Pollution Status Of Heavy Metals Research Articles

鸭绿江口近岸海域水质环境对冬季浮游动物群落结构的影响

定量分析滨海湿地近岸海域水质环境与浮游动物群落结构之间的关系对揭示海水水质环境健康状态具有重要意义。2019年12月在鸭绿江口湿地国家级自然保护区近岸海域开展了浮游动物和水环境因子调查，运用冗余分析和结构方程模型等方法探讨了水质环境对冬季浮游动物群落结构的影响。研究区共鉴定出浮游动物14种以及浮游幼虫5大类，桡足类最多占比52.63%；保护区不同功能分区间浮游动物群落结构总体差异不大，多样性指数、均匀度指数和丰富度指数平均值分别为1.34、0.51和0.59；浮游动物的种群分布与海水化学需氧量、溶解性无机氮、浮游植物群落多样性指数和铜元素含量关系显著；结构方程模型模拟结果表明，海水富营养化水平对浮游动物丰富度的效应系数为-0.26，具有显著的直接影响（P=0.01），重金属污染水平通过影响浮游植物丰富度（效应系数为-0.41，P<0.001）间接对浮游动物丰富度产生作用（间接效应系数为-0.2）。研究结果将有助于深化对海水环境和浮游动物群落结构协同演变过程的认识，为滨海湿地近岸海洋生态系统科学管理提供理论支撑。;Quantitative analysis of the relationship between the water environmental factors and zooplankton community nearshore of the coastal wetland is of great significance for assessing the sea water quality. Based on the investigation and sampling of the seawater and zooplankton nearshore of Yalu River Wetland National Nature Reserve in December 2019, the influence of environmental factors on zooplankton community structure was analyzed using Redundancy Analysis (RDA) and the Structural Equation Modeling (SEM). A total of 14 species of zooplankton and 5 groups of planktonic larvae were identified, of which the number of copepods was the highest with proportion of 52.63%. None significant difference of zooplankton community was detected among different subareas of the nature reserve. The diversity index, evenness index and richness index of zooplankton community in the study area were 1.34, 0.51, 0.59, respectively. Simulation result of the SEM showed that richness index of the zooplankton community was directly affected by the eutrophication status of the sea water with a coefficient of -0.26 (P=0.01), and was indirectly affected by the heavy metal pollution status with a coefficient of -0.2. This study provides useful insight for the relationship between sea water environmental factors and the zooplankton community, and provides basis for the scientific management of the offshore marine ecosystem of coastal wetland.

Pollution Status and Ecological Risk Assessment of Heavy Metals in Marine Sediments from the Central Arabian Gulf

Pollution Status and Ecological Risk Assessment of Heavy Metals in Marine Sediments from the Central Arabian Gulf

Evaluation of Water Quality Pollution Indices for Heavy Metal Contamination Monitoring in Surface Water of Sutlej River (India)

Globally, heavy metal contamination in aquatic environment is a growing dilemma and currently reached at an alarming rate. Surface water receives metal contamination both naturally and anthropogenically. A study was conducted during October 2018 – Dec 2019 to examine the present status of heavy metal pollution in the river Sutlej (Downstream junction of Buddha Nullah), Punjab. The prime thrust is to determine the heavy metal concentrations (Arsenic, Nickel, Cadmium, Cobalt, Chromium, Boron, Manganese, Copper, Iron, Lead and Zinc) of surface water from two points at the location site and to determine the water quality indices (Heavy metal pollution index, heavy metal evaluation index and degree of contamination). Heavy metal analysis has been done using inductively coupled plasma atomic emission spectrophotometer. The results of this study showed that the average concentration of heavy metals such as As, B, Cd, Co, Cr, Cu, Fe, Mn, Ni, Zn and Pb were 0.123?g/l, 0.144 ?g/l, 0.047 ?g/l, 0.059 ?g/l, 0.189 ?g/l, 0.281?g/l, 1.424?g/l, 0.097?g/l, 0.291?g/l, 0.904 ?g/l and 0.631 ?g/l respectively. The overall mean concentration of heavy metals was observed in the following order Fe &gt;Zn&gt;Pb&gt;Cu&gt;Ni&gt;Cr&gt;B&gt;As&gt;Mn&gt;Co&gt;Cd. The HPI and HEI (water quality indices) for As, Fe, Mn, Ni, Zn, Pb, Cd, Cr and Cu were 503.05, 55.55 respectively. It is concluded that the study area is critically polluted with heavy metals that are lethal to aquatic life and humans.

Seasonal hydrocarbon and metal assessment of water and fish from oil producing communities along Orashi River, Nigeria.

This study investigated the heavy metal and hydrocarbon pollution status of Orashi River in four communities of Imo and Anambra States of Nigeria. Water and fish (Oreochromis niloticus and Clarias gariepinus) samples were collected from the river in the dry and wet seasons. Hydrocarbon and physicochemical parameters were determined in water with standard methods. Water and fish muscles were digested and analysed for metals using atomic absorption spectrophotometry. Results of analyses indicated hydrocarbon pollution. Hardness, alkalinity, nitrate, chloride, phosphate, and sulphate were significantly higher (p < 0.05) in wet season samples. Arsenic was undetected in water samples, but higher cadmium and iron concentrations were recorded in the wet season samples. Lead concentrations in the wet season were higher at some sites than the World Health Organization guideline. Arsenic was detected in Clarias at three sites in both seasons, but iron concentrations were significantly higher (p < 0.05) than those of other metals. Lead concentrations in Clarias gariepinus were lower than the Codex limit (0.3mg/kg) except in the muscle samples from four sites. Arsenic was undetected in Oreochromis niloticus muscle samples but concentrations for lead (0.851 ± 0.203-8.604 ± 1.264mg/kg (dry season) and 0.627 ± 0.035-9.364 ± 0.786mg/kg (wet season)) exceeded the Codex limits in all samples. Health risk indices for the species indicated potential risk to the population from the consumption of Oreochromis niloticus. However, hazard index and target carcinogenic risk values indicate that people in the communities do not face significant non-carcinogenic and carcinogenic risks from cadmium and lead intake by consuming the fish species.

Analysis and Evaluation on Characteristics of Heavy Metal Pollution in the Coastal Farmland Soil along the Wuma River

The thesis is aimed to provide a reference for the sustainable utilization of farmland soils along the Wuma River, an upstream tributary of the Chishui River in Guizhou Province. Geo accumulation index method, Nemero comprehensive pollution index method, and potential ecological hazard index method were used based on the experimental data for analyzing and evaluating the heavy metal pollution status of farmland soil along Wuma River. The results showed that: (1) The contents of heavy metals Ni, Cu, Zn, Pb and Hg in farmland soil exceeded the soil background values of 9.82%, 47.80%, 13.72% and 76.06% in Guizhou Province, respectively, but did not exceed the standard limit class II based on the environmental quality. (2). The pollutants of Pb and Zn in the research area mainly come from mineral exploitation, waste residue accumulation, and transportation. The enrichment of Cr and Cu may originate from the domestic garbage dumping and incinerated waste by residents along the coast and irrational agricultural activities. The main contents of Cd, As and Hg come from soil geochemistry. (3) The ranking of accumulations of eight heavy metals was IPb&gt;IHg&gt;ICu&gt;INi&gt;IZn&gt;ICr&gt;IAs&gt;ICd, among which Pb was non-moderately polluted and the remaining heavy metals were at the clean level; Nemero comprehensive pollution index showed that As, Cr, Zn, and Ni were mildly polluted, while Pb, Hg, and Cu were moderately polluted. The ranking of potential ecological risk levels for the eight heavy metals was Hg, Pb, Cu, Ni, As, Cd, Cr, Zn. The overall ecological risk level is mild.

Speciation Characteristics and Ecological Risk Assessment of Heavy Metals in Municipal Sludge of Huainan, China.

In order to fully understand the morphological characteristics and pollution status of heavy metals in the dewatered sludge of Huainan Municipal sewage treatment plant, the physical and chemical properties were analyzed, and the content and occurrence forms of heavy metals (As, Cu, Zn, Pb, Cd, Cr, and Ni) in the sludge were studied using the geological accumulation method (Igeo), risk assessment coding method (RAC), and potential ecological risk index method to evaluate the ecological risk. The results showed that the municipal sludge in Huainan was rich in nutrients, with good prospects for agricultural utilization. There were differences in the morphological distributions of different heavy metals. The Igeo values for Ni, As, Cr, and Pb were below 0. The results of RAC indicated that the risk level of Cr in sludge was a low risk, and those of other heavy metals were moderate risks. The potential ecological risk of Cd had the highest potential ecological risk, and the other six metals were of low ecological risk. This conclusion can provide basic data and a theoretical reference for the comprehensive utilization of sludge in sewage treatment plants.

Assessment of heavy metal pollution in agricultural soil around a gold mining area in Yitong County, China, based on satellite hyperspectral imagery

Soil is one of the essential natural resources that is at risk from heavy metal pollution. The traditional sampling method for soil heavy metal monitoring and assessment cannot meet the requirements for large-scale areas. The purpose of this study was to estimate the soil heavy metal concentrations based on Gaofen 5 (GF5) satellite hyperspectral imagery for the assessment of the heavy metal pollution in the study area and to analyze the scale effect under different resolutions. A total of 96 topsoil samples were collected in this work, and these samples were analyzed for the arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) contents. To solve the problem of the insignificant features caused by the complex imaging conditions of spaceborne hyperspectral satellite imagery, the binary weight symbiotic organisms search algorithm (BWSOS) was developed. After feature selection based on the BWSOS method, the heavy metal contents are inverted by the use of support vector machine regression. The experimental results show that the BWSOS feature selection method shows a good performance, with the Rp2 values for As, Cd, Cr, Cu, Ni, Pb, and Zn being 0.67, 0.68, 0.73, 0.71, 0.66, 0.65, and 0.71, respectively. Based on the estimated heavy metal concentration maps, the geoaccumulation index (Igeo), the pollution index, and the potential ecological risk index were calculated to assess the heavy metal pollution status in the study area. The results showed that only As contamination is present at a significant level, but with a low level of potential risk for the whole study area. A comparison with the results obtained using HyMap airborne hyperspectral imagery showed that the GF5 satellite hyperspectral imagery can obtain consistent results for heavy metal pollution assessment. The airborne hyperspectral imagery can provide more fine details, whereas the spaceborne hyperspectral imagery is more suitable for large-scale pollution assessment at a low cost.

The Pollution Status of Heavy Metals in the Surface Seawater and Sediments of the Tianjin Coastal Area, North China.

Heavy metal pollution has become a great concern due to its adverse effects on the ecological system and human health. The present study investigated the concentrations of six common heavy metals (Cr, Cu, Zn, As, Cd, and Pb) in the Tianjin coastal area to understand their distribution, enrichment, sources, and potential ecological risk levels, focusing on the main contributors. The results showed that the concentration of Cu was high in the surface seawater (6.89 µg/L for the average), while Cd was the main contaminating metal in the sediments, with an average concentration of 0.77 mg/kg. The potential ecological risk index (RI) implied that the heavy metals in the sediments could cause considerable ecological risk, and Cd was the major contributor to ecological risk in this area. In particular, the field investigation showed that Cd contamination occurred as a result of anthropogenic activities, including port transportation, mariculture, and metal fabrication along the coastal area. Therefore, it is necessary to control Cd contamination in the future to improve the quality of the marine environment in Bohai Bay.

Risk assessments and health impacts of heavy metal pollution

<p indent="0mm">Heavy metal pollution is a serious global environmental issue, posing huge risks to food security and human health. As a typical biomarker of heavy metals, soil nematodes develop complex defenses in response to heavy metal exposures. Meanwhile, their gut microbiomes assist host resistance to heavy metals. Here we review the pollution status and assessment methods of heavy metals at home and abroad and summarize their effects on the behavior, physiology, and biochemistry of soil nematodes. Additionally, defense mechanisms of organisms against heavy metals are reviewed, including barrier functions of the cell wall and membrane, changes in active substances, metallothionein overexpression, and noncoding RNA regulation. We propose that the diversity and composition of the nematode gut microbiome can be used as a new indicator of heavy metal toxicity. Furthermore, long-term heavy metal exposure could lead to adaptive evolution, such as the emergence and enrichment of heavy metal hyperaccumulation, resistance, and detoxification genes. Additionally, we can map genetic changes, such as resistance mutations in genes and synergies of resistance, by quantifying the genome-level response of genetic variation under environmental stresses. Finally, we provide a prospect on the ecotoxicology of heavy metals and indicate that future research should focus on the current ecological environment and human health, explore the ecological role of soil fauna gut microbiome, and further understand the potential mechanism of occurrence and development of heavy metal toxicity and biological detoxification.

Risk assessment of bioavailable heavy metals in the water and sediments in the Yongding New River, North China.

To explore the pollution status of heavy metals and potential risks in the Yongding New River of Tianjin, China, a comparative study of concentrations of heavy metals (Cd, Cr, Cu, Pb, Zn, As, and Hg) in surface sediments from submerged areas (SA), fluctuant flooded district (FFD), and non-flooded district (NFD) was conducted. In the present study, a modified three-stage European Community Bureau of Reference sequential extraction procedure and EDTA-Na2 single extraction were used to determine the heavy metal distribution in different sediment samples. Results showed that Cd was the metal with the highest contamination level compared to a background value of Tianjin soils, particularly in SA, followed by As. The concentrations of Cr, Pb, Cu, and Zn were relatively higher in upstream. Cu and Pb had higher bioavailability when compared with the other metals, indicating the two metals were easier to be mobilized. The Pearson correlation coefficient is applied to assess the degree of correlation between heavy metals. As, Cu, Zn, and Hg had the strong correlation, implying they may have common sources. Human activity in the riparian such as agricultural production, vehicle, and burning coal increased inputs of heavy metals in the surface sediments and influenced their distribution spatially. Besides, we also calculated geo-accumulation indexes (Igeo) and eco-risk index to assess the degree of risk of heavy metals in sediments. The Igeo were higher in SA than in FFD and NFD. Based on Igeo and potential eco-risk index, Cd has the highest risk, followed by As and Hg.

Research on the treatment of heavy metal pollution in urban soil based on biochar technology

Biochar is a material for remediating soil contaminated by heavy metals, and it is also a remediation material for soil improvement. The remediation effect of biochar and its mechanism have been widely concerned in the environmental field. The most important factor that determines the effect of biochar remediation is the diversity of its physical and chemical properties. Cities are extremely important places for human life and production. From a global perspective, the area of cities only occupies less than 2% of the surface area. Urban soil refers to the general term for the original characteristics of the soil in the city or in the suburbs of the city, which are affected to varying degrees by human activities. Therefore, it is very meaningful to study the ecological effects, the chemical migration characteristics of the earth and the sources of heavy metals in urban soils. Based on the current status of heavy metal pollution in urban soils, and at the same time, due to the application potential of biochar in remediation of heavy metal contaminated soil and soil improvement, it is studied to study the effect of 400 °C sludge biochar on heavy metals (Cr, Zn, Cu) The remediation effect of contaminated soil, and at the same time, the raw material sludge is directly used as the remediation material to compare the long-term effects of sludge biochar and sludge on the physical and chemical properties of the soil, the form of heavy metals and the bioavailability, and fully consider The effect of biochar’s aging effect on the repair effect.

Environmental Risk Assessment of Recycled Products of Spent Coppery Etchant in Jiangsu Province, China.

With the vigorous development of the 5G industry, the characteristic hazardous waste, spent coppery etchant, was also produced in large quantities. In recent years, there are many companies that have begun to collect spent coppery etchant for the purpose of producing recycled products, such as copper sulfate, copper oxide, basic copper chloride, and copper powder, which often contain large amounts of heavy metals. However, due to the lack of relevant standards and applicable regulatory measures, some of the recycled products flow to the feed processing industry and even to the food processing industry. This study investigated the pollution status of heavy metals in recycled products of spent coppery etchant and evaluated the impact of recycled products exposure on human health. The results showed that the content of Zn was the highest, which was 21 times higher than the corresponding standard limit. Human health risk assessment indicated that the hazard quotients of As account for 87.5% of the entire HI value, while the average carcinogenic risk values of As for copper sulfate, copper oxide, basic copper chloride, and copper powder are 1.09 × 10−5, 3.19 × 10−5, 1.29 × 10−5, 7.94 × 10−6, respectively. Meanwhile, suggestions on the supervision of recycled products and the concentration limits of heavy metals in recycled products were put forward.

Evaluation of Heavy Metals Pollution Status of the Groundwater around Riruwai Mining Area, Kano State, Nigeria

The aim of this study was to investigate the heavy metals pollution status of the groundwater of Riruwai mining area, Kano State, Nigeria. A total of 31 groundwater samples were collected from five sampling locations which include: underground mining site (RGWI), tap water, (RGW2), surface mining ponds (RGW3), borehole (RGW4) and the well water samples (RGW5) during the dry and rainy seasons. The concentrations of seven heavy metals (As, Cd, Cr, Hg, Mn, Pb and Zn) and some physical parameters (pH, EC, and TDS) were determined using Atomic Absorption Spectrometer and Deluxe Water and Soil Analysis Kit respectively. The results of the analysis revealed that pH, EC and TDS were within the desirable limits recommended by WHO and NSDWQ in all sampling locations except in RGW1 and RGW3 for both seasons. The concentrations of heavy metals ranged as follow: As (ND to 0.15), Cd (ND to 0.1), Cr (ND to 0.25), Hg (ND to 0.09), Mn (0.12 to 0.66), Pb (0.003 to 0.06) and Zn (2.29 to 11.75), and As (0.005 to 020), Cd (0.001 to 0.15), Cr (0.001 to 0.17), Hg (ND to 0.14), Mn (0.16 to 0.92), Pb (0.007 to 0.09) and Zn (2.85 to 14.05) during the dry and rainy seasons respectively. The heavy metals concentrations changed along with the sampling sites in decreasing order of RGW1 &gt; RGW2 &gt; RGW3 &gt; RGW4 &gt; RGW5 in both seasons. The concentrations of all heavy metals were above the desirable limits recommended by WHO and NSDWQ during both seasons except well water samples (RGW5) and some few locations where the heavy metals were not detected. Therefore, it is recommended that water resources of the Riruwai mining area should be monitored closely, and more efforts should be made to reduce heavy metals concentrations level, particularly As, Cd, Cr and Zn.

Assessment of Some Heavy Metals in Water and Sediments Using Bio-Concentration Method of Al-Ma’ail River in Al-Kahla’a District, Maysan, Southern Iraq

Al-Ma'ail river is one of the small Iraqi rivers, as it extends over a distance of approximately 47 km. Al-Ma'ail river is located next to Halfaya oil field, which is the main source of pollution to Al-Ma’ail river, consequently, the environmental quality of Al-Ma'ail river is under great pressure from a variety of human activities. Although water is commonly used as an indicator of contamination by heavy metals, sediments are considered as water important in assessing the environmental situation. In this study, water and sediment samples were analyzed to assess the pollution status of heavy metals in Al-Ma'ail river, with the aim of determining its ability to sustain aquatic life. Samples were taken from five sites along Al-Ma'ail river between the branch area of Al-Ma'ail river from the Al-Kahla river (which also branches from Tigris River upon its exit from Amara City), until Al-Ma'ail river reaches pond of Umm Al-Na'aj (marshland). Ten Water and five sediment samples were collected in August 2020. Samples were analyzed for eight heavy metals: As, Cd, Cr, Cu, Pb, V, Ni and Zn, using AAS techniques. As for the water samples, all the concentrations were over the standards (except Zn which was within the limits in all samples), While Cu concentration in (samples SW1 to SW7) are within the standards (except SW8 and SW9 are close U.S.EPA and within WHO). Concentrations of heavy metals in sediments were over the limits in all samples. The bio-concentration values of heavy metals were calculated and all metal rates were found within the acceptable range for the U.S. EPA, except for vanadium, which was higher than the permissible limit and was a bio-accumulative and considered as an indicator of oil pollution. The results indicate the presence of long-term contamination of the eight selected heavy metals in the river sediments which may be of concern to the health of the aquatic ecosystem.

Heavy metal pollution status and health risk assessment vicinity to Barapukuria coal mine area of Bangladesh

Study related to pollution and subsequence health risk assessment adjacent to coal mining region is indispensable since coal mining and combustion have adverse impacts on the soil, subsoil, and plants in the surrounding area with a threat to human health and ecosystem. This study assesses the heavy metal pollution in water and soil as well as uptake in several parts of paddy plants over the three seasons around the year in the vicinity of the Barapukuria coal mine in Bangladesh, with the ultimate goal of estimating human health risks from eating the rice grown in this area. Enrichment factor (EF), pollution load index (PLI), geo-accumulation index (Igeo) and biological accumulation factor (BAF) were estimated for quantifying the pollution status in soils and plants. Collected samples were prepared and analysed by using USEPA recommended methods. PLI showed that soils irrigated by coal mine water were highly polluted by Ni, Fe, and Cr metals. The Igeo indicated that the soil in the study area was moderately contaminated by Cu, Zn and Ni. Amongst all types of samples, soil was found with the highest pollution followed by roots, stems, and grains; however, bioaccumulation was not evident. In the three varieties of rice grains tested, Zn and Fe were present with the highest concentrations. Through the rice grain, people in the area are ingesting Fe in the highest amounts and Cr with the lowest. Even though the concentration of Cr is low it is still above the oral intake level as recommended by USEPA.

Characteristics of Sludge and Associated Risk Assessment of Urban Sewage Treatment Plants

In urban solid waste management, the scientific and reasonable disposal and utilization of sewage sludge is becoming more and more important. It can be said that the pollution status and chemical properties of sewage sludge in urban sewage treatment plants can provide a basis for the scientific disposal and utilization of sludge. In this study, the characteristics of pH, moisture content, Cd, Cr, Cu, Zn, Pb, As, Hg, Ni, mineral oil, volatile phenol, PAHs, organic matter, nitrogen, phosphorus, and potassium were evaluated in sewage sludge collected from 49 sewage treatment plants in a certain city. The pollution status of heavy metals and organic pollutants, the frequency distribution of pollutant concentrations, and changes in the nutrient content were analyzed. The Nemero index and Hakanson potential ecological hazard index were used to assess the potential ecological risks of heavy metals in the agricultural utilization process of sludge. The results showed that under the condition of neutral pH values and high moisture content, the order of heavy metal content was Zn > Cu > Cr > Pb > Ni > As > Hg > Cd. The principal component analysis (PCA) results indicated that Cd, Pb, Hg, Ni, and As constituted the main load factors of the first main component of heavy metal sources. The most concentrated contents of 8 heavy metal frequency distributions among the 49 samples were 38.9-1380.0, 62.6-182.7, 63.6-181.3, 0.0-97.8, 19.3-68.4, 0.8-29.2, 0.3-8.7, and 0.01-0.96 mg·kg-1. In addition, the most concentrated frequency distribution of mineral oil, volatile phenol, and PAH concentration were 87.0%, 87.9%, and 77.6%, respectively. Moreover, the nutrient content of sludge was higher than the average level in China, and the organic matter content was 67.4%, 75.9%, and 92.5% of that of pig manure, cow dung, and chicken manure, while the content of nitrogen, phosphorus, and potassium was not very different. The Nemero index and Hakanson ecological hazard index results showed that the sludge of urban sewage treatment plant in the city has certain ecological risks. However, four sewage treatment plants were heavily polluted or highly ecologically hazardous among the 44 plants in this study, which were in line with the Standards for pollutant control of agricultural sludge. In summary, there are certain potential ecological risks for the agricultural utilization of sludge in the city, and it is necessary to reduce the heavy metal content before resourcing. More importantly, on the premise that the sludge meets the agricultural standards, a comprehensive ecological risk assessment is required to select a reasonable sludge recycling method.

Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Sediments of a Heavily Polluted Maozhou River, Southern China.

In this study, eighteen 3.30-m-long sediment profiles were sampled in Maozhou River. In order to investigate the sediment pollution status and potential sources of heavy metals, we performed heavy metal contents, grain size, organic matter concentration, moisture concentration and total phosphorus analysis, and assessed the ecological risk of heavy metal pollution in the study area using enrichment coefficient, geo-accumulation index and potential ecological risk index. The results indicated that the heavy metal concentrations in the Maozhou River sediments were 3.73-417 times higher than the soil background in Guangdong Province and the average concentrations were 0.447-15.1 times higher than Chinese lacustrine sediments. The Cr, Ni, Cu, Zn, Cd and Pb contents were significantly correlated with each other (p < 0.01), indicating similar deposition process. In addition, spatial and vertical distribution of heavy metals showed similar variation patterns and extreme high contents are distributed in the interchange area. The ecological risk of Maozhou River was much higher than other river sediments in Guangdong Province, especially for Cu, Cd and Ni. The variation pattern of potential ecological risk index is similar with that of heavy metals and the assessment results indicated high ecological risk in the Maozhou River sediments, which is in good agreement with the EF and Igeo results. This study would provide some references for the treatment of heavy metals' pollution in Maozhou River.

Heavy metal pollution and stable isotope ratios (δ13C and δ15N) in marine organisms from the Northern Beibu Gulf, South China Sea

Twenty biota species were collected from the Northern Beibu Gulf to understand the heavy metal pollution status and biomagnification characteristics. Mean concentrations (μg/g) of Mn, Zn, Pb, Cr, Ni, As, Cu, and Cd in the biota species were 0.99, 38.33, 0.14, 0.079, 0.085, 51.10, 7.92, and 0.21, respectively. As levels in most biota species exceeded the corresponding guidelines. Crabs were detected with high metal accumulation ability for each heavy metal except Pb. The ranges of δ15N and δ13C in organisms were from 8.0‰ to 15.6‰ and from −21.4‰ to −15.6‰, respectively. Cr, Mn, Ni, and As showed potential biomagnification trends in the food webs. The EDI values of these elements decreased by the sequence of As > Zn > Cu > Mn > Cd > Pb > Ni > Cr. High THQ and CR values for As indicated a potential health risk by consumption of these aquatic products.

Heavy Metal Pollution Assessment in Stream Sediments from Urban and Different Types of Industrial Areas in South Korea

ABSTRACT Stream sediments from heavily industrialized areas, including urban areas (SS), industrial complexes (US), petrochemical industries (PS), and the Onsan industrial complex (OS) in Korea, were studied to identify 19 heavy metals pollution status and the metal sources. The concentration of heavy metals, except for Li, Be, and Cs in the stream sediments from the Onsan industrial complex near the largest Cu/Zn/Pb smelting facilities, was 3 to 1,302 times higher than that in urban and other industrial areas. Moreover, owing to the smelting activity in the Onsan area, the degree of pollution by major metal products (e.g., Cu, Zn, Pb, Sn, Cd, Sb, Ag) and raw or additive materials (Cr, Ni, Mo, As, Hg) was significantly higher than that in other areas. Heavy metals in stream sediments near smelters greatly exceeded the screening levels (SEL), which could have adverse effects on the health of biota. These values also exceeded the cleanup screening levels of freshwater sediments in the USA. The highest pollution load index value of 47.8 was observed in the vicinity of the smelter (OS) and decreased in the following order: heavy industry (3.6, US) > petrochemical industry (2.4, PS) > urban streams (1.2, SS). Our results suggest that metal pollution in stream sediments might be caused by atmospheric dust generated during the smelting process, as well as sediment particles that accumulate and are washed off from impervious layers such as industrial facilities, raw material storage yards, and road surfaces.

Heavy Metals Contamination of Agricultural Land and Their Impact on Food Safety

Aims: The aim of this study is to investigate the heavy metals pollution status and health risks assessment of the vegetables grown at Danbatta irrigation lands.&#x0D; Study Design: The research involved the collection of soil, water and cultivated vegetable from irrigation lands as well as analyzing their heavy metals pollution status.&#x0D; Place and Duration of Study: Samples were collected from Danbatta irrigation lands of Kano state, Nigeria. The research study covered a period of one year.&#x0D; Methodology: This study investigates the prevalence of heavy metals pollution and related health risks associated with the vegetables grown at Danbatta local government of Kano state. This was achieved by collecting irrigation soil, water and vegetables (onion, spinach and lettuce) from the irrigation sites, which were subsequently assayed for several heavy metals such as; Pb, Mn, Cu, Fe, Zn and Co using atomic absorption spectrophotometry (AAS).&#x0D; Results: The results obtained show that the concentrations of Pb, Cu and Zn in water samples to be 0.033, 0.8, and 0.89 mg/ml, respectively, while Mn and Co were not detected. Even though concentrations of these metals in water are within FAO/WHO limits, the soil was found to be contaminated with Cu (12.17 mg/kg), Fe (152.29 mg/kg) and Zn (55.75 mg/kg). Furthermore, both spinach, lettuce and onion were contaminated with Pb, and Mn. However, only lettuce and spinach were contaminated with Cu, Fe and Zn. Health risk assessment of both adults and children show that Pb, Mn, Co and Cu, posed a significant health risk to the population as their health risk index (HRI) is greater than one. The result shows that poor agricultural practices could be responsible for contaminating the soil with heavy metals, which eventually gets accumulated in the edible parts of the plants and posed a great risk to its consumers. Impacts of heavy metals pollution is on the rise across the globe. As such, it becomes necessary to monitor our environment to checkmate the threat of these contaminants and implement a reliable strategy and stable treatment of the pollution to ensure food safety.