Tissue metal accumulations (gills, liver, kidney and muscle) in Persian sturgeon (Acipenser persicus) were compared folowing exposure to sublethal levels of waterborne Cd (50, 400 and 1000 mg•L-1) after periods of 1, 2, 4 and 14 days. 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. Cd concentration 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 mgL-1 Cd. The accumulation of Cd in cytosol of tissues is in the order of liver>gills>kidney.

Bioaccumulation of heavy metals in fauna and flora in the Ijaw area of the Niger Delta of Nigeria were investigated. The fauna-molluscs and crustacea, and flora Hibiscus esculentus and vernonia amygdalina were selected for this study. Results show that Molluscs and crustacea accumulate considerable amounts of heavy metals. Higher levels of all the metals determined Hg, Pb, Cr, Cu, Ni, and Zn were observed in the shells than in the fleshly tissues. Hibiscus esculentus and vernonia amygdalina also accumulated these heavy metals. The mercury levels in the roots of Hibiscus esculents and vernonia amygdaline is 0.010 μg/g ± 0.00, while the stem 0.17 ± 0.03 μg/g and leaves 0.25 ± 0.02μg/g was recorded for the v. amygdalina. The H. esculenta fruit has lead levels of 0.22 ± 0.03 μg/g. The levels of Cu, Ni, and Zn are generally higher than those of Hg, Pb and Cr in all the samples analyzed. There is a growing concern about the physiological and behavioral effects of environmental trace metals in human population. The toxicity of lead at high levels of exposure is well known but of a major concern is the possibility that continual exposure to relatively low levels of these heavy metals through the consumption of these fauna and flora may entail adverse health effects.

Background: Polycyclic aromatic hydrocarbons (PAHs), which consist of fused conjugated aromatic rings, not only are toxic to humans and other living organisms, but will also pollute groundwater. These compounds can be point source or non-point source and are one of the most widespread organic pollutants. Some of them are suspected carcinogens and are linked to other health problems. This study was carried out to assess the petroleum hydrocarbon phytoremediation potential of the Aeluropus littoralis species. Accumulation of PAHs in roots and upper parts of A. littoralis has been determined. Translocation factor (TF) was also calculated. Methods: In this study, soil samples were taken from the vicinity of Isfahan oil refinery, and the PAHs compounds were analyzed with gas chromatography. One-meter soil columns were prepared from the control and contaminated soil. Unplanted A. littoralis treatments were also prepared to eliminate the effects of environmental factors on the reduction of oil-based contaminants. Seventeen weeks after planting, soil columns were sampled at 25, 50, 75, and 100 cm depths, and the concentration of petroleum hydrocarbons and number of oil-degrading bacteria were counted. Moreover, the roots and shoots of A. littoralis were separated and weighed. Results: Results indicated that A. littoralis reduced the concentration of petroleum hydrocarbons to a significantly higher extent than the control treatment. Increasing depth was associated with improved petroleum hydrocarbon concentrations and decreased number of oil-degrading bacteria. Mostly, the Bioaccumulation factor (BAF) of PAHs was <1, which shows A. littoralis could be an excluder of PAHs. The results also showed that the TF of PAHs was less than one, and hence, A. littoralis could be considered as an accumulator of PAHs. Conclusion: It can be concluded that this species is suitable for use in the phytoremediation of PAHS contamination. For further confirmation, an evaluation under field conditions should be undertaken.