A comparative study on the uptake of polycyclic aromatic hydrocarbons by Anodonta californiensis

Ecotoxicological risk of polycyclic aromatic hydrocarbons (PAHs) in urban soil of Isfahan metropolis, Iran

Concentration, distribution, probable sources, and health risks of 16 polycyclic aromatic hydrocarbons (PAHs) were investigated in 52 soil samples collected within a radius 50 km from Isfahan metropolis center. Total concentration of PAHs ranged from 57.70 to 11,730.08 μg/kg averaging 2,000.56 μg/kg. Spatial PAH profiles were site-specific and higher concentration of PAHs was observed in the vicinity of industrial zones within Isfahan metropolis. The molecular indices, ring classes, and principal component analysis indicated that the sources of PAHs were both geogenic and pyrogenic. The incremental lifetime cancer risks of exposure to soil PAHs for adults and children living in the study area were 2.3×10(-2) and 2.2×10(-3), respectively. The results suggest that current PAHs levels in Isfahan metropolis soil are highly carcinogenic and may hold a serious health risk for local resident.

Contamination levels and spatial distributions of heavy metals and PAHs in surface sediment of Imam Khomeini Port, Persian Gulf, Iran

Imam Khomeini Port (IKP) is the largest Iranian commercial port. Because of many petrochemical industries and urban areas are located around this port and also having heavy ship traffic, concentrations of PAHs, mercury and other heavy metals were measured as the first time in surface sediment of the jetties. The highest concentrations of PAHs, Hg, Cu, Pb and Fe were recorded at Site 1, located in the vicinity of the petrochemical industrial zone, where ships are repaired. The highest concentration of Zn was found at Site 4, which is the jetty for loading mineral materials. The comparison between measured values in this study and some sediment quality guidelines indicated that the concentrations of mercury and PAHs are much higher than other studies. Also, the ratios of PAHs in the stations showed a mixture of both of pyrolytic and petrogenic sources with a dominance of pyrolytic sources.

Desorption of selected PAHs as individuals and as a ternary PAH mixture within a water-soil-nonionic surfactant system

Remediation of soil contaminated with polycyclic aromatic hydrocarbons (PAHs) is a major environmental concern due to the toxic and carcinogenic properties of these compounds. Desorption and partitioning of anthracene, fluorene and pyrene within soil-aqueous systems in the presence of the nonionic surfactants, Triton X-100 and Tween 80,were studied. The results showed that the addition of Tween 80 solution at 10 g/L initial concentration enhanced the desorption of PAHs by 49.6%, 10.7% and 70.2% for anthracene, fluorene, and pyrene, respectively, from soil into aqueous phase at 72 h equilibration, while the addition of Triton X-100 could enhance the desorption of PAHs from soil by 59.5%, 17.4% and 86.3% for anthracene, fluorene and pyrene, respectively, at similar experimental conditions. The desorption behaviour of the tested PAHs in a ternary mixture was changed relatively since, in the presence of less hydrophobic solutes, the solubility of more hydrophobic solutes was increased leading to a higher desorption rate. The results showed that hydrophobicity is the primary property that controls PAH desorption from soil and surfactant sorption onto the soils (Qm) in which the latter were found to be 3.75 x 10(-6) and 4.82 x 10(-6) mol/g for Triton X-100 and Tween 80, respectively.