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1.
J Acoust Soc Am ; 148(3): 1748, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33003833

RESUMO

The lockdown that Madrid has suffered during the months of March to June 2020 to try to control and minimize the spread of COVID-19 has significantly altered the acoustic environment of the city. The absence of vehicles and people on the streets has led to a noise reduction captured by the monitoring network of the City of Madrid. In this article, an analysis has been carried out to describe the reduction in noise pollution that has occurred and to analyze the changes in the temporal patterns of noise, which are strongly correlated with the adaptation of the population's activity and behavior to the new circumstances. The reduction in the sound level ranged from 4 to 6 dBA for the indicators Ld, Le, and Ln, and this is connected to a significant variation in the daily time patterns, especially during weekends, when the activity started earlier in the morning and lasted longer at midday, decreasing significantly in the afternoon.


Assuntos
Infecções por Coronavirus , Ruído , Pandemias , Pneumonia Viral , Betacoronavirus , Cidades , Monitoramento Ambiental , Humanos , Espanha
2.
Environ Monit Assess ; 192(11): 680, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025180

RESUMO

In this study, the activities of 40K, 210Pb, 232Th, 234U, 235U, and 238U in size-segregated particulate matter (PM) were measured in the Singrauli Coalfield, India. Different isotopic compositions were found relative to natural uranium ratios. The radioactivity concentration ratios in different PM sizes [PM2.5, PM10, and suspended particulate matter (SPM)] suggested that anthropogenic sources affected the uranium isotopic compositions in the area. A different isotopic composition from the natural uranium composition was found. The correlation coefficients between the measured isotopes (40K, 210Pb, 232Th, 234U, 235U, and 238U) and meteorological factors were calculated. PM emissions were affected by the meteorological conditions, which in turn, influenced the U and Th concentrations in PM. The 232Th/238U activity ratio in particulate matter was between 0.20 and 1.54 with an average value of 0.9 ± 0.5, 0.2 to 1.1 (0.8 ± 0.7), and 0.2 to 1.2 with an average value of 0.8 ± 0.8 in PM2.5, PM10, and SPM, respectively. These range were quite different from the average crustal ratio of 3.5, indicating that the 238U concentrations were elevated in this region relative to Th. However, compared with Th, the dose contribution of U to the public was negligible. The average effective dose in public owing to inhalation of natural radioactive 40K, 210Pb, 232Th, and 234U, 235U, and 238U in the atmosphere was between 0.03 and 327 nSv year-1. These doses associated with the inhalation of particulate matter were lower than world airborne reference value as reported by UNSCEAR (2000a). Graphical abstract.


Assuntos
Neoplasias , Material Particulado , Monitoramento Ambiental , Humanos , Índia , Material Particulado/análise , Radioisótopos
3.
Environ Monit Assess ; 192(11): 675, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025222

RESUMO

The largest uranium-phosphate deposit in Brazil also contains considerable levels of rare earth elements (REEs), which allows for the co-mining of these three ores. The most common methods for REE determination are time-consuming and demand complex sample preparation and use of hazardous reagents. Thus, the development of a safer and faster method to predict REEs in soil could aid in the assessment of these elements. We investigated the efficiency of near-infrared (NIR) spectroscopy to predict REEs in the soil of the uranium-phosphate deposit of Itataia, Brazil. We collected 50 composite topsoil samples in a well-distributed sampling grid along the deposit. The NIR measures in the soils ranged from 750 to 2500 nm. Three partial least squares regressions (PLSR) were selected to calibrate the spectra: full-spectrum partial least squares (PLS), interval partial least squares (iPLS), and successive projections algorithms for interval selection in partial least squares (iSPA-PLS). The concentrations of REEs were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). In addition to raw spectral data, we also used spectral pretreatments to investigate the effects on prediction results: multiplicative scatter correction (MSC), Savitzky-Golay derivatives (SG), and standard normal variate transformation (SNV). Positive results were obtained in PLS for La and ΣLREE using MSC pretreatment and in iSPA-PLS for Nd and Ce using raw data. The accuracy of the measurements was related to the REE concentration in soil; i.e., elements with higher concentrations tended to present more accurate results. The results obtained here aim to contribute to the development of NIR spectroscopy techniques as a tool for mapping the concentrations of REEs in topsoil.


Assuntos
Urânio , Brasil , Monitoramento Ambiental , Análise dos Mínimos Quadrados , Fosfatos , Solo , Espectroscopia de Luz Próxima ao Infravermelho
4.
Environ Monit Assess ; 192(11): 676, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025262

RESUMO

Long-term aerosol optical thickness (AOT) composited data (2002-2017) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra and Aqua spacecraft was used to evaluate the temporal and spatial variability of aerosol in Xiamen city by using wavelet analysis, and the relationship between the surface mass concentrations of particulate matter with aerodynamic diameters less than 2.5 µm (PM2.5) and the AOT was analyzed by using linear regression. The results showed that AOT increased gradually from 2002 to 2011, and then decreased. AOT displayed a significant 9-month periodicity in AOT was inferred wavelet analysis. AOT also showed significant annual variability in response to changes in weather and aerosol pollution. We observed highest AOT values in April, with a monthly mean of 1.00 ± 0.18. Lowest values were observed in December, with a mean AOT of 0.52 ± 0.11. Multi-year monthly AOT fluctuations were lowest in January with a low variation coefficient (0.14), and the largest fluctuations appeared in July with a high variation coefficient (0.29). Higher AOT values (~ 1.1) were predominantly located in the southern urban areas of Xiamen and lower AOT values (~ 0.3) were mainly located in northern rural regions. The aerosol pollution was serious in April with the smallest spatial variation coefficient of 0.25, and the highest spatial variation coefficient appeared in July. Highest intraannual variability predominantly occurred in the high-value areas in the center of Xiamen. AOT values remained high in Xiamen Island throughout the year with a multi-year mean of 0.87. There was a moderate correlation between ground-based PM2.5 and MODIS AOT. Therefore, we confirm the suitability of MODIS AOT to accurately estimate PM2.5 concentration and evaluate the temporal and spatial characteristics of air quality in Xiamen.


Assuntos
Monitoramento Ambiental , Material Particulado , Aerossóis/análise , China , Cidades , Material Particulado/análise
5.
Environ Monit Assess ; 192(11): 678, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025274

RESUMO

Detecting the probable impact of climate change responses on hydrological components is most important for understanding such changes on water resources. The impact of climate change on virtual parameters of water was assessed through hydrological modeling of the Wunna, Mahanadi (Middle), and Bharathpuzha watersheds. In this article, future hydrological component responses under two Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios were considered for investigating the runoff, sediment, and water storage components. RegCM4 CSIRO-Mk3.6.0 CORDEX South Asia of RCM model was used which is specially downscaled for the Asian region by IITM-India. Delta change method was adopted to remove bias correction in RCM data. Hydrological simulation for current and future periods was performed by GIS interfaced Soil Water and Assessment Tool (SWAT) model. The surface runoff of Wunna and Bharathpuzha watersheds and the yield of sediment are expected to increase further under RCP8.5 than RCP4.5 and in contrast to Mahanadi watershed. Both blue water storage (BW) and green water storage (GWS) of Wunna watershed are expected to decline under RCP4.5, and rise under RCP8.5 scenario. Both BW and GWS of Bharathpuzha are expected to increase in the future except in western region under RCP4.5 scenario. BW of Mahanadi is expected to increase in the future. However, GWS will decrease in some of the sub-basins. The model-generated results will be helpful for future water resources planning and development.


Assuntos
Mudança Climática , Hidrologia , Ásia , Monitoramento Ambiental , Índia , Modelos Teóricos
6.
Environ Monit Assess ; 192(11): 677, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025276

RESUMO

Local water quality indices (WQIs) are usually developed by modifying internationally recognized indices, which are considered reference index. In previous works on WQIs, the performance of local and reference indices has not been compared with each other. Therefore, the question crosses the mind whether using local or international indicators individually can show all qualitative aspects of a water resource. In this study, it was aimed to make this comparison between NSFWQIm (National Sanitation Foundation Water Quality Index) as the reference index and IRWQIsc (Iranian Water Quality Index for Surface Water Resource-Conventional Parameters) as the local one through a case study (Sefidroud River in northern Iran). Based on the results, the indices' performance in representing the seasonal and spatial fluctuations of the river water quality was almost similar. However, the water quality scores obtained by the two indices were somewhat different. Based on NSFWQIm, the average water quality score of the river was about 49.0, by which the water was categorized in "bad" class, while IRWQIsc represented an average score of 56.1, which corresponds to "fairly good" class. Therefore, NSFWQIm identified the water quality with stricter criteria than IRWQIsc, regarding the public health. On the other hand, according to relative standard deviations (0.17 for NSFWQIm, 0.21 for IRWQIsc) of the obtained water qualities, IRWQIsc better distinguished between high and low water qualities of the river. Accordingly, in order to better interpret the quality conditions of surface water resources in Iran, it is necessary to use both indices since NSFWQIm (reference index) attracts attention to stricter international standards and requirements, while IRWQIsc (local index) causes more focus on seasons or locations with the worst water quality.


Assuntos
Rios , Qualidade da Água , Monitoramento Ambiental , Irã (Geográfico) , Poluição da Água/análise
7.
Environ Monit Assess ; 192(11): 681, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33025312

RESUMO

Genotypic diversity among multi-drug-resistant (MDR) aquatic E. coli isolated from different sites of Yamuna River was analyzed using repetitive element PCR (rep-PCR) methods viz. ERIC-PCR and (GTG)5-PCR and compared with the MDR animal fecal isolates. The 97 E. coli isolates belonging to different serotypes, phylogroups, and multi-drug resistance patterns were analyzed. High genetic diversity was observed by both the methods; however, (GTG)5 typing showed higher discriminating potential. Combination of ERIC types (E1-E32) and (GTG)5 types (G1-G46) generated 77 genotypes. The frequency of genotypes ranged from 0.013 to 0.065. The genotype composition of E. coli isolates was highly diverse at all the sampling sites across Yamuna River except at its entry site in Delhi. The sampling sites under the influence of high anthropogenic activities showed an increase in number of unique genotype isolates. These sites also exhibited high multiple antibiotic resistance (MAR) indexes (above 0.25) suggesting high risk of contamination. Principal coordinate analysis (PCoA) showed limited clustering of genotypes based on the sampling sites. The most frequent genotypes were grouped in the positive zone of both the principal coordinates (PC1 and PC2). The genotypes of most of the animal fecal isolates were unique and occupied a common space in the negative PC1 area forming a separate cluster. High genotypic diversity among the aquatic E. coli and the drain isolates, discharging the untreated municipal waste in the river, was observed, suggesting that the sewage effluents contribute substantially to contamination of this river system than animal feces. The presence of such a high diversity among the MDR E. coli isolates in the natural river systems is of great public health significance and highlights the need of an efficient surveillance system for better management of Indian natural water bodies.


Assuntos
Escherichia coli , Rios , Animais , Monitoramento Ambiental , Escherichia coli/genética , Fezes , Genótipo , Índia , Reação em Cadeia da Polimerase
8.
Environ Monit Assess ; 192(11): 679, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025331

RESUMO

In this study, the impacts of land use/land cover (LULC) and climate change on the streamflow and sediment yield were investigated for the Payaswani River Basin, Western Ghats, India. The LULC was determined using Landsat images, and climate data were procured from five general circulation models for representative concentration pathway (RCP) 4.5 (moderate emission) and 8.5 (high emission). The land change modeler was used to derive the future LULC and its changes from 1988 (historical) to 2030 (future) by using the transition matrix method. The SWAT model was used to assess the impacts of LULC and climate change for the streamflow and sediment yield. The results showed that decrease in forests and grasslands and increase in plantation, agricultural, and urban areas from 1988 to 2030 would lead to an increase in the mean streamflow (11.23%) and sediment yield (17.41%). Under RCP 4.5, climate change would decrease the streamflow by 2.38% in 2030. However, under RCP 8.5, climate change would increase the streamflow by 0.12% in 2030. The sediment yield under RCP 4.5 and 8.5 would increase by 1.23% and 3.33%, respectively. In comparison with the baseline condition, by 2030 future changes in the LULC and climate would increase the streamflow by 7.05% and 11.71% under RCP 4.5 and 8.5, respectively. The sediment yield would increase by 7.92% and 27.11% under RCP 4.5 and 8.5, respectively. The streamflow and sediment yield were predicted to increase in the summer and winter but decrease in the monsoon season.


Assuntos
Mudança Climática , Rios , Monitoramento Ambiental , Previsões , Índia
9.
Environ Monit Assess ; 192(10): 666, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001295

RESUMO

Knowledge of the background activity concentrations of anthropogenic radionuclides before the start of operation of the new nuclear power plant in Belarus, BelNPP, is an issue of great importance for neighbouring countries. In this study, we provide the pilot characterisation of the Lithuanian part of the 30-km zone of the BelNPP, emphasising the forest plants, terrestrial mosses, forest organic and mineral topsoil to describe the preoperational radioecological state of the pine forest ecosystem. Key anthropogenic radionuclides (14C, 3H, 137Cs and 239,240Pu) were analysed. The 14C specific activity varied from 97.80 ± 1.30 to 102.40 ± 0.79 pMC. The 3H specific activity in the tissue-free water tritium form varied from 13.2 ± 2.2 TU to 20.8 ± 2.3 TU, which corresponded to the 3H level of precipitation in this region. The activity concentrations of 239,240Pu in soil and moss samples did not exceed 1 Bq/kg and were mainly due to global fallout after nuclear tests. The 137Cs inventory in the pine forest soils of the Lithuanian part of the BelNPP 30-km zone varied from 930 ± 70 to 1650 ± 430 Bq/m2. High variation of the inventory and uneven distribution in the soil profile conditioned a wide range of 137Сs activity in terrestrial plants from 1.0 ± 0.5 to 40.5 ± 1.8 Bq/kg dry weight. The abundance of microorganisms in different seasons and soil depths do not exceed the natural levels. According to PCA loads, the number of microorganisms and variability of 137Cs specific activity is determined by soil abiotic parameters.


Assuntos
Centrais Nucleares , Poluentes Radioativos do Solo/análise , Ecossistema , Monitoramento Ambiental , Florestas , Solo
10.
Environ Monit Assess ; 192(10): 665, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001326

RESUMO

With economic development and the acceleration of urbanization, China's energy demand has gradually increased and brought a lot of energy-related CO2 emissions. Energy-related CO2 emissions are affected by a variety of factors. Quantifying the correlation between energy-related CO2 and driving factors and constructing the driving factor system are conducive to predict the future energy-related CO2 emissions and analyze the impact of driving factors. In this paper, the improved grey relational analysis (IGRA) was proposed to screen the influencing factors of energy-related CO2 emissions considering the sample difference, and the factor analysis (FA) was used to reduce dimensionality of the influencing factors. Then, a carbon dioxide emission forecasting model based on the bacterial foraging optimization algorithm (BFO) and the least square support vector machine (LSSVM) was proposed. Empirical analysis results of Hebei show that the LSSVM optimized BFO significantly improves the accuracy of energy-related CO2 emissions forecasting, and IGRA-FA-BFOLSSVM model is significantly better than BP, PSOBP, SVM, and LSSVM models. The mean absolute percentage error (MAPE) of the proposed model is 0.374%. The forecasting results of the supplementary case show that the model has better generalization ability. In addition, education and technological progress have proven to be important drivers of energy-related CO2 emissions. Simultaneously, the research results can also offer more breakthrough points for policy makers to control carbon emissions.


Assuntos
Dióxido de Carbono/análise , Monitoramento Ambiental , China , Desenvolvimento Econômico , Análise Fatorial
11.
Environ Monit Assess ; 192(10): 668, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33005999

RESUMO

Watershed morphometric assessment is about measurements and calculations of land surface forms for the purpose of understanding hydro-geomorphological character and patterns. Important natural environment geo-information and summary of the spatial characteristics of Tana River Basin (TRB) in Kenya have been obtained through hydro-geomorphometric analysis. Advanced Spaceborne Thermal Emission and Reflection Radiometer Digital Elevation Model (ASTERDEM) data and ArcGIS (ESRI Inc., version 10.4.1) together with published mathematical equations were applied to extract morphometric parameters of the drainage basin, which covers a total area of 94,930 km2 and a span of 527.75 km. The quantitative morphometric analysis considered a total of 28 relief, areal, and linear hydro-morphometric characteristics of the TRB. Relief parameters of the basin suggest moderate-to-low overall watershed steepness, upland with rolling land surface patterns, rugged landforms susceptible to erosion and sediment transportation, and a landscape in evolution process tending towards maturity. This means stability of the land surface can be attained with intensive land degradation reversing strategies like erosion control measures. Areal characteristics further support the basin's susceptibility to erosion as shown by stream length, stream drainage density, and circulatory ratio values. Also, the areal aspects portray peak runoffs with short duration flashes. Linear parameter value results such as bifurcation ratio imply that infiltration capacity varies with stream orders across the watershed. This hydro-geomorphometric analysis would be useful to land and water managers, researchers and practitioners of TRB, and other similar systems in designing and planning soil and water conservation and management practices such as soil erosion control, groundwater recharge activities, catchment modelling, runoff and flood studies, prospecting groundwater mapping, and biological applications.


Assuntos
Monitoramento Ambiental , Sistemas de Informação Geográfica , Quênia , Rios , Solo
12.
Environ Monit Assess ; 192(10): 667, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33006063

RESUMO

Dental prosthesis laboratories (DPLs) are among the workplaces where predominantly manual production takes place. In such working environments, during the manual manufacturing process, which involves fine smoothing and polishing of dental prostheses, fine particulate matter is released into the ambient air. In this study, the particulate matter (PM) concentrations and elemental content of the fine particles in the working ambient air were identified in six DPLs in Kocaeli, Turkey. PM2.5 mass concentrations, measured in all the DPLs, ranged between 80.8 and 1645 µg/m3 (mean 414 ± 406). As a result of the analyses performed with an ICP-MS device (Perkin Elmer Elan®DRC-e), trace elements of Be, Cd, Hg, and, notably, Co, Cr, Mo, and Ni were found. The researchers calculated the excess lifetime cancer risks and total hazard indexes. The average total cancer risk for all the DPLs was 8 × 10-3, which is higher than the acceptable limit of 1.0 × 10-6, and the total hazard index was 187, which is greater than the acceptable limit of 1.0. Considering these high-level risks, the study concluded that there is a need for new production methods, and strict application of occupational health and safety measures, to reduce the fine particle exposure of the workers in the laboratories. In addition, there are prescribed limit values for particulate matter only for respirable particles in working environments. The establishment of limit values, especially for PM2.5 concentrations, is important for the protection of the health of the employees.


Assuntos
Prótese Dentária , Exposição Ocupacional , Monitoramento Ambiental , Humanos , Material Particulado/análise , Turquia
13.
Environ Monit Assess ; 192(11): 700, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33047214

RESUMO

To investigate the possible impact of the traffic flow of mountainous roads and the construction and operation of a long tunnel on the water quality of a reservoir, this study conducts statistical analysis on water quality, meteorological, and traffic data of the Feitsui Reservoir and its upstream tributaries over the last three decades. Results from statistical regression analysis indicate that in the upstream area where the traffic flow is low, water quality varies insignificantly with rainfall and traffic flow, providing as a background reference of natural environment. Water quality near a conventional highway on which many vehicles travel through the catchment area is significantly affected by both rainfall and traffic flow since the drainage system of a conventional highway sends its gathered water into adjacent rivers. Not only does traffic flow generate contaminants, but also the construction of the Hsuehshan Tunnel of the No. 5 Expressway, Taiwan, in the catchment area of the Feitsui Reservoir generates pollution. Drainage, silt settling and retarding basin, and wastewater treatment facilities near the construction site mitigate the impact of tunnel construction and traffic flow on the environment. The No. 5 Expressway makes good use of viaduct and tunnel structures, collecting water from pavements within the catchment area into sewage facilities, filtering it, and then emitting it outside the catchment area, forming a closed system over the Feitsui Reservoir. The Expressway now shortens travel time from two hours to 40 min and accommodates 7-13 times previous traffic flows, insignificant influencing water quality in the upstream tributaries of the reservoir, demonstrating the effectiveness of its environmental protection measures.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Rios , Taiwan , Águas Residuárias
14.
Environ Monit Assess ; 192(11): 669, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33006646

RESUMO

We examined the spatial and temporal characteristics of tropical nights (TNs) in Seoul to determine whether land use factors increase the frequency of TN. The number of TN was derived using data from 23 Automatic Weathering Stations (AWS) in Seoul for 1998-2006, and 26 AWS in Seoul and nine Gangnam-gu stations for 2007-2013. The results show that the number of TN recorded in the Seoul Automatic Synoptic Observation System (ASOS) gradually increased from 1971 to 2013. TN occurred most frequently in early August, followed by mid-August, late July, late August, mid-July, early July, early September, and mid-September. The largest annual average difference occurred between Gangnam Station and Yeomgokdong, in spite of the short physical distance (4.5 km) between two stations at Gangnam-gu. There were more TNs at high-rise buildings and commercial business district (CBD) areas with low sky view factors (SVF) than in mountain foothill areas.


Assuntos
Monitoramento Ambiental , Tempo (Meteorologia) , Seul
15.
Environ Monit Assess ; 192(11): 670, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009644

RESUMO

Antarctica is considered as one of the most pristine areas on Earth. However, increasing intensity of human presence on the sixth continent (scientific operations, functioning of the numerous scientific stations, tourism activities) makes it crucial to investigate the level of environmental pollution within the vulnerable ecosystem of Antarctica. Soils play a significant role in processes of accumulation, mobilization, redistribution of chemical elements within landscapes, and ecosystems. The aim of this work was to analyze the levels of 17 polycyclic aromatic hydrocarbons and eight trace elements in soils of King George and Ardley islands, Western Antarctica. Moreover, our work was aimed to determine the trends and reasons of anthropogenic pollution of Antarctic soils and characterization of accumulation levels of trace elements and PAHs. Results showed the predominance of light PAHs in all studied sites. The content of benzo(a)pyrene does not exceed the threshold concentration (adopted by different national environmental legislation systems). At the same time, the content of benzo(a)pyrene, which is a marker of anthropogenic contamination, is relatively low or equal to 0 in soils of reference landscapes. Cu and Zn were found as most abundant elements in all studied soils. The highest lead concentration content has been described in soil from Bellingshausen station. In general term, obtained Igeo values for trace elements in all samples were under or slightly above the 0 level, indicating low to moderate pollution of the studied soils. This study also contributes new data on trace element accumulation in soils strongly influenced by ornithogenic factor. Principal component analysis allowed to estimate the probable sources of specific trace metals and their relationship with soil variables. Ornithogenic factor has been also revealed as a driver for some trace element accumulation especially in breeding penguin colonies. High contents of organic matter in ornithogenic habitats could increase trace metal mobility, environmental risks for surrounding terrestrial environments should be considered.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Oligoelementos/análise , Regiões Antárticas , Ecossistema , Monitoramento Ambiental , Humanos , Ilhas , Solo
16.
Environ Monit Assess ; 192(11): 671, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33009943

RESUMO

Plastic pollution is an emerging issue faced worldwide owing to rapid urbanization and extensive use of plastic products. The objective of this study was to determine and highlight the spatial distribution of microplastics (MPs) in the top soils of different land use types of an urbanized city, i.e., Lahore, Pakistan, influenced by different human activities. Soil samples (n = 40) were collected from eight different land use groups including agricultural areas, drains, dumping sites, industrial areas, lawns, parks, roadsides, and wastelands to represent the influence of corresponding human actions. After cleaning the samples through wet peroxide digestion and density separation, MPs were identified under a stereomicroscope. The range of MPs in top soils within Lahore district varied from 1750 to 12,200 MPs/kg with an average of 4483 ± 2315 MPs/kg. The highest concentration of MPs was present in the parks while the lowest numbers of MPs were enumerated in soil from dumping sites. About 99% of the identified MPs particles were fibers, sheets, and fragments in shape while foams and beads accounted for the rest. Moreover, among the size ranges, the large size MPs (300-5000 µm) were found in the majority (41.16%) followed by the fine size MPs (50-150 µm; 30.67%) and medium size MPs (150-300 µm; 28.17%). The current level of MPs pollution attracts the attention of researchers for a more comprehensive investigation in the future. It also incites the policy-makers to implement the regulations to prevent plastic pollution and its environmental implications.


Assuntos
Solo , Poluentes Químicos da Água/análise , Cidades , Monitoramento Ambiental , Humanos , Microplásticos , Paquistão , Plásticos
17.
Environ Monit Assess ; 192(11): 672, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33009971

RESUMO

The effects of soil compaction on porosity (α), bulk density (ρs), and saturated hydraulic conductivity (Ksat) can create a physical barrier in the soil, reducing the vertical movement of toxic elements in the soil profile. However, the indirect effects of compaction in altering the forms and availability of heavy metals in soil have not been well-studied. This study examined the influence of compaction on forms of lead (Pb) in soils with contrasting texture. Four levels of compaction were imposed on a sandy loam and a clayey soil, which were artificially contaminated based on their maximum Pb adsorption capacity. Compaction had different effects on Pb forms depending on soil texture. In the sandy loam soil, compaction had a dual beneficial effect in mitigating the impact of Pb contamination, since it decreased Ksat, reducing metal transport to deeper soil layers, and also prevented transformation to more available Pb forms (soluble and exchangeable). Instead, there was an increase in the most environmentally stable forms of Pb (inner sphere adsorption on iron and manganese oxides). In the clayey soil, compaction caused a significant increase in soluble and exchangeable Pb, accompanied by a significant reduction in environmentally stable Pb (inner sphere adsorption on gibbsite and kaolinite). In addition, studies about Pb contents under compacted soil layers should be investigated, mainly in clayey soils with edible crops, and environmental remediation practices that involve the machines traffic (for example, phytoremediation-successive cultivation of Pb-hyperaccumulating plants) should be used with care to minimise the compaction of clayey soils.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Monitoramento Ambiental , Chumbo , Solo
18.
Environ Monit Assess ; 192(11): 674, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33011837

RESUMO

Prediction of dissolved organic carbon (DOC) based on catchment characteristics is a useful tool for efficient and effective water management, but in the case of arid and semi-arid regions, such predictive capacity is scarce. Accordingly, the main objective of this study was to evaluate the significance of principal components for predicting DOC concentrations and fluxes in nine headwater catchments of the Hiv catchment located in the Southern Alborz Mountains in the west of Tehran, Iran. To achieve this aim, data were assembled on 24 headwater catchment characteristics comprising soil properties, physiography, seasonal rainfall, and flow attributes, as well as estimates of DOC concentrations and fluxes across four seasons. The results revealed a major positive correlation between DOC and soil organic matter parameters related to soil biological processes. Using general linear modelling, an organic matter component related to soil biology, a seasonal component related to the dummy effect of sampling seasons, and a soil physical component related to soil texture were found to be the best predictors for DOC responses in the study area.


Assuntos
Ciclo do Carbono , Monitoramento Ambiental , Carbono/análise , Irã (Geográfico) , Solo
19.
Environ Monit Assess ; 192(11): 673, 2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33011855

RESUMO

Plant responses to heavy metals and their storage constitute a crucial step to understand the environmental impacts of metallic trace elements (MTEs). In controlled experiments, we previously demonstrated the tolerance and resilience of Japanese knotweed to soil artificial polymetallic contamination. Using the same experimental design, we tested here the effect of three individual MTEs on Fallopia × bohemica performance traits. Rhizome fragments from three different sites (considered as distinct morphotypes) were grown in a greenhouse for 1 month on a prairial soil artificially contaminated with either Cd, Cr (VI) or Zn at concentrations corresponding to relatively highly polluted soils. Our results confirmed the high tolerance of Bohemian knotweed to metal stress, though, plant response to MTE pollution was dependant on MTE identity. Bohemian knotweed was stimulated by Cr (VI) (increased root and aerial masses), did not display any measurable change in performance traits under Cd at the high dose of 10 mg kg-1, and uptook all MTEs in its rhizome, but only Zn was transferred to its aerial parts. We also highlighted changes in root secondary metabolism that were more accentuated with Zn, including the increase of anthraquinone, stilbene and biphenyl derivatives. These results compared to multi-contamination experiments previously published suggest complex interactions between metals and plant, depending principally on metal identity and also suggest a potential role of soil microbes in the interactions.


Assuntos
Fallopia , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Cádmio , Monitoramento Ambiental , Metabolismo Secundário , Zinco
20.
J Environ Qual ; 49(1): 119-127, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016350

RESUMO

Eutrophication is an issue of concern in many brackish lakes with an agricultural watershed. The amount of snowfall in snowy areas is anticipated to decline because of global climate change. The aim of this study was to assess the impact of changes in the inflow of snowmelt on the nutrient concentrations of a downstream brackish lake. In Lake Ogawara, a brackish lake in a snow-covered agricultural area of Japan, we examined the relationships between inflowing river discharge (D/C) during spring and total nitrogen (TN) and total phosphorus (TP) concentrations in the mixolimnion of the lake ([TNmix ] and [TPmix ], respectively) using 29 yr of monitoring data. In addition, we assessed the causal relationship between the D/C and the lake nutrient concentrations. There was large year-to-year variation in D/C during April (D/CApr ), which accounted for 7-31% of the mixolimnion volume. Significant positive correlations were observed between D/CApr and [TNmix ] from the ensuing April to September. On an annual basis, 49% of the interannual variation of the mean [TNmix ] during the ensuing April to September was explained by the interannual variation of D/CApr . Therefore, D/CApr could be useful as a simple index to [TNmix ] in the ensuing spring to summer. It is notable that the relationships between D/CApr and [TNmix ] from April to September was indicated to be acausal by statistical causal inference. Common climate conditions that increase D/CApr (i.e., a cold winter with a high level of precipitation) were found to drive other biogeochemical processes that increased [TNmix ] during the ensuing spring to summer.


Assuntos
Lagos , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise
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