Nanomaterials and Environmental Pollutans interactions
As the nanomaterial engineering revolution continues, the production, number and significance of nanomaterial-based products are only paralleled by the growing gap in our knowledge of how these new materials will interact with living systems. Mounting data are demonstrating that a small, yet relevant fraction of these materials possess toxic potential. However, the enormous diversity and ever-growing number of nanomaterials makes it impractical to utilize current testing paradigms to evaluate every new nanomaterial. To address this critical gap, one of our nanoecotoxicology projects aim to develop a rapid assay and use it to evaluate a strategic selection of nanomaterials in order to define predictive models for nanomaterial behavior in aquatic environment.
As the consequence of photocatalytic degradation, organic pollutants cannot completely mineralise largely to CO2 and H2O. Many of the intermediates formed during the degradation might be toxic than its initial structure. Alongside the determination of the intermediates, the other nano project is aimed by means of some test methods to determine probable toxic effects of either the synthesized nano-TiO2 particulates or the mentioned environmental pollutants after the photocatalytic degradation. For this purpose, toxic effect levels (LC50) and teratogenic effects (EC50) of either the TiO2 to be used as a photocatalyst and the environmental contaminants (such as bisphenol A, atrazine etc.) to be tested for photocatalytic degradation, or the degradation products formed during and after the application will be determined by means of FETAX (Frog Embryo Teratogenesis Assay-Xenopus) test for the amphibian pollywogs Xenopus laevis. Disrupting effect for endocrine system will be tried to determine by fish bio-tests and test of vitellogenesis (VTG) in zebrafish (Danio rerio).
We have a collaboration with Dr. Stacey Harper's Nanotoxicology Lab at Oregon State University, Dept. Environmental & Molecular Toxicology for studying "Forecasting the environmental fate and ecotoxicity of nanomaterials in aquatic systems" that this project is supporting by The Scientific and Technological Research Council (TUBITAK) of Turkey and National Science Foundation (NSF) of USA for three years.
Environmental Monitoring and Biomarkers Relationships
Anthropogenic activities in the Turkish inland water sources and coastal regions were intensified during the second half of the 20th century because of many reasons. Therefore, biomonitoring of both inland waters and coastal regions are very important for determining potential risk of environmental health.
Over the last two decades, there has been a remarkable growth in the boating and yacht tourism sector and in the ship building industry in Turkey. A marina/shipyard can have significant impacts on the concentrations of pollutants in the water, sediment, and tissue of organisms and pollutants from those areas may result in toxicity in the water column, sediments and in the food chain. Our one of the International and national partnership Biomonitoring Project aims to investigate the levels organic chemicals and metals in the mussels /sediments in a shipyard (Tuzla, Istanbul), in two marinas (Ä°n Bodrum, MuÄŸla and Istanbul) and the shipbreaking yard of AliaÄŸa (Izmir, Turkey) as the representatives of their sectors. The quality of seawater/disharges and the effects of chemicals by several biomarkers and toxicity tests will also be determined in the framework of the project.
The other biomonitoring project was aimed to determine the pollution effects on Karakaya Dam Lake using carp (Cyprinus carpio) as representative fish species. It is known that the dam lake is polluted by different pollution factors like as intensive agricultural activities and urban and industrial discharges for many years. It is also known that, some of this kind of pollutants may have endocrine disruption effects on both human and wild life in the ecosystem but it is not still studied in any areas of Turkey. In this project carp was the model organism as an indicator species, that this species has an economic and ecological importance in the dam lake. It is also may important model for testing endocrine disruptors and other toxicological effects. Samplings provided from the different localities during four different seasons to determine the effects of pollutants on selected enzymatically biomarkers and also endocrine disruption effects determined from the male fishes during different reproduction periods. Water and sediment samples also collected from the same localities for physic-chemical analysis.
In this context, our the other collabotarion project was also supported by TUBITAK & Tunisian Ministry of Higher Education and Scientific Research (MHESR) for working with Prof. Hamadi BOUSSETTA at UR Biochimie et Toxicologie Environnementale, Institut Supérieur Agronomique de Chott-Mariem in Tunisia for "Evaluation of Endocrine Disrupting Potential of Freshwater Bodies in Tunisia".