The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity （MWHC） after equi...The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity （MWHC） after equilibration for 24 h. The free metal concentrations （Cd^2＋, Cu^2＋, Pb^2＋, and Zn^2＋） in soil solution were determined using the Donnan membrane technique （DMT）. Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd^2＋ （3%-52%） and Zn^2＋ （11%-72%） in soil solutions were generally higher than those of Cu^2＋ （0.2%-30%） and Pb^2＋ （0.6%-10%）. Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients （Kp） and dissolved organic carbon did not show any significant influence on Kp.展开更多
Background:The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses,explicitly focusing on norovirus genogroup II(GII),astrovirus,rotavirus,Aichi virus,sapovirus,hepatitis A and...Background:The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses,explicitly focusing on norovirus genogroup II(GII),astrovirus,rotavirus,Aichi virus,sapovirus,hepatitis A and E viruses in wastewater treatment plants through droplet digital PCR(ddPCR).Enteric viruses are of significant public health concern,as they are the leading cause of diseases like gastroenteritis.Regular monitoring of environmental samples,particularly from wastewater treatment plants,is crucial for early detection and control of these viruses.This research aims to improve the understanding of the prevalence and dynamics of enteric viruses in urban India and will serve as a model for similar studies in other regions.Our protocol's objective is to establish a novel ddPCRbased methodology for the detection and molecular characterization of enteric viruses present in wastewater samples sourced from Bhopal,India.Our assay is capable of accurately quantifying virus concentrations without standard curves,minimizing extensive optimization,and enhancing sensitivity and precision,especially for low-abundance targets.Methods:The study involves fortnightly collecting and analyzing samples from nine wastewater treatment plants over two years,ensuring comprehensive coverage and consistent data.Our study innovatively applies ddPCR to simultaneously detect and quantify enteric viruses in wastewater,a more advanced technique.Additionally,we will employ next-generation sequencing for detailed viral genome identification in samples tested positive for pathogenic viruses.Conclusion:This study will aid in understanding these viruses’genetic diversity and mutation rates,which is crucial for developing tailored intervention strategies.The findings will be instrumental in shaping public health responses and improving epidemiological surveillance,especially in localities heaving sewage networks.展开更多
Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution envi...Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons(PAHs),a group of HOCs,and assess future PAH-related human health risks under varying climate change scenarios over China at a continental scale.After removing the effects of PAH emission changes,we find that the total PAH concentrations would decrease in the air,freshwater,sediment,soil,and organisms,while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°C.Consequently,the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%,while the respiratory risks are projected to rise by 0.2%–5.8%in the future.However,the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69%compared with 2009 levels in China.Our study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.展开更多
Studies have investigated the effects of heat and temperature variability(TV)on mortality.However,few assessed whether TV modifies the heat-mortality association.Data on daily temperature and mortality in the warm sea...Studies have investigated the effects of heat and temperature variability(TV)on mortality.However,few assessed whether TV modifies the heat-mortality association.Data on daily temperature and mortality in the warm season were collected from 717 locations across 36 countries.TV was calculated as the standard deviation of the average of the same and previous days’minimum and maximum temperatures.展开更多
Since the ban of polybrominated diphenyl ethers(PBDEs)and hexabromocyclododecane(HBCDD),other flame retardants may be increasingly used.Thirty-one current-use halogenated(HFRs)and 24 organophosphorous flame retardants...Since the ban of polybrominated diphenyl ethers(PBDEs)and hexabromocyclododecane(HBCDD),other flame retardants may be increasingly used.Thirty-one current-use halogenated(HFRs)and 24 organophosphorous flame retardants(PFRs)have been sought in Arctic ecosystems so far.Air measurements provide evidence of long-range atmospheric transport for the majority of these compounds,with much higher concentrations for PFRs than for HFRs.Some HFRs,i.e.bis(2-ethylhexyl)-tetrabromophthalate(BEH-TEBP),2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB)and hexabromobenzene(HBBz),had air concentrations comparable to those of PBDEs in some studies.Complementary data for seawater and ice indicate dry deposition of HFRs,while net volatilization from seawater was observed for some PFRs.Studies in the marine environment indicate a wide presence of HFRs in marine biota,but generally at low levels,i.e.typically lower than those of PBDEs.Exceptions exist,namely 2,4,6-tribromophenyl 2,3-dibromopropyl ether(TBP-DBPE)and decabromodiphenyl ethane(DBDPE),which were found in concentrations comparable to PBDEs in some species.The same was the case for 2,4,6-tribromophenyl allyl ether(TBP-AE)in a study from the terrestrial environment.PFRs generally had low concentrations in biota,probably due to metabolic transformation of PFR triesters,as suggested by in vitro studies.Elevated PFR concentrations occurred in some individuals,generally indicating a larger variability of PFRs in biota than found for HFRs.The commercially important tetrabromobisphenol A(TBBPA)was only detected sporadically,and only in abiotic matrices.展开更多
Chlorinated paraffins(CPs)present a complex mixture of congeners which are often analysed and assessed as short-,medium-and long-chain CPs,i.e.SSCCP(C10eC13),SMCCP(C14eC17)and SLCCP(C18).Their complexity makes the ch...Chlorinated paraffins(CPs)present a complex mixture of congeners which are often analysed and assessed as short-,medium-and long-chain CPs,i.e.SSCCP(C10eC13),SMCCP(C14eC17)and SLCCP(C18).Their complexity makes the chemical analysis challenging,in particular in terms of accurate quantification,but promising developments involving ultra-high resolution mass spectrometry have been presented lately.Most Arctic data exist for SCCPs,while LCCPs have not yet been studied in the Arctic.SSCCP concentrations in Arctic air often exceeded those of SMCCP,usually with a predominance of the most volatile C10 congeners,and of banned persistent organic pollutants(POPs),such as polychlorinated biphenyls(PCBs).The presence of SCCPs and MCCPs in Arctic air,as well as in the Antarctic and in the remote regions of the Tibetan plateau,provides evidence of their long-range transport including sufficient environmental persistence to reach the Arctic.Arctic vegetation accumulated SCCPs partly from air and partly through root uptake from soil,with consequences for the SCCP profile found in Arctic plants.No results have yet been reported for CPs in terrestrial Arctic animals.Results for freshwater sediment and fish confirmed the long-range transport of SCCPs and MCCPs and documented their bioaccumulation.Where additional PCB data were available,SPCB was usually higher than SSCCP in freshwater fish.Both SCCPs and MCCPs were widely present in marine Arctic biota(e.g.mussels,fish,seabirds,seals,whales,polar bears).In mussels and Atlantic cod,SMCCP concentrations exceeded those of SSCCP,while this was less clear for other marine species.Marine mammals and the long-lived Greenland shark roughly had SSCCP concentrations of 100e500 ng/g lipid weight,often dominated by C11 congeners.Biomagnification appeared to be more pronounced for SSCCP than for SMCCP,but more studies will be needed.Increasing SSCCP concentrations were observed in Arctic air and sediment over time,but not in beluga monitored since the 1980s.For both SCCPs and MCCPs,increasing c展开更多
Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phe...Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite （organic acid） and its inhibiting reversal effect reasonably depicts the experimental results.展开更多
Management and conservation efforts that support the recovery and protection of large rivers are daunting,reflecting the complexity of the challenge and extent of effort(in terms of policy,economic investment,and spat...Management and conservation efforts that support the recovery and protection of large rivers are daunting,reflecting the complexity of the challenge and extent of effort(in terms of policy,economic investment,and spatial extent)needed to afford measurable change.These large systems have generally experienced intensive development and regulation,compromising their capacity to respond to disturbances such as climate change orwildfire.Functionally,large river and basin management require insights gained from social,ecological,geophysical,and hydrological sciences.This multidisciplinary perspective can unveil the integrated relationship between a river network's biotic community and seasonally variableenvironmental conditions that are ofteninfluencedbyhumanactivities.Large rivers andtheir basins are constantly changing due to anthropogenic influences and as climate modifies patterns of temperature and precipitation.Because of these factors,the state of knowledge must advance to address changing conditions.The Willamette River,in western Oregon,USA,is a prime example of a basin that has experienced significant degradation and investment in rehabilitation in recent decades.Innovative science has facilitated development of fine-scale,spatially extensive datasets and models that can generate targeted conservation and rehabilitation actions that are prioritized across the entire river network.This prioritization allows investment decisions to be driven by site-specific conditions while simultaneously considering potentials for ecological improvement.Here,we review hydrologic,geomorphic,ecologic,and social conditions in the Willamette River basin through time—including pre-settlement,river development,andcontemporary periods—andoffer a futurevisionfor consideration.Currently,detailed informationaboutfish populations and habitat,hydrologic conditions,geomorphology,water quality,and land use can be leveraged to make informed decisions about protection,rehabilitation,and development.The time is ripe for strategic manageme展开更多
Livestock farm waste contributes substantially to annual worldwide emissions of GHG （Greenhouse Gases）, including CH4 （Methane） and CO2 （Carbon Dioxide）. However, despite evidence of global climate change and it...Livestock farm waste contributes substantially to annual worldwide emissions of GHG （Greenhouse Gases）, including CH4 （Methane） and CO2 （Carbon Dioxide）. However, despite evidence of global climate change and its adverse health effects, studies on anthropogenic contributions to the increasing levels of GHG, particularly from livestock waste management practices, have not been adequately explored, especially in less developed countries. This study determined waste management practices and outdoor levels of CH4 and CO2 at three selected livestock farms （A-C） in Ibadan, Oyo State, Nigeria. Each study farm consisted of poultry, cattle and pig units. A 30-point observational checklist documented adequacy of solid waste management practices. Ambient concentrations of CH4 and CO2 at farm buildings and at waste disposal sites were monitored every other day, twice each day of monitoring （morning and evening hours）, for eight weeks during months of September-November in 2013. Average scores for the waste management practices for Farms A-C were 29.6%, 33.3% and 18.5%, respectively. Morning and evening CH4 concentrations in parts per million （ppm） at main buildings of Farms A-C were 2,538 ± 773 and 1,916 ± 662, 2,325 ± 773 and 1,180 ± 483, and 2,389 ± 687 and 1,854 ± 571, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C main buildings were 350 ± 130 and 330 ± 110, 470 ± 100 and 440 ± 100, and 430 ± 80 and 400 ± 70, respectively. Morning and evening CH4 concentrations （ppm） at Farms A-C waste disposal sites were 2,452 ± 495 and 1,614 ± 372, 1,527 ± 390 and 1,736 ± 269, and 2,345 ± 615 and 1,690 ± 387, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C waste disposal sites were 330 ± 90, 370 ± 60 and 350 ± 30, respectively. Waste management practices were inadequate; solid waste management practices like infrequent evacuation of slurry waste and open burning of waste may have contributed to the production of CH4 and CO2. This s展开更多
The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some...The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some skin creams contained up to 2769 ppm Hg. Hg in skin creams was found to be almost 100% elemental Hg (Hg0), a volatile species of Hg. Hg0 can enter the human body through inhalation and skin absorption, potentially resulting in the serious consequence of mercury poisoning. The mercury can also volatilize, contaminating the surrounding air. Other people, for example, infants and children, who are close to or contacting the skin of the person using the cosmetics, can also absorb the mercury. Total mercury (THg) was determined by combustion/trap/CVAFS. Methyl mercury (MeHg) and inorganic mercury (Hg2+) were determined by the ethylation based method. The emission of Hg0 was determined by evaporation/trap/CVAFS. All analyses were performed in accordance with explicit quality assurance and quality control protocols and procedures.展开更多
Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of t...Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of the data to enhance the knowledge and the predictive capabilities of the flow system. This work thoroughly reanalyzes a series of pre- and post-hydraulic fracturing, single-well aquifer tests conducted in two crystalline rock wells in New Hampshire as part of an early 1970’s study. Previous analyses of the data had relied on older manual type-curve methods for predicting the possible effects of hydraulic fracturing. This work applies inverse analysis, derivative analysis, and diagnostic plots to reanalyze the 1970’s aquifer test data. Our results demonstrate that the aquifer tests were affected by changes in flow regimes, dewatering of the aquifer and discrete fractures, and changes due to well development. Increases in transmissivities are related to well development prior to hydraulic fracturing, propagation of a single, vertical fracture hydraulically connecting the two wells after stimulation and expansion of troughs of depression. After hydraulic fracturing, the estimated total yield of the individual wells increased by 2.5 times due to the hydraulic fracturing. However, the wells may be receiving water from the same source, and well interference may affect any significant increase in their combined yield. Our analyses demonstrate the value in applying inverse analysis, derivative analysis, and diagnostic plots over the conventional method of manual type-curve analysis. In addition, our improvement in the aquifer test interpretation of the 1970’s test data has implications for more reliable estimates of sustained well yields.展开更多
The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultan...The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.展开更多
As an outcome of globalization and liberalization of economic policies, exploration for and mining of minerals have become one of the recent lucrative trades in India. Due to stringent environment legislations, reclam...As an outcome of globalization and liberalization of economic policies, exploration for and mining of minerals have become one of the recent lucrative trades in India. Due to stringent environment legislations, reclamation and reforestation of the mined out sites have become obligatory. Information on distribution of nutrients before and after mining provides valuable insights while developing and executing the strategy for reclamation and revegetation of the mined out sites. Successful mine reclamation plan chiefly requires information on the soil characteristics in the area during its natural state. With this aim, investigations into spatial and temporal variations in soil nutrients and other physico-chemical parameters among three proposed bauxite mine locations near Araku valley, India were conducted. Soil samples were collected every three months for two years. At each location, samples from three sites in triplicates from four successive layers (0 - 5 cm, 5 - 10 cm, 10 - 15 cm and 15 - 20 cm depth) were collected. Concentrations of Total Organic Carbon (TOC), Total Nitrogen (TN), Total Available Phosphorous (TAP), Total Available Sulphur (TAS), C:N, C:P, and C:S decreased along the soil layers, while N:P increased. All the parameters studied varied significantly among months (GLM-ANOVA, P 0.05). Principal Component Analysis (PCA) done on the soil physico-chemical dataset showed first 5 components (Eigen Value > 1) explaining 87.3% of the total variance. Of these, the first component accounted for 21.0% and the second for 20.1% of the total variance. The principal components represented C:N/Soil N, C:P/Soil P/N:P, EC, Soil S/C:S and Soil C axes, respectively.展开更多
^222Rn and ^220Rn enter the atmosphere mainly by crossing the air interface of either soil-air or building materials. The existence of relatively high concentration maintains a large ^222Rn, ^220Rn concentration gradi...^222Rn and ^220Rn enter the atmosphere mainly by crossing the air interface of either soil-air or building materials. The existence of relatively high concentration maintains a large ^222Rn, ^220Rn concentration gradient between the materials and open air. The present paper deals with the experimental measurement of ^222Rn, ^220Rn concentrations and the associated inhalation dose rates due to them in the dwellings of different characteristics. Higher concentrations and dose rates were observed in lower volume houses and the houses with granite flooring.展开更多
Geo-energy and geo-engineering applications,such as improved oil recovery(IOR),geologic carbon storage,and enhanced geothermal systems(EGSs),involve coupled thermo-hydro-mechanical(THM)processes that result from fluid...Geo-energy and geo-engineering applications,such as improved oil recovery(IOR),geologic carbon storage,and enhanced geothermal systems(EGSs),involve coupled thermo-hydro-mechanical(THM)processes that result from fluid injection and production.In some cases,reservoirs are highly fractured and the geomechanical response is controlled by fractures.Therefore,fractures should explicitly be included into numerical models to realistically simulate the THM responses of the subsurface.In this study,we perform coupled THM numerical simulations of water injection into naturally fractured reservoirs(NFRs)using CODE_BRIGHT and TOUGH-UDEC codes.CODE_BRIGHT is a finite element method(FEM)code that performs fully coupled THM analysis in geological media and TOUGH-UDEC sequentially solves coupled THM processes by combining a finite volume method(FVM)code that solves nonisothermal multiphase flow(TOUGH2)with a distinct element method(DEM)code that solves the mechanical problem(UDEC).First,we validate the two codes against a semi-analytical solution for water injection into a single deformable fracture considering variable permeability based on the cubic law.Then,we compare simulation results of the two codes in an idealized conceptual model that includes one horizontal fracture and in a more realistic model with multiple fractures.Each code models fractures differently.UDEC calculates fracture deformation from the fracture normal and shear stiffnesses,while CODE_BRIGHT treats fractures as equivalent porous media and uses the equivalent Young’s modulus and Poisson’s ratio of the fracture.Finally,we obtain comparable results of pressure,temperature,stress and displacement distributions and evolutions for the single horizontal fracture model.Despite some similarities,the two codes provide increasingly different results as model complexity increases.These differences highlight the challenging task of accurately modeling coupled THM processes in fractured media given their high nonlinearity.展开更多
When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the mult...When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the multi-model ensemble with the paleoclimate modeling intercomparison project（PMIP） models. The reconstructed winter（summer） surface air temperature at 6 kyr before present was 0.85 oC（0.21 oC） lower（higher） than the present day over Asia, 60oE-150oE, 10oN-60oN. The seasonal variation and heating differences of land and ocean in summer at 6 kyr before present might be much larger than present day. The winter and summer precipitation of 6 kyr before present were 0.067 and 0.017 mm·day-1larger than present day, respectively. The Group B climate, which means the dry climates based on K？ppen climate classification, at 6 kyr before present decreased 17% compared to present day, but the Group D which means the continental and microthermal climates at 6 kyr before present increased over 7%. Comparison between the results from the model simulation and published paleo-proxy record agrees within the limited sparse paleo-proxy record data.展开更多
Global warming resulting from greenhouse effect has threatened to the sustainability of agriculture,forest and land surface globally.A significant rise in extreme weather events has been observed worldwide,particularl...Global warming resulting from greenhouse effect has threatened to the sustainability of agriculture,forest and land surface globally.A significant rise in extreme weather events has been observed worldwide,particularly in developing countries[1].In the changing climatic era,the economic importance of the remote sensing and geographical information system(GIS)to monitoring forests and agricultural resources is imperative to the development of agro-ecosystem services and the products responding to user needs[2].The applications of the remote sensing for forestry and agriculture,including the estimation of the land surface,biophysical variables,forest vegetation’s,methods for mapping land cover,primary soil properties,the estimation of the forest cover area,and the contribution of remote sensing for crop and water monitoring to manage adverse conditions.展开更多
Rainfall trend analysis has asupreme role for forecasting the rain events,which is very vital for tropics where the fluctuation in occurrence of rainfall is widespread.The local level rainfall trend analysis on the ot...Rainfall trend analysis has asupreme role for forecasting the rain events,which is very vital for tropics where the fluctuation in occurrence of rainfall is widespread.The local level rainfall trend analysis on the other side provides valuable information to cope up with the vehemence of global climate changes.The present study analyses the trend in the rainfall and number of rain days in a tropical town ship,Pattambi,located in the Bharathapuzha River basin of Kerala state of India.We used Man-Kendall rank correlation statistics to see the variations展开更多
文摘The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity （MWHC） after equilibration for 24 h. The free metal concentrations （Cd^2＋, Cu^2＋, Pb^2＋, and Zn^2＋） in soil solution were determined using the Donnan membrane technique （DMT）. Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd^2＋ （3%-52%） and Zn^2＋ （11%-72%） in soil solutions were generally higher than those of Cu^2＋ （0.2%-30%） and Pb^2＋ （0.6%-10%）. Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients （Kp） and dissolved organic carbon did not show any significant influence on Kp.
文摘Background:The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses,explicitly focusing on norovirus genogroup II(GII),astrovirus,rotavirus,Aichi virus,sapovirus,hepatitis A and E viruses in wastewater treatment plants through droplet digital PCR(ddPCR).Enteric viruses are of significant public health concern,as they are the leading cause of diseases like gastroenteritis.Regular monitoring of environmental samples,particularly from wastewater treatment plants,is crucial for early detection and control of these viruses.This research aims to improve the understanding of the prevalence and dynamics of enteric viruses in urban India and will serve as a model for similar studies in other regions.Our protocol's objective is to establish a novel ddPCRbased methodology for the detection and molecular characterization of enteric viruses present in wastewater samples sourced from Bhopal,India.Our assay is capable of accurately quantifying virus concentrations without standard curves,minimizing extensive optimization,and enhancing sensitivity and precision,especially for low-abundance targets.Methods:The study involves fortnightly collecting and analyzing samples from nine wastewater treatment plants over two years,ensuring comprehensive coverage and consistent data.Our study innovatively applies ddPCR to simultaneously detect and quantify enteric viruses in wastewater,a more advanced technique.Additionally,we will employ next-generation sequencing for detailed viral genome identification in samples tested positive for pathogenic viruses.Conclusion:This study will aid in understanding these viruses’genetic diversity and mutation rates,which is crucial for developing tailored intervention strategies.The findings will be instrumental in shaping public health responses and improving epidemiological surveillance,especially in localities heaving sewage networks.
基金supported by the National Key Research and Development Program of China(2017YFA0605001)the National Natural Science Foundation of China(52039001,92047303 and 41977359)
文摘Future climate change will affect the environmental fate of hydrophobic organic contaminants(HOCs)and associated human health risks,yet the extent of these effects remains unknown.Here,we couple a high-resolution environmental multimedia model with a bioaccumulation model to study the multimedia distribution of 16 priority polycyclic aromatic hydrocarbons(PAHs),a group of HOCs,and assess future PAH-related human health risks under varying climate change scenarios over China at a continental scale.After removing the effects of PAH emission changes,we find that the total PAH concentrations would decrease in the air,freshwater,sediment,soil,and organisms,while the high-molecular-weight PAH would increase in the air with climate warming from 1.5°C to 4°C.Consequently,the multi-pathway exposure human health risks predominately influenced by dietary ingestion are expected to decrease by 1.7%–20.5%,while the respiratory risks are projected to rise by 0.2%–5.8%in the future.However,the persistently high multi-pathway human health risks underscore the need for reducing future PAH emissions by 69%compared with 2009 levels in China.Our study demonstrates the urgency of limiting PAH emissions under future climate change for public health and highlights the importance of including the contribution of dietary ingestion in human health risk assessment.
基金This study was supported by the Australian Research Council(DP210102076)the Australian National Health and Medical Research Council(APP2000581)+12 种基金Y.W and B.W.were supported by the China Scholarship Council(nos.202006010044 and 202006010043)S.L.was supported by an Emerging Leader Fellowship of the Australian National Health and Medical Research Council(no.APP2009866)Y.G.was supported by Career Development Fellowship(no.APP1163693)and Leader Fellowship(no.APP2008813)of the Australian National Health and Medical Research CouncilJ.K.and A.U.were supported by the Czech Science Foundation(project no.20-28560S)N.S.was supported by the National Institute of Environmental Health Sciences-funded HERCULES Center(no.P30ES019776)Y.H.was supported by the Environment Research and Technology Development Fund(JPMEERF15S11412)of the Environmental Restoration and Conservation AgencyM.d.S.Z.S.C.and P.H.N.S.were supported by the São Paulo Research Foundation(FAPESP)H.O.and E.I.were supported by the Estonian Ministry of Education and Research(IUT34-17)J.M.was supported by a fellowship of Fundação para a Ciência e a Tecnlogia(SFRH/BPD/115112/2016)A.G.and F.S.were supported by the Medical Research Council UK(grant ID MR/R013349/1),the Natural Environment Research Council UK(grant ID NE/R009384/1),and the EU’s Horizon 2020 project,Exhaustion(grant ID 820655)A.S.and F.d.D.were supported by the EU’s Horizon 2020 project,Exhaustion(grant ID 820655)V.H.was supported by the Spanish Ministry of Economy,Industry and Competitiveness(grant ID PCIN-2017-046)A.T.byMCIN/AEI/10.13039/501100011033(grant CEX2018-000794-S).Statistics South Africa kindly provided the mortality data,but had no other role in the study.
文摘Studies have investigated the effects of heat and temperature variability(TV)on mortality.However,few assessed whether TV modifies the heat-mortality association.Data on daily temperature and mortality in the warm season were collected from 717 locations across 36 countries.TV was calculated as the standard deviation of the average of the same and previous days’minimum and maximum temperatures.
基金We acknowledge the Arctic Monitoring and Assessment Programme(AMAP)and the national programmes in the circumpolar countries for their funding and support of this work.The northern communities in circumpolar regions are acknowledged for their cooperation and collection of biological samples that yielded the data reviewed here.The Danish contribution to this work was supported by the Danish Environmental Protection Agency,under the Cooperation for Environment in the Arctic(DANCEA),grants no.MST-112-191 and MST-113-00082.
文摘Since the ban of polybrominated diphenyl ethers(PBDEs)and hexabromocyclododecane(HBCDD),other flame retardants may be increasingly used.Thirty-one current-use halogenated(HFRs)and 24 organophosphorous flame retardants(PFRs)have been sought in Arctic ecosystems so far.Air measurements provide evidence of long-range atmospheric transport for the majority of these compounds,with much higher concentrations for PFRs than for HFRs.Some HFRs,i.e.bis(2-ethylhexyl)-tetrabromophthalate(BEH-TEBP),2-ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB)and hexabromobenzene(HBBz),had air concentrations comparable to those of PBDEs in some studies.Complementary data for seawater and ice indicate dry deposition of HFRs,while net volatilization from seawater was observed for some PFRs.Studies in the marine environment indicate a wide presence of HFRs in marine biota,but generally at low levels,i.e.typically lower than those of PBDEs.Exceptions exist,namely 2,4,6-tribromophenyl 2,3-dibromopropyl ether(TBP-DBPE)and decabromodiphenyl ethane(DBDPE),which were found in concentrations comparable to PBDEs in some species.The same was the case for 2,4,6-tribromophenyl allyl ether(TBP-AE)in a study from the terrestrial environment.PFRs generally had low concentrations in biota,probably due to metabolic transformation of PFR triesters,as suggested by in vitro studies.Elevated PFR concentrations occurred in some individuals,generally indicating a larger variability of PFRs in biota than found for HFRs.The commercially important tetrabromobisphenol A(TBBPA)was only detected sporadically,and only in abiotic matrices.
基金We acknowledge the Arctic Monitoring and Assessment Programme(AMAP)and the national programmes in the circumpolar countries for their funding and support of this work.We are grateful to Derek Muir,Cynthia de Wit and Simon Wilson for insightful discussions of the topic and to Tom Harner for providing SCCP data from the GAPS program.The northern communities in circumpolar regions are acknowledged for their cooperation and collection of biological samples that yielded the data reviewed here.The Danish contribution to this work was supported by the Danish Environmental Protection Agency,under the Cooperation for Environment in the Arctic(DANCEA),grants no.MST-112-191 and MST-113-00082.The National Laboratory for Environmental Testing(NLET)at Environment and Climate Change Canada is acknowledged for the analysis of air samples from Alert.
文摘Chlorinated paraffins(CPs)present a complex mixture of congeners which are often analysed and assessed as short-,medium-and long-chain CPs,i.e.SSCCP(C10eC13),SMCCP(C14eC17)and SLCCP(C18).Their complexity makes the chemical analysis challenging,in particular in terms of accurate quantification,but promising developments involving ultra-high resolution mass spectrometry have been presented lately.Most Arctic data exist for SCCPs,while LCCPs have not yet been studied in the Arctic.SSCCP concentrations in Arctic air often exceeded those of SMCCP,usually with a predominance of the most volatile C10 congeners,and of banned persistent organic pollutants(POPs),such as polychlorinated biphenyls(PCBs).The presence of SCCPs and MCCPs in Arctic air,as well as in the Antarctic and in the remote regions of the Tibetan plateau,provides evidence of their long-range transport including sufficient environmental persistence to reach the Arctic.Arctic vegetation accumulated SCCPs partly from air and partly through root uptake from soil,with consequences for the SCCP profile found in Arctic plants.No results have yet been reported for CPs in terrestrial Arctic animals.Results for freshwater sediment and fish confirmed the long-range transport of SCCPs and MCCPs and documented their bioaccumulation.Where additional PCB data were available,SPCB was usually higher than SSCCP in freshwater fish.Both SCCPs and MCCPs were widely present in marine Arctic biota(e.g.mussels,fish,seabirds,seals,whales,polar bears).In mussels and Atlantic cod,SMCCP concentrations exceeded those of SSCCP,while this was less clear for other marine species.Marine mammals and the long-lived Greenland shark roughly had SSCCP concentrations of 100e500 ng/g lipid weight,often dominated by C11 congeners.Biomagnification appeared to be more pronounced for SSCCP than for SMCCP,but more studies will be needed.Increasing SSCCP concentrations were observed in Arctic air and sediment over time,but not in beluga monitored since the 1980s.For both SCCPs and MCCPs,increasing c
基金The National Natural Science Foundation of China （No. 50178040） the Royal Society of UK and the Hi-Tech Research and Development Program（863） of China（No. 2003AA601080）
文摘Pollution by polycyclic aromatic hydrocarbons（PAHs） is widespread due to tmsuitable disposal of industrial waste. They are mostly defined as priority pollutants by environmental protection authorities worldwide. Phenanthrene, a typical PAH, was selected as the target in this paper. The PAH-degrading mixed culture, named ZM, was collected from a petroleum contaminated river bed. This culture was injected into phenanthrene solutions at different concentrations to quantify the biodegradation process. Results show near-complete removal of phenanthrene in three days of biodegradation if the initial phenanthrene concentration is low. When the initial concentration is high, the removal rate is increased but 20%-40% of the phenanthrene remains at the end of the experiment. The biomass shows a peak on the third day due to the combined effects of microbial growth and decay. Another peak is evident for cases with a high initial concentration, possibly due to production of an intermediate metabolite. The pH generally decreased during biodegradation because of the production of organic acid. Two phenomenological models were designed to simulate the phenanthrene biodegradation and biomass growth. A relatively simple model that does not consider the intermediate metabolite and its inhibition of phenanthrene biodegradation cannot fit the observed data. A modified Monod model that considered an intermediate metabolite （organic acid） and its inhibiting reversal effect reasonably depicts the experimental results.
文摘Management and conservation efforts that support the recovery and protection of large rivers are daunting,reflecting the complexity of the challenge and extent of effort(in terms of policy,economic investment,and spatial extent)needed to afford measurable change.These large systems have generally experienced intensive development and regulation,compromising their capacity to respond to disturbances such as climate change orwildfire.Functionally,large river and basin management require insights gained from social,ecological,geophysical,and hydrological sciences.This multidisciplinary perspective can unveil the integrated relationship between a river network's biotic community and seasonally variableenvironmental conditions that are ofteninfluencedbyhumanactivities.Large rivers andtheir basins are constantly changing due to anthropogenic influences and as climate modifies patterns of temperature and precipitation.Because of these factors,the state of knowledge must advance to address changing conditions.The Willamette River,in western Oregon,USA,is a prime example of a basin that has experienced significant degradation and investment in rehabilitation in recent decades.Innovative science has facilitated development of fine-scale,spatially extensive datasets and models that can generate targeted conservation and rehabilitation actions that are prioritized across the entire river network.This prioritization allows investment decisions to be driven by site-specific conditions while simultaneously considering potentials for ecological improvement.Here,we review hydrologic,geomorphic,ecologic,and social conditions in the Willamette River basin through time—including pre-settlement,river development,andcontemporary periods—andoffer a futurevisionfor consideration.Currently,detailed informationaboutfish populations and habitat,hydrologic conditions,geomorphology,water quality,and land use can be leveraged to make informed decisions about protection,rehabilitation,and development.The time is ripe for strategic manageme
文摘Livestock farm waste contributes substantially to annual worldwide emissions of GHG （Greenhouse Gases）, including CH4 （Methane） and CO2 （Carbon Dioxide）. However, despite evidence of global climate change and its adverse health effects, studies on anthropogenic contributions to the increasing levels of GHG, particularly from livestock waste management practices, have not been adequately explored, especially in less developed countries. This study determined waste management practices and outdoor levels of CH4 and CO2 at three selected livestock farms （A-C） in Ibadan, Oyo State, Nigeria. Each study farm consisted of poultry, cattle and pig units. A 30-point observational checklist documented adequacy of solid waste management practices. Ambient concentrations of CH4 and CO2 at farm buildings and at waste disposal sites were monitored every other day, twice each day of monitoring （morning and evening hours）, for eight weeks during months of September-November in 2013. Average scores for the waste management practices for Farms A-C were 29.6%, 33.3% and 18.5%, respectively. Morning and evening CH4 concentrations in parts per million （ppm） at main buildings of Farms A-C were 2,538 ± 773 and 1,916 ± 662, 2,325 ± 773 and 1,180 ± 483, and 2,389 ± 687 and 1,854 ± 571, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C main buildings were 350 ± 130 and 330 ± 110, 470 ± 100 and 440 ± 100, and 430 ± 80 and 400 ± 70, respectively. Morning and evening CH4 concentrations （ppm） at Farms A-C waste disposal sites were 2,452 ± 495 and 1,614 ± 372, 1,527 ± 390 and 1,736 ± 269, and 2,345 ± 615 and 1,690 ± 387, respectively. Morning and evening CO2 concentrations （ppm） at Farms A-C waste disposal sites were 330 ± 90, 370 ± 60 and 350 ± 30, respectively. Waste management practices were inadequate; solid waste management practices like infrequent evacuation of slurry waste and open burning of waste may have contributed to the production of CH4 and CO2. This s
文摘The concentration of mercury (Hg) was accurately determined in more than 228 drugs, cosmetics and household products manufactured in a variety of countries. Some drugs were found to contain up to 4424 ppb Hg, and some skin creams contained up to 2769 ppm Hg. Hg in skin creams was found to be almost 100% elemental Hg (Hg0), a volatile species of Hg. Hg0 can enter the human body through inhalation and skin absorption, potentially resulting in the serious consequence of mercury poisoning. The mercury can also volatilize, contaminating the surrounding air. Other people, for example, infants and children, who are close to or contacting the skin of the person using the cosmetics, can also absorb the mercury. Total mercury (THg) was determined by combustion/trap/CVAFS. Methyl mercury (MeHg) and inorganic mercury (Hg2+) were determined by the ethylation based method. The emission of Hg0 was determined by evaporation/trap/CVAFS. All analyses were performed in accordance with explicit quality assurance and quality control protocols and procedures.
文摘Aquifer test methods have greatly improved in recent years with the advent of inverse analysis, derivative analysis, and diagnostic plots. Updated analyses of past aquifer tests allow for improved interpretations of the data to enhance the knowledge and the predictive capabilities of the flow system. This work thoroughly reanalyzes a series of pre- and post-hydraulic fracturing, single-well aquifer tests conducted in two crystalline rock wells in New Hampshire as part of an early 1970’s study. Previous analyses of the data had relied on older manual type-curve methods for predicting the possible effects of hydraulic fracturing. This work applies inverse analysis, derivative analysis, and diagnostic plots to reanalyze the 1970’s aquifer test data. Our results demonstrate that the aquifer tests were affected by changes in flow regimes, dewatering of the aquifer and discrete fractures, and changes due to well development. Increases in transmissivities are related to well development prior to hydraulic fracturing, propagation of a single, vertical fracture hydraulically connecting the two wells after stimulation and expansion of troughs of depression. After hydraulic fracturing, the estimated total yield of the individual wells increased by 2.5 times due to the hydraulic fracturing. However, the wells may be receiving water from the same source, and well interference may affect any significant increase in their combined yield. Our analyses demonstrate the value in applying inverse analysis, derivative analysis, and diagnostic plots over the conventional method of manual type-curve analysis. In addition, our improvement in the aquifer test interpretation of the 1970’s test data has implications for more reliable estimates of sustained well yields.
文摘The present study aims at measuring the activity concentrations of ^210Po and ^210Pb in the potable water of Eloor, a major industrial belt in the Ernakulam district of Kerala, India with an aim of evaluating resultant ingestion dose to critical population. The industrial units located in Eloor discharge their treated effluents into the river Periyar and the surrounding environs. The two major industries of interest with respect to NORMs are the fertilizer plant, processing rock phosphate and the monazite processing plant, which had been in operation for the last 50 years. For sampling, Eloor region was divided into four zones and a total of 55 water samples from different locations were collected and analysed as per standard analytical procedure manual of BARC. The ^210Po concentration ranged between 0.3 to 4.7 mBq.L^-1 and ^210Pb ranged from 0.6 to 4.3 mBq.L^-1. All values are well below the limit of 0.1 Bq.Ll recommended by World Health Organization. Statistical analysis shows a good co-relation between ^210Po and ^210Pb in the water samples analyzed and the mean activity concentration is found to be relatively high in the western region of Eloor compared to other regions. The annual effective dose equivalent to man from ^210Po and ^210Pb through drinking water intake were estimated and found to be 1.13 μSv.y^-1 and 0.99 μSv.y^-1 respectively, which is well below the reference level of committed effective dose （100 μSv.y^-1） recommended by WHO.
文摘As an outcome of globalization and liberalization of economic policies, exploration for and mining of minerals have become one of the recent lucrative trades in India. Due to stringent environment legislations, reclamation and reforestation of the mined out sites have become obligatory. Information on distribution of nutrients before and after mining provides valuable insights while developing and executing the strategy for reclamation and revegetation of the mined out sites. Successful mine reclamation plan chiefly requires information on the soil characteristics in the area during its natural state. With this aim, investigations into spatial and temporal variations in soil nutrients and other physico-chemical parameters among three proposed bauxite mine locations near Araku valley, India were conducted. Soil samples were collected every three months for two years. At each location, samples from three sites in triplicates from four successive layers (0 - 5 cm, 5 - 10 cm, 10 - 15 cm and 15 - 20 cm depth) were collected. Concentrations of Total Organic Carbon (TOC), Total Nitrogen (TN), Total Available Phosphorous (TAP), Total Available Sulphur (TAS), C:N, C:P, and C:S decreased along the soil layers, while N:P increased. All the parameters studied varied significantly among months (GLM-ANOVA, P 0.05). Principal Component Analysis (PCA) done on the soil physico-chemical dataset showed first 5 components (Eigen Value > 1) explaining 87.3% of the total variance. Of these, the first component accounted for 21.0% and the second for 20.1% of the total variance. The principal components represented C:N/Soil N, C:P/Soil P/N:P, EC, Soil S/C:S and Soil C axes, respectively.
文摘^222Rn and ^220Rn enter the atmosphere mainly by crossing the air interface of either soil-air or building materials. The existence of relatively high concentration maintains a large ^222Rn, ^220Rn concentration gradient between the materials and open air. The present paper deals with the experimental measurement of ^222Rn, ^220Rn concentrations and the associated inhalation dose rates due to them in the dwellings of different characteristics. Higher concentrations and dose rates were observed in lower volume houses and the houses with granite flooring.
基金financial support received from the“Iran’s Ministry of Science Research and Technology”(PhD students’sabbatical grants)funding from the European Research Council under the European Union’s Horizon 2020 Research and Innovation Program through the Starting Grant GEoREST(www.georest.eu)(Grant Agreement No.801809)+1 种基金support by the Korea-EU Joint Research Program of the National Research Foundation of Korea through Grant No.NRF2015K1A3A7A03074226funded by the Korean Government’s Ministry of Science and Information and Communication Technology(ICT)in the framework of the European Union’s Horizon 2020 Research and Innovation Program(Grant No.691728)。
文摘Geo-energy and geo-engineering applications,such as improved oil recovery(IOR),geologic carbon storage,and enhanced geothermal systems(EGSs),involve coupled thermo-hydro-mechanical(THM)processes that result from fluid injection and production.In some cases,reservoirs are highly fractured and the geomechanical response is controlled by fractures.Therefore,fractures should explicitly be included into numerical models to realistically simulate the THM responses of the subsurface.In this study,we perform coupled THM numerical simulations of water injection into naturally fractured reservoirs(NFRs)using CODE_BRIGHT and TOUGH-UDEC codes.CODE_BRIGHT is a finite element method(FEM)code that performs fully coupled THM analysis in geological media and TOUGH-UDEC sequentially solves coupled THM processes by combining a finite volume method(FVM)code that solves nonisothermal multiphase flow(TOUGH2)with a distinct element method(DEM)code that solves the mechanical problem(UDEC).First,we validate the two codes against a semi-analytical solution for water injection into a single deformable fracture considering variable permeability based on the cubic law.Then,we compare simulation results of the two codes in an idealized conceptual model that includes one horizontal fracture and in a more realistic model with multiple fractures.Each code models fractures differently.UDEC calculates fracture deformation from the fracture normal and shear stiffnesses,while CODE_BRIGHT treats fractures as equivalent porous media and uses the equivalent Young’s modulus and Poisson’s ratio of the fracture.Finally,we obtain comparable results of pressure,temperature,stress and displacement distributions and evolutions for the single horizontal fracture model.Despite some similarities,the two codes provide increasingly different results as model complexity increases.These differences highlight the challenging task of accurately modeling coupled THM processes in fractured media given their high nonlinearity.
基金funded by the National Institute of Fisheries Science of Korea (No. RP-2016-ME-036)
文摘When considering potential global warming projections, it is useful to understand the impact of each climate condition at 6 kyr before present. Asian paleoclimate was simulated by performing an integration of the multi-model ensemble with the paleoclimate modeling intercomparison project（PMIP） models. The reconstructed winter（summer） surface air temperature at 6 kyr before present was 0.85 oC（0.21 oC） lower（higher） than the present day over Asia, 60oE-150oE, 10oN-60oN. The seasonal variation and heating differences of land and ocean in summer at 6 kyr before present might be much larger than present day. The winter and summer precipitation of 6 kyr before present were 0.067 and 0.017 mm·day-1larger than present day, respectively. The Group B climate, which means the dry climates based on K？ppen climate classification, at 6 kyr before present decreased 17% compared to present day, but the Group D which means the continental and microthermal climates at 6 kyr before present increased over 7%. Comparison between the results from the model simulation and published paleo-proxy record agrees within the limited sparse paleo-proxy record data.
文摘Global warming resulting from greenhouse effect has threatened to the sustainability of agriculture,forest and land surface globally.A significant rise in extreme weather events has been observed worldwide,particularly in developing countries[1].In the changing climatic era,the economic importance of the remote sensing and geographical information system(GIS)to monitoring forests and agricultural resources is imperative to the development of agro-ecosystem services and the products responding to user needs[2].The applications of the remote sensing for forestry and agriculture,including the estimation of the land surface,biophysical variables,forest vegetation’s,methods for mapping land cover,primary soil properties,the estimation of the forest cover area,and the contribution of remote sensing for crop and water monitoring to manage adverse conditions.
文摘Rainfall trend analysis has asupreme role for forecasting the rain events,which is very vital for tropics where the fluctuation in occurrence of rainfall is widespread.The local level rainfall trend analysis on the other side provides valuable information to cope up with the vehemence of global climate changes.The present study analyses the trend in the rainfall and number of rain days in a tropical town ship,Pattambi,located in the Bharathapuzha River basin of Kerala state of India.We used Man-Kendall rank correlation statistics to see the variations
