The Land Snail, Eobania vermiculata, as a Bioindicator of the Heavy Metal Pollution in the Urban Areas of Sulaimani, Iraq

Land snails are crucial consumers in the terrestrial environment and beneficial significant bioindicators to evaluate the chemical impact in the ecosystem, especially on urban lands. The present study aimed to investigate the concentration of heavy metals such as As, Cr, Ni, Pb, and Zn in urban soil and study whether Eobania vermiculata acts as a bioindicator for heavy metal contamination in an urban area. Thirty soil and snail samples in triplicate from each sampling site were taken from the urban areas of Suliamani. After a microwave-assisted digestion procedure, every sample was analyzed by inductively coupled plasma-optical emission spectrometry. Results showed that the concentration of chromium (Cr) in each snail sample was significantly high. The maximum Cr concentration (15.87 mg kg−1) was recorded in the snail sample collected from Ali Kamal Park, which was adjacent to a very crowded traffic road. The As concentration in snail samples ranged from 0.08 to 1.004 mg kg−1, and it was below the permissible limits. However, the concentrations of heavy metals in urban soil locations were below their background measurements, except for nickel (Ni) which was above the permissible limits. The safest site in the study area was Chaviland 1, while the most contaminated site was the Ha-wary Shar Park. The snails bioaccumulated metals in their tissues in the following order, Cr > Zn > Ni, and this bioaccumulation occurred more on the main road locations, which represented potentially contaminated places due to anthropogenic activities. Moreover, there was no correlation among the heavy metals within the soil samples when compared to the similar metals in the snail samples, due to the low concentration of heavy metals in soil, excluding Ni, from where the snail samples were collected. Consequently, the land snail, E. vermiculata, is an appropriate sentinel organism for some metals, mainly for Cr, and the bioindicator monitoring with this snail should be extended to mixtures of heavy metals, since such relationships frequently occur in soil.

Geogenic and anthropogenic sources identification and ecological risk assessment of heavy metals in the urban soil of Yazd, central Iran

Urban soil pollution with heavy metals is one of the environmental problems in recent years, especially in industrial cities. The aim of this study is to evaluate the role of geogenic and anthropogenic sources in the urban soil pollution in Yazd, Iran. For this purpose, 30 top-soil (0–10 cm) samples from Yazd within an area of 136.37 Km2 and population of nearly 656 thousand are collected, and the concentration of heavy elements is measured. To evaluate factors affecting the concentration of heavy elements in urban soils and determine their possible sources, Multivariate statistical analysis, including correlation coefficient, principal components analysis (PCA) and cluster analysis (CA) are performed. Enrichment Factor (EF), Geo-accumulation index (Igeo), and Modified potential ecological Risk Index (MRI) are used to assess the level and extension of contamination. Results of this study suggest that As, Cd, Pb and Zn are affected by anthropogenic source, while the concentrations of Fe, Mn, Ni, Cr, Co, Cu and Cs have come from mostly natural geologic sources. As, Cd and Pb are considerably enriched in the area, provided moderately enriched for the elements Mn, Zn and Cu. However, the other heavy elements show minimal enrichment. Igeo reveal that Co, Cr, Cs, Cu, Fe, Mn, Zn and Ni with negative values are unpolluted, Pb posed unpolluted to moderately polluted, and As and Cd represent high polluted. Based on the results of the ecological risk factor, the heavy metals of Mn, Ni, Cr, Zn and Cu have a low ecological risk level. More specifically, we find that Pb shows a moderated ecological risk in 39% of the urban soil in the studied area. As and Cd with respectively 100 and 72% contribution have considerable and very high ecological risk. According to the results of MRI, the area is in a very high ecological risk level, and appropriate management practice is essential to reduce the pollution of heavy elements in this area.

Pseudomonas zeiradicis from corn and Pseudomonas soyae from soybean, two new Pseudomonas species and endophytes from agricultural crops

Two novel Pseudomonas species associated with healthy plants and other habitats are described from the United States. They are Pseudomonas zeiradicis strain PI116 from corn in Missouri, compost from Massachusetts, urban soil from Iowa and water of Lake Erie; and Pseudomonas soyae strain JL117 from soybean in Indiana and Wisconsin, and soil in Wyoming. No plant pathogenic strains are known for any of the novel species based on genome comparisons to assemblies in GenBank.