Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bott...Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bottles with different persulfate dosages and groundwater tables were set up to simulate persulfate remediation of organic pollutants(aniline).The results found sulfate to be the main end-product(83.0%–99.5%)of persulfate remediation after10 days.Moreover,H_(2)S accounted for 93.4%–99.4%of sulfur reduction end-products,suggesting that H_(2)S was the final fate of sulfur.H_(2)S was released rapidly after one to three days at a maximum concentration of 33.0 ppm,which is sufficient to make a person uncomfortable.According to the fitted curve results,H_(2)S concentration decreased to a safe concentration(0.15 ppm)after 20–85 days.Meanwhile,the maximum concentration of methanethiol reached 0.6 ppm.These results indicated that secondary pollution from persulfate remediation could release harmful gases over a long time.Therefore,persulfate should be used more carefully as a remediation agent for soil contamination.展开更多
Artisanal gold mining,a labor-intensive and antiquated technique,is a growing industry and the source of income for rural communities all over the world.However,artisanal gold mining has potential negative and long-te...Artisanal gold mining,a labor-intensive and antiquated technique,is a growing industry and the source of income for rural communities all over the world.However,artisanal gold mining has potential negative and long-term effects on economy,environment,and society.This study collected soil samples from 16 sample points including a control point to examine the pollution degrees and spatial distribution of heavy metals,as well as ecological and health risks associated with heavy metal pollution in the Ijero-Ekiti mining site,Nigeria.Geographical Information System(GIS)and remote sensing technologies were used to identify regions with high concentrations of heavy metals and assess the environmental impact of gold mining activities.The results show that the mean heavy metal concentrations of 16 soil pointa are 8.94(±5.97)mg/kg for As,0.18(±0.54)mg/kg for Cd,0.11(±1.06)mg/kg for Co,14.32(±3.43)mg/kg for Cr,6.89(±0.64)mg/kg for Cu,48.92(±11.77)mg/kg for Fe,135.81(±30.75)mg/kg for Mn,5.92(±0.96)mg/kg for Ni,5.72(±1.66)mg/kg for Pb,and 13.94(±1.38)mg/kg for Zn.The study reveals that heavy metal concentration in soils follows the order of Mn>Fe>Cr>Zn>As>Cu>Ni>Pb>Co>Cd.An analysis of soil samples indicates that 3 principal components(PCs)account for 70.008%of the total variance and there are strong positive correlations between various pairs of heavy metals.The total potential ecological risk index(309.599)in the study area is high.Non-carcinogenic risk suggests that there may be long-term health impacts on people who work in the mining areas due to chronic exposure to the environment.Based on the study,the hazard index of carcinogenic health risks associated with heavy metals through ingestion is 520.00×10^(–4).Dermal contact from As and Cr also increases the risk of cancer,with the highest hazard index value of 18.40×10^(–4).The lowest exposure pathway,with the hazard index value of 0.68×10^(–4),indicates that the inhalation of heavy metals has a comparatively low risk of cancer.This study recommends the formulation of policies to monitor the Ijero-Ekiti mining site and other regions in Nigeria where indiscriminate artisanal gold mining activities exist.展开更多
Liquefaction is one of the major catastrophic geohazards which usually occurs in saturated or partially saturated sandy or silty soils during a seismic event. Evaluating the potential liquefaction risks of a seismical...Liquefaction is one of the major catastrophic geohazards which usually occurs in saturated or partially saturated sandy or silty soils during a seismic event. Evaluating the potential liquefaction risks of a seismically prone area can significantly reduce the loss of lives and damage to civil infrastructures. This research is mainly focused on the earthquake-induced liquefaction risk assessment based on Liquefaction Potential Index (LPI) values at different earthquake magnitudes (M = 5.0, 7.0 and 8.0) with a peak ground acceleration (a<sub>max</sub>) of 0.28 g in the Rohingya Refugee camp and surrounding areas of Ukhiya, Cox’s Bazar, Bangladesh. Standard Penetration Test (SPT) results have been evaluated for potential liquefaction assessment. The soils are mainly composed of very loose to loose sands with some silts and clays. Geotechnical properties of these very loose sandy soils are very much consistent with the criteria of liquefiable soil. It is established from the grain size analysis results;the soil of the study area is mainly sand dominated (SP) with some silty clay (SC) which consists of 93.68% to 99.48% sand, 0.06% to 4.71% gravel and 0% to 6.26% silt and clay. Some Clayey Sand (SC) is also present. The silty clay can be characterized as medium (CI) to high plasticity (CH) inorganic clay soil. LPI values have been calculated to identify risk zones and to prepare risk maps of the investigated area. Based on these obtained LPI values, four (4) susceptible liquefaction risk zones are identified as low, medium, high and very high. The established “Risk Maps” can be used for future geological engineering works as well as for sustainable planning, design and construction purposes relating to adaptation and mitigation of seismic hazards in the investigated area.展开更多
Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the pres...Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.展开更多
For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of i...For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of inhalation exposure for decades. Polycyclic aromatic hydrocarbons (PAHs) are the by-products of incomplete combustion.展开更多
While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from t...While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from the three subjects, we discovered that the three subjects possessed the whole CYP2A6 gene deletion (CYP2A6*4C), a novel genetic polymorphism of the CYP2A6 gene. Genetically engineered Salmonella YG7108 cells expressing human CYP2A6 or CYP2E1 together with the NADPH-CYP reductase were established in our laboratory to compare the mutagen-producing capacity of these enzymes for various N-nitrosamines. We found that CYP2E1 was responsible for the metabolic activation of N-nitrosamines with relatively short alkyl chains, whereas CYP2A6 was involved in the metabolic activation of N-nitrosamines possessing relatively bulky alkyl chains such as a tobacco-specific nitrosamine, NNK, which has been known to cause lung tumor in rodents. Thus, to examine a hypothesis that individuals possessing the CYP2A6*4C have the reduced risk of lung cancer due to the lack of the capacity of the metabolic activation of certain carcinogens in tobacco smoke, a case-control study was performed.展开更多
The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great sign...The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.展开更多
The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected fr...The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected from the Bandama, Comoé, and Bia Rivers in south and south eastern Côte d’Ivoire (West Africa), were analyzed for total metal concentrations and chemical speciation. The results showed that the river sediments were considerably contaminated by Cd and moderately contaminated by As, Cu, Pb, and Zn. Significant spatial variations were observed among the stations but not between the rivers. Metals Cd and Cu were likely to cause more ecological risks. The speciation analysis unravelled that the metal(loid)s partitioned mainly in the residual fraction, with the potential mobile fraction varying from 14% to 28%. The study calls for establishment of strict policies relative to the application of fertilizers and agrochemicals and mining activities to protect the environment and human health risks.展开更多
The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management o...The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management of these systems extremely difficult.Following the digital revolution in many areas of our lives,the water sector has begun to benefit from digital transformation.Effective utilization of remotely sensed weather and soil moisture data for more efficient irrigation(i.e.,for food production),better detection of anomalies and faults in pipe networks using artificial intelligence,the use of nature-inspired optimization to improve the management and planning of systems,and greater use of digital twins and robotics all exhibit great potential to change and improve the ways in which complex water systems are managed.However,there are additional risks associated with these developments,including—but not limited to—cybersecurity,incorrect use,and overconfidence in the capability and accuracy of digital solutions and automation.This paper identifies key advances in digital technology that have found application in the water sector,and applies forensic engineering principles to failures that have been experienced in industries further ahead with automation and digital transformation.By iden-tifying what went wrong with new digital technologies that might have contributed to high-profile acci-dents in the car and aircraft industries(e.g.,Tesla self-driving cars and the Boeing 737 MAX),it is possible to identify similar risks in the water sector,learn from them,and prevent future failures.The key findings show that:①Automation will require“humans in the loop”;②human operators must be fully aware of the technology and trained to use it;③fallback manual intervention should be available in case of tech-nology malfunctioning;④while redundant sensors may be costly,they reduce the risks due to erroneous sensor readings;⑤cybersecurity risks must be considered;and⑥ethics issues have to be considered,given the increasing automation and interconnectedness of water systems.These findings also point to major research areas related to digital transformation in the water sector.展开更多
Soil,crop and residents'hair over Xiaoqinling gold mining region,China,which was selected as a case study,were sampled and analyzed for Hg,Cd,Pb,Cu,Cr,As and Zn concentrations.The concentrations of heavy metals in...Soil,crop and residents'hair over Xiaoqinling gold mining region,China,which was selected as a case study,were sampled and analyzed for Hg,Cd,Pb,Cu,Cr,As and Zn concentrations.The concentrations of heavy metals in soil or crop and hair samples were used to assess their potential ecological risks,or to find the responses to these metals as evidences to prove the potential risk was coming down to observed harm,respectively.The results showed that,these metals in soil were ranked by severity of ecological risk as Hg>Cd>Pb>Cu>Cr>As>Zn,based on their single-element indexes.In the view of the potential ecological risk indexes,of all soil samples,about half had significantly high or high potential ecological risk,which covered more than 74%of the studied region.Most of the risks were 97.41%from Hg,Pb and Cd,especially,84.37%from Hg.Both the single-element and potential ecological risk indexes indicated that,the ecological risk grades had a special spatial characteristic,and increased from northwest to southeast generally.This was agreed with the spatial distribution of the strength in gold mining activities over the studied region.The concentrations of Hg and Pb were higher than their relative backgrounds in the corps,and were even 9.48 and 25.09 times higher than their relative backgrounds in residents'hair,respectively.All these showed that the heavy metals in the soil had a high potential ecological risk,especially,had been affecting these crops'growing and yield,and even the residents'health through food strains.Obviously,these metals'potential ecological harm had been coming down to observed harm to the ecology.展开更多
Using the data of regional seismic network, this paper analyzes the current faulting behaviors of different segments of the Anninghe-Zemuhe fault zone, western Sichuan, and identifies the likely risky segments for pot...Using the data of regional seismic network, this paper analyzes the current faulting behaviors of different segments of the Anninghe-Zemuhe fault zone, western Sichuan, and identifies the likely risky segments for potential large earthquakes. The authors map the probable asperities from the abnormally low b-value distribution, develop and employ a method for identifying current faulting behaviors of individual fault segment from the combinations of multiple seismicity parameter values, and make an effort to estimate the average recurrence intervals of character-istic earthquakes by using the parameters of magnitude-frequency relationship of the asperity segment. The result suggests that the studied fault zone contains 5 segments of different current faulting behaviors. Among them, the Mianning-Xichang segment of the Anninghe fault has been locked under high stress, its central part is probably an asperity with a relatively large scale. The Xichang-Puge segment of the Zemuhe fault displays very low seismicity under low stress. Both the locked segment and the low-seismicity segment can be outlined on the across-profile of relocated hypocenter depths. The Mianning-Xichang segment is identified to be the one with potential large earth-quake risk, for which the average recurrence interval between the latest M = 6.7 earthquake in 1952 and the next characteristic event is estimated to be 55 to 67 years, and the magnitude of the potential earthquake between 7.0 and 7.5. Also, it has been preliminarily suggested that for a certain fault segment, its faulting behaviors may change and evolve with time gradually.展开更多
[Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,...[Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,and the pollution indices and potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were calculated to assess the potential ecological risk of heavy metal pollution.[Result] In surface sediment in Weishan Lake,the average contents of Cu,Zn,Pb,Cd,Cr and Ni were 64.78,185.05,78.76,0.17,37.76 and 46.84mg/kg respectively.Cr and Cd weren’t beyond standards in all stations,while Cu and Pb exceeded standards in all stations,with average super-standard multiple of 0.85 and 0.31,respectively,and Zn content wasn’t beyond standard in S2 station,with average super-standard multiple of 0.24.The average pollution indices of Cu,Zn,Pb,Cd and Cr were 1.85,1.23,1.31,0.34 and 0.47 respectively,with average comprehensive pollution index of 5.21,which showed that heavy metal pollution was light.In addition,heavy metal pollution in entryway portion and sea-route portion were more serious than that of breeding portion.Potential ecological risk assessment showed that the average potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were 9.25,1.23,6.56,10.34 and 0.94 respectively,with average comprehensive potential ecological risk index of 28.33,and it revealed that potential ecological risk of heavy metals was slight.Besides,the potential ecological risk order of heavy metal pollution was sea-route portion>entryway portion>breeding portion.[Conclusion] The study could provide references for the regulation and improvement of ecological environment in Weishan Lake in the east route of south-to-north water transfer project.展开更多
On the basis of sedimentation principles and environmental chemical characteristics of heavymetal, combine international new methods-face graph on heavy metal pollution assessment withmulti-variable graph expression, ...On the basis of sedimentation principles and environmental chemical characteristics of heavymetal, combine international new methods-face graph on heavy metal pollution assessment withmulti-variable graph expression, the article made a synthetical assessment study on state of heavymetal pollution and potential ecological risk of Taizi River sediment in Benxi City reach. The re-sults of the study indicated that the state of heavy metal pollution of Taizi River in Benxi Cityreach is very serious, appropriate counter measures should be taken.展开更多
The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecolog...The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecological risk of heavy metals. The results showed that average values of potential ecological risk indexes of heavy metals at all stations increased slightly from 32.09 to 30.54 after establishment of TCISMR. Optimal semivariance simulation showed that the contents of five heavy metals have strong spatial correlations in August 2010(before), while this correlations weakened in April 2013(after establishment of TCISMR), suggesting that the main sources of heavy metals changed. The Hakanson Risk Index(HRI) values in Donghai levee, central and southern parts of Zhanjiang harbor were high up to 60.13 and 46.46, respectively. And Zhanjiang Bay Channel, the areas around special marine reserves, the artificial reef areas and mangrove areas at south of Techeng Island are the areas with low ecological risk and high ecological value, which should be treated as the prior ecological protection areas. Our study provided a priority control pattern of heavy metal pollution in TCISMR, which greatly benefits the sustainable development and resource protection in Zhanjiang Bay.展开更多
The chemical and physical properties of soil are critical factors that affect human health. The current geochemical study is designed to evaluate the concentrations of heavy metals (Cr, Pb, and Zn) in the soil in Iowa...The chemical and physical properties of soil are critical factors that affect human health. The current geochemical study is designed to evaluate the concentrations of heavy metals (Cr, Pb, and Zn) in the soil in Iowa (IA), Kansas (KS), and Nebraska (NE). The basic descriptive statistical results suggest that there are some limited levels of the heavy metals in the soils that come from anthropogenic inputs. The results of three environmental metrics, the enrichment factor (EF), geoaccumulation (Igeo), and potential ecological risk (PERI), have been calculated, evaluated, and compared. EF values show that soils contain minimal enrichment of Cr, Pb, and Zn in the study area. In addition, PERI values presented low risk with Cr, Pb, and Zn. However, Igeo </span><span style="font-family:Verdana;">values showed no contamination of Cr, Pb, and Zn in the study area. These results suggest that the elevated levels of these heavy metals are dominated by the historic agricultural inputs derived from long-term anthropogenic applications, especially in the regions with extensive human activities, which means that soil is the sink for heavy metals released into the environment.展开更多
This study is performed to know the contamination level of heavy metals on the surrounding agricultural soils at the site of Barapukuria Coal Mine Company Limited (BCMCL). Total concentrations of eight heavy metals (C...This study is performed to know the contamination level of heavy metals on the surrounding agricultural soils at the site of Barapukuria Coal Mine Company Limited (BCMCL). Total concentrations of eight heavy metals (Cu, As, Cd, Zn, Pb, Cr, Ni and Mn) were measured in that soil. To calculate the contamination level, the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>) and Hakanson potential ecological risk index were done. I<sub>geo</sub> values indicated that the study areas at all stations were suffering from moderate contamination with As. The results of enrichment factor revealed that soils in all stations were in extremely high enrichment condition by As metal. Under Hakanson potential ecological risk index, the contamination coefficient () and potential ecological risk index () were calculated. The degree of contamination at BCMCL area reflects moderate contamination. By considering the ecological risk index of a particular heavy metal, the order is as follows: Cd > As > Cu > Pb > Ni > Cr > Zn and Cd has the highest risk index and poses the greatest damage to the BCMCL area’s soil. EF, I<sub>geo</sub> values and potential ecological risk index indicate that there is considerable As and Cd pollution, mainly caused by coal mine drainage water.展开更多
The comprehensive control efficiency for the formation potentials(FPs) of a range of regulated and unregulated halogenated disinfection by-products(DBPs)(including carbonaceous DBPs(C-DBPs), nitrogenous DBPs(N...The comprehensive control efficiency for the formation potentials(FPs) of a range of regulated and unregulated halogenated disinfection by-products(DBPs)(including carbonaceous DBPs(C-DBPs), nitrogenous DBPs(N-DBPs), and iodinated DBPs(I-DBPs)) with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment(coagulation–sedimentation, pre-sand filtration), ozone-biological activated carbon(O_3-BAC) advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated.The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide,and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O_3-BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON.After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles(HANs)》haloacetamides(HAMs) 〉haloacetic acids(HAAs) 〉 trihalomethanes(THMs) 〉 halonitromethanes(HNMs) 》I-DBPs(I-HAMs and I-THMs). I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored.展开更多
Emissions derived from the consumption of organic solvents have been proven to be the primary industrial source of volatile organic compounds(VOCs).In conjunction with epidemiologic studies, water-based paints(WBPs) a...Emissions derived from the consumption of organic solvents have been proven to be the primary industrial source of volatile organic compounds(VOCs).In conjunction with epidemiologic studies, water-based paints(WBPs) and solvent-based paints(SBPs) were selected as representatives of newly developed solvents and traditional solvents, respectively,to simulate the effects of consuming solvents emitted during industrial production.And non-carcinogenic and carcinogenic risks to residents near emission sources were studied in detail.The results showed that the spatial distribution of health risks varied with meteorological conditions and type of emission source, and the prevailing wind direction strongly affected the distribution range and shape of the influenced area.The areas of influence maximized on heavy-polluting days for both WBP and SBP emission sources with the total span reaching 804 m and 16 km, respectively;meanwhile, the areas of influence for carcinogenic risk resulting from WBP emission sources were 1.2 and 2.3 times greater than those measured on fine and rainy days, respectively, and 1.8 and 2.9 times greater for SBP emission sources.Compared with WBPs, the total spans of negatively influenced regions resulting from SBP emission sources were 10.4, 12.5 and 19.9 times greater on fine, rainy and heavypolluting days, respectively.Therefore, carcinogenic risk was the dominant health threat for populations residing close to solvent-consuming industrial emission sources.The findings suggest that newly developed solvents are capable of significantly reducing consequent health threats, nevertheless, they could still pose occasional threats to nearby residents under specific meteorological conditions.展开更多
We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator (MSWI). We collected 20 soi...We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator (MSWI). We collected 20 soil samples, with an average pH of 8.1, and another fly ash sample emitted from the MSWI to investigate the concentrations of these elements in soils. We determined the concentrations of these elements by inductively coupled plasma-optical emission spectrometer (ICP-OES), except for Hg, which we measured by AF-610B atomic fluorescence spectrometer (AFS). We assessed the risks of these elements through the use of geoaccumulation index (/geo), potential ecological risk index (R/), hazard quotient (HQi) and cancer risk (Riski). The results showed that concentrations of potentially harmful elements in soil were influenced by the wind direction, and the concentrations of most elements were higher in the area northwest of the MSWI, compared with the area southeast of the incinerator, with the exception of As; these results were in accordance with those results acquired from our contour maps. According to the I^o values, some soil samples were clearly polluted by Hg emissions. However, the health risk assessment indicated that the concentrations of Hg and other elements in soil did not pose non-carcinogenic risks to the local populations. This was also the case for the carcinogenic risks posed by As Cr and Ni. The carcinogenic risk posed by As was higher in the range 6.49 × 10 -9.58 × 10 -6, but this was still considered to be an acceptable level of risk.展开更多
基金supported by the National Key R&D Program of China (No.2018YFC1800506)the Key R&D Program of Zhejiang Province (No.2020C03083)。
文摘Persulfate is considered a convenient and efficient remediation agent for organic contaminated soil.However,the potential risk of sulfur into the soil remediation by persulfate remains ignored.In this study,glass bottles with different persulfate dosages and groundwater tables were set up to simulate persulfate remediation of organic pollutants(aniline).The results found sulfate to be the main end-product(83.0%–99.5%)of persulfate remediation after10 days.Moreover,H_(2)S accounted for 93.4%–99.4%of sulfur reduction end-products,suggesting that H_(2)S was the final fate of sulfur.H_(2)S was released rapidly after one to three days at a maximum concentration of 33.0 ppm,which is sufficient to make a person uncomfortable.According to the fitted curve results,H_(2)S concentration decreased to a safe concentration(0.15 ppm)after 20–85 days.Meanwhile,the maximum concentration of methanethiol reached 0.6 ppm.These results indicated that secondary pollution from persulfate remediation could release harmful gases over a long time.Therefore,persulfate should be used more carefully as a remediation agent for soil contamination.
文摘Artisanal gold mining,a labor-intensive and antiquated technique,is a growing industry and the source of income for rural communities all over the world.However,artisanal gold mining has potential negative and long-term effects on economy,environment,and society.This study collected soil samples from 16 sample points including a control point to examine the pollution degrees and spatial distribution of heavy metals,as well as ecological and health risks associated with heavy metal pollution in the Ijero-Ekiti mining site,Nigeria.Geographical Information System(GIS)and remote sensing technologies were used to identify regions with high concentrations of heavy metals and assess the environmental impact of gold mining activities.The results show that the mean heavy metal concentrations of 16 soil pointa are 8.94(±5.97)mg/kg for As,0.18(±0.54)mg/kg for Cd,0.11(±1.06)mg/kg for Co,14.32(±3.43)mg/kg for Cr,6.89(±0.64)mg/kg for Cu,48.92(±11.77)mg/kg for Fe,135.81(±30.75)mg/kg for Mn,5.92(±0.96)mg/kg for Ni,5.72(±1.66)mg/kg for Pb,and 13.94(±1.38)mg/kg for Zn.The study reveals that heavy metal concentration in soils follows the order of Mn>Fe>Cr>Zn>As>Cu>Ni>Pb>Co>Cd.An analysis of soil samples indicates that 3 principal components(PCs)account for 70.008%of the total variance and there are strong positive correlations between various pairs of heavy metals.The total potential ecological risk index(309.599)in the study area is high.Non-carcinogenic risk suggests that there may be long-term health impacts on people who work in the mining areas due to chronic exposure to the environment.Based on the study,the hazard index of carcinogenic health risks associated with heavy metals through ingestion is 520.00×10^(–4).Dermal contact from As and Cr also increases the risk of cancer,with the highest hazard index value of 18.40×10^(–4).The lowest exposure pathway,with the hazard index value of 0.68×10^(–4),indicates that the inhalation of heavy metals has a comparatively low risk of cancer.This study recommends the formulation of policies to monitor the Ijero-Ekiti mining site and other regions in Nigeria where indiscriminate artisanal gold mining activities exist.
文摘Liquefaction is one of the major catastrophic geohazards which usually occurs in saturated or partially saturated sandy or silty soils during a seismic event. Evaluating the potential liquefaction risks of a seismically prone area can significantly reduce the loss of lives and damage to civil infrastructures. This research is mainly focused on the earthquake-induced liquefaction risk assessment based on Liquefaction Potential Index (LPI) values at different earthquake magnitudes (M = 5.0, 7.0 and 8.0) with a peak ground acceleration (a<sub>max</sub>) of 0.28 g in the Rohingya Refugee camp and surrounding areas of Ukhiya, Cox’s Bazar, Bangladesh. Standard Penetration Test (SPT) results have been evaluated for potential liquefaction assessment. The soils are mainly composed of very loose to loose sands with some silts and clays. Geotechnical properties of these very loose sandy soils are very much consistent with the criteria of liquefiable soil. It is established from the grain size analysis results;the soil of the study area is mainly sand dominated (SP) with some silty clay (SC) which consists of 93.68% to 99.48% sand, 0.06% to 4.71% gravel and 0% to 6.26% silt and clay. Some Clayey Sand (SC) is also present. The silty clay can be characterized as medium (CI) to high plasticity (CH) inorganic clay soil. LPI values have been calculated to identify risk zones and to prepare risk maps of the investigated area. Based on these obtained LPI values, four (4) susceptible liquefaction risk zones are identified as low, medium, high and very high. The established “Risk Maps” can be used for future geological engineering works as well as for sustainable planning, design and construction purposes relating to adaptation and mitigation of seismic hazards in the investigated area.
文摘Crude oil spills have inflicted extensive disruption upon the Niger Delta ecosystem, resulting in crop loss and severe environmental damage. Such spills exacerbate heavy metal concentration within soil due to the presence of metallic ions. The Okpare-Olomu community has borne the brunt of crude oil pollution from illicit bunkering, sabotage, and equipment malfunction. This study targets an evaluation of ecological hazards linked to heavy metals (HMs) in crude oil impacted agriculturally soils within Okpare-Olomu in Ughelli South LGA of Delta State. In this study, 24 topsoil samples were obtained from areas affected by crude oil pollution;the heavy metal content was evaluated through atomic absorption spectrometry. The concentration ranges for HMs (mg/kg) in soil were: 24.1 - 23,174 (Cu);0.54 - 37.1 (Cd);9.05 - 54 (Cr);12 - 174 (Ni);18.5 - 8611 (Pb);and 148 - 9078 (Zn) at a soil depth of 0 - 15 cm. Notably, metal concentrations were recorded to be above permissible World Health Organization limits. Predominantly, Zn and Pb recorded higher heavy metal concentration when compared to other heavy metals analysed, notably at sampling points PT7 through PT24. Zinc and Pb contamination exhibited highly significant contamination factors, and contamination severity was evidenced across all sample points, signifying a grave risk level. Pollution load indices indicated pervasive extreme pollution levels. Geoaccumulation indices signaled moderate to strong pollution, mainly by Pb and Zn. Ecological risk assessments revealed variable levels of heavy metal contamination, from low to very high, with potential ecological risk reflecting markedly elevated levels. This study underscores the imperative for soil remediation to rectify ecological imbalances in agriculturally affected soil constituents.
基金funded by the National Natural Science Foundation of China(41390240 and 41571130010)the 111 Project(B14001)
文摘For lifetime non-smokers, lung cancer risk is mainly associated with inhalation exposure to air pollution. For the Chinese population, indoor air pollution due to solid fuel combustion has been the primary source of inhalation exposure for decades. Polycyclic aromatic hydrocarbons (PAHs) are the by-products of incomplete combustion.
文摘While we studied pharmacokinetics of SM-12502 which was under development as an anti-PAF agent, we found three subjects showing a slow metabolic phenotype in its pharmacokinetics. Analyzing the genes for CYP2A6 from the three subjects, we discovered that the three subjects possessed the whole CYP2A6 gene deletion (CYP2A6*4C), a novel genetic polymorphism of the CYP2A6 gene. Genetically engineered Salmonella YG7108 cells expressing human CYP2A6 or CYP2E1 together with the NADPH-CYP reductase were established in our laboratory to compare the mutagen-producing capacity of these enzymes for various N-nitrosamines. We found that CYP2E1 was responsible for the metabolic activation of N-nitrosamines with relatively short alkyl chains, whereas CYP2A6 was involved in the metabolic activation of N-nitrosamines possessing relatively bulky alkyl chains such as a tobacco-specific nitrosamine, NNK, which has been known to cause lung tumor in rodents. Thus, to examine a hypothesis that individuals possessing the CYP2A6*4C have the reduced risk of lung cancer due to the lack of the capacity of the metabolic activation of certain carcinogens in tobacco smoke, a case-control study was performed.
基金supported by the Science and Technology Research Project to Henan Provincial Department of Natural Resources(Henan Natural Resources Letter[2019]373–10)。
文摘The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.
文摘The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected from the Bandama, Comoé, and Bia Rivers in south and south eastern Côte d’Ivoire (West Africa), were analyzed for total metal concentrations and chemical speciation. The results showed that the river sediments were considerably contaminated by Cd and moderately contaminated by As, Cu, Pb, and Zn. Significant spatial variations were observed among the stations but not between the rivers. Metals Cd and Cu were likely to cause more ecological risks. The speciation analysis unravelled that the metal(loid)s partitioned mainly in the residual fraction, with the potential mobile fraction varying from 14% to 28%. The study calls for establishment of strict policies relative to the application of fertilizers and agrochemicals and mining activities to protect the environment and human health risks.
文摘The provision of water and sanitation services is a key challenge worldwide.The size,complexity,and critical nature of the water and wastewater infrastructure providing such services make the planning and management of these systems extremely difficult.Following the digital revolution in many areas of our lives,the water sector has begun to benefit from digital transformation.Effective utilization of remotely sensed weather and soil moisture data for more efficient irrigation(i.e.,for food production),better detection of anomalies and faults in pipe networks using artificial intelligence,the use of nature-inspired optimization to improve the management and planning of systems,and greater use of digital twins and robotics all exhibit great potential to change and improve the ways in which complex water systems are managed.However,there are additional risks associated with these developments,including—but not limited to—cybersecurity,incorrect use,and overconfidence in the capability and accuracy of digital solutions and automation.This paper identifies key advances in digital technology that have found application in the water sector,and applies forensic engineering principles to failures that have been experienced in industries further ahead with automation and digital transformation.By iden-tifying what went wrong with new digital technologies that might have contributed to high-profile acci-dents in the car and aircraft industries(e.g.,Tesla self-driving cars and the Boeing 737 MAX),it is possible to identify similar risks in the water sector,learn from them,and prevent future failures.The key findings show that:①Automation will require“humans in the loop”;②human operators must be fully aware of the technology and trained to use it;③fallback manual intervention should be available in case of tech-nology malfunctioning;④while redundant sensors may be costly,they reduce the risks due to erroneous sensor readings;⑤cybersecurity risks must be considered;and⑥ethics issues have to be considered,given the increasing automation and interconnectedness of water systems.These findings also point to major research areas related to digital transformation in the water sector.
基金Project(1212010741003)supported by the Ministry of Land and Resources of ChinaProject(SJ08-ZT08)supported by the Natural Science Foundation of Shaanxi Province,ChinaProject(NCET-07-0694)supported by Program for University Talents in the NewCentury,China
文摘Soil,crop and residents'hair over Xiaoqinling gold mining region,China,which was selected as a case study,were sampled and analyzed for Hg,Cd,Pb,Cu,Cr,As and Zn concentrations.The concentrations of heavy metals in soil or crop and hair samples were used to assess their potential ecological risks,or to find the responses to these metals as evidences to prove the potential risk was coming down to observed harm,respectively.The results showed that,these metals in soil were ranked by severity of ecological risk as Hg>Cd>Pb>Cu>Cr>As>Zn,based on their single-element indexes.In the view of the potential ecological risk indexes,of all soil samples,about half had significantly high or high potential ecological risk,which covered more than 74%of the studied region.Most of the risks were 97.41%from Hg,Pb and Cd,especially,84.37%from Hg.Both the single-element and potential ecological risk indexes indicated that,the ecological risk grades had a special spatial characteristic,and increased from northwest to southeast generally.This was agreed with the spatial distribution of the strength in gold mining activities over the studied region.The concentrations of Hg and Pb were higher than their relative backgrounds in the corps,and were even 9.48 and 25.09 times higher than their relative backgrounds in residents'hair,respectively.All these showed that the heavy metals in the soil had a high potential ecological risk,especially,had been affecting these crops'growing and yield,and even the residents'health through food strains.Obviously,these metals'potential ecological harm had been coming down to observed harm to the ecology.
基金Chinese Joint Seismological Science Foundation (102002).
文摘Using the data of regional seismic network, this paper analyzes the current faulting behaviors of different segments of the Anninghe-Zemuhe fault zone, western Sichuan, and identifies the likely risky segments for potential large earthquakes. The authors map the probable asperities from the abnormally low b-value distribution, develop and employ a method for identifying current faulting behaviors of individual fault segment from the combinations of multiple seismicity parameter values, and make an effort to estimate the average recurrence intervals of character-istic earthquakes by using the parameters of magnitude-frequency relationship of the asperity segment. The result suggests that the studied fault zone contains 5 segments of different current faulting behaviors. Among them, the Mianning-Xichang segment of the Anninghe fault has been locked under high stress, its central part is probably an asperity with a relatively large scale. The Xichang-Puge segment of the Zemuhe fault displays very low seismicity under low stress. Both the locked segment and the low-seismicity segment can be outlined on the across-profile of relocated hypocenter depths. The Mianning-Xichang segment is identified to be the one with potential large earth-quake risk, for which the average recurrence interval between the latest M = 6.7 earthquake in 1952 and the next characteristic event is estimated to be 55 to 67 years, and the magnitude of the potential earthquake between 7.0 and 7.5. Also, it has been preliminarily suggested that for a certain fault segment, its faulting behaviors may change and evolve with time gradually.
基金Supported by Natural Science Foundation of Shandong Province (ZR2010CL004)Doctoral Research Foundation of Zaozhuang University+2 种基金Key Program of Zaozhuang UniversityYouth Foundation of Zaozhuang UniversityKey Discipline Construction Project of Hydrobiology of Zaozhuang University
文摘[Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,and the pollution indices and potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were calculated to assess the potential ecological risk of heavy metal pollution.[Result] In surface sediment in Weishan Lake,the average contents of Cu,Zn,Pb,Cd,Cr and Ni were 64.78,185.05,78.76,0.17,37.76 and 46.84mg/kg respectively.Cr and Cd weren’t beyond standards in all stations,while Cu and Pb exceeded standards in all stations,with average super-standard multiple of 0.85 and 0.31,respectively,and Zn content wasn’t beyond standard in S2 station,with average super-standard multiple of 0.24.The average pollution indices of Cu,Zn,Pb,Cd and Cr were 1.85,1.23,1.31,0.34 and 0.47 respectively,with average comprehensive pollution index of 5.21,which showed that heavy metal pollution was light.In addition,heavy metal pollution in entryway portion and sea-route portion were more serious than that of breeding portion.Potential ecological risk assessment showed that the average potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were 9.25,1.23,6.56,10.34 and 0.94 respectively,with average comprehensive potential ecological risk index of 28.33,and it revealed that potential ecological risk of heavy metals was slight.Besides,the potential ecological risk order of heavy metal pollution was sea-route portion>entryway portion>breeding portion.[Conclusion] The study could provide references for the regulation and improvement of ecological environment in Weishan Lake in the east route of south-to-north water transfer project.
文摘On the basis of sedimentation principles and environmental chemical characteristics of heavymetal, combine international new methods-face graph on heavy metal pollution assessment withmulti-variable graph expression, the article made a synthetical assessment study on state of heavymetal pollution and potential ecological risk of Taizi River sediment in Benxi City reach. The re-sults of the study indicated that the state of heavy metal pollution of Taizi River in Benxi Cityreach is very serious, appropriate counter measures should be taken.
基金jointly funded by the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (No.2013K0011)the State Oceanic Administration Key Laboratory of Sea area Management Technology Fund (No.201711)+2 种基金the Guangdong MEPP Fund (No.GDOE [2019]A46)the GDNRC (No.[2020]067)the South China Sea Branch Secretary fund (No.1673)。
文摘The concentrations of five metals(Cu, Pb, Zn, Cd and Hg) were measured in sediments obtained before and after the establishment of Techeng Island Special Marine Reserves(TCISMR) in Zhanjiang Bay to evaluate the ecological risk of heavy metals. The results showed that average values of potential ecological risk indexes of heavy metals at all stations increased slightly from 32.09 to 30.54 after establishment of TCISMR. Optimal semivariance simulation showed that the contents of five heavy metals have strong spatial correlations in August 2010(before), while this correlations weakened in April 2013(after establishment of TCISMR), suggesting that the main sources of heavy metals changed. The Hakanson Risk Index(HRI) values in Donghai levee, central and southern parts of Zhanjiang harbor were high up to 60.13 and 46.46, respectively. And Zhanjiang Bay Channel, the areas around special marine reserves, the artificial reef areas and mangrove areas at south of Techeng Island are the areas with low ecological risk and high ecological value, which should be treated as the prior ecological protection areas. Our study provided a priority control pattern of heavy metal pollution in TCISMR, which greatly benefits the sustainable development and resource protection in Zhanjiang Bay.
文摘The chemical and physical properties of soil are critical factors that affect human health. The current geochemical study is designed to evaluate the concentrations of heavy metals (Cr, Pb, and Zn) in the soil in Iowa (IA), Kansas (KS), and Nebraska (NE). The basic descriptive statistical results suggest that there are some limited levels of the heavy metals in the soils that come from anthropogenic inputs. The results of three environmental metrics, the enrichment factor (EF), geoaccumulation (Igeo), and potential ecological risk (PERI), have been calculated, evaluated, and compared. EF values show that soils contain minimal enrichment of Cr, Pb, and Zn in the study area. In addition, PERI values presented low risk with Cr, Pb, and Zn. However, Igeo </span><span style="font-family:Verdana;">values showed no contamination of Cr, Pb, and Zn in the study area. These results suggest that the elevated levels of these heavy metals are dominated by the historic agricultural inputs derived from long-term anthropogenic applications, especially in the regions with extensive human activities, which means that soil is the sink for heavy metals released into the environment.
文摘This study is performed to know the contamination level of heavy metals on the surrounding agricultural soils at the site of Barapukuria Coal Mine Company Limited (BCMCL). Total concentrations of eight heavy metals (Cu, As, Cd, Zn, Pb, Cr, Ni and Mn) were measured in that soil. To calculate the contamination level, the enrichment factor (EF), geoaccumulation index (I<sub>geo</sub>) and Hakanson potential ecological risk index were done. I<sub>geo</sub> values indicated that the study areas at all stations were suffering from moderate contamination with As. The results of enrichment factor revealed that soils in all stations were in extremely high enrichment condition by As metal. Under Hakanson potential ecological risk index, the contamination coefficient () and potential ecological risk index () were calculated. The degree of contamination at BCMCL area reflects moderate contamination. By considering the ecological risk index of a particular heavy metal, the order is as follows: Cd > As > Cu > Pb > Ni > Cr > Zn and Cd has the highest risk index and poses the greatest damage to the BCMCL area’s soil. EF, I<sub>geo</sub> values and potential ecological risk index indicate that there is considerable As and Cd pollution, mainly caused by coal mine drainage water.
基金supported by the National Major Science and Technology Project of China (No.2015ZX07406-004)
文摘The comprehensive control efficiency for the formation potentials(FPs) of a range of regulated and unregulated halogenated disinfection by-products(DBPs)(including carbonaceous DBPs(C-DBPs), nitrogenous DBPs(N-DBPs), and iodinated DBPs(I-DBPs)) with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment(coagulation–sedimentation, pre-sand filtration), ozone-biological activated carbon(O_3-BAC) advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated.The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide,and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O_3-BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON.After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles(HANs)》haloacetamides(HAMs) 〉haloacetic acids(HAAs) 〉 trihalomethanes(THMs) 〉 halonitromethanes(HNMs) 》I-DBPs(I-HAMs and I-THMs). I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored.
基金supported by the Ministry of Science and Technology of the People’s Republic of China (No.2020YFC1806303)the Beijing Municipal Science & Technology Commission (No.Z171100004417029)。
文摘Emissions derived from the consumption of organic solvents have been proven to be the primary industrial source of volatile organic compounds(VOCs).In conjunction with epidemiologic studies, water-based paints(WBPs) and solvent-based paints(SBPs) were selected as representatives of newly developed solvents and traditional solvents, respectively,to simulate the effects of consuming solvents emitted during industrial production.And non-carcinogenic and carcinogenic risks to residents near emission sources were studied in detail.The results showed that the spatial distribution of health risks varied with meteorological conditions and type of emission source, and the prevailing wind direction strongly affected the distribution range and shape of the influenced area.The areas of influence maximized on heavy-polluting days for both WBP and SBP emission sources with the total span reaching 804 m and 16 km, respectively;meanwhile, the areas of influence for carcinogenic risk resulting from WBP emission sources were 1.2 and 2.3 times greater than those measured on fine and rainy days, respectively, and 1.8 and 2.9 times greater for SBP emission sources.Compared with WBPs, the total spans of negatively influenced regions resulting from SBP emission sources were 10.4, 12.5 and 19.9 times greater on fine, rainy and heavypolluting days, respectively.Therefore, carcinogenic risk was the dominant health threat for populations residing close to solvent-consuming industrial emission sources.The findings suggest that newly developed solvents are capable of significantly reducing consequent health threats, nevertheless, they could still pose occasional threats to nearby residents under specific meteorological conditions.
基金Acknowledgements This study was supported by The National Basic Research Program of China (Grant No. 2015CB453103), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB14020100) and the National Natural Science Foundation of China (Grant Nos. 21477150 and 21321004).
文摘We assessed the contamination levels of Mn, Zn, Cr, Cu, Ni, Pb, As and Hg and the risks posed by these potentially harmful elements in top-soils around a municipal solid waste incinerator (MSWI). We collected 20 soil samples, with an average pH of 8.1, and another fly ash sample emitted from the MSWI to investigate the concentrations of these elements in soils. We determined the concentrations of these elements by inductively coupled plasma-optical emission spectrometer (ICP-OES), except for Hg, which we measured by AF-610B atomic fluorescence spectrometer (AFS). We assessed the risks of these elements through the use of geoaccumulation index (/geo), potential ecological risk index (R/), hazard quotient (HQi) and cancer risk (Riski). The results showed that concentrations of potentially harmful elements in soil were influenced by the wind direction, and the concentrations of most elements were higher in the area northwest of the MSWI, compared with the area southeast of the incinerator, with the exception of As; these results were in accordance with those results acquired from our contour maps. According to the I^o values, some soil samples were clearly polluted by Hg emissions. However, the health risk assessment indicated that the concentrations of Hg and other elements in soil did not pose non-carcinogenic risks to the local populations. This was also the case for the carcinogenic risks posed by As Cr and Ni. The carcinogenic risk posed by As was higher in the range 6.49 × 10 -9.58 × 10 -6, but this was still considered to be an acceptable level of risk.