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2.
Mar Pollut Bull ; 151: 110813, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056606

RESUMO

Turkey, with her two important straits, is geographically in the middle of one of the major transportation routes and will continue to face risks the oil tankers pose in those sensitive areas. This paper revisits the site of an oil tanker accident that occurred at the northern entrance of the Istanbul Strait in 1994. The aim of the study was to simulate the same accident in PISCES-II Simulator to compare the response actions of the time with the present capabilities. Effort is also made to understand how the negative impacts of an oil spill accident can be lessened. Therefore, the study is planned to set to cover two separate response scenarios for the identical oil spill incident, actually simulating the 1994 M/T Nassica accident. The results showed that oil pollution response in places with strong currents like Istanbul Strait needs special care to sea conditions as well as related assets.


Assuntos
Vazamento de Resíduos Químicos/estatística & dados numéricos , Poluição por Petróleo/estatística & dados numéricos , Poluição Química da Água/estatística & dados numéricos , Transportes , Turquia
3.
Mar Pollut Bull ; 151: 110820, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056613

RESUMO

This study evaluates the geographical distribution of Pb, Cd, Cr, Ni, Co, Cu, Zn, Mn and Fe in wild mussels Mytilus galloprovincialis as well as in associated suspended particulate matter (SPM) and sediments from the Algerian coast. The bioaccumulation (metal concentrations in tissue), bioavailability (metal indices) and bioconcentration of trace metals from the adjacent environment were assessed. The computed pollution load index (PLI) indicates that the sediments are not polluted by these metals, except for Zn which shows a moderate level of contamination. All the metals in SPM samples are in a 'safe range' with respect to the computed degree of contamination (DC < 2). The target hazard quotients (THQ) and the hazard index (HI) values indicate a risk level with Fe. However, the Cr measured in mussels is considered 'extreme', according to the consumption rate limit for mussels (CRlim) which limits their consumption to 0.5 kg/day.


Assuntos
Exposição Dietética/estatística & dados numéricos , Monitoramento Ambiental , Metais/análise , Poluentes Químicos da Água/análise , Animais , Bivalves , Ecossistema , Humanos , Metais Pesados , Medição de Risco , Oligoelementos , Poluição Química da Água/estatística & dados numéricos
4.
Chemosphere ; 248: 126015, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32032874

RESUMO

Sixteen polycyclic aromatic hydrocarbons (PAHs) in a sediment core from Dianchi Lake, southwest China, were analysed. The influence of changes in China's energy structure for 2-6 ringed PAHs was investigated to assess sources and the impact of socioeconomic development on temporal changes in concentrations. The concentration of the ΣPAH16 ranged from 746 to 2293 ng g-1. Prior to the 1960s relatively low concentrations of the ΣPAH16 and a larger proportion of 2-3-ring PAHs indicated that biomass combustion was the main source of PAHs. A rapid increase in the concentrations of 2-3 ring PAHs between 1975 and 2004 was attributed to population growth and coal consumption. A declining trend since 2004 was interpreted as being due to local changes in household energy usage. Increased concentrations of 4-ring PAH between 1975-2005 and 5-6-ring PAHs between the 1980s to 2004 showed correlations with increased coal consumption and the number of motor vehicles, respectively. These were caused by rapid urbanization and industrialization in the Dianchi watershed following the implementation of the Reform and Open Policy in 1978. A subsequent decline in the concentrations of 4-ring and 5-6-ring PAHs may have been due to decreased coal consumption and improvements in emission standards, respectively. Source apportionment by a PMF model revealed that coal combustion (29.2%), vehicle emissions (24.2%), petrogenic sources (21.8%), and biomass combustion (24.9%) were the sources of PAHs in the lake sediment core, and that coal combustion was the most important regional source of PAHs pollution.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Biomassa , China , Carvão Mineral/análise , Desenvolvimento Econômico , Poluição Ambiental/análise , Sedimentos Geológicos/química , Desenvolvimento Industrial , Lagos/química , Urbanização , Emissões de Veículos/análise
5.
Environ Pollut ; 258: 113688, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32004855

RESUMO

The automatic identification (location, segmentation, and classification) by UAV- based optical imaging of spills of transparent floating Hazardous and Noxious Substances (HNS) benefits the on-site response to spill incidents, but it is also challenging. With a focus on the on-site optical imaging of HNS, this study explores the potential of single spectral imaging for HNS identification using the Faster R-CNN architecture. Images at 365 nm (narrow UV band), blue channel images (visible broadband of ∼400-600 nm), and RGB images of typical HNS (benzene, xylene, and palm oil) in different scenarios were studied with and without Faster R-CNN. Faster R-CNN was applied to locate and classify the HNS spills. The segmentation using Faster R-CNN-based methods and the original masking methods, including Otsu, Max entropy, and the local fuzzy thresholding method (LFTM), were investigated to explore the optimal wavelength and corresponding image processing method for the optical imaging of HNS. We also compared the classification and segmentation results of this study with our previously published studies on multispectral and whole spectral images. The results demonstrated that single spectral UV imaging at 365 nm combined with Faster R-CNN has great potential for the automatic identification of transparent HNS floating on the surface of the water. RGB images and images using Faster R-CNN in the blue channel are capable of HNS segmentation.


Assuntos
Substâncias Perigosas/análise , Hidrocarbonetos/análise , Redes Neurais de Computação , Poluição Química da Água/análise , Poluição por Petróleo/análise , Análise Espectral
6.
PLoS One ; 15(1): e0227367, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31917823

RESUMO

Sediment profile and mud shrimp (Austinogebia edulis) from the coastal wetland of central Taiwan in 2017 and 2018 were analyzed for concentration, source, and composition of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbon (PAHs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs; DDT and HCB), and polychlorinated biphenyls (PCBs). Sediment profiling indicated PAH concentrations reaching 254.38 ng/g dw in areas near industrial areas and PAH concentrations of 41.8 and 58.42 ng/g dw in sampling areas further from industrial areas, suggesting that the determining factor for spatial distribution of POPs might be proximity to contaminant sources in industrial zones. Based on molecular indices, PAHs were substantially of both pyrolytic and petrogenic origins. The main sources for PCBs were Aroclor 1016 and 1260 and the congener BDE-209 was the dominant component among PBDE congeners. While we were unable to obtain live mud shrimp samples from the heavily contaminated areas, in samples from less contaminated areas, the risk assessment on mud shrimp still illustrated a borderline threat, with DDT concentrations almost reaching standardized values of Effects Range-Low (ERL). Bioaccumulation factors for DDTs and PCBs (17.33 and 54.59, respectively) were higher than other POPs in this study. Further study is essential to assess and understand the impact of these chemicals on the wetland ecosystem near this heavily industrialized area.


Assuntos
Decápodes/química , Sedimentos Geológicos/química , Hidrocarbonetos/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Animais , Monitoramento Ambiental , Taiwan , Poluição Química da Água , Áreas Alagadas
7.
Chemosphere ; 246: 125797, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31918104

RESUMO

In this review, we present comparative and comprehensive views on the foundations, potentials and limitations of the previously reported mathematical models for the estimation of the concentration of disinfection byproducts (DBPs) generated during the chlor(am)ination of water. To this end, DBPs models were divided into two major categories: static variable (SV) and dynamic variable (DV) or differential models. In SV models, variables remain in their original form throughout a chlor(am)ination modelling period while DV models consider the changes driven by a chlor(am)ination treatment as the variables. This classification and the comparative study of the two types of models led to a better understanding of the assumptions, potentials, and limitations of the existing DBP models. In opposition to several claims in the literature, certain DV models based on UV absorbance/fluorescence failed to selectively track the chromophores responsible for DBP formation. In this critical review, a conceptual model for the photophysics of dissolved organic matter (DOM) based on the theory of electron delocalization was proposed to explain some inconsistent spectroscopic properties of DOM following chlor(am)ination and several unique photophysical properties of DOM. New insights for the development and deployment of mathematical models were also provided to estimate DBPs in various settings.


Assuntos
Desinfetantes/análise , Monitoramento Ambiental/métodos , Modelos Teóricos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Desinfetantes/química , Desinfecção/métodos , Halogenação , Água , Purificação da Água/métodos
8.
Chemosphere ; 247: 125887, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978656

RESUMO

Studies conducted globally have identified wastewater effluent as a key source of UV filters released into the aquatic environment. We assessed the annual release of UV filters from wastewater treatment plant effluent in Australia and evaluated the removal of these chemicals during wastewater treatment. Effluent samples were collected from 33 sites alongside matching influent samples. Sample collection predominately occurred during the Australian Census in August 2016, which allowed for accurate per capita normalisation of the results. A subset of sites was also sampled over the Southern Hemisphere summer (December-February) period. Five UV filters were detected with at least one detected in 95% of effluent samples. The summed concentration of UV filters ranged from 130 ng L-1 to 8400 ng L-1 and averaged 2800 (±1900) ng L-1. Of the target UV filters, 2-phenylbenzimidazole-5-sulfonic acid (PBSA) and benzophenone 4 (BP4) showed the lowest removal efficiencies (11 ± 36% and 51 ± 43%, respectively) across all sites and were the most abundant in effluent. Average estimated removal efficiencies of the other compounds were between 59 (±24) % (4-methylbenzylidene camphor (4-MBC)) and 74 (±22) % (benzophenone 1 (BP1)). We did not find a trend in seasonal differences in the per capita release of UV filters in effluent samples. We estimate that approximately 40% of UV filter loads measured in influent are breaking through to the effluent resulting in the release of approximately 20 kg day-1 of the selected UV filters into the aquatic environment from treated wastewater effluent in Australia.


Assuntos
Monitoramento Ambiental , Protetores Solares/análise , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , Austrália , Benzofenonas , Cânfora/análogos & derivados , Estações do Ano , Protetores Solares/química , Águas Residuárias/química
9.
Chemosphere ; 247: 125907, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978658

RESUMO

Coastal waters are the critical ecologically fragile regions under the influence of the fastest economic developing pace and the extensive anthropogenic activities in coastal zone. Little information on the seasonal distribution, risks, and sources of endocrine disrupting chemicals (EDCs) which are emerging contaminants to pose potential risks at very low concentrations in coastal waters at continental-scale is available. This study investigated the coastline-based distribution, risks, and sources of target EDCs in coastal water of China. EDCs in coastal waters of China showed significant spatio-temporal variation with phenolic compounds serving as predominant EDCs. Bisphenol A (BPA) was detected in all water samples with average concentration of 449.2/186.3 ng/L in winter/summer while estrone was the main steroidal estrogen with the average concentration of 87.2/2.7 ng/L in winter/summer. EDCs in coastal waters of South China Sea Area showed higher concentrations. EDCs in coastal waters exerted high ecological risks and estrone/BPA averagely accounted for over 61%/71% of total risk quotient in winter/summer. Average estradiol equivalent concentration of all target EDCs reached 68.87/1.76 ng/L in winter/summer. EDCs in coastal waters did not pose potential non-cancer health risks for humans. The positive matrix factorization (PMF) model was firstly used to identify and quantify possible sources of EDCs. The PMF analysis showed that wastewater and sewage might be the main source for EDCs in coastal waters. EDCs in coastal waters showed high estradiol equivalent concentration and ecological risks at continental-scale, highlighting that EDCs contamination has become a crucial stress affecting the sustainable development of coastal regions.


Assuntos
Disruptores Endócrinos/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Compostos Benzidrílicos , China , Estradiol/análise , Estrogênios/análise , Estrona/análise , Humanos , Fenóis , Medição de Risco , Estações do Ano , Esgotos/química , Águas Residuárias/análise , Poluição Química da Água/estatística & dados numéricos
10.
Mar Pollut Bull ; 150: 110577, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31910512

RESUMO

Oil Spill Chemicals (OSCs) represent a risk to the environment and human health, especially in nearshore environments used for recreational purposes. Importantly, the starting point for human health risk assessment is to define the concentration of OSCs at nearshore locations. The objective of this study was to evaluate nearshore sampling data of OSC concentrations in different environmental matrices within time-space specific categories. The categories correspond to OSC concentration values for samples collected prior to nearshore oiling, post nearshore oiling and at no time impacted by oil as predicted by historic oil spill trajectories generated by an Oil Spill Trajectory Model. In general, concentration values for the post category were higher than prior which were higher than unimpacted. Results show differences in PAH concentration patterns within each matrix and for each category. Concentration frequency distributions for most chemicals in each category were log-normally distributed.


Assuntos
Monitoramento Ambiental , Poluição por Petróleo/estatística & dados numéricos , Petróleo , Poluentes Químicos da Água , Poluição Química da Água/estatística & dados numéricos , Humanos
11.
Sci Total Environ ; 704: 134883, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31780178

RESUMO

Heavy metal contamination in surface water of the Three Gorges Reservoir (TGR) is a distinctly important issue for the water security of the Yangtze River Basin in China. Surface water samples of 46 river sections in the main stream and tributaries of the entire TGR area were collected during high and low water level operation periods of 2015 to 2016 to investigate the spatial-temporal distribution characteristics of six heavy metals (As, Cd, Cr, Cu, Pb and Zn) and assess their health risks. Results indicated that average concentrations of heavy metals in the surface water were lower than the threshold values for the first-grade water quality based on the Chinese standard of GB3838-2002 except for Zn. Heavy metals concentrations at high water levels was slightly lower compared with that at the low water levels in the main stream, As, Cd, Cr and Cu exhibited certain inter-annual decline variations in 2015 and 2016. Heavy metals showed distinctly regional variation and mainly distributed in upstream urban sections of the TGR area. The total health risks caused by heavy metals at the low water level periods, most of which exceeded the maximum acceptable risk level recommended by ICRP (5×10-5 a-1), were slightly higher than that at the high water level periods. The average annual health risks caused by carcinogenic and non-carcinogenic heavy metals was ranked as Cr > As > Cd > Pb > Cu > Zn, meanwhile this value via drinking water ingestion was 2 to 3 orders of magnitude larger than that of dermal contact. Carcinogenic heavy metals of Cr and As were the main causes of health risk and should be prioritized as the main focus of aquatic environment risk management in the TGR area.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , China , Humanos , Medição de Risco , Qualidade da Água
12.
Environ Sci Pollut Res Int ; 27(6): 6009-6021, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31863380

RESUMO

Marine pollution is an important driver of ocean biodiversity loss, which can be mitigated by the construction of artificial reefs (ARs). Many studies have explored how ARs affect marine organisms, but our understanding of the changes in heavy metals and petroleum hydrocarbons after AR construction is limited. In the current study, we assessed the heavy metal and petroleum hydrocarbon contents of the seawater (surface and bottom seawater) and surface sediment before and after AR construction in AR habitat and in nearby non-reef control habitat in the Pearl River Estuary, China. AR construction tended to decrease the contents of Cu, Pb, Cd, and Hg but tended to increase Zn content in seawater and in surface sediment. Petroleum hydrocarbon content changed irregularly in seawater and surface sediment. Effects of AR construction were similar in the nearby non-reef habitat vs. the AR habitat. Seawater heavy metal and petroleum hydrocarbon contents were correlated with the seawater physicochemical properties (mainly temperature, inorganic nitrogen, chemical oxygen demand, available phosphate, and suspended particulate organic matter), and sediment heavy metal content was correlated with sediment organic matter content. Additional studies over longer time periods and at larger spatial scales are needed to clarify how AR construction affects heavy metal and petroleum hydrocarbon contents in marine environments.


Assuntos
Monitoramento Ambiental , Petróleo , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos , China , Estuários , Sedimentos Geológicos , Hidrocarbonetos/análise , Metais Pesados/análise , Rios , Água do Mar
13.
Environ Sci Pollut Res Int ; 27(6): 6126-6138, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31865590

RESUMO

To fully understand the environmental quality of sediments in the Yarlung Tsangpo River Basin, surface sediments of the mainstream of the Yarlung Tsangpo River and its five major tributaries were studied. In 2017, a total of 201 samples from the Yarlung Tsangpo River and its tributaries were collected during three water seasons. Fifteen trace elements (including Cd and heavy metals such as Cr, Cu, Pb, and As), which have great environmental effects, were analyzed. The results show that titanium, manganese, and chromium are the main heavy metals in the sediments of the Yarlung Zangbo River, accounting for 51%, 10%, and 7% of the total of 15 heavy metal elements measured, respectively. There were no significant differences among the heavy metal contents in the sediments of Yarlung Tsangpo River among three water seasons, but there were significant spatial variations. During the same period, the concentration of each element in the tributary sediments was generally higher than that in the mainstream. According to three different ecological risk assessment models, it is calculated that the heavy metal elements in the surface sediments of the river basin are at low or no pollution risk.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , Poluição Química da Água/estatística & dados numéricos , China , Sedimentos Geológicos , Metais Pesados , Medição de Risco , Rios
14.
Sci Total Environ ; 699: 134186, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31671306

RESUMO

The purpose of this paper is to show that a number of pesticides is found in groundwater and drinking water resources and to define measures that should reduce the pesticide load in groundwater resources for drinking water in the future. Although the pesticide load that enters groundwater bodies in the Netherlands has gradually decreased over the past ten years, good drinking water quality in the future is not guaranteed. Currently, a number of pesticides ise found in groundwater abstracted for the production of drinking water, worldwide. The most frequently found compounds in the Netherlands are the herbicides BAM (2,6-dichlorobenzonitrile), bentazon and mecoprop. In shallow groundwater, the same compounds are generally found as in deeper groundwater that is abstracted for the production of drinking water, mainly bentazon and mecoprop. Additionally, DEET (N,N-Diethyl-meta-toluamide) is frequently found in shallower groundwater. In order to reduce the pesticide load in groundwater resources for drinking water in the future, 43 measures have been inventoried and ranked based on their scores for 'effectiveness' and for 'practicability'. This paper describes both the most effective measures, with high scores on practicability, and those with limitations regarding practicability. These measures are the most relevant with respect to the frequently found compounds that are still authorised, i.e., bentazon, mecoprop and DEET and, to a lesser extent, glyphosate (due to the presence of its metabolite AMPA (aminomethylphosphonic acid) and glyphosate itself) and isoproturon. The implementation of abstraction-specific 'Drinking Water Protection Files', including the systematic collection of data about the relevant water abstraction and the sources and activities that can negatively affect water quality, is recommended.


Assuntos
Água Potável/química , Política Ambiental , Praguicidas/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/legislação & jurisprudência , Abastecimento de Água/legislação & jurisprudência , Água Potável/análise , Monitoramento Ambiental , Água Subterrânea/química , Governo Local , Poluição Química da Água/prevenção & controle , Recursos Hídricos
15.
Chemosphere ; 238: 124604, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31450113

RESUMO

Accurate in silico predictions of chemical substance ecotoxicity has become an important issue in recent years. Most conventional methods, such as the Ecological Structure-Activity Relationship (ECOSAR) model, cluster chemical substances empirically based on structural information and then predict toxicity by employing a log P linear regression model. Due to empirical classification, the prediction accuracy does not improve even if new ecotoxicity test data are added. In addition, most of the conventional methods are not appropriate for predicting the ecotoxicity on inorganic and/or ionized compounds. Furthermore, a user faces difficulty in handling multiple Quantitative Structure-Activity Relationship (QSAR) formulas with one chemical substance. To overcome the flaws of the conventional methods, in this study a new method was developed that applied unsupervised machine learning and graph theory to predict acute ecotoxicity. The proposed machine learning technique is based on the large AIST-MeRAM ecotoxicity test dataset, a software program developed by the National Institute of Advanced Industry Science and Technology for Multi-purpose Ecological Risk Assessment and Management, and the Molecular ACCess System (MACCS) keys that vectorize a chemical structure to 166-bit binary information. The acute toxicity of fish, daphnids, and algae can be predicted with good accuracy, without requiring log P and linear regression models in existing methods. Results from the new method were cross-validated and compared with ECOSAR predictions and show that the new method provides better accuracy for a wider range of chemical substances, including inorganic and ionized compounds.


Assuntos
Ecotoxicologia/métodos , Aprendizado de Máquina , Poluentes Químicos da Água/toxicidade , Poluição Química da Água/análise , Animais , Simulação por Computador , Daphnia/efeitos dos fármacos , Peixes , Modelos Lineares , Modelos Teóricos , Relação Quantitativa Estrutura-Atividade , Medição de Risco/métodos , Software , Poluentes Químicos da Água/química
16.
Chemosphere ; 238: 124688, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524623

RESUMO

Microplastic pollution has received increased attention recently due to potential threat to marine biota and human health. This study reports microplastic (MP) content in brown shrimp (Metapenaeus monocerous) and tiger shrimp (Penaeus monodon) inhabiting in the shallow and offshore waters of the Northern Bay of Bengal, Bangladesh. Gastrointestinal tract (GT) of shrimps (n = 150) were examined for MPs following alkali digestion, microscopic observation and chemical analysis by micro-Fourier Transformed Infrared Spectroscope (µFTIR). A total of 33 and 39 MP items were found in P. monodon and M. monocerous, averaging 3.40 ±â€¯1.23 and 3.87 ±â€¯1.05 items/g GT, respectively. Among various shapes, types and colours of MP, filament (57-58%), fiber (32-57%) and black (48-51%) were dominant amongst the various particles identified. Tiger shrimp had high numbers (23 items) of larger size fractions of MPs (1-5 mm) but brown shrimp had high numbers (15 items) of smaller MPs (250-500 µm), and µ-FTIR data confirmed 13 particles of polyamide-6 and 6 particles of rayon polymers. These results provide a baseline of MP contamination in seafood from Bangladesh that should be useful for future monitoring efforts.


Assuntos
Caprolactama/análogos & derivados , Celulose/análise , Monitoramento Ambiental/métodos , Microplásticos/análise , Penaeidae/química , Polímeros/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Animais , Bangladesh , Baías/química , Caprolactama/análise , Trato Gastrointestinal/química , Alimentos Marinhos/análise , Espectroscopia de Infravermelho com Transformada de Fourier
17.
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
18.
Chemosphere ; 239: 124770, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726525

RESUMO

Over twenty thousand persons rely on water from Atuwara River for drinking and other domestic purposes, hence the need to ascertain the human health risk inherent in such practice. Seventy-two water samples were collected from River Atuwara during the dry and wet seasons of 2018, and the concentration of heavy metals (Pb, As, Ni, Cr, Zn, Cu, and Cd) were measured using ICP-OES. A newly developed human health risk assessment method, HHRISK code was used to estimate the health risks associated with consumption of water from Atuwara River. Results obtained revealed that the concentration of heavy metals in the river was as follows: Cd < Ni < Pb < Cr < Cu < As < Zn in the wet season and Cd < Pb < Ni < Cu < Cr < As < Zn during the dry season. Principal component analysis suggested that industrial effluents, agricultural activities and base-rock interaction are responsible for pollution of Atuwara River. The cumulative hazard index (HIcum) obtained was 678.0 ±â€¯36.8 (for adult) and 1392.0 ±â€¯132 (for child) for non-carcinogenic risks. A cumulative carcinogenic risk (CRcum) of 1.01E-1±5.26E-3 and 4.96E-2±5.05E-3 was obtained for adult and children respectively, suggesting that up to 1 in 10 adults and 1 in 20 children may suffer from cancer over their lifetime as a result of consumption and exposure to water from River Atuwara. These results highlight the fact that unavailability of safe drinking water in many parts of the world remains a real and persistent risk which must be tackled.


Assuntos
Água Potável/química , Monitoramento Ambiental/métodos , Metais Pesados/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Adulto , Agricultura , Criança , Humanos , Nigéria , Análise de Componente Principal , Medição de Risco , Rios , Estações do Ano , Qualidade da Água
19.
Chemosphere ; 245: 125613, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864061

RESUMO

The heavy metal cadmium (Cd) is a hazardous pollutant known to exert various toxic effects and other sublethal to lethal effects on aquatic organisms, and can be commonly found in environment. The genus Bacillus was one of dominant probiotics, which was commonly used in aquaculture. The aim of this study was to evaluate the effects of dietary administration of Bacillus cereus (B. cereus) on bioaccumulation, oxidative stress and intestinal microbiota of Carassius auratus gibelio (C. gibelio) after Cd exposure. Fish were exposed for 4 weeks to waterborne Cd at 0, 1 and 2 mg/L and/or dietary B. cereus at 108 cfu/g. At 2 and 4 weeks, the fish were sampled and bioaccumulation, antioxidant activity and intestinal microbiota were assessed. Waterborne Cd exposure caused marked alterations in the composition of the microbiota. Dietary supplementation with B. cereus can reverse the changes in the composition of intestinal microbiota in Cd exposure and increase the abundance of Bacteroides, Akkermansia, Cetobacterium in the 0 and 1 mg/L Cd. The results obtained indicate that B. cereus can provide a significant protective effect on the toxicity of cadmium by inhibiting alterations in the levels of bioaccumulation and antioxidant enzyme including Superoxide dismutase (SOD), catalase (CAT), total antioxidant (T-AOC), glutathione (GSH), malonaldehyde (MDA) and Glutathione-S-transferase (GST). The present findings imply that dietary supplement of B. cereus can effectively protect C.gibelio to combat cadmium toxicity.


Assuntos
Bacillus cereus/fisiologia , Bioacumulação/efeitos dos fármacos , Cádmio/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Carpa Dourada/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Probióticos/farmacologia , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Suplementos Nutricionais/microbiologia , Glutationa/metabolismo , Malondialdeído/metabolismo , Superóxido Dismutase/metabolismo , Poluição Química da Água
20.
Artigo em Inglês | MEDLINE | ID: mdl-31874287

RESUMO

Pharmaceutical drugs are usually and continuously carried to the aquatic environment in different ways. Thus, they are pseudo-persistent in the environment, and they may exert deleterious effects on aquatic organisms. The objective of the present study was to investigate the acute and chronic effects of two widely used pharmaceutical drugs, paracetamol (analgesic and antipyretic) and propranolol (ß-blocker) on the activity of specific biomarkers (namely cholinesterase enzymes and lactate dehydrogenase) of the neotropical fish Phalloceros harpagos. The obtained results indicate an inhibition of the activity of the enzyme lactate dehydrogenase (LDH) after acute exposure to paracetamol, and an increase in cholinesterase activity in acutely propranolol-exposed fish. Chronic exposure to both drugs did not modify the enzymatic activities. Such short-term changes in enzymatic activities may be harmful to organisms, altering the preferential pathway of energy metabolism, and may induce behavioral changes that may compromise prey capture and predator escape, and in the longer term may induce population declines.


Assuntos
Acetaminofen/toxicidade , Colinesterases/metabolismo , Ciprinodontiformes/metabolismo , L-Lactato Desidrogenase/metabolismo , Propranolol/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Poluição Química da Água
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