Nooshin Sajjadi

In developing countries, the use of bioindicators could be a good way to transmit pollutants to the environment. In this study, the accumulation of heavy metals such as lead, zinc and cadmium in Columba livia feathers in males and females and live and dead species inside in the Industrial town of Zinc-Zanjan and comparison with control species outside the industrial town were studied. The feathers of 164 pigeons were collected and dissolved by chemical digestion method. In this study, heavy metals were measured by the avanta GBC atomic absorption device. The mean concentrations of lead, zinc and cadmium were determined greater in dead female pigeons, dead male pigeons, live female pigeons, and live male pigeons respectively. This was also the case with the control species. Statistical analysis of data was performed with SAS software. (P ≤ 0.05, 95% confidence level) and (P ≤ 0.01, 99% confidence level) were considered as significant differences. The results of statistical tests in the samples inside in the Industrial town of Zinc-Zanjan showed that there is a significant statistical relationship between gender and live and dead bird and elements of lead, zinc and cadmium, while for the control species outside industrial town were different. Significant levels of heavy metals in bird feathers indicate their usefulness as a non-invasive tool to show the concentration of metals in pigeons to control the level of pollution in the environment. The present study showed that Columba livia had suitable biological characteristics for use as a bioindicator of industrial pollution.

The present study was carried out with the aim of green synthesis of iron oxide nanoparticles by a distilled extract of SR (Ramalina sinensis), a local species of Fandoghlu forest in Ardabil. Among effective compounds in the extract of this local plant to remove lead and cadmium toxic metals are carbohydrates and phenolic compounds and the green synthesis of Fe₃O₄ nanoparticles was accomplished in a 1 h period at 70 degrees Celsius, with gradual addition of ammonia to the distiled extract obtained from plant. Synthesized iron oxide nanoparticles have been confirmed by various techniques such as ultra-violet spectrophotometry, XRD, FT-IR, SEM, and EDAX elemental analysis. In the spectrum obtained from the UV-spectrophotometer, the peak appearing at 310 ± 5 nm indicates the electron transfer of oxygen to the synthesized iron from the SR lichen. The XRD spectrum also showed the characteristics of Ɵ2 Theta=30.55, 36, and 43.35, which confirmed with iron oxide nanoparticles. The uniform spherical nature of iron oxide nanoparticles (III) in size from 20 to 40 nm were visible using SEM images. The obtained peak at 514 cm⁻¹ in the infrared spectrum showed the formation of a new bond between iron and oxygen. The thermodynamic studies and adsorption investigation showed that lead was followed by the Langmuir adsorption model (R² = 0.999) and cadmium was followed by Freundlich absorption model (R² = 0.986) and the process of removing is spontaneous and exothermic. The data obtained from kinetic studies of removing lead and cadmium from aqueous solutions were fitted in a second-order kinetic model with an appropriate correlation coefficient of 0.99. The ability to remove lead and cadmium by magnetic nanoparticles of iron oxide was respectively 82% and 77% for initial concentration of 50 mg/l and pH in the range of 5–4.

Among aquatic creatures, molluscs are one of the main phylums of marine organisms because of their vast biodiversity, nutrition advantages and their natural compounds. Chemical ecology discusses study of natural compounds in organisms, analyzes their structures and tracing their production and variation in response to environmental parameters. There are about 600 natural compounds identified, in which their metabolism are studied more in four classes of molluscs: polyplacophora, gastropoda, cephalopoda and bivalves. The main identified compounds are amino acids, lipids and fatty acids, terpens and steroids. Fatty acids and lipids are the main pre-structures for biological membranes, and their physical characteristics create membrane structure and its activities. Therefore, many cell functions depend on membrane activity and chemical composition of membrane lipids and environmental parameters as follows. Normally, the omega 6 to omega 3 ratio has moderate amounts in natural food sources. The more the ratio closer to 1, the more body metabolism could be sensitive for absorption. Environmental parameters, such as temperature, salinity, pH and food type source, could change the amount and structure of natural compounds. Biological factors such as sex type, reproduction and breeding cycles, different tissues and their activities could receive different types of natural compounds.