The used water for human consumption must be free of microorganisms and chemicals that cause risk in the human health. In this study, water quality of 18 rural area of Abarkouh was determined and compared the conventi...The used water for human consumption must be free of microorganisms and chemicals that cause risk in the human health. In this study, water quality of 18 rural area of Abarkouh was determined and compared the conventional monitoring method (According to ISIR (Institute of Standards and Industrial Research of Iran), 1053 and 4208) and use of electronic system method (Patent in industrial property general office of Iran, 77815). Free chlorine monitoring and pH test done by health workers in the conventional method and the results will be sent to the Health Network monthly. Sampling for microbiological testing is done monthly based on population (According to ISIR, 4208). On the electronic system, the procedure is also done by health workers, but the result will be sent to the receiver device by using a cell phone. According to the chlorine test results if the free chlorine residual reported zero, microbiological sampling was done by a health expert. Finally, the number of chlorine test and microbiological sampling and the results of these experiments collected in the both methods and recorded in SPSS 22 then were analyzed by using chi-square test and Fisher exact test. The result of microbiological experiments shows that the sampling rate decreased 29% in using of electronic system method in comparison to the conventional monitoring method while the number of microbial defect detection increased 19% in drinking water networks monitoring by electronic system. Using of electronic system monitoring can reduce the rate and cost of microbiological sampling and its experiments and increase accuracy of these tests, in this way it will increase the quality and safety of drinking water in distribution network in small and dispersed rural communities.展开更多
This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was obser...This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was observed among the different waters, with the predominance of Proteobacteria. While Verrucomicrobia was also a major phylum group in colored water. Limnobacter was the major genus group in colored water, but Undibacterium predominated in normal tap water. The coexistence of Limnobacter as well as Sediminibacterium and Aquobocterium might contribute to the formation of colored water.展开更多
Introduction:The utilization of facility delivery is crucial to achieve sustainable development goals by reducing maternal and neonatal deaths.This study aimed to compare the distributions and determinants of childbir...Introduction:The utilization of facility delivery is crucial to achieve sustainable development goals by reducing maternal and neonatal deaths.This study aimed to compare the distributions and determinants of childbirth in health facilities in urban and rural regions of Bangladesh.Methods:Cross-sectional data from the 2017-2018 Bangladesh Demographic and Health Survey were analyzed.Multilevel logistic regression was applied.Results:A total of 4751 women were included in the analyses.Only 50%of childbirths took place in health facilities,63.4%and 44.6%in urban and rural regions,respectively.Overall,the odds of the association between facility delivery and the studied factors were similar.Multiparous women had significantly lower odds of facility delivery in both rural(adjusted odds ratio[AOR]=0.3,95%confidence interval[CI]:0.2 to 0.5)and urban(AOR=0.2,95%CI:0.1 to 0.5)regions.In both regions,women with higher education levels,highly educated husbands,antenatal care(ANC),and higher wealth indexes had significantly higher odds of facility delivery.Conclusion:Several common associated factors were identified.However,differences were observed regarding distributions of these factors.The differences in facility delivery utilization could result from lower ANC utilization,socioeconomic status,and transportation facilities in rural regions than urban regions;therefore,improving these conditions could increase facility delivery in these regions.展开更多
From the situations about the incomes and life quality of the urban and rural residents,the thesis briefly introduces the status quo of the urban-rural income gap and explores the impact of the income gap on social ec...From the situations about the incomes and life quality of the urban and rural residents,the thesis briefly introduces the status quo of the urban-rural income gap and explores the impact of the income gap on social economy:firstly,it hampers economic development;secondly,it is detrimental to the social development.Then the thesis analyzes the role of a sound social security in narrowing urban-rural income gap:at first,it broadens the institutional environment of improving the agricultural efficiency;secondly,it eliminates the uncertainties influencing the farmers' income;thirdly,it improves the farmers' capacity to increase income;at last,it enhances the farmers' consciousness of wealth.Next the thesis inquires into the problems existing in the system of rural social security:the first problem is more obviously fragmented system;the second is inadequate security projects and narrower coverage;the third is an obvious lack of equality in urban and rural security;the fourth is even less sound management system;the last is the lagging of legislation.Afterwards the thesis proposes the countermeasures and suggestions to improve the system of rural social security and narrow urban-rural income gap:firstly,to integrate the social security system in rural areas;secondly,to perfect security projects and enhance the security system;thirdly,to integrate the administrative management of social security;at last,to enforce the legal system.展开更多
The aim of this study is to determine the types of heavy metals frequently present in Makkah wells and the possible environmental causes of their distribution and accumulation. Makkah lies in a mountain range dominate...The aim of this study is to determine the types of heavy metals frequently present in Makkah wells and the possible environmental causes of their distribution and accumulation. Makkah lies in a mountain range dominated by different types of rocks from the Precambrian and Lower Paleozoic eras, as well as subordinate sedimentary rocks and basaltic lava flow from the Tertiary and Quaternary periods. Natural contaminants in Makkah wells water can be attributed to the unique location. Many epidemiological studies have identified associations between the ingestion of wells water contaminated with heavy metals and increased risk of some illnesses. This study presents exclusive information on the levels and distribution of 9 heavy metals—arsenic, barium, cadmium, chromium, cobalt, copper, lead, mercury, and selenium—in the wells water in various rural and urban areas of Makkah city. These naturally occurring elements are considered significant markers of water purity. More than 160 wells were involved in this three-year investigation. Water samples were collected during different seasons in order to assess any changes in the distribution and concentration of these heavy metals throughout the year. The collected water samples were filtered and digested before analysis using inductively coupled plasma mass spectrometry (ICP/MS). We found the following sequence of concentrations of heavy metals in the studied wells: Ba > Se >Cr > As > Co > Cu> Hg > Pb > Cd. Arsenic, barium, chromium, and selenium were the most abundant contaminants in the wells studied. The concentrations of the other heavy metals ranged from non-detectable to 3 μg/L. Although low, these values are also reported in comparisons with the local and international strict values and standards which govern the maximum contaminant levels permitted for long-term daily consumption.展开更多
The population migration in Hubei Province was frequent in history,accompanied by the migration of surnames,so it is important to study their population surnames.We take Xiantao City as an example to explore the isony...The population migration in Hubei Province was frequent in history,accompanied by the migration of surnames,so it is important to study their population surnames.We take Xiantao City as an example to explore the isonymic structure of small and medium-sized cities in Hubei.The surname distributions of 223327 residents registered in 2013 were analyzed in 5 towns and 105 villages of Xiantao.The number of different surnames found was 422.As for surnames,theα-value reflects the influence of ethnic composition on the abundance of surnames.The correlation between the isonymic distance and the geographic distance between villages was calculated and indicated that Euclidean distance was weakly correlated with the geographic distance(r=0.177±0.012),and the isonymic distance increased with the geographical distance.Furthermore,the dendrogram and PCA built from the matrix of Euclidean distances between villages identified a main surname differentiation between the urban and rural areas.展开更多
Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper pr...Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.展开更多
Azole fungicides(AFs)play an important role in the prevention and treatment of fungal diseases in agricultural crops.However,limited studies are addressing the fate and ecological risk of AFs in the urban water cycle ...Azole fungicides(AFs)play an important role in the prevention and treatment of fungal diseases in agricultural crops.However,limited studies are addressing the fate and ecological risk of AFs in the urban water cycle at a large watershed scale.To address this gap,we investigated the spatiotemporal distribution and ecological risk of twenty AFs in the lower reaches of the Yangtze River across four seasons.Carbendazim(CBA),tebuconazole(TBA),tricyclazole(TCA),and propiconazole(PPA)were found to be the dominant compounds.Their highest concentrations were measured in January(188.3 ng/L),and November(2197.1 ng/L),July(162.0 ng/L),and November(1801.9 ng/L),respectively.The comparison between wastewater treatment plants(WWTPs)effluents and surface water suggested that industrial WWTPs are major sources of AFs in the Yangtze River.In particular,TBA and PPA were found to be the most recalcitrant AFs in industrial WWTPs,while difenoconazole(DFA)was found to be the most potent pollutant in municipal WWTPs,with an average removal rate of less than60%.The average risk quotient(RQ)for the entire AFs was 6.45 in the fall,which was higher than in January(0.98),April(0.61),and July(0.40).This indicates that AFs in surface water posed higher environmental risks during the dry season.Additionally,the exposure risk of AFs via drinking water for sensitive populations deserves more attention.This study provides benchmark data on the occurrence of AFs in the lower reaches of the Yangtze River,and offers suggestions for better reduction of AFs.展开更多
Antibiotic resistance in aquatic environment has become an important pollution problem worldwide. In recent years, much attention was paid to antibiotic resistance in urban drinking water systems due to its close rela...Antibiotic resistance in aquatic environment has become an important pollution problem worldwide. In recent years, much attention was paid to antibiotic resistance in urban drinking water systems due to its close relationship with the biosafety of drinking water. This review was focused on the mechanisms of antibiotic resistance, as well as the presence, dissemination and removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the urban drinking water system. First, the presence of ARB and ARGs in the drinking water source was discussed. The variation of concentration of ARGs and ARB during coagulation, sedimentation and filtration process were provided subsequently, in which filtration was proved to be a promising technology to remove ARGs. However, biological activated carbon (BAC) process and drinking water distribution systems (DWDSs) could be incubators which promote the antibiotic resistance, due to the enrichment of ARGs and ARB in the biofilms attached to the active carbon and pipe wall. Besides, as for disinfection process, mechanisms of the inactivation of ARB and the promotion of conjugative transfer of ARGs under chlorine, ozone and UV disinfection were described in detail. Here we provide some theoretical support for future researches which aim at antibiotic resistance controlling in drinking water.展开更多
It is extremely important to analyze the contaminative behaviors of Perfluoroalkyl acids(PFAAs) due to their serious threats to urban environments which are closely related to humans. Current study aimed to explore th...It is extremely important to analyze the contaminative behaviors of Perfluoroalkyl acids(PFAAs) due to their serious threats to urban environments which are closely related to humans. Current study aimed to explore the distribution, source apportionment and ecological risk assessment of PFAAs in surface water from Shijiazhuang, China. The concentrations of ΣPFAAs ranged from 19.5 to 125.9 ng/L in the investigation area. Perfluorobutanesulfonic acid(PFBS) and perfluoropentanoic acid(PFPeA) were the predominant contaminants(mean value: 14.3 ng/L and 16.6 ng/L, respectively). The distribution of PFAAs according to geospatial analysis and hierarchical clustering analysis(HCA) showed that higher levels of ΣPFAAs were detected in the southern surface water of Shijiazhuang and there was a stepwise decrease from the wet season to the dry season. Furthermore, based on source apportionment,the dominant potential sources were found to be wastewater treatment plant(WWTP) effluents and industrial discharge. The risk quotients(RQs) revealed low ecological risks of all PFAAs for aquatic organisms in Shijiazhuang surface water. Collectively, this study provided basic data for regulatory strategies for controlling PFAA pollutions in urban surface water.展开更多
Radon levels were measured in 59 water samples of rural and urban places of Bangalore city following procedures of standardized techniques. Though water level of radon above 100 Bqll-1 of WHO is ascribed to causes of ...Radon levels were measured in 59 water samples of rural and urban places of Bangalore city following procedures of standardized techniques. Though water level of radon above 100 Bqll-1 of WHO is ascribed to causes of lung cancer and leukaemia, very low levels were found in different urban and rural places, but urban-rural gradient observed significantly higher urban levels than rural levels. Correlation between depth of water sampled and radon levels estimated indicates that in urban places, lower water depth is related to higher radon levels, while it is vice versa in rural. It is due to more water use for rural agriculture and more urban water pollution and granite quarries. In comparison to other countries, it is observed that water radon levels are at wide ranges from the lowest to the highest estimated with different techniques and differ due to types of water, soil, rocks and sampling season.展开更多
文摘The used water for human consumption must be free of microorganisms and chemicals that cause risk in the human health. In this study, water quality of 18 rural area of Abarkouh was determined and compared the conventional monitoring method (According to ISIR (Institute of Standards and Industrial Research of Iran), 1053 and 4208) and use of electronic system method (Patent in industrial property general office of Iran, 77815). Free chlorine monitoring and pH test done by health workers in the conventional method and the results will be sent to the Health Network monthly. Sampling for microbiological testing is done monthly based on population (According to ISIR, 4208). On the electronic system, the procedure is also done by health workers, but the result will be sent to the receiver device by using a cell phone. According to the chlorine test results if the free chlorine residual reported zero, microbiological sampling was done by a health expert. Finally, the number of chlorine test and microbiological sampling and the results of these experiments collected in the both methods and recorded in SPSS 22 then were analyzed by using chi-square test and Fisher exact test. The result of microbiological experiments shows that the sampling rate decreased 29% in using of electronic system method in comparison to the conventional monitoring method while the number of microbial defect detection increased 19% in drinking water networks monitoring by electronic system. Using of electronic system monitoring can reduce the rate and cost of microbiological sampling and its experiments and increase accuracy of these tests, in this way it will increase the quality and safety of drinking water in distribution network in small and dispersed rural communities.
基金financially supported by State Environmental Protection Key Laboratory of Microorganism Application and Risk Control(No.MARC2012D010)National Water Special Program(No.2012ZX07404-002)International Science&Technology Cooperation Program of China(No.2010DFA91830)
文摘This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was observed among the different waters, with the predominance of Proteobacteria. While Verrucomicrobia was also a major phylum group in colored water. Limnobacter was the major genus group in colored water, but Undibacterium predominated in normal tap water. The coexistence of Limnobacter as well as Sediminibacterium and Aquobocterium might contribute to the formation of colored water.
文摘Introduction:The utilization of facility delivery is crucial to achieve sustainable development goals by reducing maternal and neonatal deaths.This study aimed to compare the distributions and determinants of childbirth in health facilities in urban and rural regions of Bangladesh.Methods:Cross-sectional data from the 2017-2018 Bangladesh Demographic and Health Survey were analyzed.Multilevel logistic regression was applied.Results:A total of 4751 women were included in the analyses.Only 50%of childbirths took place in health facilities,63.4%and 44.6%in urban and rural regions,respectively.Overall,the odds of the association between facility delivery and the studied factors were similar.Multiparous women had significantly lower odds of facility delivery in both rural(adjusted odds ratio[AOR]=0.3,95%confidence interval[CI]:0.2 to 0.5)and urban(AOR=0.2,95%CI:0.1 to 0.5)regions.In both regions,women with higher education levels,highly educated husbands,antenatal care(ANC),and higher wealth indexes had significantly higher odds of facility delivery.Conclusion:Several common associated factors were identified.However,differences were observed regarding distributions of these factors.The differences in facility delivery utilization could result from lower ANC utilization,socioeconomic status,and transportation facilities in rural regions than urban regions;therefore,improving these conditions could increase facility delivery in these regions.
基金Supported by Jiangxi Social Sciences Project(08SH035)Key Project of National Social Sciences Fund(08AZD005)
文摘From the situations about the incomes and life quality of the urban and rural residents,the thesis briefly introduces the status quo of the urban-rural income gap and explores the impact of the income gap on social economy:firstly,it hampers economic development;secondly,it is detrimental to the social development.Then the thesis analyzes the role of a sound social security in narrowing urban-rural income gap:at first,it broadens the institutional environment of improving the agricultural efficiency;secondly,it eliminates the uncertainties influencing the farmers' income;thirdly,it improves the farmers' capacity to increase income;at last,it enhances the farmers' consciousness of wealth.Next the thesis inquires into the problems existing in the system of rural social security:the first problem is more obviously fragmented system;the second is inadequate security projects and narrower coverage;the third is an obvious lack of equality in urban and rural security;the fourth is even less sound management system;the last is the lagging of legislation.Afterwards the thesis proposes the countermeasures and suggestions to improve the system of rural social security and narrow urban-rural income gap:firstly,to integrate the social security system in rural areas;secondly,to perfect security projects and enhance the security system;thirdly,to integrate the administrative management of social security;at last,to enforce the legal system.
文摘The aim of this study is to determine the types of heavy metals frequently present in Makkah wells and the possible environmental causes of their distribution and accumulation. Makkah lies in a mountain range dominated by different types of rocks from the Precambrian and Lower Paleozoic eras, as well as subordinate sedimentary rocks and basaltic lava flow from the Tertiary and Quaternary periods. Natural contaminants in Makkah wells water can be attributed to the unique location. Many epidemiological studies have identified associations between the ingestion of wells water contaminated with heavy metals and increased risk of some illnesses. This study presents exclusive information on the levels and distribution of 9 heavy metals—arsenic, barium, cadmium, chromium, cobalt, copper, lead, mercury, and selenium—in the wells water in various rural and urban areas of Makkah city. These naturally occurring elements are considered significant markers of water purity. More than 160 wells were involved in this three-year investigation. Water samples were collected during different seasons in order to assess any changes in the distribution and concentration of these heavy metals throughout the year. The collected water samples were filtered and digested before analysis using inductively coupled plasma mass spectrometry (ICP/MS). We found the following sequence of concentrations of heavy metals in the studied wells: Ba > Se >Cr > As > Co > Cu> Hg > Pb > Cd. Arsenic, barium, chromium, and selenium were the most abundant contaminants in the wells studied. The concentrations of the other heavy metals ranged from non-detectable to 3 μg/L. Although low, these values are also reported in comparisons with the local and international strict values and standards which govern the maximum contaminant levels permitted for long-term daily consumption.
基金National Social Science Foundation of China(No.20BYY045).
文摘The population migration in Hubei Province was frequent in history,accompanied by the migration of surnames,so it is important to study their population surnames.We take Xiantao City as an example to explore the isonymic structure of small and medium-sized cities in Hubei.The surname distributions of 223327 residents registered in 2013 were analyzed in 5 towns and 105 villages of Xiantao.The number of different surnames found was 422.As for surnames,theα-value reflects the influence of ethnic composition on the abundance of surnames.The correlation between the isonymic distance and the geographic distance between villages was calculated and indicated that Euclidean distance was weakly correlated with the geographic distance(r=0.177±0.012),and the isonymic distance increased with the geographical distance.Furthermore,the dendrogram and PCA built from the matrix of Euclidean distances between villages identified a main surname differentiation between the urban and rural areas.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3202002)the National Natural Science Foundation of China(Grant Nos.52025092,52209087 and 52379065).
文摘Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.
基金supported by the National Natural Science Foundation of China(Nos.52270072,4222780043)。
文摘Azole fungicides(AFs)play an important role in the prevention and treatment of fungal diseases in agricultural crops.However,limited studies are addressing the fate and ecological risk of AFs in the urban water cycle at a large watershed scale.To address this gap,we investigated the spatiotemporal distribution and ecological risk of twenty AFs in the lower reaches of the Yangtze River across four seasons.Carbendazim(CBA),tebuconazole(TBA),tricyclazole(TCA),and propiconazole(PPA)were found to be the dominant compounds.Their highest concentrations were measured in January(188.3 ng/L),and November(2197.1 ng/L),July(162.0 ng/L),and November(1801.9 ng/L),respectively.The comparison between wastewater treatment plants(WWTPs)effluents and surface water suggested that industrial WWTPs are major sources of AFs in the Yangtze River.In particular,TBA and PPA were found to be the most recalcitrant AFs in industrial WWTPs,while difenoconazole(DFA)was found to be the most potent pollutant in municipal WWTPs,with an average removal rate of less than60%.The average risk quotient(RQ)for the entire AFs was 6.45 in the fall,which was higher than in January(0.98),April(0.61),and July(0.40).This indicates that AFs in surface water posed higher environmental risks during the dry season.Additionally,the exposure risk of AFs via drinking water for sensitive populations deserves more attention.This study provides benchmark data on the occurrence of AFs in the lower reaches of the Yangtze River,and offers suggestions for better reduction of AFs.
文摘Antibiotic resistance in aquatic environment has become an important pollution problem worldwide. In recent years, much attention was paid to antibiotic resistance in urban drinking water systems due to its close relationship with the biosafety of drinking water. This review was focused on the mechanisms of antibiotic resistance, as well as the presence, dissemination and removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the urban drinking water system. First, the presence of ARB and ARGs in the drinking water source was discussed. The variation of concentration of ARGs and ARB during coagulation, sedimentation and filtration process were provided subsequently, in which filtration was proved to be a promising technology to remove ARGs. However, biological activated carbon (BAC) process and drinking water distribution systems (DWDSs) could be incubators which promote the antibiotic resistance, due to the enrichment of ARGs and ARB in the biofilms attached to the active carbon and pipe wall. Besides, as for disinfection process, mechanisms of the inactivation of ARB and the promotion of conjugative transfer of ARGs under chlorine, ozone and UV disinfection were described in detail. Here we provide some theoretical support for future researches which aim at antibiotic resistance controlling in drinking water.
基金supported by the National Natural Science Foundation of China (Nos. 41907321, 21777182)the Natural Science Foundation of Hebei Province (No. B2019208273)State Key Laboratory of Environmental Chemistry and Ecotoxicology, RCEES, Chinese Academy of Sciences (No. KF2018-17)。
文摘It is extremely important to analyze the contaminative behaviors of Perfluoroalkyl acids(PFAAs) due to their serious threats to urban environments which are closely related to humans. Current study aimed to explore the distribution, source apportionment and ecological risk assessment of PFAAs in surface water from Shijiazhuang, China. The concentrations of ΣPFAAs ranged from 19.5 to 125.9 ng/L in the investigation area. Perfluorobutanesulfonic acid(PFBS) and perfluoropentanoic acid(PFPeA) were the predominant contaminants(mean value: 14.3 ng/L and 16.6 ng/L, respectively). The distribution of PFAAs according to geospatial analysis and hierarchical clustering analysis(HCA) showed that higher levels of ΣPFAAs were detected in the southern surface water of Shijiazhuang and there was a stepwise decrease from the wet season to the dry season. Furthermore, based on source apportionment,the dominant potential sources were found to be wastewater treatment plant(WWTP) effluents and industrial discharge. The risk quotients(RQs) revealed low ecological risks of all PFAAs for aquatic organisms in Shijiazhuang surface water. Collectively, this study provided basic data for regulatory strategies for controlling PFAA pollutions in urban surface water.
文摘Radon levels were measured in 59 water samples of rural and urban places of Bangalore city following procedures of standardized techniques. Though water level of radon above 100 Bqll-1 of WHO is ascribed to causes of lung cancer and leukaemia, very low levels were found in different urban and rural places, but urban-rural gradient observed significantly higher urban levels than rural levels. Correlation between depth of water sampled and radon levels estimated indicates that in urban places, lower water depth is related to higher radon levels, while it is vice versa in rural. It is due to more water use for rural agriculture and more urban water pollution and granite quarries. In comparison to other countries, it is observed that water radon levels are at wide ranges from the lowest to the highest estimated with different techniques and differ due to types of water, soil, rocks and sampling season.