The soil of many places of eastern India contains high amount of arsenic, due to several geogenic activities in this area. In the specific regions of the country where there is no such type of Geogenic activities, the soil is found to be almost free of arsenic. In such places where there are industries, the soil is being contaminated with the arsenic due to anthropogenic activities. One of such site which was selected for the study was in close vicinity to the textile industries in Jaipur, Rajasthan, India discharging their effluents having 423 µg/g arsenic. While the soil sample collected from the far eastern part of Tezpur Assam, India, contaminated by Geogenic sources contained 443µg/g arsenic. Four arsenite resistant bacterial strains were isolated from each of the samples. Strains SE-3 and TB-1 isolated from Jaipur and Tezpur, respectively showed highest minimum inhibitory concentration of 46.5mM and 38.7mM sodium arsenite. Based on 16S rDNA sequencing and nucleotide homology and Phylogenetics analysis strain, SE-3 was identified as Pseudomonas sp. SE-3 (accession no. KP730605) and TB-1 as Bacterium TB-1 (accession no KP866680). Complete oxidation of arsenite to less toxic form arsenate was observed in Pseudomonas sp. SE-3, while 64.6% by Bacterium TB-1. The arsenite oxidation was supported on the molecular level by confirming the presence of aox gene by PCR amplification. The enzyme activity of arsenite oxidase was also established. Arsenic hyper tolerant bacteria isolated from these soils having arsenite oxidizing ability show a promising way for the bioremediation of arsenic in contaminated soil.

Background: Natural radionuclides are always present in the environment.Human exposure to the background radiation is inevitable. It is therefore important to assess health risk associated with these radionuclides.Materials and Methods: The distribution of natural radionuclides 238U, 232Th and 40K in soil samples collected from all the twenty (20) local Governments headquarter areas in Ogun state, Nigeria were determined by gamma spectroscopy using a high-purity germanium detector. The measured concentrations were used in estimating the radiological risk pose to people living in these communities.Results: The activity concentrations measured ranged between 3 ± 1 Bqkg-1 (O0a) to 27 ± 6 Bqkg-1 (odeda) for 238U, 10 ± 1 Bqkg-1 (O0a) to 126 ± 6 Bqkg-1 (Ijebu Igbo) for 232Th and 7 ± 6 Bqkg-1 (Aiyetoro) to 497 ± 1 Bqkg-1 (Odeda) for 40K. The mean radium equivalent calculated was 77.6 Bqkg-1 which is lower than 370 Bqkg-1 of the world average and the hazard indices calculated were lower than unity.Conclusion: The absorbed rate and annual effective dose estimated for most of the locations are in good agreement with world average values except for Akomoje, Ake-Abeokuta, Ogere, Ijebu-Igbo and Odeda.

Hazardous elements in the marine environment potentially affect the safety of seafood production in the area. Some elements are considered as essential elements for humans in a low concentration, but some others are toxic and believed to induce cancer even though at a trace level. This paper has studied the source of hazardous elements contamination in Lampung Bay, Indonesia, whether anthropogenic or geogenic. Sampling was conducted at a one-mile distance from the shore. Some stations were also located in the river mouth to investigate how much inland pollution affects the bay. The mean enrichment factor (EF) for each hazardous element are 0.62, 3.09, 2.79, 4.18, 2.03, 6.10, and 2.05 for Cr, Ni, Cu, Zn, Cd, As and Pb, respectively, showing that all elements influenced by anthropogenic source except Cr. This result is proven by the lower geo-accumulation index (Igeo) normalisation, meaning the influence of geogenic sources is limited. Further statistical analysis using principal component analysis (PCA) showed that the river mouth sampling stations influenced the concentration of hazardous elements in the bay. Although the concentration of the elements is below the maximum level of the quality standard for marine sediment in almost all sampling stations, continuing monitoring of the environmental healthiness of the bay is encouraged to ensure the sustainability of fisheries production in this area.

In this study, the distribution of heavy metals (As, Cr, Ni, V, Mn, Fe, Zn, Pb) and sulfur in soil samples collected around the petrochemical complex and petroleum refinery at Abadan has been investigated. For this purpose, 22 surface soil samples were taking into consideration the prevailing wind direction (NW-SE). Sample number 22 is a control sample and was collected from a rural area. After preparation in the laboratory, the samples were analyzed using the ICP-OES method to assess concentrations of different elements. Also, the pH and organic matter content of samples were measured using standard methods. Pollution levels in the soil samples were investigated using different indices, including enrichment factor, contamination factor, contamination degree, saturation degree of metals and Potential acute toxicity. The mean concentrations of elements in the samples were compared to the mean concentration of these metals in the upper crust, soil worldwide, and EPA standards. The results of calculating the geochemical indices indicated that soil samples are more contaminated with S, Pb and Zn. The statistical analysis showed that nickel, vanadium, iron, manganese may be mainly derived from geogenic sources. Lead and zinc may originate from traffic and vehicle emissions as well as the petrochemical complex and petroleum refinery activities. As and Cr have both a geogenic and an anthropogenic origin. High concentrations of sulfur in the study area originated from the petrochemical complex and petroleum refinery activities.

Mud volcano is a natural and attractive phenomenon which is generally found as a dome-like feature and basin-shaped in some cases. Mud volcanoes comprise mixtures of water, mud and gas. They are found in most parts of the world particularly in the Alps and Himalaya belts. In Iran, most of the mud volcanoes appear in the coastal plains of the Caspian and Oman seas. Mud volcanoes are commonly considered as indicating presence of oil and gas reserves, and are used to predict subsurface hydrocarbon fields. One or two mud volcanoes were formerly found between Minab and Jask in the Hormozgan Province. Remote sensing study followed by a field work of 30 days in this research led, for the first time, to the identification of 15 mud volcanoes in the Hormozgan Province using clustering analysis. During the field study, a sediment sample was taken from each mud volcano, which was then geochemically analyzed by ICP-OES. In the meantime, grain size was also determined for each sample. The SPSS software was used to process the data. After determining correlation coefficients, clustering analysis, and relationship between different factors obtained from Scuter plot, it turned out that AL, Fe, Ni, V, Sc, Ti, Cr, Zn, CU, Mn, Na, K, Li and Be in the mud volcanoes aregeogenic/continental in origin, while the source of Ca, Mn and S is marine/intra-basinal and biogenic.

Many factors are involved in the production of healthy crop products and their monitoring requires a process-based and systemic approach at all stages from site selection to consumption. The present paper draws upon national and international experiences reflected in reviews in order to identify the most important factors affecting crop quality; the results will be expectedly exploited toward designing future studies and developing measures to improve crop qulity. Soil is the medium in which agricultural production takes place. Although geological formations with high concentrations of pollutants (especially heavy metals) might pollute soil resources, human activities inlcuding polluting industrial activities, improper application of agricultural inputs such as pesticides, chemical and organic fertilizers (especially phosphate fertilizers and non-standard sewage sludge), undertreated effluents, and atmospheric deposits (especially in urban and peri-urban areas) are some of the factors that expose soil and agricultural production more severely to the adverse of effects of such pollutants. Water pollution cannot be divorced from that of soil as they are closely related. While certain reports attribute soil pollution in parts of Iran solely to heavy metals with geohydrological origins, long-time crop irrigation using wastewater with high pollutant loads should not be ignored as a serious source of soil pollution. It should be noted that management plays a pivotal role in growing healthy products via using healthy inputs while maintaining biodiversity but that this cannot be achieved in the absence of such healthy basic resources as: a) soil, b) water, and c) air. In other words, unhealthy crops with pollutant loads result from both production processes and the environmental factors affecting them. A review of some domestic studies revealed that extensive background experience is required in the various sampling, measurement, and reporting skills, given the high sensitivity of these processes, to arrive at sound interpretations of the results of nitrate and heavy metals concentrations reported in some domestic journals. These studies have reported high concentrations of nitrate in spinach, lettuce, and celery but lower concentrations in such fruits as tomatoes, watermelon, and cantaloupe. Crops such as cucumbers, celery, and potatoes reportedly accounted for the highest nitrate concentration exceeding the allowable nitrate limits but minimum levels in tomatoes, watermelons, and cantaloupes. This is while heavy metal contaminations in plants have not been extensively reported on. Production of crops with allowable limits of pollutants presupposes due consideration of the factors outlined above. The approach proposed in this article requires soil fertility management, proper selection of crop species and cultivars, prohibited farming in contaminated lands, and avoidance of soil exposure to atmospheric deposition and polluted waters. These goals, in turn, may be achieved through accurate monitoring of agricultural product quality and identification of high-risk farming regions.

The KhoyPlain is located in the north of West Azarbaijan province, northwest of Iran. The study area has a cold and arid climate with the annual mean precipitation of about 344 mm. The purpose of this study is evaluating of hydro chemical properties of groundwater and determination of arsenic contamination at this plain. According to the hydro chemical analysis of 36 collected groundwater samples, in some zones of the area, arsenic contamination is exceed the world health organization (WHO) standard for drinking water. The arsenic concentrations of the water samples were increased in the east and southeast part of the study area. Based on the cluster analysis, the samples were posed in three clusters. Each of the clusters divided into subgroups based on heavy metals contain such as arsenic and iron. There is a positive correlation relationship between arsenic and iron, copper, sodium, chlorine, sulfate and EC. The high correlation of arsenic with iron and copper show the high impact of oxides and hydroxides of these elements in absorbing and accompanying in the sediments and consequently in the groundwater. The most saturation indices of arsenic were for FeAsO4:2H2O and Ca3 (AsO4)2:4H2O compounds, showing that change of saturation indices for these two compounds is similar and increasing from recharge to discharge area. Based on factor analysis method, three main effective factors were distinguished on hydrochemistry of the study area. In the first factor, chlorine, sodium, potassium, arsenic, copper, iron and electrical conductivity are effective elements, which have geogenic origin. Consequently, the origin of arsenic can be geogenicthatis related to geological factors, rocks and sediments that come from alteration of geological formations. Therefore, dissolution of minerals from the Miocene deposits such as marl, shale, sandstone and red conglomerate and the Pliocene conglomerate, and interbedded marl and sandstone are the effective sources of arsenic in the aquifer.

BACKGROUND AND OBJECTIVES: Solid wastes are composed of organic and inorganic pollutants (heavy metals) that can contaminate soil, underground and surface water; resulting in serious health challenges to humans. The bioavailability of cadmium, chromium, copper, lead and nickel on dumpsite soils, were investigated during the wet and dry seasons of 2018 by a sequential extraction method (Tessier). METHODS: The soils were sampled from eight points within each of two dumpsites in Ilisan-Remo, Ogun State. Top soil of 0– 15 cm depth was sampled, air-dried and sieved. The extracted soil samples were analysed for heavy metal concentrations using flame atomic absorption spectrometer. FINDINGS: In the dumpsite soils examined, cadmium, chromium, copper and lead were majorly bound to the residual fractions at the first and second dumpsites, respectively for both seasons with mean concentrations (mg/kg) of: Cd – 0. 65 ± 0. 12 and 1. 20 ± 0. 07, Cr – 36. 83 ± 5. 70 and 26. 83 ± 3. 57, Cu – 28. 37 ± 3. 69 and 8. 04 ± 0. 32, Pb – 12. 40 ± 2. 34 and 14. 11 ± 2. 44, but Ni was found mainly in the Fe-Mn oxide fraction during the wet season, with mean concentrations (mg/kg) of 6. 22 ± 1. 33 and 8. 24 ± 0. 78, for dumpsites A and B, respectively. The values obtained for these metals were higher during the dry season than a wet season and there were no metals in the mobile fractions for wet season. However, cadmium and lead were found in the carbonate fraction during the dry season, resulting in their bioavailability in the soils. CONCLUSION: The speciation results revealed that heavy metals were more bioavailable in the residual fractions. The absence of mobile fractions in the soils indicated that metals are not bioavailable for plants uptake at present condition; hence, the metals obtained are of geogenic rather than anthropogenic origin.

Groundwater quality of a region can influence the health of its inhabitants. A number of studies have so far been conducted on chemometric analysis of groundwater and shown that the major contaminants present in groundwater of Indian territories are salinity, fluoride, nitrates, arsenic and heavy metals. However, some recent studies have reported the presence of natural uranium and other radionuclides, of geogenic origin, in groundwater at several places in India.