Assessment of seawater pollution by heavy metals (lead & cadmium) in the Qeshm rocky shore: use of the sea urchin, Echinometra mathaei, as a bioindicator

The general purpose of this study is to investigate the degree of heavy metal accumulation in hard and soft tissue of sea urchin, and determining these tissues as the most suitable bioindicator for lead and cadmium in the environment of the sampling stations. The way of doing this assessment was MOOPAM. Samples were prepared and classified according to sea urchin organ (soft tissue, hard tissue, Tube feet, Test, Lantern Structure and spines) and then lead and cadmium were measured in them. Result of this study shows that hard tissue is a better index of lead and cadmium than soft tissue. The result of bioaccumulation of lead in the related tissue was found to be in the following order: Soft tissue=21, hard tissue=28.1, Test=20.8, Lantern Structure=20.5 and spines=23.9. The result of bioaccumulation of cadmium in the related tissue was found to be in the following order: Soft tissue=9. 7, hard tissue=5.01, Test=4.2, Lantern Structure=4.06 and spines=5.53.

The possible identification and introduction of metallothionein in Persian Sturgeon (Acipenser persicus)

Due to anthropogenic activities, toxic metals still represent a threat for various marine organisms. Metallothionein (MT) and cadmium concentration in gills, liver, and kidney tissues and cadmium partitioning in soluble (cytosol) and insoluble fractions of mentioned tissues of Persian sturgeon (Acipenser persicus) were determined following exposure to sub-lethal levels of waterborne cadmium (Cd) (50, 400 and 1000 μg L-1) after 1, 2, 4 and 14 days. The increases of MT from background levels in comparison to controls were 4.6-, 3-, and 2.8-fold for kidney, liver, and gills, respectively after 14 days. The matallothionein concentration in liver was in the range of 56.89-168.44 μgL-1 and for kidney and gills, 39.78-189.30 and 28.15-91.20 μgL-1, respectively. The results showed that MT level change in the kidney is time and concentration dependent. Also, cortisol measurement revealed elevation at the day 1 of exposure and that followed by MT increase in the liver. Cd concentrations in the cytosol of experimental tissues were measured and the results indicated that Cd levels in the cytosol of liver, kidney, and gills increased 240.71-, 32.05-, and 40.16-fold, respectively 14 days after exposure to 1000 μgL-1 Cd. The accumulation of Cd in cytosol of tissues is in the order of liver > gills > kidney. Spearman correlation coefficients showed the MT content in kidney is correlated with Cd concentration, the value of which is more than in liver and gills. Thus, kidney can be considered as a tissue indicator in Acipenser persicus for waterborne Cd contamination. Also, tissue metal accumulations (gills, liver, kidney and muscle) in Persian sturgeon (Acipenser persicus) were compared following exposure to sublethal levels of waterborne Cd (50, 400 and 1000 μg L-1) after periods of 1, 2, 4 and 14 days. Meanwhile, the trends of Cd concentration increase in different tissues during the exposure periods and concentrations were modelled as equations. The obtained results indicate that at the end of 4 and 14 days of exposure, total tissue cadmium concentration followed the pattern: liver> gill> kidney> muscle. Calculation of bioconcentration factor (BCF) after 14 days exposure showed that at low and high concentrations, highest BCFs were found in kidney and liver, respectively. According to the results, the accumulation capacity of muscle was the lowest at all exposure concentrations. The hematological parameters including osmolarity, total protein, cortisol and glucose of plasma were measured, too. Total protein of plasma was in the range of 416.90-1068.10 mg dl-1 plasma.Total protein decreased not significantly (P≥0.05) after exposure to Cd. Cortisol increased after 1 day exposure that followed by significant (P≤0.05) elevation of glucose. The range of cortisol was very vast and it was determined between 0.03 to 16.21 ng mL-1. The content of plasma osmolarity was in the range of 282.33-294.20 mOsmol L-1.Osmolarity of treated fish plasma showed no significant decrease (P≥0.05). Total protein in gills, liver, and kidney showed that at high concentrations of metal, protein content decreased significantly (P≤0.05) in the liver after 4 and 14 days exposure. Thus, total protein of liver and glucose of plasma can be used as general biomarkers of exposure to Cd. Also, the metallothionein and cadmium were measured in gills, kidney and liver of 8 wild Persian sturgeon caught in coast of Guilan Province. According to the results, the concentration of metallothionein was in the range of 45.87-154.66 microgram per liter with the maximum and minimum concentrations in liver and gills, respectively. The trend of cadmium concentration in cytosol of tissues was: liver> kidney> gills. The results of Spearman correlation test showed that there was a significant positive correlation between metallothionein and cadmium in cytosol of liver (r2= 0.850, p≤ 0.01). In the kidney, the correlation between cadmium and metallothionein was significantly positive (r2= 0.731, p≥ 0.05). But there was not such significant correlation in the gills (p≥ 0.05).

Application of chitosan loaded with metal oxide nano particles to remove lead present from sea water

Chitosan is a natural polymer obtained by deacetylation of chitin. After cellulose chitin is the second most abundant polysaccharide in nature. It is biologically safe, non-toxic, biocompatible and biodegradable polysaccharide. Chitosan loaded with zinc oxide nanoparticles have gained more attention bio sorbent because of their better stability, low toxicity, simple and mild preparation method and high sorption capacity. Chitosan loaded with zinc oxide nanoparticles have been prepared of chitosan. The physicochemical properties of nanoparticles were characterized by Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM) Analysis. Its sorption capacity for lead and cadmium ions studied. Factors such as initial concentration of lead ions, cadmium ions sorbent amount, contact time, pH and temperature were investigated. It is found that chitosan loaded with zinc oxide nanoparticles could sorb lead and cadmium ions effectively, this sorption rate was affected significantly by initial concentration of lead and cadmium ions, sorbent amount, contact time, pH of solution. The maximum of percentage of lead sorption was 98 % with initial concentration 3 mg/l and sorbent amount 0.05 g, pH 11 in 45 min and cadmiumwas90 %with initial concentration 3mg/l and sorbent amount 0.05 g, pH 11 in45 min. Consequently chitosan loaded with zinc oxide nanoparticles demonstrated greater fixation ability for lead ions than cadmium ions.