A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg...A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg, 40.10 - 94.60 mg/kg, 35.14 - 110.48 mg/kg, 38.86g - 245.36 mg/kg, with a mean value of 37.24 mg/kg, 60.76 mg/kg, 80.49 mg/kg, and 145.99 mg/kg, respectively. The high degree of variation of Pb, Zn, and Cu, reflected that the heavy metals were mainly interfered by human factors. The content values of ∑DDTs ranged from 5.01 ng/g to 105.08 ng/g with a mean of 36.94 ng/g, while the ∑HCHs ranged from 6.52 ng/g to 48.65 ng/g with an average of 23.29 ng/g, indicated that DDTs were highly used than HCHs in the study area. The relatively low α-HCH/γ-HCH ratio and relatively high o,p’-DDT/p,p’-DDT ratio indicated the application of lindane and dicofol on regional agricultural soil. The mean Igeo values was Pb (2.9) > Cu (1.5) > Cr (-0.31) > Zn (-0.35), revealing that the soil in Hohhot City was not polluted by Cr and Zn (Igeo 0), moderate polluted by Cu (1 Igeo 2), moderate to heavy pollution by Pb (2 Igeo 3). The range of potential ecological risk index of metals was from 35.02 to 132.96, indicating low to moderate potential ecological risk. HCHs in all soil samples were less than 50 ng/g, which could be considered as unpolluted, while DDTs in several samples were between 50 and 500 ng/g, which could be regarded as having low pollution.展开更多
Based on the dynamic analysis and research of pollution risk of groundwater sources, this paper creates the dynamic assessment method of pollution risk of groundwater source area under the theory of "source-pathw...Based on the dynamic analysis and research of pollution risk of groundwater sources, this paper creates the dynamic assessment method of pollution risk of groundwater source area under the theory of "source-pathway-receptor", and applies this method to one typical fissure karst groundwater source area in northern China. Following the 30-year petroleum pollutant migration simulation and pollution risk assessment of groundwater source area, this study finds that the very high risk zone is mainly located in Q Petrochemical Company and the surrounding area and the area adjacent to River Z. Within this period of thirty years, the pollution risk of groundwater source area has showed a dynamic trend that features an inverted "V" shape. The ratio of very high risk zone to the total area will be 18.1%, 17.47% and 16.62% during the tenth year, the twentieth year and the thirtieth year separately, and will reach the highest level of 19.45% during the fifteenth year. Meanwhile, the vertical migration distance of pollutant centre concentration changed from the surface soil at the outset to the deepest point of about 250 meters underground during the tenth year. The results of this risk assessment indicate the dynamic feature of pollution risk. The dilution, degradation and migration of petroleum pollutants in groundwater system contribute to an ultimate decline in pollution risk.展开更多
The heavy metal contamination status of Bight of Bonny sea bed sediment w<span>as investigated. Sediment samples were collected from eleven locations grouped into three stations. The samples were analyzed to det...The heavy metal contamination status of Bight of Bonny sea bed sediment w<span>as investigated. Sediment samples were collected from eleven locations grouped into three stations. The samples were analyzed to determine the heavy met</span><span>als (Fe, Pb, Ni, Zn, Mn, Co, Cd, Cu, Cr) concentration using atomic absorption spectrophotometer. Index model analyses, such as geo-accumulation</span> index (I-geo), Enrichment factor (EF), and Pollution load index (PLI) were used for pollution assessment of sea bed sediment. The most predominant heavy metals in the upstream sediment were Fe;13.57 ± 1.838 mg/kg, cobalt;7.987 ± 3.550 mg/kg, and Ni;1.020 ± 0.802 mg/kg, midstream sediment were Fe;8.554 ± 3.010 mg/kg, Co;8.520 ± 4.00 mg/kg, and Ni;1.140 ± 0.879 mg/kg, while the downstream sediment result had Fe;11.12 ± 3.825 mg/kg, Co;7.275 ± 1.700 mg/kg, and Cd;1.025 ± 0.159 /kg. The I-geo results indicate that Cu, Mn, Pb, Cr, Fe, Zn, Ni, and Co were in their background concentrations while Cd had I-geo</span><span style="font-family:""> </span><span style="font-family:"">></span><span style="font-family:""> </span><span style="font-family:"">3 which implies a moderately or heavily polluted env<span>ironment. The EF indicates metal enrichment from anthropogenic sour</span>ces fo<span>r Co, Ni, Pb, Cd, Cu, and Cr while Fe and Mn predicate biogenic origin. The PLI of the heavy metals in the three sample stations of sea bed sediment was found to be generally low (<1). The Enrichment Factor and geo-ac</span>cumulation index strongly suggest the Bight of Bonny sea bed sediment contamination by Cd from anthropogenic sources.展开更多
It is of great significance to study the degree and source of soil heavy metal pollution in geological high background value area for remediation of local contaminated soil. The 0 - 20 cm topsoil was taken around the ...It is of great significance to study the degree and source of soil heavy metal pollution in geological high background value area for remediation of local contaminated soil. The 0 - 20 cm topsoil was taken around the mining area, and the contents of Pb, Zn, Ni, Cd, Hg, Cu and As in the soil were measured. Single-factor pollution index, Nemeiro comprehensive pollution index and potential ecological risk index were used to evaluate the degree of heavy metal pollution and ecological risk. Finally, multivariate statistical analysis was used to analyze the sources of soil heavy metals. The results show that the measured elements are polluted to different degrees, mainly due to the ecological environment problems caused by extensive mining development methods and inefficient utilization of resources. The key link is the release of pollutants at the source. Effectively blocking the release at the source can cut off the possibility of pollutants entering the food chain and the circulation of materials in the ecosystem. The results of potential ecological risk index showed that the potential ecological damage of seven heavy metals was ranked as follows: Cd (97.67) > Hg (68.97) > As (14.29) > Pb (11.55) > Ni (4.62) > Zn (1.61) > Cu (1.45) had a high ecological risk coefficient, and the potential comprehensive ecological risk index was 200.16 and the degree was medium. Principal component analysis shows that the sources of heavy metals are divided into Pb, Cd, As, Zn and Hg mainly from human activities such As mining, while Ni and Cu mainly come from soil parent materials, mining and agricultural activities.展开更多
Subterranean estuaries(STE)are important seawater-groundwater mixing zones with complex biogeochemical processes,which play a vital role in the migration and transformation of dissolved materials.In this study,we firs...Subterranean estuaries(STE)are important seawater-groundwater mixing zones with complex biogeochemical processes,which play a vital role in the migration and transformation of dissolved materials.In this study,we first investigated the spatial distributions of dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous(DIP),dissolved inorganic silicon(DSi)and metal elements(As,Ba,Cr,Cu,Fe,Mn,Ni,Pb,and Zn)in STE including upper intertidal,seepage face and subtidal zones.We then estimated submarine groundwater discharge(SGD)and associated nutrient and metal element fluxes.From the generalized Darcy’s law method,SGD was estimated to be 30.13 cm/d,which was about 7 times larger than the inflow(4.16 cm/d).The nutrient and metal fluxes from SGD were estimated to be(5.33±4.99)mmol/(m^(2)·d)for DIN,(0.22±0.03)mmol/(m^(2)·d)for DIP,(16.20±2.05)mmol/(m^(2)·d)for DSi,(1325.06±99.10)μmol/(m^(2)·d)for Fe,(143.41±25.13)μmol/(m^(2)·d)for Mn,(304.06±81.07)μmol/(m^(2)·d)for Zn,(140.21±13.33)μmol/(m^(2)·d)for Cu,(84.49±2.94)μmol/(m^(2)·d)for Pb,(37.38±5.51)μmol/(m^(2)·d)for Ba,(27.88±3.89)μmol/(m^(2)·d)for Cr,(10.10±6.33)μmol/(m^(2)·d)for Ni,and(6.25±3.45)μmol/(m^(2)·d)for As.The nutrient and metal fluxes from SGD were relatively higher than those from the inflow,suggesting that nearshore groundwater acted as the sources of nutrients and metal elements discharging into the sea.The environmental potential pollution of coastal seawater was evaluated by pollution factor index(Pi),comprehensive water quality index(CWQI),and ecological risk index(ERI).Pb mainly caused potential danger of nearshore environment with considerable contamination(Pi=5.78±0.19),heavy pollution(CWQI=4.09)and high ecological risk(ERI=18.00).This study contributed to better understanding the behavior of nutrients and metal elements and improving the sustainable management of STE under the pressure of anthropogenic activities and climate change.展开更多
Hainan Island is the most important tropical fruit production area in China.In this study,372 soil samples and corresponding fruit and irrigation water samples were collected from Hainan orchards and analysed to deter...Hainan Island is the most important tropical fruit production area in China.In this study,372 soil samples and corresponding fruit and irrigation water samples were collected from Hainan orchards and analysed to determine the concentrations of six heavy metal(loid)s:Cd,Hg,As,Pb,Cr,and Cu.The pollution status,potential risks,possible sources,and spatial distribution patterns of soil heavy metal(loid)s were comprehensively investigated.The fruit and irrigation water samples had negligible amounts of heavy metal(loid)s,and the potential human health risk for fruit consumers was at a safe level.The heavy metal(loid)concentrations in most soil samples were lower than the national risk screening values.However,significant local accumulation of heavy metal(loid)s,especially Cd,Cr,and Cu,relative to their background values was observed.Moreover,the combined effects of the heavy metal(loid)s only led to a mild pollution level and low ecological risk throughout the study area.Noncarcinogenic risks were not observed among the local residents,and carcinogenic risks were within an acceptable range.The acidic soil in the study area increased the risk of soil Cd pollution,and organic matter affected the distribution of the tested metal(loid)s in the soil.Uncommon geogenic sources with high background values were the sources of Cr and Cu,anthropogenic activities primarily led to Cd,Pb,and As contamination,and a combination of anthropogenic and natural sources was responsible for Hg emissions.The research suggested that appropriate strategies must be implemented to track and reduce soil heavy metal contaminants in the northern and western region of the Hainan orchard area.The results can provide valuable information for policies on pollution prevention and management,the environment,and human health protection in the study region.展开更多
The aim of the present investigation was to research the distribution characteristics of copper in water and sediment of the Liao River, China. The concentrations of copper in water and sediment showed significant dif...The aim of the present investigation was to research the distribution characteristics of copper in water and sediment of the Liao River, China. The concentrations of copper in water and sediment showed significant difference at different sampling stations. The distribution characteristics of copper in water and sediment were obtained by using discrete and continuous numerical characteristics. The results indicated that the average concentrations of copper in water and sediment decreased slightly after its accumulation. While the deviations of the concentrations of copper in water and sediment from the expectation increased significantly after its accumulation. The skewness distributions of the concentrations of copper in water and sediment did not change much before and after its accumulation. The kurtosis distributions of the concentrations of copper in water and sediment decreased significantly after its accumulation. Therefore, the precise distribution characteristics of copper in water and sediment were obtained through the combination of the discrete and continuous numerical characteristics. .展开更多
Background: Groundwater is an important source of water. Since the control and removal of pollution are expensive, it is essential to identify the possible sources of contamination and to correctly classify groundwate...Background: Groundwater is an important source of water. Since the control and removal of pollution are expensive, it is essential to identify the possible sources of contamination and to correctly classify groundwater on the basis of its intrinsic and integrated vulnerability. Objectives: To group ground water chemical ions and heavy metals parameters into similar groups. Method: The investigation made use of standard analytical procedures. All sampling, conservation, transportation and analysis followed standard procedures described in APHA (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while kept in an icebox. Results: Sampling records from the same area are generally assigned to the same cluster during hierarchical cluster analysis (HCA). The cluster diagram shows the grouping of the heavy metal in the study area during wet and dry seasons. It reveals that 5 distinct clusters were identified for wet season and 4 clusters were identified during dry season. Also, it reveals that 5 distinct clusters were identified for wet season and for dry season, 4 distinct clusters were identified. Conclusion: The findings of this study are significant for policymakers and agencies in terms of dealing with the issues identified to enhance sustainable livelihood practices in the oil rich Niger Delta region of Nigeria. Therefore, decision-makers should take proper initiatives to get local people aware of the endangered zones before use, as drinking water is key to good health. Similarly, multinational oil companies will find it useful in their quest for viable social corporate responsibility and remediation plans in their respective host communities. The method proved to be a useful and objective tool for environmental planning.展开更多
Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality...Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives.By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark(CLAB).The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator.Such a benchmark can provide an overall air quality assessment for areas of interest.A case study is presented for Dallas County(U.S.A.)applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019.Six air pollutants considered are:ozone,carbon monoxide,nitrogen dioxide,sulfur dioxide,benzene and particulate matter less than 2.5 micrometres.These pollutants are assessed individually and in terms of CLAB,and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019.Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years.The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs.Conducting CLAB analysis on an ongoing basis,using a relevant near-past time interval for benchmarking that covers several years,can reveal useful monthly,seasonal and annual trends in overall air quality.This type of medium-term,benchmarked air quality data analysis is well suited for ecosystem monitoring.展开更多
Haze or smog episodes,which are characterized by the presence of paniculate matter at diameters less than2.5 urn(PM2.5),have attracted increasing attention during the pastfew decades[1].PM2.5 has adverse effects onhum...Haze or smog episodes,which are characterized by the presence of paniculate matter at diameters less than2.5 urn(PM2.5),have attracted increasing attention during the pastfew decades[1].PM2.5 has adverse effects onhuman respiratory health as well as on air visibility[2,3].IntheBeijing-Tianjin-Hebei(BTH)region of China,haze has become especially serious in recent years because of industrial ex-展开更多
The results of dispersion modeling of carbon monoxide are reported in this paper. The results of applying the technique of Rapid Assessment of Sources of Environmental Pollution (RASEP) database and the Air Monitoring...The results of dispersion modeling of carbon monoxide are reported in this paper. The results of applying the technique of Rapid Assessment of Sources of Environmental Pollution (RASEP) database and the Air Monitoring State System in the City of Puebla, México, were employed. Concentrations of carbon monoxide emitted by cars inferred by RASAP technique with those reported by the environmental monitoring station “Nymphs”, were compared. The date of 21 June 2005-2010 was selected during the peak hour traffic flow. The dispersion of carbon monoxide was modeled by software DISPER and SCRI software, in order to infer the exposure levels of carbon monoxide in the study area. The estimated and monitored concentrations were evaluated with the Mexican regulations for population’s health protection. Regarding the dispersion model, SCRI was discarded for the target validation because it only allows modeling on specific areas. Moreover, the modeling software allowed DISPER simulations with linear sources of car exhaust, so this advantage is considered appropriate to continue using this program. Both estimates obtained by RASEP, as modeled by DISPER and recorded by the monitoring system exceed the maximum permissible limits of NOM-021-SSA1-1993 getting an impermissible for the area of influence of the assessment monitoring station. The DISPER software has potential use for such evaluations, but more work is required on the system for their inferences can be validated by reproducible physical and chemical measurements.展开更多
Due to the unclear distribution characteristics and causes of fluoride in groundwater of Mihe-Weihe River Basin(China),there is a higher risk for the future development and utilization of groundwater.Therefore,based o...Due to the unclear distribution characteristics and causes of fluoride in groundwater of Mihe-Weihe River Basin(China),there is a higher risk for the future development and utilization of groundwater.Therefore,based on the systematic sampling and analysis,the distribution features and enrichment mechanism for fluoride in groundwater were studied by the graphic method,hydrogeochemical modeling,the proportionality factor between conventional ions and factor analysis.The results show that the fluorine content in groundwater is generally on the high side,with a large area of medium-fluorine water(0.5–1.0 mg/L),and high-fluorine water is chiefly in the interfluvial lowlands and alluvial-marine plain,which mainly contains HCO_(3)·Cl-Na-and HCO_(3)^(-)Na-type water.The vertical zonation characteristics of the fluorine content decrease with increasing depth to the water table.The high flouride groundwater during the wet season is chiefly controlled by the weathering and dissolution of fluorine-containing minerals,as well as the influence of rock weathering,evaporation and concentration.The weak alkaline environment that is rich in sodium and poor in calcium during the dry season is the main reason for the enrichment of fluorine.Finally,an integrated assessment model is established using rough set theory and an improved matter element extension model,and the level of groundwater pollution caused by fluoride in the Mihe-Weihe River Basin during the wet and dry seasons in the Shandong Peninsula is defined to show the necessity for local management measures to reduce the potential risks caused by groundwater quality.展开更多
A total of 713 research papers about field monitor experiments of heavy metals in farmland and urban soils in China,published from 2000 to 2019,were obtained.A meta-analysis was conducted to evaluate the level of Chin...A total of 713 research papers about field monitor experiments of heavy metals in farmland and urban soils in China,published from 2000 to 2019,were obtained.A meta-analysis was conducted to evaluate the level of China's heavy metal pollution in soils,mainly focusing on eight heavy metals.It was found that the average concentrations of cadmium(Cd),lead(Pb),zinc(Zn),copper(Cu),mercury(Hg),chromium(Cr),nickel(Ni),and arsenic(As)in China were 0.19,30.74,85.86,25.81,0.074,67.37,27.77 and 8.89 mg/kg,respectively.Compared with the background value(0.097 mg/kg),the Cd content showed a twofold(0.19 mg/kg)rise in farmland soils and a threefold(0.29 mg/kg)rise in urban soils.The decreasing order of the mean Igeo was Cd(1.77)>Pb(0.62)>Zn(0.60)>Cu(0.58)>Hg(0.57)>Cr(0.54)>Ni(0.47)>As(0.28).Nearly 33.54%and 44.65%of sites in farmland and urban soils were polluted with Cd.The average concentrations of eight heavy metals were not sensitive change in recent two decades in farmland and urban soils.The average P_n values for urban(2.52)and farmland(2.15)soils showed that heavy metal pollution in urban soils was more serious than that in farmland,and the middle Yangtze River regions,where industrial activity dominates,were the most polluted.The meta-analysis comprehensively evaluated the current pollution situation of soil heavy metal,and provided important basis for soil management and environment prevention in China.展开更多
Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to so...Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to soil nutrient cycles.However,there is a growing lack of recognition and summary of the historic advancements that use soil enzymology as the proposal of evaluation methods.Here,we review the most common methods of heavy metal pollution evaluation based on enzyme activities,which include single enzyme index,combined enzyme index,enzyme-based functional diversity index,microbiological stress index,and ecoenzymatic stoichiometry models.This review critically examines the advantages and disadvantages of these methods based on their execution complexity,performance,and ecological implications and gets a glimpse of avenues to come to improved future evaluation systems.Indices based on a single enzyme are variable and have no consistent response to soil heavy metals,and the following three composite indices are characterized by the loss of many critical microbial processes,which thus not conducive to reflect the effects of heavy metals on soil ecosystems.Considering the dexterity of ecoenzymatic stoichiometry methods in reflecting changes in soil functions under heavy metal stress,we propose that microbial metabolic limitations quantified by ecoenzymatic stoichiometry models could be promising indicators for enhancing the reality and acceptance of results and further improving the potential for actual utility in environmental decision-making.展开更多
The characteristics of eight heavy metals(lead,zinc,copper,nickel,chromium,cadmium,mercury and arsenic)in the surface soil of the historical slag area of the Au ore dressing plant in the South-West of Luoyang City wer...The characteristics of eight heavy metals(lead,zinc,copper,nickel,chromium,cadmium,mercury and arsenic)in the surface soil of the historical slag area of the Au ore dressing plant in the South-West of Luoyang City were investigated and evaluated in terms of a pollution index,potential ecological hazards and health risks.The results showed that the average amounts of the heavy metals Pb,Zn and As in the soils of plots S3,S5,S7,S12 and S18 exceeded the soil pollution risk screening values.The Mero comprehensive pollution index in plots S7,S12 and S18 was greater than 3,indicating severe pollution.The severe pollution plot integrated the potential ecological risk index(RI)of each sampling point,which was in the order of RI_(S12)>RI_(S18)>RI_(S7)>RI_(S5)>RI_(S3).Among the heavy metals,Cd poses the greatest threat to ecological and human health.The effects of heavy metals in soil on the single non-carcinogenic health risk index(HQ)and the non-carcinogenic total risk index through three exposure pathways were in the order of HQ_(Hg)<HQ_(Cu)<HQ_(Ni)<HQ_(Zn)<HQ_(Cd)<HQ_(Cr)<HQ_(Pb)<HQ_(As)<1,which meant that the adult and child total carcinogenic risk(TCR)and individual carcinogenic health risk indices CRAs and CRCd were above the maximum acceptable human health level recommended by the USEPA(10^(-6)).TCRAs and TCRCd accounted for 75.65%and 23.94%of the adult TCR,respectively.TCR^(As) and TCR^(Cd) accounted for 75.93%and 23.97%of the child TCR,respectively.Overall,the TCR of children was greater than that of adults.In summary,the soil in the historical slag area of the Au ore dressing plant constitutes a serious threat to the surrounding ecological environment and to residents.展开更多
Nowadays,more people tend to spend their recreational time in large national parks,and trace metal(loid)s in soils have attracted long-term attention due to their possible harm to human health.To investigate the pollu...Nowadays,more people tend to spend their recreational time in large national parks,and trace metal(loid)s in soils have attracted long-term attention due to their possible harm to human health.To investigate the pollution levels,potential sources and health risks of trace metal(loid)s in road soils,a total of eight trace metal(loid)s(including As,Cd,Cr,Cu,Ni,Pb,Zn and Hg)from 47 soil samples along roads were studied in the Huangshan National Park in Southeast China.The results showed that the concentrations of As,Cd,Pb,Zn and Hg appeared different degrees of pollution compared with their corresponding background values.According to the pollution indices,Hg and Cd were recognized as significant pollutants presenting moderate to high ecological risk.Combining principal component analysis and positive matrix factorization model,the results showed that traffic,industrial,agricultural and natural sources were the potential origins of trace metal(loid)s in this area,with contribution rates of 39.93%,25.92%,10.53%and 23.62%,respectively.Non-carcinogenic risks were all negligible,while the carcinogenic risk of As was higher than the limit(1×10^(-6)).Moreover,children were more susceptible to trace metal(loid)s by ingestion which appeared to be a more important exposure pathway than dermal contact and inhalation.The contribution rates of different sources to non-carcinogenic risks and carcinogenic risks were similar among children and adults,while traffic and industrial sources have a significant impact on health risks.This study will give more insights to control the environmental risks of trace metal(loid)s in national parks.展开更多
Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological tox...Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological toxicity of PAHs is essential to abate their pollution and biological risks.The 16 priority PAHs in different lakeside city estuarine sediments in the northern Taihu Lake in China were determined using gas chromatography-mass spectrometry.Results showed that total concentrations of PAHs(ΣPAHs)ranged from 672.07 to 5858.34 ng g^(^(-1)),with a mean value of 2121.37 ng g^(^(-1)).High-molecular-weight PAHs(4-6 rings)were dominant,accounting for 85%of theΣPAHs detected.Due to the barrier of gate/dam in the estuarine area,the concentrations of PAHs in the sediments were significantly different between the river mouth and lake side.Changes in total organic carbon(TOC)content and the spatial distribution of PAHs in the sediments were consistent.Sediment pollution assessment explored using the fuzzy evaluation model indicated 75%of slight PAH pollution.Some estuarine sediments(22%)concentrated in the east of the Wuli Lake in the Meiliang bay of the Taihu Lake were moderately or heavily polluted.The PAHs may lead to occasional detrimental biological consequences in the area.Diagnostic ratios and principal component analysis-multiple linear regression suggested vehicle emission and natural gas combustion as the primary PAH contributors(81%).展开更多
文摘A total of 52 soil samples of Hohhot City were collected and four heavy metals and eight organochlorine pesticides were analyzed. The results showed that Cr, Cu, Zn, and Pb in soil were in range of 20.54 - 48.15 mg/kg, 40.10 - 94.60 mg/kg, 35.14 - 110.48 mg/kg, 38.86g - 245.36 mg/kg, with a mean value of 37.24 mg/kg, 60.76 mg/kg, 80.49 mg/kg, and 145.99 mg/kg, respectively. The high degree of variation of Pb, Zn, and Cu, reflected that the heavy metals were mainly interfered by human factors. The content values of ∑DDTs ranged from 5.01 ng/g to 105.08 ng/g with a mean of 36.94 ng/g, while the ∑HCHs ranged from 6.52 ng/g to 48.65 ng/g with an average of 23.29 ng/g, indicated that DDTs were highly used than HCHs in the study area. The relatively low α-HCH/γ-HCH ratio and relatively high o,p’-DDT/p,p’-DDT ratio indicated the application of lindane and dicofol on regional agricultural soil. The mean Igeo values was Pb (2.9) > Cu (1.5) > Cr (-0.31) > Zn (-0.35), revealing that the soil in Hohhot City was not polluted by Cr and Zn (Igeo 0), moderate polluted by Cu (1 Igeo 2), moderate to heavy pollution by Pb (2 Igeo 3). The range of potential ecological risk index of metals was from 35.02 to 132.96, indicating low to moderate potential ecological risk. HCHs in all soil samples were less than 50 ng/g, which could be considered as unpolluted, while DDTs in several samples were between 50 and 500 ng/g, which could be regarded as having low pollution.
基金Foundation project:the Specific Research on Public Service of Environmental Protection in China(201009009)
文摘Based on the dynamic analysis and research of pollution risk of groundwater sources, this paper creates the dynamic assessment method of pollution risk of groundwater source area under the theory of "source-pathway-receptor", and applies this method to one typical fissure karst groundwater source area in northern China. Following the 30-year petroleum pollutant migration simulation and pollution risk assessment of groundwater source area, this study finds that the very high risk zone is mainly located in Q Petrochemical Company and the surrounding area and the area adjacent to River Z. Within this period of thirty years, the pollution risk of groundwater source area has showed a dynamic trend that features an inverted "V" shape. The ratio of very high risk zone to the total area will be 18.1%, 17.47% and 16.62% during the tenth year, the twentieth year and the thirtieth year separately, and will reach the highest level of 19.45% during the fifteenth year. Meanwhile, the vertical migration distance of pollutant centre concentration changed from the surface soil at the outset to the deepest point of about 250 meters underground during the tenth year. The results of this risk assessment indicate the dynamic feature of pollution risk. The dilution, degradation and migration of petroleum pollutants in groundwater system contribute to an ultimate decline in pollution risk.
文摘The heavy metal contamination status of Bight of Bonny sea bed sediment w<span>as investigated. Sediment samples were collected from eleven locations grouped into three stations. The samples were analyzed to determine the heavy met</span><span>als (Fe, Pb, Ni, Zn, Mn, Co, Cd, Cu, Cr) concentration using atomic absorption spectrophotometer. Index model analyses, such as geo-accumulation</span> index (I-geo), Enrichment factor (EF), and Pollution load index (PLI) were used for pollution assessment of sea bed sediment. The most predominant heavy metals in the upstream sediment were Fe;13.57 ± 1.838 mg/kg, cobalt;7.987 ± 3.550 mg/kg, and Ni;1.020 ± 0.802 mg/kg, midstream sediment were Fe;8.554 ± 3.010 mg/kg, Co;8.520 ± 4.00 mg/kg, and Ni;1.140 ± 0.879 mg/kg, while the downstream sediment result had Fe;11.12 ± 3.825 mg/kg, Co;7.275 ± 1.700 mg/kg, and Cd;1.025 ± 0.159 /kg. The I-geo results indicate that Cu, Mn, Pb, Cr, Fe, Zn, Ni, and Co were in their background concentrations while Cd had I-geo</span><span style="font-family:""> </span><span style="font-family:"">></span><span style="font-family:""> </span><span style="font-family:"">3 which implies a moderately or heavily polluted env<span>ironment. The EF indicates metal enrichment from anthropogenic sour</span>ces fo<span>r Co, Ni, Pb, Cd, Cu, and Cr while Fe and Mn predicate biogenic origin. The PLI of the heavy metals in the three sample stations of sea bed sediment was found to be generally low (<1). The Enrichment Factor and geo-ac</span>cumulation index strongly suggest the Bight of Bonny sea bed sediment contamination by Cd from anthropogenic sources.
文摘It is of great significance to study the degree and source of soil heavy metal pollution in geological high background value area for remediation of local contaminated soil. The 0 - 20 cm topsoil was taken around the mining area, and the contents of Pb, Zn, Ni, Cd, Hg, Cu and As in the soil were measured. Single-factor pollution index, Nemeiro comprehensive pollution index and potential ecological risk index were used to evaluate the degree of heavy metal pollution and ecological risk. Finally, multivariate statistical analysis was used to analyze the sources of soil heavy metals. The results show that the measured elements are polluted to different degrees, mainly due to the ecological environment problems caused by extensive mining development methods and inefficient utilization of resources. The key link is the release of pollutants at the source. Effectively blocking the release at the source can cut off the possibility of pollutants entering the food chain and the circulation of materials in the ecosystem. The results of potential ecological risk index showed that the potential ecological damage of seven heavy metals was ranked as follows: Cd (97.67) > Hg (68.97) > As (14.29) > Pb (11.55) > Ni (4.62) > Zn (1.61) > Cu (1.45) had a high ecological risk coefficient, and the potential comprehensive ecological risk index was 200.16 and the degree was medium. Principal component analysis shows that the sources of heavy metals are divided into Pb, Cd, As, Zn and Hg mainly from human activities such As mining, while Ni and Cu mainly come from soil parent materials, mining and agricultural activities.
基金The National Key R&D Program of China under contract No.2021YFC3200501the National Natural Science Foundation of China under contract Nos 42107055 and 42130703the Fund of Shenzhen Science and Technology Innovation Committee under contract No.20200925174525002.
文摘Subterranean estuaries(STE)are important seawater-groundwater mixing zones with complex biogeochemical processes,which play a vital role in the migration and transformation of dissolved materials.In this study,we first investigated the spatial distributions of dissolved inorganic nitrogen(DIN),dissolved inorganic phosphorous(DIP),dissolved inorganic silicon(DSi)and metal elements(As,Ba,Cr,Cu,Fe,Mn,Ni,Pb,and Zn)in STE including upper intertidal,seepage face and subtidal zones.We then estimated submarine groundwater discharge(SGD)and associated nutrient and metal element fluxes.From the generalized Darcy’s law method,SGD was estimated to be 30.13 cm/d,which was about 7 times larger than the inflow(4.16 cm/d).The nutrient and metal fluxes from SGD were estimated to be(5.33±4.99)mmol/(m^(2)·d)for DIN,(0.22±0.03)mmol/(m^(2)·d)for DIP,(16.20±2.05)mmol/(m^(2)·d)for DSi,(1325.06±99.10)μmol/(m^(2)·d)for Fe,(143.41±25.13)μmol/(m^(2)·d)for Mn,(304.06±81.07)μmol/(m^(2)·d)for Zn,(140.21±13.33)μmol/(m^(2)·d)for Cu,(84.49±2.94)μmol/(m^(2)·d)for Pb,(37.38±5.51)μmol/(m^(2)·d)for Ba,(27.88±3.89)μmol/(m^(2)·d)for Cr,(10.10±6.33)μmol/(m^(2)·d)for Ni,and(6.25±3.45)μmol/(m^(2)·d)for As.The nutrient and metal fluxes from SGD were relatively higher than those from the inflow,suggesting that nearshore groundwater acted as the sources of nutrients and metal elements discharging into the sea.The environmental potential pollution of coastal seawater was evaluated by pollution factor index(Pi),comprehensive water quality index(CWQI),and ecological risk index(ERI).Pb mainly caused potential danger of nearshore environment with considerable contamination(Pi=5.78±0.19),heavy pollution(CWQI=4.09)and high ecological risk(ERI=18.00).This study contributed to better understanding the behavior of nutrients and metal elements and improving the sustainable management of STE under the pressure of anthropogenic activities and climate change.
基金supported by Hainan Provincial Natural Science Foundation of China(Grant No.322QN358,421QN284,320QN300).
文摘Hainan Island is the most important tropical fruit production area in China.In this study,372 soil samples and corresponding fruit and irrigation water samples were collected from Hainan orchards and analysed to determine the concentrations of six heavy metal(loid)s:Cd,Hg,As,Pb,Cr,and Cu.The pollution status,potential risks,possible sources,and spatial distribution patterns of soil heavy metal(loid)s were comprehensively investigated.The fruit and irrigation water samples had negligible amounts of heavy metal(loid)s,and the potential human health risk for fruit consumers was at a safe level.The heavy metal(loid)concentrations in most soil samples were lower than the national risk screening values.However,significant local accumulation of heavy metal(loid)s,especially Cd,Cr,and Cu,relative to their background values was observed.Moreover,the combined effects of the heavy metal(loid)s only led to a mild pollution level and low ecological risk throughout the study area.Noncarcinogenic risks were not observed among the local residents,and carcinogenic risks were within an acceptable range.The acidic soil in the study area increased the risk of soil Cd pollution,and organic matter affected the distribution of the tested metal(loid)s in the soil.Uncommon geogenic sources with high background values were the sources of Cr and Cu,anthropogenic activities primarily led to Cd,Pb,and As contamination,and a combination of anthropogenic and natural sources was responsible for Hg emissions.The research suggested that appropriate strategies must be implemented to track and reduce soil heavy metal contaminants in the northern and western region of the Hainan orchard area.The results can provide valuable information for policies on pollution prevention and management,the environment,and human health protection in the study region.
文摘The aim of the present investigation was to research the distribution characteristics of copper in water and sediment of the Liao River, China. The concentrations of copper in water and sediment showed significant difference at different sampling stations. The distribution characteristics of copper in water and sediment were obtained by using discrete and continuous numerical characteristics. The results indicated that the average concentrations of copper in water and sediment decreased slightly after its accumulation. While the deviations of the concentrations of copper in water and sediment from the expectation increased significantly after its accumulation. The skewness distributions of the concentrations of copper in water and sediment did not change much before and after its accumulation. The kurtosis distributions of the concentrations of copper in water and sediment decreased significantly after its accumulation. Therefore, the precise distribution characteristics of copper in water and sediment were obtained through the combination of the discrete and continuous numerical characteristics. .
文摘Background: Groundwater is an important source of water. Since the control and removal of pollution are expensive, it is essential to identify the possible sources of contamination and to correctly classify groundwater on the basis of its intrinsic and integrated vulnerability. Objectives: To group ground water chemical ions and heavy metals parameters into similar groups. Method: The investigation made use of standard analytical procedures. All sampling, conservation, transportation and analysis followed standard procedures described in APHA (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while kept in an icebox. Results: Sampling records from the same area are generally assigned to the same cluster during hierarchical cluster analysis (HCA). The cluster diagram shows the grouping of the heavy metal in the study area during wet and dry seasons. It reveals that 5 distinct clusters were identified for wet season and 4 clusters were identified during dry season. Also, it reveals that 5 distinct clusters were identified for wet season and for dry season, 4 distinct clusters were identified. Conclusion: The findings of this study are significant for policymakers and agencies in terms of dealing with the issues identified to enhance sustainable livelihood practices in the oil rich Niger Delta region of Nigeria. Therefore, decision-makers should take proper initiatives to get local people aware of the endangered zones before use, as drinking water is key to good health. Similarly, multinational oil companies will find it useful in their quest for viable social corporate responsibility and remediation plans in their respective host communities. The method proved to be a useful and objective tool for environmental planning.
文摘Medium-term air quality assessment,benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes.By using daily and monthly averaged data,medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives.By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark(CLAB).The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator.Such a benchmark can provide an overall air quality assessment for areas of interest.A case study is presented for Dallas County(U.S.A.)applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019.Six air pollutants considered are:ozone,carbon monoxide,nitrogen dioxide,sulfur dioxide,benzene and particulate matter less than 2.5 micrometres.These pollutants are assessed individually and in terms of CLAB,and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019.Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years.The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs.Conducting CLAB analysis on an ongoing basis,using a relevant near-past time interval for benchmarking that covers several years,can reveal useful monthly,seasonal and annual trends in overall air quality.This type of medium-term,benchmarked air quality data analysis is well suited for ecosystem monitoring.
基金supported by the National Basic Research Program of China(Grant No.2014CB744302)the Specially Funded Program on National Key Scientific Instruments and Equipment Development(Grant No.2012YQ140005)+1 种基金the China Petroleum and Chemical Industry Association Science and Technology Guidance Program(Grant No.2016-01-07)the National Nature Science Foundation of China(Grant No.11574401)
文摘Haze or smog episodes,which are characterized by the presence of paniculate matter at diameters less than2.5 urn(PM2.5),have attracted increasing attention during the pastfew decades[1].PM2.5 has adverse effects onhuman respiratory health as well as on air visibility[2,3].IntheBeijing-Tianjin-Hebei(BTH)region of China,haze has become especially serious in recent years because of industrial ex-
文摘The results of dispersion modeling of carbon monoxide are reported in this paper. The results of applying the technique of Rapid Assessment of Sources of Environmental Pollution (RASEP) database and the Air Monitoring State System in the City of Puebla, México, were employed. Concentrations of carbon monoxide emitted by cars inferred by RASAP technique with those reported by the environmental monitoring station “Nymphs”, were compared. The date of 21 June 2005-2010 was selected during the peak hour traffic flow. The dispersion of carbon monoxide was modeled by software DISPER and SCRI software, in order to infer the exposure levels of carbon monoxide in the study area. The estimated and monitored concentrations were evaluated with the Mexican regulations for population’s health protection. Regarding the dispersion model, SCRI was discarded for the target validation because it only allows modeling on specific areas. Moreover, the modeling software allowed DISPER simulations with linear sources of car exhaust, so this advantage is considered appropriate to continue using this program. Both estimates obtained by RASEP, as modeled by DISPER and recorded by the monitoring system exceed the maximum permissible limits of NOM-021-SSA1-1993 getting an impermissible for the area of influence of the assessment monitoring station. The DISPER software has potential use for such evaluations, but more work is required on the system for their inferences can be validated by reproducible physical and chemical measurements.
基金This work was supported by the Natural Science Foundation of Shandong Province(China)(Nos.ZR2020KE023 and ZR2021MD057)and the National Natural Science Foundation of China(No.42002282).
文摘Due to the unclear distribution characteristics and causes of fluoride in groundwater of Mihe-Weihe River Basin(China),there is a higher risk for the future development and utilization of groundwater.Therefore,based on the systematic sampling and analysis,the distribution features and enrichment mechanism for fluoride in groundwater were studied by the graphic method,hydrogeochemical modeling,the proportionality factor between conventional ions and factor analysis.The results show that the fluorine content in groundwater is generally on the high side,with a large area of medium-fluorine water(0.5–1.0 mg/L),and high-fluorine water is chiefly in the interfluvial lowlands and alluvial-marine plain,which mainly contains HCO_(3)·Cl-Na-and HCO_(3)^(-)Na-type water.The vertical zonation characteristics of the fluorine content decrease with increasing depth to the water table.The high flouride groundwater during the wet season is chiefly controlled by the weathering and dissolution of fluorine-containing minerals,as well as the influence of rock weathering,evaporation and concentration.The weak alkaline environment that is rich in sodium and poor in calcium during the dry season is the main reason for the enrichment of fluorine.Finally,an integrated assessment model is established using rough set theory and an improved matter element extension model,and the level of groundwater pollution caused by fluoride in the Mihe-Weihe River Basin during the wet and dry seasons in the Shandong Peninsula is defined to show the necessity for local management measures to reduce the potential risks caused by groundwater quality.
基金supported by the National Key Research and Development Plan(Nos.2016YFD0800202,2017YFD0800700)。
文摘A total of 713 research papers about field monitor experiments of heavy metals in farmland and urban soils in China,published from 2000 to 2019,were obtained.A meta-analysis was conducted to evaluate the level of China's heavy metal pollution in soils,mainly focusing on eight heavy metals.It was found that the average concentrations of cadmium(Cd),lead(Pb),zinc(Zn),copper(Cu),mercury(Hg),chromium(Cr),nickel(Ni),and arsenic(As)in China were 0.19,30.74,85.86,25.81,0.074,67.37,27.77 and 8.89 mg/kg,respectively.Compared with the background value(0.097 mg/kg),the Cd content showed a twofold(0.19 mg/kg)rise in farmland soils and a threefold(0.29 mg/kg)rise in urban soils.The decreasing order of the mean Igeo was Cd(1.77)>Pb(0.62)>Zn(0.60)>Cu(0.58)>Hg(0.57)>Cr(0.54)>Ni(0.47)>As(0.28).Nearly 33.54%and 44.65%of sites in farmland and urban soils were polluted with Cd.The average concentrations of eight heavy metals were not sensitive change in recent two decades in farmland and urban soils.The average P_n values for urban(2.52)and farmland(2.15)soils showed that heavy metal pollution in urban soils was more serious than that in farmland,and the middle Yangtze River regions,where industrial activity dominates,were the most polluted.The meta-analysis comprehensively evaluated the current pollution situation of soil heavy metal,and provided important basis for soil management and environment prevention in China.
基金the National Natural Science Foundation of China(41977031)the Science Foundation for Distinguished Youth of Shaanxi Province(2020JC-31).
文摘Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to soil nutrient cycles.However,there is a growing lack of recognition and summary of the historic advancements that use soil enzymology as the proposal of evaluation methods.Here,we review the most common methods of heavy metal pollution evaluation based on enzyme activities,which include single enzyme index,combined enzyme index,enzyme-based functional diversity index,microbiological stress index,and ecoenzymatic stoichiometry models.This review critically examines the advantages and disadvantages of these methods based on their execution complexity,performance,and ecological implications and gets a glimpse of avenues to come to improved future evaluation systems.Indices based on a single enzyme are variable and have no consistent response to soil heavy metals,and the following three composite indices are characterized by the loss of many critical microbial processes,which thus not conducive to reflect the effects of heavy metals on soil ecosystems.Considering the dexterity of ecoenzymatic stoichiometry methods in reflecting changes in soil functions under heavy metal stress,we propose that microbial metabolic limitations quantified by ecoenzymatic stoichiometry models could be promising indicators for enhancing the reality and acceptance of results and further improving the potential for actual utility in environmental decision-making.
基金supported by the National Natural Science Foundation of China(41201224)Henan Province Science and Technology Research Project(192102110050)Project for the Training of Young Backbone Teachers of Higher Education Institutions in Henan Province(2018GGJS047).
文摘The characteristics of eight heavy metals(lead,zinc,copper,nickel,chromium,cadmium,mercury and arsenic)in the surface soil of the historical slag area of the Au ore dressing plant in the South-West of Luoyang City were investigated and evaluated in terms of a pollution index,potential ecological hazards and health risks.The results showed that the average amounts of the heavy metals Pb,Zn and As in the soils of plots S3,S5,S7,S12 and S18 exceeded the soil pollution risk screening values.The Mero comprehensive pollution index in plots S7,S12 and S18 was greater than 3,indicating severe pollution.The severe pollution plot integrated the potential ecological risk index(RI)of each sampling point,which was in the order of RI_(S12)>RI_(S18)>RI_(S7)>RI_(S5)>RI_(S3).Among the heavy metals,Cd poses the greatest threat to ecological and human health.The effects of heavy metals in soil on the single non-carcinogenic health risk index(HQ)and the non-carcinogenic total risk index through three exposure pathways were in the order of HQ_(Hg)<HQ_(Cu)<HQ_(Ni)<HQ_(Zn)<HQ_(Cd)<HQ_(Cr)<HQ_(Pb)<HQ_(As)<1,which meant that the adult and child total carcinogenic risk(TCR)and individual carcinogenic health risk indices CRAs and CRCd were above the maximum acceptable human health level recommended by the USEPA(10^(-6)).TCRAs and TCRCd accounted for 75.65%and 23.94%of the adult TCR,respectively.TCR^(As) and TCR^(Cd) accounted for 75.93%and 23.97%of the child TCR,respectively.Overall,the TCR of children was greater than that of adults.In summary,the soil in the historical slag area of the Au ore dressing plant constitutes a serious threat to the surrounding ecological environment and to residents.
基金supported by the Major Project of the National Social Science Foundation of China(No.14ZDB140)。
文摘Nowadays,more people tend to spend their recreational time in large national parks,and trace metal(loid)s in soils have attracted long-term attention due to their possible harm to human health.To investigate the pollution levels,potential sources and health risks of trace metal(loid)s in road soils,a total of eight trace metal(loid)s(including As,Cd,Cr,Cu,Ni,Pb,Zn and Hg)from 47 soil samples along roads were studied in the Huangshan National Park in Southeast China.The results showed that the concentrations of As,Cd,Pb,Zn and Hg appeared different degrees of pollution compared with their corresponding background values.According to the pollution indices,Hg and Cd were recognized as significant pollutants presenting moderate to high ecological risk.Combining principal component analysis and positive matrix factorization model,the results showed that traffic,industrial,agricultural and natural sources were the potential origins of trace metal(loid)s in this area,with contribution rates of 39.93%,25.92%,10.53%and 23.62%,respectively.Non-carcinogenic risks were all negligible,while the carcinogenic risk of As was higher than the limit(1×10^(-6)).Moreover,children were more susceptible to trace metal(loid)s by ingestion which appeared to be a more important exposure pathway than dermal contact and inhalation.The contribution rates of different sources to non-carcinogenic risks and carcinogenic risks were similar among children and adults,while traffic and industrial sources have a significant impact on health risks.This study will give more insights to control the environmental risks of trace metal(loid)s in national parks.
基金supported by the National Natural Science Foundation of China (No. 41673107)the National Water Pollution Control and Treatment Science and Technology Major Project, China (No. 2017ZX07203-005)the Major Project of Jiangsu Provincial Department of Education, China (No. 20KJA170001)。
文摘Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous toxic organic pollutants in the natural environment that are strongly associated with socioeconomic activities.Exploring the distribution,sources,and ecological toxicity of PAHs is essential to abate their pollution and biological risks.The 16 priority PAHs in different lakeside city estuarine sediments in the northern Taihu Lake in China were determined using gas chromatography-mass spectrometry.Results showed that total concentrations of PAHs(ΣPAHs)ranged from 672.07 to 5858.34 ng g^(^(-1)),with a mean value of 2121.37 ng g^(^(-1)).High-molecular-weight PAHs(4-6 rings)were dominant,accounting for 85%of theΣPAHs detected.Due to the barrier of gate/dam in the estuarine area,the concentrations of PAHs in the sediments were significantly different between the river mouth and lake side.Changes in total organic carbon(TOC)content and the spatial distribution of PAHs in the sediments were consistent.Sediment pollution assessment explored using the fuzzy evaluation model indicated 75%of slight PAH pollution.Some estuarine sediments(22%)concentrated in the east of the Wuli Lake in the Meiliang bay of the Taihu Lake were moderately or heavily polluted.The PAHs may lead to occasional detrimental biological consequences in the area.Diagnostic ratios and principal component analysis-multiple linear regression suggested vehicle emission and natural gas combustion as the primary PAH contributors(81%).
