A review of ecological risk assessment and associated health risks with heavy metals in sediment from India

Heavy metal (HM) pollution in sediment is a serious concern particularly in developing nations, warranting an extensive survey to understand the current situation and propose possible remedial measures. This paper compiles the data of HMs cadmium (Cd), iron (Fe), cobalt (Co), manganese (Mn), arsenic (As), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn) and nickel (Ni) in aquatic sediment from India from 1979 to 2017. It was found that mean values of Cu, Co, Zn, Pb, As, and Cr in Indian sediment were high in comparison to the Australian Interim Sediment Quality Guidelines, World Surface Rock Average, and the Threshold Effect Level for freshwater ecosystems. Anthropogenic activities, lithogenic factors, and sand intrusion are the main factors associated with HM pollution as observed using cluster analysis and principal component analysis. The results of contamination indices indicate that HM contamination ranged from average to high, in the sediment. The ecological risk assessment results showed that 11% HMs present very high risk. The cancer risk, due to the high contents of Cd, As, and Cr the ingestion pathway, showed high risk of cancer through food/water contaminated with sediment. At source reduction of HMs in industrial effluents by effluent treatment plants, and plantation of phytoremediating rooted macrophytes in sediment may help in HM mitigation of the sediment.     

Distribution and source differentiation of PAHs and PCBs among size and density fractions in contaminated harbor sediment particles and their implications in toxicological assessment

Sediment samples collected from Kaohsiung Harbor (Taiwan) were analyzed for 15 priority polycyclic aromatic hydrocarbons (PAHs) and 118 individual polychlorinated biphenyl (PCB) congeners in various particle size fractions and two density fractions. The PAHs in the low density fraction were a much more sensitive and effective indicator of the PAH source than those in the sediment as a whole. Hierarchical cluster analysis of PAH analytes in the low density sediments revealed significant differences in compositional patterns between locations and among size fractions. In the sediment samples from both study sites, the low density fraction particles had up to 155 and 150 times higher concentrations of PAHs and PCBs, respectively, than those in the corresponding high density fractions. In addition, the total toxic benzo[a]pyrene and 2,3,7,8-tetrachlorodibenzodioxin (TCDD, dioxin) equivalents in the sediment low density fractions were much higher (up to 170 and 273 times, respectively) than the corresponding high density fractions.     

Distribution,sources, and ecological risk assessment of polycyclic aromatic hydrocarbons in surface sediments from the Nantong Coast,China

The distribution, sources, and ecological risk assessment of 16 polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the Nantong coast in China were investigated. The results indicated that the total concentrations of the 16 PAHs in the surface sediments from the study area ranged from 1.4 to 87.1 ng g^? 1 dw (mean value 19.9 ng g^? 1 dw), which were generally low compared to the adjacent offshore area and other coastal zones around the world. The selected PAH ratios and the principal components analysis for each site showed that petroleum combustion and petrogenic pollution (mainly caused by petroleum spills) were the dominant PAHs sources in the surface sediments of the coast. The ecological risk assessment indicated that most of the individual PAHs had few negative effects in this area.     

太湖流域西氿湖沉积岩芯中重金属污染及潜在生态风险

通过对太湖流域西沈湖沉积物岩芯XJ2中Cu、Pb、Zn、Cd、Cr等5种重金属元素总量的分析,结合测年结果,揭示了不同时间段重金属污染物的分布特征,并利用Hakansen潜在生态风险评价法对沉积物岩芯的污染状况及潜在生态风险的历史变化进行了研究.结果表明岩芯受Cd元素污染最重,其它4种元素较Cd则轻得多,因此Cd元素是影响该地区沉积物潜在生态风险的绝对主导因素.从20世纪初叶开始,沉积物中的重金属元素污染及其相应的潜在生态风险开始上升,并且上升幅度不断加剧,到20世纪90年代达到最大值,沉积物污染及潜在生态风险级别均为"很高",随后便开始迅速下降,然而直到2004年这两个参数仍然维持在"很高"级别.     

Distribution and ecological risk assessment of some heavy metals in coastal surface sediments along the Red Sea,Egypt

The ecological risk assessment for Al,Zn,Cu,Ni,V,Pb,Cd,and Hg in surface sediment collected from the Egyptian Red Sea coast was evaluated using the Geo-accumulation Index(I_(geo)).Sediment Enrichment Factor(SEF) and Potential Ecological Risk Index(PERI) methods.The predominant heavy metal,aluminum,showed high concentrations along both of Aqaba Gulf(4378.8 ± 2554.1 μg/g) and southern part of the Red Sea(2972.8 + 1527.5 μg/g).while it recorded the lowest concentration in Suez Gulf(829.7 ± 398.2 μg/g).The determined heavy metal concentrations had the order of Al Zn -Ni V Pb Cu Cd Hg.The statistical analyses showed some correlations among the heavy metals contents.Several international sediment quality guidelines were used to estimate the quality of the collected sediments.Interestingly,the recorded average heavy metals concentrations were lower than those of the permissible contents for sediment quality guidelines.The Geo-accumulation index calculations(I_(geo)) proved that the investigated region could be classified as an unpolluted area.Sediment Enrichment Factor(K_(SEF)) study showed high values in Suez Gulf region.The single pollution index analysis of heavy metals in the sediments(C~i_f) indicated that Al,Zn,V,and Pb were of natural origin,while Ni,Cd and Hg were seriously affected by human activities.Interestingly,amongst,all the determined heavy metals,Cd and Hg gave moderate ecological risk indicators.     

Distribution of heavy metals in water and sediment of an urban river in a developing country: A probabilistic risk assessment

River water and sediment embody environmental characteristics that give valuable eco-environmental information.Due to rapid industrialization,the aquatic environment of any urban river can be seriously polluted by heavy metals（HMs）.The global concern is caused by heavy metal pollution because of its potential harm to aquatic ecosystems and human health.In the Bhairab River,Bangladesh,surface sediment concentrations of globally alarming toxic metals such as arsenic（As）,chromium（Cr）,cadmium（Cd）,an...     

Towards quantitative ecological risk assessment of elevated carbon dioxide levels in the marine environment

The environmental impact of elevated carbon dioxide (CO₂) levels has become of more interest in recent years. This, in relation to globally rising CO₂ levels and related considerations of geological CO₂ storage as a mitigating measure. In the present study effect data from literature were collected in order to conduct a marine ecological risk assessment of elevated CO₂ levels, using a Species Sensitivity Distribution (SSD). It became evident that information currently available from the literature is mostly insufficient for such a quantitative approach. Most studies focus on effects of expected future CO₂ levels, testing only one or two elevated concentrations. A full dose-response relationship, a uniform measure of exposure, and standardized test protocols are essential for conducting a proper quantitative risk assessment of elevated CO₂ levels. Improvements are proposed to make future tests more valuable and usable for quantitative risk assessment.     

Ecological risk assessment of eutrophication in Songhua Lake, China

The Songhua Lake in the Northeast China is chosen as a study case in this paper. Monitoring of samples and analysis 18 indexes related to the eutrophication in the Songhua Lake had been conducted in 2002–2004. Ecological risk assessment methods are employed here. The study results showed that total phosphorus and total nitrogen were main risk factors to impact on the eutrophication of the Songhua Lake, and influence of the phosphorus on the lake eutrophication was larger than that of nitrogen. Algal growth potential test was also conducted to validate the results. High phosphorus and high nitrogen concentrations were mostly distributed in Huifahekou and Jiaohe sites of the Songhua Lake. Threshold values of total phosphorus, total nitrogen and Chl-a concentrations from dose-effective examination were 0.065 mg/L, 0.843 mg/L, and 11.90 μg/L, respectively. The probability of the eutrophication appeared in the Songhua Lake was 0.69, of them, risk-free type area was 19.21% of total lake area, slight risk type area was 30.10%, middle risk type area was 16.50%, heavy risk type area was 25.8%, hyper risk type area was 8.39%. In order to control the eutrophication in the Songhua Lake, maximum permission discharges of total phosphorus and total nitrogen to the lake would be 2,123.78, 7,018.82 t/a, respectively.     

甲氧氯的水质基准、沉积物质量基准及生态风险评价

甲氧氯(methoxychlor,MXC)作为一种有机氯杀虫剂,由于在农业生产中的广泛应用,使其在水环境和沉积物中的检出频率均较高,并且对各种水生物种均具有毒性作用。因此,制定中国MXC水质基准(water quality criteria,WQC)和沉积物质量基准(sediment quality criteria,SQC),并开展生态风险评估,对保护中国水生生物至关重要。基于收集和筛选的17种水生生物的急性毒性数据和10种水生生物的慢性毒性数据。选取物种敏感性分布(species sensitivity distribution,SSD)模型的最佳拟合对WQC进行推导,MXC对水生生物的短期水质基准(SWQC)和长期水质基准(LWQC)分别为0.75和0.11μg/L。通过相平衡分配法,在WQC的基础上进一步推导出SQC,沉积物质量基准高值(SQC-H)和沉积物质量基准低值(SQC-L)分别为0.73和0.11 mg/kg。此外,通过收集中国地表水和沉积物中的MXC暴露浓度数据,利用风险商值法(risk quotients,RQ)进行生态风险评价,结果表明我国部分区域的地表水和沉积...     

Distribution of geochemical fractions of phosphorus and its ecological risk in sediment cores of a largest brackish water lake,South Asia

The current study focuses on the vertical profile of different geochemical fractions of phosphorus-loosely bound(Lo–P),aluminium bound(Al–P),iron bound(Fe–P),calcium bound(Ca–P),and organic bound phosphorus(O–P)along with ecological risk assessment of sediment cores from Chilika Lake,eastcoast of India.The percentage contribution of the different fractions to the sedimentary phosphorus in the sediment column of the whole lake are on the order:O–P(33.2%)>Ca–P(20.3%)>Fe–P(18%)>Al–P(6.7%)>Lo–P(0.35%).The Phosphorus Pollution Index(PPI)revealed the contamination of lake sediment with phosphorus.The principal component and cluster analyses highlighted the anthropogenic contribution of phosphorus.The negative loading of Ca–P with Ca points towards its origin from marine shells.The discriminate analysis showed that the variables like Ca–P,bio-available phosphorus(BAP),and pH were able to effectively discriminate the sectors in a significant manner.     

广西青狮潭水库水体喹诺酮类抗生素的分布特征及生态风险评价

利用高效液相色谱法对桂林市青狮潭水库喹诺酮类抗生素（氧氟沙星（OFX）、诺氟沙星（NOR）、环丙沙星（CIP）、恩诺沙星（ENR））进行监测,并分析其污染来源和生态风险.结果表明：青狮潭水库水体中氧氟沙星、诺氟沙星、环丙沙星和恩诺沙星的检出浓度范围分别为50.00~660.13、3.70~5.00、3.49~6.22和4.59~6.06 ng/L;与国内河流抗生素浓度水平相比,青狮潭水库水体中喹诺酮类抗生素浓度处于中等偏低水平;青狮潭水库水体喹诺酮类抗生素浓度与水体理化性质的相关性分析表明：NOR浓度与pH相关性极显著、与浊度相关性显著,CIP浓度与总磷浓度相关性显著,OFX和ENR浓度与理化指标无显著相关性;生态风险评价结果表明青狮潭水库东湖区、西湖区水体中OFX存在高风险,NOR、CIP与ENR处于中等风险水平.     

太湖沿岸区浅层底泥重金属污染分析及生态风险评价

近年来太湖底泥重金属污染越来越受到各方关注.为了解太湖沿岸区底泥重金属污染状况,基于2018年太湖全湖污染底泥勘察项目中重金属监测数据,对梅梁湖、竺山湖、西部沿岸区、南部沿岸区、东太湖、贡湖6个太湖沿岸湖区浅层(0～30 cm深度区间)底泥中Hg、Cd、As、Pb、Cu、Zn、Cr、Ni 8种重金属元素含量进行分析,运...     

基于土地利用动态变化的太湖地区景观生态风险评价

在GIS和RS技术支持下,以遥感数据和土地利用数据为基础,以行政区划为评价单元,定量分析太湖地区1990-2008年土地利用变化及其转化关系;从土地利用变化和景观结构角度构建景观生态风险评价模型,定量评价了研究区内景观生态风险的时空动态变化特征.结果表明:太湖地区景观生态风险分布与区内土地利用方式和强度具有较高关联.景...     

抚仙湖表层沉积物AVS与SEM分布特征及其生态风险评估

以高原深水抚仙湖为研究对象,分析了全湖16个样点表层沉积物（0~5 cm）的酸可挥发性硫化物（AVS）和同步提取重金属（SEM）的分布特征,并利用∑SEM和AVS的物质的量浓度比对全湖重金属潜在生态风险进行了评估.结果表明：AVS在南北湖区分布存在明显差异,南部湖区分布均匀,平均含量仅为0.074±0.043 μmol/g,而北部湖区则由湖岸带向北湖心（N9）呈现出递增趋势,平均含量高达0.317±0.485 μmol/g.SEM在南北湖区分布较为集中,南部湖区主要集中在路居河口（S2）,北部湖区主要分布在老凹地（N5）和东大河口（N4）.除牛摩河口（S5）、梁王河口（N3）和北湖心（N9）外,其余所有点位[∑SEM]/[AVS]>1,且南部湖区平均[∑SEM]/[AVS]值（3.51±1.91）显著高于北湖湖区（2.19±2.10）.因此抚仙湖全湖尤其是南部湖区重金属生态风险应引起高度重视.     

Geochemical fractionation and ecological risks assessment of benthic sediment-bound heavy metals from coastal ecosystems off the Equatorial Atlantic Ocean

This study determines the pollution, fractionation, and ecological risks of sediment-bound heavy metals from coastal ecosystems off the Equatorial Atlantic Ocean. Contamination Factor(CF), pollution load index(PLI), and geoaccumulation index(Igeo) were used to assess the extent of the heavy metal pollution, while the potential ecological risk was evaluated using the risks assessment code(RAC) and Hkanson potential ecological risk. The analysis revealed concentrations(mg/g, dw) of the cadmium(Cd),chromium(Cr), copper(Cu), nickel(Ni), and lead(Pb) in sediments for wet and dry seasons vary from 4.40-5.08, 14.80-21.09. 35.03-44.8, 2.14-2.28, and 172.24-196.39, respectively. The results also showed that the metal fractionation percentages in the residual, oxidizable, and reducible fractions are the most significant, while the exchangeable and carbonate bound trace metals are relatively low. The RAC values indicate no risk for Cd and Ni and low risk for other metals at all the studied sites during both seasons.Potential ecological risk analysis of the heavy metal concentrations indicates that Cd had high individual potential ecological risk, while the other metals have low risk at all investigated sites. The multi-elemental potential ecological risk indices(R_1) indicate high ecological risk in all the ecosystems.     

Distribution,sources and ecological risk assessment of PAHs in surface sediments from Guan River Estuary,China

The contamination of surface sediments in Guan River Estuary, China, by polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. Total concentrations of 21 PAHs ranged from 90 to 218 ng/g with an average of 132.7 ng/g, which is relatively low in comparison with other estuaries around the world. PAH concentrations appeared to be positively correlated with clay content and negatively correlated with sediment grain size. Source identification implied that the PAHs originated mainly from pyrolytic sources. However, source patterns may be continuously changed to a petrogenic origin due to the heavy ship traffic and continuous discharge of oily sewage in this area. The PAH levels were also compared with international Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated low negative effects for most individual PAHs. However, toxic effects related to FLO would occur occasionally in most locations in the estuary.     

Assessing metal toxicity in sediments using the equilibrium partitioning model and empirical sediment quality guidelines: A case study in the nearshore zone of the Bohai Sea,China

Surface sediments were collected from five nearshore (wastewater discharges, aquaculture facilities and a seaport) sites in Bohai Bay and Laizhou Bay, China. The equilibrium partitioning (EqP) model and empirical sediment quality guidelines (SQGs) were applied to assess the potential metal toxicity in the collected sediments. The results show that, based on the EqP model, 35% of stations exhibited potential metal toxicity. Several metals (Cu, Ni and Cr) exceeded the empirical SQGs (9–93% of the time), however these guidelines may not be suitable for use in the Bohai Sea owing to the background concentrations. The EqP model is a more useful method for assessing potential metal toxicity in Bohai Sea sediment than the empirical SQGs. Additionally, we have provided new understanding about methods for assessing sediment metal toxicity in the Bohai Sea that may be useful in other coastal areas in China.     

Harmonization of international risk assessment protocol

For over centuries developments in food production and new food safety management systems in most developed countries have been perceived by many to be efficient in the prevention of food-borne disease. Nevertheless a number of problems remain dominant, one of these being the high level of food-borne microbiological disease which seems, for some pathogens, to have increased over the last decades. The development of an interdisciplinary approach with direct interaction between surveillance and risk analysis systems is described as a potential basis for improved prevention of food-borne disease. Quantitative microbiological risk assessment is a relatively new scientific approach, able to link data from food within the entire food chain and the various data on human disease to provide a clear estimation of risk. Today food safety is one of the WHOs top eleven priorities; the Organization calls for more systematic and aggressive steps to be taken to reduce significantly the risk of microbiological food-borne diseases. Dealing with this challenge is one of the major challenges for the 21st century in regard to food safety, implying a significant re-direction of food microbiology efforts in many parts of the world.     

千岛湖表层沉积物中有机氯农药的残留特征及生态风险评价

对千岛湖表层沉积物中21种有机氯农药(OCPs)的残留现状进行调查,明确HCHs与DDTs的组成特征及源解析,并评估其生态风险.结果表明,千岛湖表层沉积物中共检出12种OCPs,各采样点位OCPs总量的浓度范围在0.43~12.70 ng/g之间,平均值为5.28±4.84 ng/g,处于低残留水平,其中DDTs是主要的残留物,街口、大坝前点位样品出现OCPs高残留.工业DDTs的历史使用是千岛湖表层沉积物DDTs残留的主要来源,仅街口点位样品存在林丹的污染并有新的DDTs输入,应引起重视.利用沉积物质量基准法、沉积物质量标准法分别对千岛湖表层沉积物中OCPs的生态风险进行评价,结果表明部分点位样品中OCPs的残留现状对该区生物可能存在生态风险.     

Correlation assessment and monitoring of the potential pollutants in the surface sediments of Pyeongchang River, Korea

The study provides a baseline for the assessment of the organic and inorganic pollution specially, heavy metal contamination in the surface sediments of Pyeongchang River,South Korea.The assessment of the study areas was done with respect to metal pollution load,ecological risk and geoaccumulated risk.Based upon the used indices,a priority index(P_index) was used to rank the utmost contaminated sites.Though the concentrations of mercury in all sediments were below the guideline, the significant enriched contamination was observed by all applied indices.As expected,the values of pollution load index（PLI）,ecological risk index（RI） and geoaccumulation risk index(I_geo) demonstrated lower heavy metal contamination in upstream areas compared to the downstream. Admittedly,sediments were unpolluted to slightly-polluted according to PLI while high to extremely high ecological risks were observed in several sediment samples.Furthermore,all the samples were uncontaminated as per I_geo.After simplification of I_geo,the P_index,showed the utmost contaminated sediments with a value of 2.537.Notably,protective measures should be taken to the highly contaminated areas which are prioritized by P_index Admittedly,the maximum concentrations of total organic carbon,total nitrogen,inorganic nitrogen,total phosphorous,inorganic phosphorous,calcium, magnesium,sodium and potassium were significantly observed as 7.8×10⁴,3,185,36,1,032,3.7, 1,5163,2,881,669 and 4,076mg/kg accordingly.