Concentration Values Of Heavy Metals Research Articles

Effect of Petroleum Illegal Refining Activities on Cassava Plant in the Niger Delta

The evolution of illegal refining was briefly discussed leading to an experimental research of its effects on cassava plant which is a major staple food in the region. Two deactivated illegal refinery sites were selected for the studies; cassava plant (tubers, stem and leaves) samples were taken from these sites with a control and then analyzed for the concentrations of Heavy Metals, BTEX, PAHs and THC. The results show that the mean concentration of heavy metals in cassava tuber were Pb (5.31±0.17 mg/kg), Cd (6.44±0.23mg/kg), Cr (5.25±0.02 mg/kg), As (9.27±0.04 mg/kg), Zn (5.30±0.17 mg/kg), Cu (4.17±0.06 mg/kg), Ni (13.52±0.01 mg/kg) and Co (40.66±0.00) (mg/kg) for site A; while site B has Pb (0.15±0.03 mg/kg), Cd (0.107±0.06 mg/kg), Cr (0.167±0.03 mg/kg), As (1.83±0.02 mg/kg), Zn (0.063±0.02 mg/kg), Cu (0.079±0.04 mg/kg), Ni (0.113±0.01 mg/kg) and Co (0.082±0.05 mg/kg). The mean concentration values of heavy metals in cassava tuber were higher than the control mean values. Plant Concentration Factor was also calculated from the studies. Result also showed higher mean concentration values of BTEX and PAHs for cassava plant (tuber, stem and leaves) when compared with control values and WHO permissible limits for plants. The overall result indicates the contamination and pollution of cassava plant from both studied sites due to illegal petroleum crude oil refining activities.

Utilization possibilities of steel slag as backfill material in coastal structures

The aim of this study is to investigate the utilization possibilities of steel slags, basic oxygen furnace (BOF) and electric arc furnace (EAF) slags, as backfill material in coastal structures. Within the scope of the study, physical, mechanical and chemical properties of the steel slags were investigated and their potential to create environmental risks were evaluated. The results showed that soundness loss and filler content ratio were below the limit values for steel slags to be used as backfill material. It was determined that the density, porosity, water absorption and Los Angeles abrasion ratios of steel slags were generally higher than natural aggregates. In order to reach the California Bearing Ratio (CBR) limit (> 25%), the maximum particle size of the steel slag was reduced to 25 mm. In this particle size, CBR of the slag samples generally gave better results compared to the natural aggregate (38%), except for Kardemir and Asil samples. In addition, the concentration values of heavy metals (Cu, Cd, Cr, Pb, Ni, Zn, Hg and As) were below the limit values specified in the regulation. It is suggested that EAF slags should be aged for at least 6 months and BOF slags for at least 24 months in open air conditions before being used as backfill material in coastal structures after the maximum particle size is reduced to 25 mm.

Use of the nematode Caenorhabditis elegans in toxicity tests in water samples from the Calera river, Ecuador

The province of El Oro is the most important gold mining area in Ecuador, but the activity has caused damage to the ecosystem and human health, due to the dumping of extraction waste loaded with heavy metals into the Calera River, which is a tributary with the Yellow River of the Puyango river. This work presents the results of the evaluation of the toxicity of the water and sediments of the Calera River using the nematode Caenorhabditis elegans as a bioindicator for environmental monitoring. The quantification of heavy metals by atomic absorption spectroscopy in samples collected along the Calera River, both in water and in sediments, revealed that the concentration in water was below the permissible limits established by the Ecuadorian Environmental Standard, while in the sediment sample, the concentration values of heavy metals considerably exceeded the permissible limits, particularly Arsenic and Cadmium, which were the ones detected with the highest concentrations. In the bioassays with C. elegans subjected to different concentrations and exposure times of 12, 18, 24 and 36 hours, no mortality rate was detected in the water samples analyzed, which is attributed to the low concentration of heavy metals. The exposure of the nematodes to the sediment extracts, induced mortality in all the samples, mainly in those coming from the sector in which the rock material processing plants are located.

Heavy metal pollution in agricultural soils of a typical volcanic area: Risk assessment and source appointment.

Heavy metals are naturally occurring elements with high natural background levels in the volcanic area. Therefore, it is necessary to conduct a risk assessment and identify potential sources of heavy metals. In this study, 4488 soil samples (0-20cm) were collected in Chengmai County, a typical volcanic area in Hainan Province, and analyzed for eight heavy metals and major oxides. Pollution level, ecological risks, and health risks were evaluated by geo-accumulation index (Igeo), pollution index (PI), potential ecological risk index (RI), hazard index (HI), and carcinogenic risks (CR). The positive matrix factorization (PMF) model was further used to determine the priority source of heavy metals. The average values of heavy metal concentrations in soil were 7.06, 0.07, 156.88, 33.43, 0.05, 72.47, 19.48, and 67.51mgkg-1 for As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn, respectively. Except for Pb, the average concentrations of all heavy metals exceeded background concentration in Hainan soils, indicating different degrees of heavy metal enrichment. The Igeo and PI showed that the main pollutant element in volcanic soils was Ni, followed by Cr and Cu. The RI shows that the percentage of soil samples with considerable or worse potential ecological risk was 44.4% of the total samples, with Hg, As, Cd, and Ni causing high ecological risks. The estimated average daily doses of heavy metals were below the tolerable limits and the HI values were below one for both adults and children, indicating that the residents had an acceptable potential non-carcinogenic risk. However, the potential carcinogenic risk of exposure to Cr, Ni, and As was unacceptable for residents, with high CR values exceeding 10-4, especially for children. Based on the PMF, five major sources of heavy metals were found in the study area: Ni, Cu, and Zn mainly from parent materials, As and Pb from daily life and vehicle emissions, Cd from agricultural activities, Hg from industrial activities, and Cr from parent materials under different environmental conditions. Significant positive correlations between Al2O3, TFe2O3, Mn, soil organic carbon (SOC), and heavy metals reflect that aluminium-rich minerals, Fe-Mn oxides, and SOC are the most critical factors affecting heavy metal accumulation in volcanic agricultural soils.

Human Health Risk Assessment of Heavy Metal Contamination in an Artisanal Gold Mining Community of Kogi State, Nigeria

Artisanal and small-scale gold mining (ASGM) is known to improve the standard of living in the host communities and economic performance of countries involved. However, despite the positive impact on the economy, ASGM is a significant point source of uncontrolled mobilization of hazardous chemicals, notably heavy metals into the environmental media such as soil, air and water. This study assessed human health risk of exposure to heavy metals in soil around artisanal gold mining in Ike community of Kogi State. Twelve (12) soil samples obtained from the gold mining area were analysed for heavy metals (As, Cd, Ni, Pb and Zn) using Atomic Absorption Spectrometry (AAS). Measured concentrations of these metals were used to calculate health risk of children and adults using health risk assessment models. The results showed that mean values of heavy metal concentrations in the soil reflected low metal load (<1) with decreasing order of As>Pb>Zn>Ni>Cd. The results obtained from analysis of non-carcinogenic risk demonstrated that hazard index values of various heavy metals for three exposure pathways (ingestion, dermal and inhalational) were < 1 for children and adults populations. However, As recorded hazard index values > 1 for ingestion pathway for both populations. It was found that As recorded carcinogenic risk of 1.85E-03 for children and 9.86E-04 for adults and Cd recorded 4.67E-04 for children. These values exceeded the safety limit, ranging from 1E-06 to 1E-04, as stated by US Environmental Protection Agency. The study showed that As might pose carcinogenic and non-carcinogenic risks for both populations. Also, Cd might pose carcinogenic risk for children. Hence, As and Cd would be regarded as elements of serious concern in the study area.

Pilot groundwater radon mapping and the assessment of health risk from heavy metals in drinking water of southwest, Nigeria

Radon and heavy metals are sources of groundwater pollution and are identified as potential carcinogens. Southwest Nigeria's populace mostly relies on groundwater source for drinking. This study aims to map radon distribution in groundwater of southwest Nigeria and to determine the health risk of radon and heavy metal in drinking water. Radon concentrations of 145 groundwater samples were measured using RAD7 electronic radon detector and heavy metal concentrations of 52 groundwater samples were measured using atomic absorption spectrophotometer. Radon concentration distributions were delineated using geographical information system. Radon concentration of water samples ranges between 1.6 Bq l−1 and 271 Bq l−1 with an average value of 35.9 ± 38.4 Bq l−1. The average groundwater radon concentration is higher than US-EPA recommended level of 11.1 Bq l−1 but lower than the WHO recommended limit of 100 Bq l−1. The estimated average annual effective radiation doses to infants, children, and adults are 29 μSvy−1, 41 μSvy−1 and 92 μSvy−1 respectively. The radon distribution map of the study area reveals regions of high, medium, and low groundwater radon concentrations. The average concentration values of heavy metals in groundwater samples are of the order Mn > Zn > Pb > Cu > Cr > Ni > Cd. 84% of groundwater exhibits good to excellent quality in terms of heavy metal pollution. However, about 16% of the samples which lie in the sedimentary regions of Ogun and Lagos States exhibit poor to very poor quality. Overall, ingestion of groundwater in the study area may not pose a serious health hazards from radon ingestion and heavy metal toxicity.

HEAVY METALS AND CONTAMINATION PARAMETERS REMOVAL BY DIFFERENT PLANT FROM WASTEWATER IN HYBRID CONSTRUCTED WETLANDS

Water is essential requirement for every living creature on our planet to grow and prosper. The progress expansion and increased population of Sulaimani city caused increased in water demand and need for reusing of waste water for irrigation. This study aims to remove some waste water heavy metals and parameters by root and shoot of Macrophytes in Hybrid Constructed wetlands (HCW). HCW are designed as (Vertical-Horizontal and Horizontal-Vertical) along with sand filtration implemented with two local Macrophytes (Typha angustifolia and phragmate australis). The plant root and shoot were analyzed in beginning and end of the study to determine the removal rate. The result shows increase in the mean concentration values of heavy metals and waste water parameters in root and shoo of both T. angustifolia and Ph. australis in HCW (H&V) and (V&H). Therefore, Macrophytes in HCW can be used to remove heavy metals and other parameters from waste water used for irrigation.

Source Identification and Spatial Distribution of Heavy Metal Concentrations in Shallot Fields in Brebes Regency, Central Java, Indonesia

Shallots have been widely planted as the primary commodity crop in Brebes Regency, Central Java, Indonesia. Information on the distribution of heavy metals in the shallot fields of Brebes Regency, Central Java, Indonesia, is not yet available. Hence, the present study was conducted to identify the concentration and spatial distribution of several heavy metals (Pb, Cd, Co, Cr, and Ni) and their possible sources in the shallot fields through a field survey and a series of laboratory and statistical tests. The total concentration of heavy metals was analyzed from 184 sampling points of the shallot fields in Brebes Regency, Central Java, Indonesia, during the dry season from August to October 2019. The heavy metals concentration was as follows: Cr > Ni > Pb > Co > Cd. The values of total Pb, Cd, Co, Cr, and Ni concentrations in the soils were 7.84–18.94, 0.99–2.31, 3.02–9.98, 10.40–49.55, and 10.17–26.62 mg kg−1, respectively. All these concentration values of heavy metals are still lower than the critical values for agricultural soils and lower than the topsoil background values except Cd. Based on the concentration of heavy metals, the shallot fields in Brebes Regency, Central Java, are classified as uncontaminated soils. Multivariate and geostatistical analyses were employed to determine and describe the metals’ origin. Pb, Cr, and Ni mainly originate from a natural source, while Cd and Co are from anthropogenic sources (agricultural practices and industry).

Occurrence, monitoring and risk assessment of toxic substances in sewage water treatment plants: A case study, great Cairo, Egypt.

An evaluation process on the validity of wastewater treatment plants effluents for irrigation was done. Chemical and microbial pollutants were measured occasionally in five WWTPs spread in great Cairo, Egypt. The results revealed that WWTPs used secondary treatment (Chlorination) were had the capability to scrape much amount of microbial pollutants, while the units that have only primary treatments were unable to eliminate the microbial organisms. Although the processes used at WWTPs were unspecific for inorganic contaminants removal, metals were reduced in effluents to more than 50 % about the influents. This reduce was attributed to the adsorption of metals on activated sludge which used in aeration stage. In spite of low concentration values of heavy metals in the effluents, these values were conducted to cause hazard effects for aquatic organisms especially Cd, Cu, Pb and Zn based on predict no effect concentration criteria. Water quality index was calculated to identify the applicability of WWTPs effluents for sign in irrigation. The results cleared that the effluents of all units studied weren’t applicable for irrigation purpose. These consequences can affect directly on biological cycles. Thus it seems that more consideration of bio conservation protocols is so important.

Assessment of Heavy Metals in Water Contaminated with Petroleum Products in Keffi Local Government Area, Nasarawa State, Nigeria.

This work assessed the presence of heavy metals in water contaminated with petroleum products in Keffi Local Government Area. Two water sampling station were selected based on the stratified method of sampling of Antau River. Station A is located along Federal Government College Keffi popularly known as Antau Bridge where Agricultural and mechanical activities, with sales of petroleum product take place. Station B was located at Dadin Kowa known as Gada Manu where human activities such as bathing and washing takes place which served as control. The distance between stations is 1km. The procedural plan of this study was monthly sampling of water from both Stations. Materials such as funnel, sampling container, distilled water, conical flask, filter paper, 50ml polypropylene centrifuge tube, cooler were used. Heavy metal concentration was determined using X – ray Fluorescent Spectroscopy (XRF) at the Center for Energy Research and Training (CERT), Ahmadu Bello University Zaria. The water parameters of the four samples were determined using the Extech instrument. The result on Physico – chemical parameters revealed the values obtained from contaminated water samples to be pH (7.31), Dissolved Oxygen (1.14), Electrical Conductivity (8.22), Total Dissolved Solid (4.13), Temperature (27.45) and Salinity (0.091) while the controlled Station at point B were pH (7.43), DO (7.35), EC (3.14), TDS (1.54), Temperature (26.75), Salinity (0.o94) respectively. From the result obtained, the heavy metal contaminated samples had the following values: Mg (29.31±), Al (218.69±), Si (230.12±), S (1153.65±), Cl (54.25±), Ca (106.56±), Ti (23.66±), Cr (3.15±), Fe (15.92±), Cd (7.54±). For the control sample at point B, the following values were obtained: Mg (27.49±), Al (223.71±), Si (243.21±), S (94.84±), Cl (23.52±), Ca (28.44±), Ti (32.99±), Fe (16.63±), Cd (7.67±) respectively. The P-value was 0.8105 (p>0.05) for the water quality parameters while for the concentration of heavy metal P-value was 0.2054 (p>0.05). This implies that there was no significant difference between the concentrations of elements. However, the concentration values of heavy metals in the contaminated water at Station A and control water samples at Station B were higher than the World Health Organization values (Standard) for drinking water

Health Risk Assessment of Heavy Metals Accumulated on PM2.5 Fractioned Road Dust from Two Cities of Pakistan.

The aim of this study is to identify and investigate levels of toxic heavy metals in PM2.5 fractioned road dust to better understand the associated inhalation risk and potential health impacts. To achieve this aim, concentrations of seven traffic generated heavy metals (Cu, Pb, Zn, Cd, Ni, Sb, and Cr) were determined in the PM2.5 fraction of road dust samples from four different locations (offices, residential, hospital, and school) in two cities (Karachi and Shikarpur) of Pakistan using ICP-MS. The average concentration values of heavy metals in Karachi were as follows: 332.9 mg/kg Cu, 426.6 mg/kg Pb, 4254.4 mg/kg Zn, 62.3 mg/kg Cd, 389.7 mg/kg Ni, 70.4 mg/kg Sb, 148.1 mg/kg Cr, whereas the average concentration values of heavy metals in Shikarpur were 245.8 mg/kg Cu, 538.4 mg/kg Pb, 8351.0 mg/kg Zn, 57.6 mg/kg Cd, 131.7 mg/kg Ni, 314.5 mg/kg Sb, 346.6 mg/kg Cr. The pollution level was assessed through two pollution indices enrichment factor (EF) and geoaccumulation index (Igeo). These indices showed moderate to extreme level pollution in studied areas of both cities. The health risk assessment through inhalation contact was conducted according to the United States Environmental Protection Agency’s (USEPA) model for children and adults. Both non-cancerous and cancerous risks were characterised in the road dust samples for each location. As yet, there is not a single study on the concentrations of heavy metals in PM2.5 fractions of road dust in Karachi and Shikarpur, findings of this research will facilitate researchers for further investigations in current field.

Occurrence, Monitoring and Risk Assessment of Toxic Substances in Sewage Water Treatment Plants: A Case Study, Great Cairo, Egypt. متابعة, رصد وتقییم المخاطر البیئیه للمواد السامه بمحطات معالجة الصرف الصحی: دراسة خاصه, القاهرة الکبری, مصر.

An evaluation process on the validity of wastewater treatment plants effluents for irrigation was done. Chemical and microbial pollutants were measured occasionally in five WWTPs spread in great Cairo, Egypt. The results revealed that WWTPs used secondary treatment (Chlorination) were had the capability to scrape much amount of microbial pollutants, while the units that have only primary treatments were unable to eliminate the microbial organisms. Although the processes used at WWTPs were unspecific for inorganic contaminants removal, metals were reduced in effluents to more than 50 % about the influents. This reduce was attributed to the adsorption of metals on activated sludge which used in aeration stage. In spite of low concentration values of heavy metals in the effluents, these values were conducted to cause hazard effects for aquatic organisms especially Cd, Cu, Pb and Zn based on predict no effect concentration criteria. Water quality index was calculated to identify the applicability of WWTPs effluents for sign in irrigation. The results cleared that the effluents of all units studied weren’t applicable for irrigation purpose. These consequences can affect directly on biological cycles. Thus it seems that more consideration of bio conservation protocols is so important.

Assessment of Heavy Metals in Guinea Sorrel (Hibiscus sabdariffa) Cultivated on Fadama Soils in Maiduguri, Nigeria

River Ngadda is one of the main sources of water used by the resident of Maiduguri Metropolis The proximity of the people to the river encourages a lot of irrigation farming along the river bank during the dry season especially vegetables therefore, concentration values of heavy metals namely Aluminum, Cobalt, Iron, Lanthanum, Manganese, Chromium, Rubidium, Scandium, Samarium, Thorium, Vanadium and Zinc were determined in Guinea Sorrel (Hibiscus sabdariffa) vegetable samples obtained at six different locations on different dry season farming (Fadama) sites along the bank of river Ngadda and Alau dam in Maiduguri, Nigeria. Instrumental neutron activation analysis (INAA) technique which is a sensitive method for determination of major, minor and trace element in a matrix was used to assessed the heavy metal accumulation levels in Guinea Sorrel with the aim to establish the food safety status from heavy metals concentration levels for guinea sorrel cultivated along the bank of river Ngadda and Alau dam and consumed on a daily basis as compared to WHO/FAO recommended maximum permissible limit (MPL) for edible vegetables. The result obtained showed that the concentration values of Al ranged from 932 ± 18 to 3369 ± 54 ppm, Co 0 .12 ± 0.03 to 40 ± 4 ppm, La 1.00 ± 0.03 ppm to 38 ± 4 ppm, Manganese 112 ± 0.4 to 176 ± 1 ppm, Rubidium 4 ± 0.5 to 21 ± 1ppm, Sc 0.10 ± 0.007 to 27 ± 1 ppm Sm 0.106 ± 0.004 to 17.2 ± 0.4 ppm, V 1.10 ± 0.3 to 4 ± 1 ppm and Zn 17 ± 3 to 63 ± 4 ppm, and Fe 379 ± 33 ppm to 2316 ± 65 ppm. This result indicates that the maximum concentrations of Fe, Cr, Mn and Co, in guinea sorrel from most of the sites were above the acceptable limits given by FAO/WHO for edible vegetables. Therefore, it is certain that there is the health risk associated with the continuous consumption of guinea sorrel vegetables cultivated from the study site and authors of this work hereby recommends that investigation of this kind should be carried out from time to time so as to know the buildup or otherwise of heavy metals in guinea sorrel cultivated in the study sites.

Assessment of some heavy metals concentrations in soil and groundwater around refuse dumpsite in Ibadan Metropolis, Nigeria

This study reports the determination of some heavy metals’ concentration in soil and groundwater around refuse dumpsites in five locations in Ibadan Metropolis, Nigeria. Five samples were collected from each soil and ground water locations and analysed for heavy metals(Cd, Co, Pb, Cr, Zn, Mn and Ni)using Atomic Absorption Spectrophotometry. The soil samples were obtained in triplicates at 25cm depth intervals whereas the water samples were obtained from hand dug wells less than 10 m deep. The range of the values of heavy metal concentrations obtained in water is Co (0.01-0.04), Pb (0.01-0.02), Cr (0.02-0.05), Zn (0.40-0.70), Mn (0.02-0.05) and Ni (0.02-0.05), but Cadmium was not detected. The concentrations of Pb and Ni in ground water obtained from Arapaja, Aleshinloye and Alafara were higher than the World Health Organization (WHO) and Standard Organisation of Nigeria (SON) limits. The results obtained showed that the concentrations of Cd, Co, Pb, Ni and Cr in soil exceeded the WHO and SON permissible limits. However, Zn and Mn were below the limit.
 Keywords: Heavy metals, Dumpsite, Groundwater, Soil samples, Concentrations.

ОЦЕНКА УРОВНЯ ЗАГРЯЗНЕНИЯ ТЯЖЕЛЫМИ МЕТАЛЛАМИ ДОННЫХ ОТЛОЖЕНИЙ РЕК ВОСТОЧНОГО ДОНБАССА (РОСТОВСКАЯ ОБЛАСТЬ, РОССИЯ)

Introduction. River bottom sediments are a significant link in the biogeochemical cycles of water bodies and an accumulator of pollutants. The purpose of this study is to assess the level of heavy metal pollution of river sediments within the coal-mining areas of the East Donbass (Rostov Region, Russian Federation) to assess the potential risk for the population using surface water as a source of water supply. Methods. It is suggested to use the pelitic fraction for a more accurate assessment of the heavy metal pollution level of river sediments. It is proposed to use the average continental shale concentration as a baseline value for the pelitic fraction. Contamination factor (Cf), degree of contamination (Cd) and geo-accumulation index (Igeo) were used to assess the degree of heavy metal pollution of the bottom sediments in the East Donbass rivers. Results. Studies of the chemical composition and the level of bottom sediments pollution in the East Donbass rivers showed that the concentration values of heavy metals vary greatly. Assessing the degree of heavy metal pollution of the river sediments in the East Donbass allows us to classify them mainly as moderately contaminated (uncontaminated to moderately contaminated). At the same time, the level of river sediments pollution in the Seversky Donets basin is generally lower than that in the Tuzlov basin. Conclusion. The results will be used to improve the system for assessing water and bottom sediments quality in the region as well as evaluate the environmental risk to public health. Although the results showed a moderate level of heavy metal contamination of the East Donbass rivers sediments, the potential hazard of secondary pollution of the aquatic environment with metals deposited in sediments remains. Pollution of water and river bottom sediments is directly linked to the potential risk to public health because these rivers are used as sources of drinking water for towns and countryside.

The potential of integrating landscape, geochemical and economical indices to analyze watershed ecological environment

A river watershed is a complex ecosystem, and its spatial structure and temporal dynamics are driven by various natural factors such as soil properties and topographic features, human activities, and their interactions. In this study, we explored the characteristics of the ecosystem and environment of watershed by analyzing and modeling the relationships among socio-economic indices, heavy metal elements and landscape metrics. Landsat 8 data were used to generate a land cover classification map and to derive landscape pattern indices. Governmental finance statistics yearbook data were referred to provide socio-economic indices. Moreover, 9 samples were collected from the upstream to the downstream to obtain the values of heavy metal concentrations in the water body. Then, both correlation and regression analyses were applied to analyze and model the relationships among these indices. The results of this study showed that 1) The ecological status and process (social economy, land cover, water and soil pollution) of this river watershed could be explained by analyzing the relationships among the socio-economic indices, heavy metal elements and landscape pattern indices selected based on correlation analysis; 2) The accumulated socio-economic indices were significantly correlated with Al, Fe and Ni and should be applied to the integrated assessment of the watershed ecological environment; 3) Cu, Zn and Pb were the main elements that showed significant correlations with the forest land; 4) Some landscape patterns indices such as Total Area (TA) and Effective Mesh Size (MESH) could be used to the integrated assessment of the watershed characteristics because of their strong correlations with the area (or area percentage) of important landscape types; and 5) transportation land had a close relationship with per capita Gross Domestic Product (GDP). This study implied that analyzing and modeling the relationships among the socio-economic indices, heavy metal elements and landscape pattern indices can provide a powerful tool for characterizing the ecosystem of the river watershed and useful guidelines for the watershed management and sustainable development.

Heavy metal bioaccumulation in <i>Callinectes amnicola</i> and <i>Farfantepenaeus notialis</i> from three selected tropical water bodies in Lagos, Nigeria.

The bioaccumulation of heavy metals in organisms is as a result of pollutants discharge generated by anthropogenic and natural activities which has become a tremendous concern in developing nations. The levels of cadmium, copper, chromium, lead, zinc and nickel in the tissue of Callinectes amnicola and Farfantepenaeus notialis collected from Igbese River, Makoko and Lekki Lagoon were evaluated for a period of eight months. Heavy metals analysis was done using Atomic Absorption Spectrophotometer. The mean concentration values of heavy metals in the tissues of lagoon crab recorded are-Cr (0.14, 0.71 and 0.19 mg/l), Cu (2.17, 1.27, 1.51 mg/l), Pb (0.47, 0.26, 0.15 mg/l), Zn (0.04, 1.05, 0.63 mg/l), Ni (0.33, 0.30, 0.19 mg/l) in Igbese River, Makoko site and Lekki Lagoon respectively. While metal concentration in tissue of shrimps observed are-Cr (0.28, 0.18 and 0.14)mg/l, Cu (1.21, 1.03, 0.56) mg/l, Pb (0.26, 0.19, 0.13) mg/l, Zn (0.74, 1.11, 0.36) mg/l, Ni (0.28, 0.27, 0.15) mg/l across Igbese river, Makoko site and Lekki lagoon respectively. There was a significant difference (P Ni > Zn > Cr > Cu > Cd. The bioaccumulation factor (BAF) of the metal from sediments to tissues of lagoon crabs and shrimps observed highest accumulation in comparisonwith water to tissues. The observed metals with higher BAF values were Pb (0.81, 1.82 and 1.60) in lagoon crabs and Pb (1.46, 2.68 and 2.00) in shrimps and Zn (1.23, 1.01 and 1.32) in lagoon crabs and Zn (1.73, 0.95 and 2.31) in shrimp's bioaccumulated from sediment across Igbese river, Makoko site and Lekki Lagoon respectively. While the least BAF metal was Cu with values of 0.03, 0.12 and 0.03 in lagoon crabs and 0.06, 0.15 and 0.09 in shrimp's bioaccumulated from water across Igbese river, Makoko site and Lekki Lagoon respectively. The results revealed that heavy metals concentrations in the lagoon crab and pink shrimp were below the threshold levels associated with toxicological effects and regulatory permissible limits. Key words : Bioaccumulation, Callinectes amnicola , Heavy metals, Lagoons, Farfantepenaeus notialis ,

Kondisi Terumbu Karang di Perairan Sisi Timur Pulau Tikus, Bengkulu

<strong>Condition of Coral Reefs in the Waters of the East Side of Tikus Island, Bengkulu. </strong> Tikus Island is located in the Province of Bengkulu. This small island is about 10 km from the City of Bengkulu. The area is only about 19,800 m2. The waters in the east side of the island was often used as location for the unloading and loading of coal from small ships into large ship (coal transhipment), to be taken to other places. This is because the condition of the port of Baai in Bengkulu is not yet possible for large ships to enter the harbour area. The study to determine the condition of coral reefs in the waters of the east side of Tikus Island was conducted in November 2012. Coral reef data collection was conducted at three stations using Line Intercept Transect (LIT). In addition, the water clarity was also measured using a Secchi disk. The results showed that the water clarity on the east side of Tikus Island was still good for coral growth, with values ranging from 9 to10 m. The percentage of live coral cover was 38.89 ± 5.02%, which was categorized as "fair". This condition was relatively better compared to several other locations that were also located in the Indian Ocean. Supporting data such as the high diversity and density of indicator fish Chaetodontidae as well as the values of heavy metal concentrations in the water columns that are still below the threshold values for marine lives, strengthen the results obtained. Regardless of the presence or absence of negative impacts of coal transhipment occurring in the waters of the east side of Tikus Island, the coral reefs were still in a normal condition. <br />

Spatial Distribution of Heavy Metals and the Environmental Quality of Soil in the Northern Plateau of Spain by Geostatistical Methods.

The environmental quality of soil in the central part of the Northern Plateau of Spain has been analyzed by studying the heavy metal content of 166 samples belonging to the horizons A, B and C of 89 soil profiles. The analysis to assess the environmental risk of heavy metals in the soil was carried out by means of the spatial distribution of nine heavy metals and the use of several pollution indices. The results showed that the concentration values of heavy metals ( ± S) in the superficial soil horizons were the following: With a total of 6.71 ± 3.51 mg·kg−1, the contents of Cd is 0.08 ± 0.06 mg·kg−1, Co is 6.49 ± 3.21 mg·kg−1, Cu is 17.19 ± 10.69 mg·kg−1, Cr is 18.68 ± 12.28 mg·kg−1, Hg is 0.083 ± 0.063 mg·kg−1, Ni is 12.05 ± 6.76 mg·kg−1, Pb is 14.10 ± 11.32 mg·kg−1 and Zn is 35.31 ± 14.63 mg·kg−1. These nine metals exceed the values of the natural geological background level of Tertiary period sediments and rocks that form part of the Northern Plateau in Spain. Nemerow and Potential Ecological Risk indices were calculated, with the “improved” Nemerow index allowing pollution within the soil superficial horizons to be determined. The data obtained indicated that the majority of the soil (54.61%) showed low to moderate contamination, 22.31% showed moderate contamination and 21.54% of the samples were not contaminated. If we consider the Potential of Ecological Risk Index (RI), the largest percentage of soil samples showed low (70.79%) to moderate (25.38%) ecological risk of potential contamination, where the rest of the soil presented a considerable risk of contamination. The nine trace elements were divided into three principal components: PC1 (Cu, Cr, Ni, Co and Zn), PC2 (As and Hg) and PC3 (Cd). All metals accumulated in the soil came from parent rock, agricultural practices and the run-off of residual waters towards rivers and streams caused by industrial development and an increase in population density. Finally, cartography of the spatial distribution of the heavy metal contents in the soil of the Northern Plateau of Spain was generated using Kriging interpolation methods. Furthermore, the total heavy metal contents in three soil orders present in the area, namely Entisols, Inceptisols, and Alfisols, were analyzed. Other soil parameters, such as the organic matter content, pH, clay content and cation exchange capacity, was measured to determine their influence on and correlation with the heavy metal contents.

The Determination of Some Pollution Parameters, Water Quality and Heavy Metal Concentrations of Aci Lake (Karapinar/Konya, Turkey)

Abstract Water quality parameters were measured in Acı Lake. The measurements were carried out in water samples taken from five different stations over ten months. According to the results of the analyses done on the samples of water, without taking into consideration the differences of seasons and stations, the average annual values of heavy metal concentrations for Cr, Cu and Ni were found to be 0.10 mg/l, 0.11 mg/l and 0.19 mg/l dry weight, respectively. Surprisingly, Co and Cd metals were not detected at any station or at any season. Other water quality parameters, namely pH, turbidity and nitrate, fall in the intermediate value range for these measures. The comparisons of the measured parameters and the metal concentration with the water quality index show that the water quality of Acı Lake prevents the water being used as irrigation water due to high salt levels.