on food controls is only partially available online and the language used is prevalently local and English to a lesser extent.     

Organic tracers identification as a convenient strategy in industrial landfills monitoring

Today, a significant environmental problem is due to the presence of industrial landfills, some of them old, which can release toxic compounds into the environment (Chemosphere 42 (2001) 415; Chemosphere 31 (1995) 3455). The identification of directly linked to the leachate tracers of contamination in the wells around the landfills, as early markers of a potential risk for the environment and/or man, is a good strategy for an early evaluation of contamination. Our protocol developed for wells water characterization is based on solid phase extraction combined with GC-MS and HPLC-MS/MS.In this way a list of organic contaminants of a specific industrial landfill is obtained, giving a solid basis also for the risk assessment. Here we present some specific examples and the use of these pollutants for environmental monitoring.     

Simultaneous analysis of 50 pesticides in water samples by solid phase extraction and GC-MS

A multiresidue analysis of 50 pesticides has been developed as a rapid screening method for organic contaminants in water samples. Solid phase extraction was accomplished with two adsorbents in a single column. Simultaneous analysis was performed with gas chromatography-mass spectrometry (GC-MS). The limits of detection for each pesticide are at sub-ppb levels. This method was used to check contamination of water from the Adige river (Northern Italy).