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1.
Rev Environ Contam Toxicol ; 251: 1-24, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31011831

RESUMO

Heavy metal pollution in surface water is a global environmental problem. This study analyzed the trends, health risks, and sources of eight dissolved heavy metal species in river and lake water across five continents (Africa, Asia, Europe, North America, and South America; Oceania was excluded owing to a lack of data) for the period 1970-2017. We wanted to assess the effects of various implemented countermeasures to pollution and to determine those that could be adopted worldwide. Collectively, the water system showed increasing trends for Cd, Cr, Cu, Ni, Mn, and Fe and decreasing trends for Pb and Zn. The mean dissolved concentrations of most heavy metals were highest in Asia and lowest in Europe. Most heavy metals had low non-carcinogenic risks over this period. The cancer risks associated with Pb were lower than the hazardous level on all five continents over the five decades, whereas the cancer risks related to Cr exceeded the hazardous level in the 1970s, 2000s, and 2010s, and in Africa, Asia, and North America over the entire period. Mining and manufacturing were consistently found to be critical sources of metal pollution from 1970 to 2017. However, the heavy metal sources differed significantly by continent, with waste discharge and rock weathering dominant in Africa; mining and manufacturing, along with rock weathering, are dominant in Asia and South America; fertilizer and pesticide use, along with rock weathering, are dominant in North America; and mining and manufacturing, waste discharge, and rock weathering are dominant in Europe. Global trends in the metal loadings in water and in relevant pollution-control measures suggest that countermeasures in Europe have successfully controlled heavy metal pollution. The successful measures include implementing rigorous standards for metal emissions, limiting the metal concentrations in products, and rigorously treating metal-contaminated waste. Therefore, the measures implemented in Europe should be extended worldwide to treat heavy metal pollution in water.


Assuntos
Exposição Ambiental/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Humanos , Lagos , Rios
2.
Sci Total Environ ; 689: 1125-1132, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31466152

RESUMO

Pollution by heavy metals and metalloids is detrimental to human health due to their toxic, genotoxic, and carcinogenic effects. The traditional approach to assess the extent of environmental and occupational exposures of metals is human biomonitoring (HBM). This method has several limitations, including invasiveness, sampling bias, cost- and time-intensiveness, and ethical issues. This suggests the need for a more robust, non-invasive, epidemiological tool for assessment of exposure to metals and their public health effects. Recently, wastewater-based epidemiology (WBE) has been suggested and utilized as a novel approach to accurately determine the extent of exposure to multiple substances on the population level. We suggest the potential application of WBE to the study of metal exposure on the population level, including possible biomarkers for wastewater analysis of 10 metals belonging to three categories according to health effects and nutritional benefits, and its public health implications. Similar to previous studies of exposure to regulated or illegal drugs, unregulated legal substances, and pesticides, WBE can be applied to the study of metal exposure in a given community. Parental substance biomarkers (PSBs), metabolic substance biomarkers (MSBs), and non-substance biomarkers (NSBs) of 10 common metals are available for consideration in wastewater analysis. The use of WBE would allow for the interpretation of the relationship between metal exposure and population health, reveal synergistic effects of different health factors, and model public health risks under different scenarios.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Metais Pesados/análise , Águas Residuárias/química , Poluição Química da Água/estatística & dados numéricos , Monitoramento Ambiental , Humanos , Medição de Risco , Águas Residuárias/estatística & dados numéricos , Poluentes Químicos da Água/análise
3.
Chemosphere ; 232: 152-163, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31154175

RESUMO

Agriculture is considered as the main source of water contamination by pesticides. However, food packaging or processing industries are also recognised as relevant point sources of contamination by these compounds, not yet investigated in depth. The objective of this work has been to improve current knowledge about the presence and concentration of pesticides in the effluent of a food processing industry, as well as to investigate their main transformation products (TPs). An analytical strategy combining target and suspect analysis has been applied to provide an evaluation of the effluents. The methodology involves solid-phase extraction (SPE) of wastewater samples followed by (i) liquid chromatography quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for quantitative target analysis and (ii) liquid chromatography coupled to quadrupole-time-of-flight high resolution mass spectrometry (LC-QTOF-HRMS) to identify non-target pesticides and possible TPs. The results revealed the presence of 17 of the target pesticides analysed and 3 additional ones as a result of the suspect screening performed by HRMS. The TPs were investigated for the pesticides found at the highest concentrations: imazalil (7038-19802 ng/L), pyrimethanil (744-9591 ng/L) and thiabendazole (341-926 ng/L). Up to 14 TPs could be tentatively identified, demonstrating the relevance of this type of studies. These data provide a better understanding of the occurrence of pesticides and their TPs in agro-food industrial effluents.


Assuntos
Praguicidas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Agricultura , Cromatografia Líquida/métodos , Monitoramento Ambiental , Indústria Alimentícia , Indústria de Processamento de Alimentos , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos , Tiabendazol/análise , Águas Residuárias/análise , Poluição Química da Água/estatística & dados numéricos
4.
Chemosphere ; 231: 546-561, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31151015

RESUMO

The present study evaluated the ecological and human health risk associated with concentrations of legacy organochlorine pesticide residues in Ikpoba River, a major River in the heart of Benin City, a Nigerian urban town located in Edo State. Standard methods were used to collect, extract and analyze samples, while risk assessment was carried out using standard models and indices. Results showed varying pesticide concentrations in both sediment and water samples with α-HCH (0.24 ±â€¯0.11 µg L-l), predominant in water, whereas dieldrin (0.99 ±â€¯0.33 µg kg-l) was the highest concentration in sediment. Compared to the Sediment Quality Guidelines (SQGs), this study concentrations of pesticides in sediments were below the values of effect range medium, effect range low, probable effect level and threshold effects level, suggesting low environmental hazard to benthic organisms. However, on exposure to contaminated sediments, probabilistic ecological risk assessment using Monte Carlo techniques showed potential risk to algae, daphnid and fish. Human health risk estimates using dermal and ingestion exposure deterministic and probabilistic routes revealed a potential risk to adults and children exposed to contaminated water and sediment. Estimates for detected pesticides exceeded the threshold level, indicating potential cancer effects for both children and adults who rely on the resources of the river. This study highlights the need for concerted efforts to curb the threat of pesticides and other contaminants in the aquatic environment by all relevant stakeholders in Nigeria and Africa as a whole.


Assuntos
Ecossistema , Monitoramento Ambiental , Resíduos de Praguicidas/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Animais , Dieldrin , Sedimentos Geológicos/química , Hexaclorocicloexano , Hidrocarbonetos Clorados/análise , Nigéria , Praguicidas/análise , Medição de Risco , Rios/química
5.
Sci Total Environ ; 681: 497-502, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31121400

RESUMO

Medical Geology is a growing field in Uruguay and the groundwater quality has been the focus of multiple studies, being As levels one of its main concerns. The aim of this study was the application of analytical methodologies for the assessment of total arsenic and inorganic arsenic species, fluoride, iron, manganese and sulfate in groundwater samples from private wells, used for human consumption, and to evaluate the possible correlations among these parameters. The accuracy of the methods was ensured by using certified reference materials. A total of 48 groundwater samples from Uruguay were analyzed. The concentration ranges found were: tAs (1.72-120.48) µg L-1, F- (0.024-1.528) mg L-1, Fe (0.62-211.38) µg L-1 and Mn (0.11-8.705) µg L-1. Almost half of the samples presented tAs concentration levels above those recommended by WHO for drinking water (10 µg L-1), with the corresponding risks for human health. Results showed higher As(V) levels in the samples, which is in agreement with the oxidant conditions of the wells. Pearson correlations were performed, resulting in strong positive correlations for As/F-, As(V)/F- and As(V)/SO42-. As levels in groundwater and its relationship with other inorganic parameters, should be deeply studied to prevent long-term health effects.


Assuntos
Arsênico/análise , Exposição Dietética/estatística & dados numéricos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Exposição Dietética/análise , Monitoramento Ambiental , Fluoretos , Água Subterrânea , Humanos , Ferro , Manganês , Sulfatos , Uruguai , Abastecimento de Água
6.
Sci Total Environ ; 659: 1577-1584, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096367

RESUMO

The objective of this paper is to determine whether deep tubewells installed through arsenic mitigation efforts in rural Bangladesh provide better drinking water microbial quality compared to shallow tubewells. We conducted a stratified random cross-sectional survey of 484 households to assess microbial contamination of deep tubewell water at source and at point of use (POU) compared to shallow tubewell water using the Compartment Bag Test. In addition, we measured storage time, distance, travel time and ownership status among both sets of users to assess deep tubewell efficacy and under what conditions they offer poorer or better water quality. Differences in tubewell characteristics were compared using non-parametric Mann-Whitney U tests and two-proportion Z-tests. Prevalence ratios of microbial contamination stratified by water quality, storage time and distance to tubewells and ownership were estimated using unadjusted Mantel-Haenszel tests. There was no significant difference in microbial contamination between shallow and deep tubewells at source. The presence of POU water microbial contamination in storage containers in deep tubewell households was 1.11 times the prevalence in shallow tubewell storage containers (95% CI = 0.97-1.27). Deep tubewell users stored water longer and walked significantly farther to obtain water compared to shallow tubewell users. Among deep tubewell households, those residing farther away from the source were 1.24 times as likely to drink contaminated water from storage containers compared to those located nearby (95% CI = 1.04-1.48). Our findings suggest that deep tubewells have comparable water quality to shallow tubewells at source, but increasing distance from the household exacerbates risk of microbial contamination at POU.


Assuntos
Arsênico/análise , Monitoramento Ambiental , Microbiologia da Água , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Poços de Água , Bangladesh/epidemiologia , Estudos Transversais , Água Subterrânea , Humanos , População Rural , Poluição Química da Água/prevenção & controle , Qualidade da Água , Abastecimento de Água/estatística & dados numéricos
7.
Environ Monit Assess ; 191(6): 365, 2019 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-31089888

RESUMO

Accurately measuring and estimating trends and variations in nutrient levels is a significant part of managing emerging eutrophic lakes in developing countries. This study developed an integrated approach containing Seasonal Trend Decomposition using Loess (STL) and a dynamic nonlinear autoregressive model with exogenous input (NARX) network to decompose and estimate the nutrient concentrations in Lake Erhai, a preliminary eutrophic lake in China. The STL decomposition results indicated that total nitrogen (TN) concentration of Lake Erhai progressively descended from 2006 to 2014, except for some agriculture area. The total phosphorus (TP) concentration showed an increasing trend from 2006 to 2013 and then decreased in 2014, but in the area near the tourist attractions, TP increased continuously from 2011 to 2014. Seasonal variations in TN and TP indicated that the lowest water quality of Lake Erhai occurred from July to October. Based on results obtained with STL, TP was selected as the sensitive parameter, as it showed a significant deterioration trend, and the area near the tourist attractions was selected as the sensitive area. Three variables (DO, pH, and water temperature) were selected as input parameters to estimate TP using the dynamic NARX model. The NARX modeling results demonstrated that it can accurately estimate TP concentrations with low root-mean-square error (0.0071 mg/L). The study establishes a new approach to better understand trends and variations in nutrient levels and to better refine estimates by identifying more easily accessible physical parameters in a preliminary eutrophic lake.


Assuntos
Monitoramento Ambiental/métodos , Eutrofização , Modelos Químicos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Agricultura , China , Lagos/química , Nitrogênio/análise , Fósforo/análise , Estações do Ano , Temperatura Ambiente , Qualidade da Água
8.
Sci Total Environ ; 676: 222-230, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31048154

RESUMO

The presence of active pharmaceutical ingredients (APIs) in the environment is of growing concern and effluents from wastewater treatment works (WwTWs) are one of the major sources. This research combines the outputs of a multimillion pound UK program of work to evaluate the fate of APIs in the wastewater treatment process. A combination of analysis of measured data and modelling has been applied to 18 APIs, representing a wide range of medicinal application and physico-chemical characteristics. Some isomers (for atorvastatin) and metabolites (for sertraline, carbamazepine and erythromycin) were also included. High variability was observed between removal rates for individual APIs between WwTW, which after statistical analysis could not be explained by the nominal WwTW process (e.g. activated sludge or trickling filter). Nor was there a clear relationship between API removal and physico-chemical parameters such as pKa, charge or log Kow. A publically available sewage process model, SimpleTreat 4.0 which has been rigorously validated and is now being used for exposure assessment with REACH legislation for organic chemicals and within the Biocidal Products Regulation by the European Medicines Agency for APIs, was used to estimate removal rates with which to compare with measured data. SimpleTreat provided estimates of removal rates within ±30% of observed values for the majority of the APIs measured, with the use of readily available WwTW specific parameters such as flow, total suspended solids and BOD data. The data and correlations provided in this study provide support for any future considerations regarding the management of API discharge to the aquatic environment.


Assuntos
Preparações Farmacêuticas/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Monitoramento Ambiental , Águas Residuárias/química
9.
Sci Total Environ ; 676: 756-766, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31055207

RESUMO

An overview about the presence of arsenic (As) in groundwaters of Argentina, made by a transdisciplinary group of experts is presented. Aspects on As occurrence, effects of As on human health, regulations regarding the maximum allowable amount of As in drinking water as well as bottled water, and analytical techniques for As determination are presented. The most affected region in Argentina is the Chaco-Pampean plain, covering around 10 million km2, where approximately 88% of 86 groundwater samples collected in 2007 exceeded the World Health Organization (WHO) guideline value. In the Salí river basin, As concentrations ranged from 11.4 to 1660 µg/L, with 100% of the samples above the WHO guideline value. In the Argentine Altiplano (Puna) and Subandean valleys, 61% of 62 samples collected from surface and groundwaters exceeded the WHO limit. Thus, it can be estimated that, at present, the population at risk in Argentina reaches around four million people. Pathologies derived from the chronic consumption of As, the metabolism of As in the human body and the effects of the different As chemical forms, gathered under the name HACRE (hidroarsenicismo crónico regional endémico in Spanish, for chronic regional endemic hydroarsenicism) are described. Regarding the regulations, the 10 µg/L limit recommended by the WHO and the United States Environmental Protection Agency has been incorporated in the Argentine Food Code, but the application is still on hold. In addition, there is disparity regarding the maximal admitted values in several provinces. Considerations about the As concentrations in bottled water are also presented. A survey indicates that there are several Argentine laboratories with the suitable equipment for As determination at 10 µg/L, although 66% of them are concentrated in Buenos Aires City, and in the Santa Fe, Córdoba and Buenos Aires provinces. Conclusions and recommendations of this first part are provided.


Assuntos
Arsênico/análise , Exposição Ambiental/estatística & dados numéricos , Política Ambiental/legislação & jurisprudência , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Argentina , Exposição Ambiental/análise , Poluição Química da Água/legislação & jurisprudência , Abastecimento de Água/legislação & jurisprudência , Abastecimento de Água/estatística & dados numéricos
10.
Environ Monit Assess ; 191(6): 318, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31044287

RESUMO

The representativeness of aquatic ecosystem monitoring and the precision of the assessment results are of high importance when implementing the EU's Water Framework Directive that aims to secure a good status of waterbodies in Europe. However, adapting monitoring designs to answer the objectives and allocating the sampling resources effectively are seldom practiced. Here, we present a practical solution how the sampling effort could be re-allocated without decreasing the precision and confidence of status class assignment. For demonstrating this, we used a large data set of 272 intensively monitored Finnish lake, coastal, and river waterbodies utilizing an existing framework for quantifying the uncertainties in the status class estimation. We estimated the temporal and spatial variance components, as well as the effect of sampling allocation to the precision and confidence of chlorophyll-a and total phosphorus. Our results suggest that almost 70% of the lake and coastal waterbodies, and 27% of the river waterbodies, were classified without sufficient confidence in these variables. On the other hand, many of the waterbodies produced unnecessary precise metric means. Thus, reallocation of sampling effort is needed. Our results show that, even though the studied variables are among the most monitored status metrics, the unexplained variation is still high. Combining multiple data sets and using fixed covariates would improve the modeling performance. Our study highlights that ongoing monitoring programs should be evaluated more systematically, and the information from the statistical uncertainty analysis should be brought concretely to the decision-making process.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Clorofila/análogos & derivados , Clorofila/análise , Ecossistema , Monitoramento Ambiental/estatística & dados numéricos , Europa (Continente) , Finlândia , Lagos , Fósforo/análise , Rios , Qualidade da Água
11.
Environ Pollut ; 250: 511-519, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31026698

RESUMO

Monitoring spatial and temporal chemical status of water bodies is crucial to assist environmental policy, identify the chemical fingerprints, and further reduce the source orientated pollutants. Elbe River is one of the major rivers affected by anthropogenic activities in vicinity countries. This study assessed the spatiotemporal changes in response to source shift of Cd, Cu, Ni, Pb, and Zn in the suspended particulate matter (SPM) at upstream, midstream, and downstream of the Elbe River reach in Saxony state, Germany. The average contents of trace metals in SPM was found in the order of Zn (676 mg/kg) ¼ Pb (79 mg/kg) > Cu (74 mg/kg) > Ni (48 mg/kg) ¼ Cd (3.2 mg/kg). According to the Mann-Kendall trend test, Cd, Cu, Pb, and Zn showed significant declines over 1998-2016. The results of source apportionment indicate industrial, urban, natural, and historical mining sources influencing the metal contents in the Elbe River of Saxony. The contributions of industrial and urban pollution decreased by 58.2% from 1998 to 2007 to 2008-2016. The contribution of the natural source was steady over the last two decades.


Assuntos
Monitoramento Ambiental , Rios/química , Oligoelementos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Poluição Ambiental/análise , Alemanha , Metais/análise , Metais Pesados/análise , Mineração , Material Particulado/análise
12.
Water Sci Technol ; 79(3): 544-555, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30924809

RESUMO

Total phosphorus (TP) standards for lakes differ from those for rivers in GB3838-2002. This disjunction may lead to the failure of lake-water quality improvement plans that control nutrient inputs from inflow rivers. With monthly monitoring data for the period 2009-2015, Northwest Lake Taihu was regarded as a case study and the BATHTUB model was utilised to simulate the correspondence between concentrations of TP in the lake and in its inflow rivers. A control plan for TP in Northwest Lake Taihu's inflow rivers is proposed. To guarantee the fulfillment of the control goals of TP in the lake, concentration of TP in the inflow rivers of North Zone, Zhushan Bay, Meiliang Bay and Gonghu Bay should be reduced by 50%, 58%, 18% and 11%, respectively, and TP flux loads should be maintained under 227.35, 173.39, 113.69 and 90.62 ta-1, respectively. Meanwhile, total TP influxes from Northwest Lake Taihu should be maintained under 604.63 ta-1. A control plan that is more restrictive than GB3838-2002 should be proposed to address the TP pollution of the lake. This research provides the foundation for quantifying reduction of the nutrient loading from the catchment and for maintaining Lake Taihu and other typical eutrophic lakes.


Assuntos
Modelos Estatísticos , Fósforo/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , China , Monitoramento Ambiental , Lagos/química , Controle de Qualidade , Rios , Qualidade da Água
13.
Water Sci Technol ; 79(2): 334-341, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30865604

RESUMO

China has achieved significant progress on wastewater treatment and aquatic environmental protection. However, leakage (in- and exfiltration) of sewer systems is still an issue. By using the statistical data of water and wastewater in 2016 in China, and the person loads (PLs) of water and wastewater in Singapore, the leakage fractions of hydraulic flow, organic carbon (COD), nitrogen (N) and phosphorus (P) mass loading, and in-sewer COD biological removal in the sewer systems of China (except Hong Kong, Macau and Taiwan), Shanghai, Guangzhou and Beijing were reported for the first time. The fractions of hydraulic flow infiltration (13%, Shanghai and Guangzhou) and exfiltration (39%, China) were calculated. Except Beijing, whose sewer networks are under appropriate management with small leakage fractions, the exfiltration fractions of COD (including in-sewer biological COD removal) ranged from 41% (Shanghai) to 66% (China) and averaged 55%; N ranged from 18% (Shanghai) to 48% (China) and averaged 33%; and P ranged from 23% (Shanghai and Guangzhou) to 44% (China) and averaged 30%. The exfiltrated sewage, COD, N and P not only wastes resources, but also contaminates the aquatic environment (especially groundwater) and contributes to 'black and odorous water bodies'. In- and exfiltration in the sewer network leads to low influent COD concentration, C/N ratio and high inorganic solids and inert particulate COD concentrations of many municipal wastewater treatment plants (WWTPs) causing high cost for nutrient removal, poor resource recovery, additional reactor/settler volume requirement and other operational problems. Therefore, tackling sewer leakage is of primary importance to today's environment in China. Recommendations for the inspection of sewer systems and the rehabilitation of damaged sewers as well as the development of design and operation guidelines of municipal WWTPs tailored to the specific local sewage characteristics and other conditions are proposed.


Assuntos
Esgotos , Eliminação de Resíduos Líquidos/métodos , Poluição Química da Água/estatística & dados numéricos , China , Drenagem Sanitária , Odorantes , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/estatística & dados numéricos , Águas Residuárias/análise , Águas Residuárias/química , Poluição Química da Água/análise , Poluição Química da Água/economia
14.
Sci Total Environ ; 664: 474-486, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30759411

RESUMO

Although polycyclic aromatic hydrocarbons (PAHs) are toxic pollutants for which some are known carcinogens, there is limited information on the cancer risk such substances pose to the population via marine sediments, despite a significant part of the world's food supply being derived from the coastal environment. This study was conducted in a heavily industrialized and urbanized coastal area, in Trinidad. PAHs were quantified in sediments during the dry and wet seasons and were observed to be significantly higher in the wet season compared to the dry season. Also emerging from this study is that PAH levels were lower, in the areas where natural gas is the dominant energy source for industries, compared with those areas where crude oil-based fossil fuel is predominantly used. Perylene levels were demonstrated to be of biogenic origin near the protected wetland area. It was observed that nearshore sediment PAHs concentrations were higher than offshore levels. The sources of PAHs, identified by Positive Matrix Factorization (PMF) in the marine sediments, were vehicular combustion of gasoline and diesel, biomass burning, industrial combustion and oil spills. The mean Incremental Lifetime Cancer Risks (ILCR) due to fish consumption from this region during the dry and wet seasons was >1 × 10-4, indicating a high cancer risk to the human population. The annual non-cancer risk (HQ) was high >1 at the 90th percentile level with an adverse risk to about 14% of the population. These results can be utilized for developing an effective environmental management policy for coastal areas in Trinidad and the wider Caribbean region, given that much of the islands' populations depend on the coastal regions for seafood. In addition, these results may assist in boosting current efforts of policymakers, towards phasing out crude oil-based fossil fuels for cleaner energy sources, such as compressed natural gas.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Áreas Alagadas , Região do Caribe , Monitoramento Ambiental , Sedimentos Geológicos , Neoplasias
15.
Sci Total Environ ; 664: 865-873, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-30769310

RESUMO

Intensive agriculture and rapid urbanization have increased nutrient inputs to Lake Taihu in recent decades. This resulted in eutrophication. We aim to better understand the sources of river export of total dissolved nitrogen (TDN) and phosphorus (TDP) to Lake Taihu in relation to critical nutrient loads. We implemented the MARINA-Lake (Model to Assess River Inputs of Nutrients to seAs) model for Lake Taihu. The MARINA-Lake model quantifies river export of dissolved inorganic and organic N and P to the lake by source from sub-basins. Results from the PCLake model are used to identify to what extent river export of nutrients exceeds critical loads. We calculate that rivers exported 61 kton of TDN and 2 kton of TDP to Lake Taihu in 2012. More than half of these nutrients were from human activities (e.g., agriculture, urbanization) in Sub-basins I (north) and IV (south). Most of the nutrients were in dissolved inorganic forms. Diffuse sources contributed 90% to river export of TDN with a relatively large share of synthetic fertilizers. Point sources contributed 52% to river export of TDP with a relatively large share of sewage systems. The relative shares of diffuse and point sources varied greatly among nutrient forms and sub-basins. To meet critical loads, river export of TDN and TDP needs to be reduced by 46-92%, depending on the desired level of chlorophyll-a. There are different opportunities to meet the critical loads. Reducing N inputs from synthetic fertilizers and P from sewage systems may be sufficient to meet the least strict critical loads. A combination of reductions in diffuse and point sources is needed to meet the most strict critical loads. Combining improved nutrient use efficiencies and best available technologies in wastewater treatment may be an effective opportunity. Our study can support the formulation of effective solutions for lake restoration.


Assuntos
Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/prevenção & controle , China , Eutrofização , Lagos/química , Poluição Química da Água/estatística & dados numéricos
16.
Environ Monit Assess ; 191(3): 160, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771003

RESUMO

The Arabian Gulf is considered as a hub for global oil industry. Thus the Arabian Gulf marine environment is under permanent threat from oil spills due to oil exploitation, production, and transportation. Oil pollution poses adverse effects on marine environment, society, and economy. Oil spill incidents that occurred in Bahrain caused damage to marine environment and threatened the vital coastal facilities along the coastline of Bahrain. This study determined the exposure levels of coastal facilities in Bahrain to oil spills. The General NOAA Operational Modeling Environment (GNOME) model was validated and applied to hypothetical oil spill scenarios. The modeling results showed that the coastal facilities on the north-eastern coastline are more probable to be hit by oil spills, while those on the northern coastline are susceptible to receive more quantity of oil. The time required for oil to reach the western coastline is shorter compared to the other coastlines. The modeling outcomes can be utilized in contingency planning, setting the protection priorities and allocation and mobilization of response resources in both governmental and private sectors. The implications of the present study could be applied on a regional scale to ensure an integrated response to combat and or minimize oil pollution in the Arabian Gulf.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Poluição por Petróleo/estatística & dados numéricos , Poluição Química da Água/estatística & dados numéricos , Barein , Monitoramento Ambiental/métodos
17.
Environ Monit Assess ; 191(3): 141, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30734086

RESUMO

Preoxidation is an important unit process which can partially remove organic and microbial contaminations. Due to the high concentrations of organic matter entering the water treatment plant, originating from surface water resources, preoxidation by using chlorinated compounds may increase the possibility of trihalomethane (THM) formation. Therefore, in order to reduce the concentration of THMs, different alternatives such as injection of potassium permanganate are utilized. The present study attempts to investigate the efficiency of the microbial removal from raw water entering the water treatment plant No. 1 in Mashhad, Iran, through various doses of potassium permanganate. Then, an examination of the predictive models is done in order to indicate the residual Escherichia coli and total coliform resulted from injecting the potassium permanganate. Finally, the coefficients of the proposed models were optimized using the genetic algorithm. The results of the study show that 0.5 mg L-1 of potassium permanganate would remove 50% of total coliform as well as 80% of Escherichia coli in the studied water treatment plant. Also, assessing the performance of different models in predicting the residual microbial concentration after injection of potassium permanganate suggests the Gaussian model as the one resulting the highest conformity. Moreover, it can be concluded that employing smart models leads to an optimization of the injected potassium permanganate at the levels of 27% and 73.5%, for minimum and maximum states during different seasons of a year, respectively.


Assuntos
Modelos Teóricos , Permanganato de Potássio/metabolismo , Poluição Química da Água/estatística & dados numéricos , Purificação da Água/métodos , Biodegradação Ambiental , Monitoramento Ambiental , Irã (Geográfico) , Oxidantes , Oxirredução , Permanganato de Potássio/análise , Trialometanos , Água , Microbiologia da Água , Poluentes Químicos da Água/análise , Purificação da Água/estatística & dados numéricos
18.
Water Environ Res ; 91(4): 351-363, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30698906

RESUMO

Based on recent water quality data collected from 763 monitoring sections nationwide, this study examined the concentration of major pollutants in China's major rivers. A spatial autocorrelation analysis confirmed that river pollution was spatially uneven and clustered. While pollution of surface water was a nationwide concern, most serious water pollution happened in the Huai, Hai, Yellow, and Liao river Basins in Northern China. The results of the spatial regression analysis showed that GDP per capita, surface water stock, population, and economic structure were all significantly correlated with surface water pollution, with population having strongest impact, followed by level of economic development. By investigating the common characteristics shared by the "hotspot" cities where serious water pollution occurred, this study recommended a regional or basin approach to assessing water quality and controlling river pollution that cuts across jurisdiction boundaries. While China has made considerable progress in improving water productivity, there is still enormous potential in water conservation. It is also imperative to restructure local economy and develop water-efficient, less polluting industries and services. PRACTITIONER POINTS: River pollution in China was spatially uneven and clustered. Most serious water pollution happened in the Huai, Hai, Yellow, and Liao river basins in Northern China. GDP per capita, surface water stock, population, and economic structure correlated with surface water pollution, with population having strongest impact. A regional or basin approach was recommended to assess water quality and controlling river pollution across jurisdiction boundaries. It is also imperative to restructure local economy and develop water-efficient, less polluting industries and services.


Assuntos
Rios/química , Análise Espacial , Poluição Química da Água/estatística & dados numéricos , China , Meio Ambiente , Análise de Regressão , Fatores Socioeconômicos , Qualidade da Água
19.
Environ Monit Assess ; 191(2): 52, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30617634

RESUMO

Heavy metal pollution from untreated industrial wastewater has become a major concern to the environment and public health in many rapidly growing cities in low-income countries. Previous studies on heavy metals of urban wastewater systems have focused on long-term (weekly or seasonal) variations, while only few studies investigated short-term (daily) variation to capture potential bulk discharges. To monitor and enforce wastewater discharge regulations and reduce industrial pollution, a better understanding of the short-term variation of these pollutants and industrial discharge practices is needed. The aim of this study is to assess the daily variation of heavy metals and physicochemical parameters along the major urban wastewater system in Kampala, Uganda. Over 1 week, daily water samples were collected at 16 locations and analyzed for lead (Pb), mercury (Hg), copper (Cu), and chromium (Cr) and a range of physicochemical parameters. Additionally, 25 key informant interviews with industries were administered to investigate their potential to contaminate the environment. Among 78 water samples, 29 exceeded the national standards for Pb (> 0.1 mg/L) and one for Hg (> 0.01 mg/L). High daily variation and peak concentrations were detected which are likely due to industries retaining their effluents and discharging them irregularly. Although 24 industries used heavy metals in their manufacturing processes and are likely to discharge heavy metals, only ten industries had a wastewater treatment system in place. Our results show that repeated measurements of heavy metals over short time intervals are needed to capture their high daily variation in an urban wastewater system. Furthermore, there is an urgent need to register industries and to assess their effluent composition in order to select appropriate wastewater management measures.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Cromo , Cidades , Cobre , Poluentes Ambientais , Mercúrio , Uganda
20.
Environ Monit Assess ; 191(2): 53, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30617928

RESUMO

Globally, Chile is the second largest producer of mussels, with 99% of production concentrated in the inland sea of the Los Lagos Region, Southern Chile. This study reveals that seasons produce a drastic difference in the cadmium concentration (Cd) in marine mussels in bay, channel, and fjord ecosystems in this area. As the global mussel industry continues its rapid expansion, a complete understanding of cadmium pathways is critical in order to minimize the cadmium content in harvests. In this study, biweekly sampling was conducted in Chiloé (Southern Chile), during five consecutive seasons from June 2014 to November 2015. Cadmium in the soft tissues (ST) and in the content of the digestive gland (CDG) of Mytilus chilensis were investigated, in addition to resuspensions and seston to determine the effect of the seasons on metal bioassimilation capacity. In spring, the (Cd) between CDG and ST varied by approximately 2 mg Cd kg-1 dry mass (DM). In summer and autumn, the (Cd) in CDG increased from 3 to 6 mg Cd kg-1 while the (Cd) in ST decreased from 2.5 to 1.5 mg Cd kg-1 DM. The three ecosystems showed the same cadmium bioconcentration trends in all seasons, revealing coherent global trends. These findings should caution the industry and coastal populations about the seasonal variability and intensity of cadmium metal transfer to biofilters, especially because of the adverse effects of cadmium consumption on human health. Additionally, this study found that mussels in natural beds concentrate more Cd (> 1 mg Cd kg-1 DM) than in industrial facilities. Multiregression analysis showed and explained the cadmium in CDG for three ecosystems: channel (R2 0.9537), bay (R2 0.5962), and fjord (R2 0.4009). The independent variable nocturnal seston was able to explain the increase in cadmium.


Assuntos
Aquicultura , Cádmio/metabolismo , Monitoramento Ambiental , Mytilus/metabolismo , Poluentes Químicos da Água/metabolismo , Poluição Química da Água/estatística & dados numéricos , Animais , Cádmio/análise , Chile , Alimentos Marinhos/análise , Estações do Ano , Poluentes Químicos da Água/análise
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