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1.
Food Chem ; 366: 130527, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34284186

RESUMEN

A novel dual quantum dot nanobeads-based fluorescence-linked immunosorbent assay (QBs-FLISA) was successfully developed for simultaneously detecting aflatoxin B1 (AFB1) and zearalenone (ZEN) in feedstuffs. Dual CdSe/ZnS quantum dot nanobeads with different diameters that emit red and green fluorescence were conjugated with anti-AFB1 and anti-ZEN monoclonal antibodies to prepare fluorescent probes, which greatly enhance analytical performance. Under the optimal conditions, the limits of detection for AFB1 and ZEN were 9.3 and 102.1 pg mL-1, respectively. The recoveries ranged from 82.50% to 116.21% with relative standard deviation less than 11.3%. Compared with traditional enzyme-linked immunosorbent assay, detection sensitivities of AFB1 and ZEN using QBs-FLISA were increased 20 and 5 folds, respectively. In addition, results of feedstuff samples analyzed by QBs-FLISA and liquid chromatography tandem mass spectrometry showed a good agreement (R2 = 0.99).


Asunto(s)
Puntos Cuánticos , Zearalenona , Aflatoxina B1/análisis , Contaminación de Alimentos/análisis , Inmunoadsorbentes , Límite de Detección , Zearalenona/análisis
2.
Food Chem ; 366: 130592, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34293549

RESUMEN

An exhaustive migration study of eight corks, made of ethylene-vinyl acetate, was carried out to identify any non-volatile and volatile compounds using an untargeted approach. The challenge associated with the structural elucidation of unknowns was undertaken using both ultra-high-performance liquid chromatography coupled to an ion-mobility separation quadrupole-time of flight mass spectrometer and gas chromatography mass spectrometry. A total of fifty compounds were observed to migrate from the corks, and among these additives such as antioxidants (Butyl 4-hydroxybenzoate, Irganox 1010, Irganox 1075, Irgafos 168 and BHT) or lubricants (EBO and octadecanamide, N,N'-1,2-ethanediylbis-) were identified. A high proportion (84%) of the detected compounds was non-intentionally added substances (NIAS), and included several cyclic oligomers with different chain sequences. NIAS, such as 2,6-bis(1,1-dimethylethyl)-4-ethyl and 7,9-ditert-butyl-1-oxaspiro[4.5]deca-6,9-diene-2,8-dione, break-down products, including hexa-, hepta- and nonadecanamide, N,N'-1,2-ethanediylbis-, and oxidation products were also identified. One cork was found to be unsuitable for use as a food contact material.


Asunto(s)
Contaminación de Alimentos , Embalaje de Alimentos , Cromatografía Liquida , Etilenos , Contaminación de Alimentos/análisis , Cromatografía de Gases y Espectrometría de Masas , Espectrometría de Masas , Compuestos de Vinilo
3.
Food Chem ; 366: 130588, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34314930

RESUMEN

1H NMR fingerprinting of edible oils and a set of multivariate classification and regression models organised in a decision tree is proposed as a stepwise strategy to assure the authenticity and traceability of olive oils and their declared blends with other vegetable oils (VOs). Oils of the 'virgin olive oil' and 'olive oil' categories and their mixtures with the most common VOs, i.e. sunflower, high oleic sunflower, hazelnut, avocado, soybean, corn, refined palm olein and desterolized high oleic sunflower oils, were studied. Partial least squares (PLS) discriminant analysis provided stable and robust binary classification models to identify the olive oil type and the VO in the blend. PLS regression afforded models with excellent precisions and acceptable accuracies to determine the percentage of VO in the mixture. The satisfactory performance of this approach, tested with blind samples, confirm its potential to support regulations and control bodies.


Asunto(s)
Contaminación de Alimentos , Aceites Vegetales , Contaminación de Alimentos/análisis , Espectroscopía de Resonancia Magnética , Aceite de Oliva/análisis , Aceites Vegetales/análisis , Espectroscopía de Protones por Resonancia Magnética , Aceite de Girasol
4.
Food Chem ; 366: 130654, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34325246

RESUMEN

Patulin (PAT) is a potent mycotoxin commonly found in apples and apple-based products such as juice, thus affecting global food safety. Therefore, development of fast and simple analytical methods to effectively control its contamination is of great importance. This study developed and validated a technique for the analysis of PAT in samples of industrialized apple juice based on liquid-liquid extraction and using acetonitrile as the extraction solvent. Detection via mass spectrometry was performed after Atmospheric Pressure Chemical Ionization (APCI). Mean recoveries of 97.5, 92.49 and 96.92% were reached for 4, 8 and 20 µg/L of PAT, respectively. The analyte was monitored with an APCI source in negative ion mode to identify its fragments. The 24 analyzed samples presented PAT levels below the limit of quantification. It may be concluded that the method fulfilled all of the validation criteria, thus being appropriate for routine surveillance of PAT in apple juice.


Asunto(s)
Malus , Patulina , Bebidas/análisis , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Contaminación de Alimentos/análisis , Patulina/análisis , Espectrometría de Masas en Tándem
5.
Food Chem ; 367: 130734, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34359003

RESUMEN

Isocycloseram is a new isoxazoline insecticide that can efficiently control the diamondback moth in cruciferous crops. The aim of this study was to establish a method for the determination of isocycloseram residues in/on cabbage and in the soil using HPLC-UV at 264 nm. A field test was conducted in December 2019 and 2020 to monitor isocycloseram dissipation in Jiangxi, China. Acetonitrile was used to extract isocycloseram from cabbage and soil. C18 and GCB were used to purify cabbage extracts, whereas soil extracts did not require purification. At the addition level of 0.01-1.0 mg/kg, the average recoveries in cabbage and soil were 91.81-109.95% and 89.89-104.08% respectively. After having applied 10% isocycloseram DC, isocycloseram dissipated faster in the cabbage matrix. Isocycloseram residues on cabbage leaves could be removed through simple cleaning methods, especially by soaking in 2% citric acid.


Asunto(s)
Brassica , Residuos de Plaguicidas , Contaminantes del Suelo , Cromatografía Líquida de Alta Presión , Semivida , Residuos de Plaguicidas/análisis , Suelo , Contaminantes del Suelo/análisis
6.
Food Chem ; 368: 130808, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34419793

RESUMEN

As stingless bee honey (SBH) is gaining in popularity in the Malaysian market, it is now prone to adulteration. The higher price of SBH compared to floral honey has led to the use of unusual adulterants such as vinegar and even floral honey to mimic the unique taste and appearance of SBH. Since the current AOAC 998.12 method fails to detect these adulterants as their δ13C values are in the range for C3 plants, untargeted 1H NMR metabolomics was proposed. Principal component analysis of SBH 1H NMR fingerprints was able to distinguish authentic SBHs from adulterated ones down to 1% adulteration level for selected adulterants. Discriminant analysis showed promising results in distinguishing the preliminary datasets of authentic SBHs from the adulterated ones, including discriminating SBHs adulterated with different adulterants derived from C3 and C4 plants. Hence, to assure any emerging adulterant can be detected, all 1H NMR regions should be considered.


Asunto(s)
Miel , Animales , Abejas , Contaminación de Medicamentos , Miel/análisis , Espectroscopía de Resonancia Magnética , Metabolómica , Espectroscopía de Protones por Resonancia Magnética
7.
Food Chem ; 368: 130765, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34474243

RESUMEN

In this research, more than 302,000 images of five different types of extra virgin olive oils (EVOOs) have been collected to train and validate a system based on convolutional neural networks (CNNs) to carry out their classification. Furthermore, comparable deep learning models have also been trained to detect and quantify the adulteration of these EVOOs with other vegetable oils. In this work, three groups of CNN models have been tested for (i) the classification of all EVOOs, (ii) the detection and quantification of adulterated samples for each individual EVOO, and (iii) a global version of the previous models combining all EVOOs into a single quantifying CNN. This last model was successfully validated using 30,195 images that were initially isolated from the initial database. The result was an algorithm capable of detecting and accurately classifying the five types of EVOO and their respective adulteration concentrations with an overall hit rate of >96%. Therefore, EVOO droplet analyses via CNNs have proven to be a convincing quality control tool for the evaluation of EVOO, which can be carried by producers, distributors, or even final consumers, to help locate adulterations.


Asunto(s)
Contaminación de Alimentos , Aceites Vegetales , Contaminación de Medicamentos , Contaminación de Alimentos/análisis , Redes Neurales de la Computación , Aceite de Oliva/análisis
8.
Environ Monit Assess ; 193(11): 707, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623523

RESUMEN

Today, environmental pollution, air pollution in particular, is among the most important problems in the world. Air pollution, which has become a global issue, is estimated to cause the death of around 1 in 8 people worldwide. Due to the significance of air pollution, all components of air pollution are of great importance for human health, and thus the studies on air pollution are highly important, especially in areas with high population density. In this study, it was aimed to determine the regional and periodic change of CO2 and particulate matter pollution in the city of Misurata, one of the important cities of Libya. The study was conducted in the city centre of Misurata, and the measurements were made once in every three days between November and February at 7 different locations selected in the city centre. As a result of the measurements made, the changes in the pollution parameters were evaluated on the basis of zones and months. As a result of the study, the cleanest areas were found to be the industrial area (B3) located in the east of the city and the zone (B4), where the Al-Swehli farm was located, while the dirtiest areas were found to be the main street (B1 and B2) in the city centre and the city centre, in general. In terms of months, the lowest CO2 values were obtained in January, and the highest value was in February, whereas the lowest particulate matter values were obtained in January and the highest values in December.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Dióxido de Carbono , Monitoreo del Ambiente , Humanos , Material Particulado/análisis
9.
Environ Monit Assess ; 193(11): 705, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623520

RESUMEN

Trace metals are vital to primary productivity and play an essential role as main components in regulating oceanic biogeochemical cycles. Dissolved and particulate trace metals within the water column may vary due to primary production, temperature, and nutrient changes, factors that may also vary spatially and temporally. Furthermore, assessment of trace metals mainly relies on in situ observation, and so wide-area investigation of trace-metal concentration may be challenging and subject to technical constraints. A specific approach is therefore necessary that combines biogeochemical proxies, satellite data, and trace-metal linear correlation. This study aims to assess the potential spatio-temporal variability of sea surface cadmium (Cd) and copper (Cu) concentrations in Indonesian seas and surrounding areas. The correlations of Cd and Cu concentrations with primary production and nutrient data were used to convert hindcast satellite data into estimates of the metals' concentrations. The potential variability of trace metals can be determined by overlaying both data. Indonesia's Fisheries Management Areas (FMAs) were used for data clustering and analysis. The results show that Cd and Cu trace metals have similar distribution patterns throughout the year. However, dissolved Cu has a more diverse coverage area than dissolved Cd, including within the Halmahera, Seram, and Maluku Seas (FMAs 716 and 717), the Makassar Strait (FMA 717), and the Java-Sumatra upwelling area (FMA 573). Both Cd and Cu concentrations in the Java-Sumatra upwelling region follow the periodic upwelling pattern. Overall, both Cd and Cu show a declining trend in concentration from 2012 to 2019. It is estimated that dissolved Cd concentration declined from 1500-2000 pmol/kg in 2012 to 1000-1500 pmol/kg in 2019 for all locations. Dissolved Cu concentration decreased from 30-35 nmol/kg in 2012 to 25-30 nmol/kg in 2019. Estimated dissolved Cd and Cu follow the linear functions of silicate (SiO4), nitrate (NO3), and primary productivity. The fluctuation of anthropogenic activities and global warming are likely to indirectly impact the decline in metal concentrations by affecting nutrients and primary productivity.


Asunto(s)
Metales Pesados , Oligoelementos , Cadmio/análisis , Cobre/análisis , Monitoreo del Ambiente , Metales Pesados/análisis , Oligoelementos/análisis
10.
Environ Monit Assess ; 193(11): 703, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623531

RESUMEN

The Nile River is the soul of Egypt, providing more than 95% of its freshwater demand. However, it receives different pollutants discharged into the water body along its stretch from Aswan (downstream of the High Dam) to Cairo, which is approximately 950 km. Alternatively, sediments play an important role in the dynamics of the entire aquatic environment and act as a sink or a source of pollution in the overlying water under various conditions. This study assessed sediment quality and its heavy metal levels. Several indices and human health risks were determined to assess the potential ecological risk of the Nile River sediment. On the basis of the index results, Cd registered the highest pollution ranking, whereas Fe, Mn, Zn, Cu, and Ni had the lowest effect. In another context, southern sites represented the lowest ecological risk relative to the central and northern sectors. The results of the noncarcinogenic hazard indices, hazard quotient, and hazard index in addition to the lifetime cancer risk were below the acceptable international limits, confirming that there are no adverse effects on the exposed population due to the Nile sediment.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Egipto , Monitoreo del Ambiente , Sedimentos Geológicos , Humanos , Metales Pesados/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis
11.
Environ Monit Assess ; 193(11): 708, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34623541

RESUMEN

Air pollution is associated with several severe physical, behavioral, and psychological health risks and glitches. Air pollution has been linked to 11 million premature deaths in Pakistan, out of the total 153 million premature deaths worldwide. Air pollution is continuously growing as a threatening challenge for Pakistan. Keeping this in view, the current study was designed to assess air pollution in terms of air quality index (AQI), particulate matters (PM2.5 and PM10), SO2, NO2, and O3 over six districts of Malakand division, Northern Pakistan. The second part of the study appraised the associated self-reported effects of air pollution on Pakistani students and the practices, perceptions, and awareness of the students regarding air pollution through a closed-ended questionnaire, administered to 4100 students. The first section of the questionnaire was focused on the physical effects associated with air pollution; the second section was focused on air pollution-linked behavior and psychology; the third portion was focused on perception and awareness of the subjects, whereas the final section was focused on practices and concerns of the subjects regarding air pollution. The students reported that exposure to air pollution significantly affected their physical health, behavior, and psychology. The subjects were aware of the different air pollutants and health complications associated with air pollution, and therefore had adopted preventive measures. It was concluded that air pollution had adverse impacts on the physical and psychological health of the respondents, which consequently altered their behavior. Mass awareness, proper mitigating plan, suitable management, and implementation of strict environmental laws are suggested before the air gets further polluted and becomes life-threatening.


Asunto(s)
Contaminación del Aire , Monitoreo del Ambiente , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Humanos , Pakistán , Autoinforme , Estudiantes
12.
Environ Monit Assess ; 193(11): 709, 2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34625850

RESUMEN

This study assessed the contamination of streams with potentially toxic elements (PTEs) in sediments around mining, quarrying, and cultivation areas in Akamkpa and environs Southeastern Nigeria. Analysis done using ICP MS technique shows that barium (Ba) and lead (Pb) recorded mean concentrations above their average shale content (ASC) in stream sediments. Chromium (Cr) exceeded Canadian Interim Sediment Quality Guideline (ISQG) and US Environmental Protection Agency (USEPA) screening benchmark value. Pb exceeded Canadian ISQG value but tallies with USEPA benchmark value. Pearson's correlation exhibited significant correlation (p < 0.01) of molybdenum (Mo) with copper (Cu) and Pb; Cu with Pb, vanadium (V), and Ba; V with Cu, Pb, iron (Fe), Ba, and beryllium (Be); and Fe with Be and V. Principal component (PC 1) consists of Pb, Mo, cobalt (Co), Cu, arsenic (As), Cr, V, and nickel (Ni) and showed significant correlation. Geo accumulation index (I-geo) values for Mo, Cu, V, Pb, Zn, Ni, Co, Mn, and Ba fall under unpolluted (0) to moderately polluted (1-2) classes. Maximum enrichment factor (EF) values show extremely high and significant enrichment of Ba and Pb in few locations. Co, Cr, Cu, Mn, and Zn possess maximum EF values classified as moderate enrichment. Ni, Mo, As, and V obtained maximum EF values classified as depleted to minimal enrichment. Modified pollution index (MPI) values showed high PTEs contamination in mostly cultivation locations. Single element potential ecological risk (EiR) mean values trend EiR (As) > EiR (Pb) > EiR (Co) > EiR (Cr) > EiR (Cu) > EiR (V) > EiR (Ni) > EiR (Zn). Comprehensive potential ecological risk (RI) shows medium risk "B" and strong risk "C" levels in few locations. The use of multiple pollution indices such as I-geo, EF, EiR, and RI in pollution assessment indicated similar trend of PTEs contamination of stream sediments. Levels of PTEs contamination are elevated in cultivation areas more than in granite quarrying and mining areas. This study serves as a benchmark for conducting suitable environmental management strategies to scientists in Nigeria and other parts of the world.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Sulfato de Bario , Canadá , Monitoreo del Ambiente , Sedimentos Geológicos , Metales Pesados/análisis , Nigeria , Medición de Riesgo , Ríos , Dióxido de Silicio , Estados Unidos , Contaminantes Químicos del Agua/análisis
13.
Environ Monit Assess ; 193(11): 697, 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34618243

RESUMEN

Short-duration high-strength human tourism activities (SHHTA) can result in more air pollution emissions owing to increase motor vehicle usage, energy consumption and cooking fume emissions. Because of the strong uncertainty of human tourism behaviour, it is difficult to accurately assess the impact of SHHTA on air quality of natural scenic spots. To overcome this difficulty, we propose a novel ensemble empirical mode decomposition and detrended cross-correlation analysis (EEMD-DCCA) model to assess the influence of short-duration high-strength human tourism activities (SHHTA) on air quality. Zhangjiajie in China was selected as the study area. Hourly concentrations of NO2 were analysed from 1 January 2016 to 31 December 2018 at two monitoring sites, in an urban area and a scenic spot. Through EEMD, the main modes of NO2 with short-duration high-frequency were obtained for both sites. The DCCA method was used to study the cross-correlation relationship between high-frequency modes of NO2 for the urban area and scenic spot. The results show that high-frequency modes of NO2 between the two sites displayed long-range cross-correlation at the 24-h time scale. Furthermore, the quantitative impacts of meteorological factors (e.g. precipitation, temperature, and wind speed) on the DCCA exponent for high-frequency modes of NO2 at the two sites were investigated. The novel model proposed in this study is not restricted by the uncertainty of pollution emission inventory. The relationship between meteorological factors and DCCA exponents corresponds to the hypothesis that NO2 pollution of the natural scenic spot mainly came from SHHTA.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Monitoreo del Ambiente , Humanos , Turismo
14.
Environ Monit Assess ; 193(11): 701, 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34622329

RESUMEN

For the efficient functioning of a landfill, compacted bentonite is an acclaimed liner element due to its excellent adsorption capability, minimal hydraulic conductivity, and superior specific surface area (SSA). However, the leachate generation within the landfill worsens the liner material's quality, causing migration of the leachates, contaminating groundwater, and causing pollution of surrounding environment. With this perspective, a comparative assessment of the influence of real and simulated municipal solid waste (MSW) leachate on two different bentonites has been carried out in the present investigation. The two bentonites, differing precisely by their cation exchange capacity (CEC), liquid limit (LL), and swelling capability, were examined for variation in their LL, free swell (FS), and hydraulic behaviour concerning their interaction with both leachates. Results depicted that in both the leachates, LL and FS, swelling potential (SP) and pressure declined, whereas hydraulic conductivity (HC) rose. Furthermore, the bentonite quality greatly influenced the LL, FS, SP, swelling pressure, and hydraulic behaviour. Bentonite having higher CEC, SSA, and swelling ability experienced a higher variability in the LL (55.5 and 65.2% decrease), free swelling (76.9 and 83.1% decrease), SP, swelling pressure (53.3 and 56.4% decrease), and HC (13.1 and 49.4 times increase) values when permeated with simulated and real MSW leachates, respectively. The study also showed that the real MSW leachate interaction causes a higher variation in bentonite behaviour than its simulated counterpart. The study's findings would prove beneficial to design engineers for selecting bentonite types for landfill liners.


Asunto(s)
Eliminación de Residuos , Contaminantes Químicos del Agua , Bentonita , Monitoreo del Ambiente , Residuos Sólidos , Instalaciones de Eliminación de Residuos , Contaminantes Químicos del Agua/análisis
15.
Environ Monit Assess ; 193(11): 699, 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34622348

RESUMEN

In response to the Minamata Convention on Mercury, international organizations, governments, nonprofit organizations, and other institutions as well as individuals have worked to promote the development and implementation of safe and environmentally healthy practices, processes, and products. It is expected that the accumulation of mercury in the natural environment will decrease in volume each year. However, even after Hg ceases to be used, the Hg already accumulated in forests will continue to pose an ecological risk. Forest fires are serious events, partly because they release accumulated Hg from the environment. In this study, the effects of forest fires on the accumulation and chemical species of Hg in soil, related to the mobilization of Hg, were investigated. The research was conducted in secondary forests located near artisanal small-scale gold mining sites, where Hg is used for the amalgamation of gold in Camarines Norte, Philippines. The results showed that the original Hg accumulation level in the burned forest was not as high as that in the control forest, and that burn severity might have affected only the surface soil (0-5 cm). However, the proportion of water-soluble Hg, which was derived from ash, was increased by fire. Therefore, it is suggested that forest fires not only increase the release of Hg into the atmosphere but also increase the outflow risk to the aquatic system through rainfall.


Asunto(s)
Mercurio , Incendios Forestales , Monitoreo del Ambiente , Oro , Humanos , Mercurio/análisis , Minería , Suelo
16.
J Environ Sci (China) ; 109: 45-56, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34607673

RESUMEN

Stringent quarantine measures during the Coronavirus Disease 2019 (COVID-19) lockdown period (January 23, 2020 to March 15, 2020) have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of 2019. Particularly, 22.7% decrease in NO2 and 3.0% increase of O3 was observed in Tianjin, nonlinear relationship between O3 generation and NO2 implied that synergetic control of NOx and VOCs is needed. Deteriorating meteorological condition during the COVID-19 lockdown obscured the actual PM2.5 reduction. Fireworks transport in 2020 Spring Festival (SF) triggered regional haze pollution. PM2.5 during the COVID-19 lockdown only reduced by 5.6% in Tianjin. Here we used the dispersion coefficient to normalize the measured PM2.5 (DN-PM2.5), aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM2.5 reduction, which reduced by 17.7% during the COVID-19 lockdown. In terms of PM2.5 chemical composition, significant NO3- increase was observed during the COVID-19 lockdown. However, as a tracer of atmospheric oxidation capacity, odd oxygen (Ox = NO2 + O3) was observed to reduce during the COVID-19 lockdown, whereas relative humidity (RH), specific humidity and aerosol liquid water content (ALWC) were observed with noticeable enhancement. Nitrogen oxidation rate (NOR) was observed to increase at higher specific humidity and ALWC, especially in the haze episode occurred during 2020SF, high air humidity and obvious nitrate generation was observed. Anomalously enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Control de Enfermedades Transmisibles , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , SARS-CoV-2
17.
Environ Monit Assess ; 193(11): 693, 2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34611743

RESUMEN

Plastics (n = 3880) have been sampled from 39 beaches of ten Swiss lakes of varying sizes, hydrodynamics, and catchments, with a selection (n = 598) analysed for potentially hazardous (and regulated) chemical elements (As, Ba, Br, Cd, Cr, Hg, Pb, Sb, Se) by X-ray fluorescence spectrometry. Plastic objects and fragments with identifiable or unidentifiable origins were present on all beaches surveyed, and were often most abundant in proximity to major riverine inputs. Chemical elements were detected in between two (Hg) and 340 (Ba) samples with maximum concentrations exceeding 2% by weight for Ba, Cd, Cr, Pb, and Sb. Inter-element relationships and characteristics of the samples suggest that elements are largely present as various additives, including pigments (e.g., Cd2SSe, PbCrO4), stabilizers (in polyvinyl chloride), and flame retardants (Br). Observations are similar to, and complement, those previously reported in Switzerland's largest lake (Lake Geneva). Comparison of concentrations of targeted chemical elements in beached plastic with currently used plastics illustrate the interest of these types of measurements in providing an insight into the persistence of plastics in standing stocks and in lakes. This information could help to introduce management schemes that consider whether plastic pollution is new or old and act accordingly.


Asunto(s)
Retardadores de Llama , Plásticos , Monitoreo del Ambiente , Retardadores de Llama/análisis , Lagos , Suiza
18.
J Environ Sci (China) ; 110: 38-47, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34593193

RESUMEN

To assess groundwater nitrate contamination and its human health risks, 489 unconfined groundwater samples were collected and analyzed from Zhangjiakou, northern China. The spatial distribution of principle hydrogeochemical results showed that the average concentrations of ions in descend order was HCO3-, SO42-, Na+, Ca2+, Cl-, NO3-, Mg2+ and K+, among which the NO3- concentrations were between 0.25 and 536.73 mg/L with an average of 29.72 mg/L. In total, 167 out of 489 samples (~ 34%) exceeded the recommended concentration of 20 mg/L in Quality Standard for Groundwater of China. The high NO3- concentration groundwater mainly located in the northern part and near the boundary of the two geomorphic units. As revealed by statistical analysis, the groundwater chemistry was more significantly affected by anthropogenic sources than by the geogenic sources. Moreover, human health risks of groundwater nitrate through oral and dermal exposure pathways were assessed by model, the results showed that about 60%, 50%, 32% and 26% of the area exceeded the acceptable level (total health index>1) for infants, children, adult males and females, respectively. The health risks for different groups of people varied significantly, ranked: infants> children> adult males>adult females, suggesting that younger people are more susceptible to nitrate contamination, while females are more resistant to nitrate contamination than males. To ensure the drinking water safety in Zhangjiakou and its downstream areas, proper management and treatment of groundwater will be necessary to avoid the health risks associated with nitrate contamination.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Nitratos/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
19.
Sci Total Environ ; 781: 146691, 2021 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-34594059

RESUMEN

Levels of total mercury were measured in tissue of six species of migratory fish (alewife, American shad, blueback herring, rainbow smelt, striped bass, and sea lamprey), and in roe of American shad for two consecutive years collected from the Penobscot River or its estuary. The resultant mercury levels were compared to reference doses as established in the U.S. Environmental Protection Agency (EPA) Integrated Risk Information System and wildlife values. Mercury concentrations ranged from 4 µg/kg ww in roe to 1040 µg/kg ww in sea lamprey. Sea lamprey contained the highest amounts of mercury for both seasons of sampling. Current health advisories are set at sufficient levels to protect fishers from harmful consumption of the fish for mercury alone, except for sea lamprey. Based upon published wildlife values for mink, otter, and eagle, consumption of rainbow smelt, striped bass, or sea lamprey poses a risk to mink; striped bass and sea lamprey to otter; and sea lamprey to eagle. For future consideration, the resultant data may serve as a reference point for both human health and wildlife risk assessments for the consumption of anadromous fish. U.S. EPA works with federally recognized Tribes across the nation greatly impacted by restrictions on sustenance fishing, to develop culturally sensitive risk assessments.


Asunto(s)
Mercurio , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Estuarios , Peces , Humanos , Maine , Mercurio/análisis , Ríos , Contaminantes Químicos del Agua/análisis
20.
Environ Monit Assess ; 193(10): 682, 2021 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-34595610

RESUMEN

Local primary emissions of air pollutants are responsible for public health, decreasing productivity, and cultural activities in local residential areas. In this study, an integrated air quality observation and modeling system with a geographical information system (GIS) was developed to characterize the air pollution caused by local primary emission sources. This integrated system could provide air quality monitoring, data analysis, and visualization results that reflect air pollutant concentration data in a study area containing a local rural village (LRV) and an asphalt manufacturing facility (AMF). Additionally, the model was used to estimate the contributions of air quality from an emission source at the receptor and determine the control factor for the emission rate or meteorological changes. From the forward and backward modeling results, we found that the concentrations of particulate matter smaller than 2.5 µm (PM2.5) concentrations in the village were affected by the unique meteorological and emission conditions. The PM2.5 concentration was significantly increased for the cases with a slow wind speed of 1 m/s or high wind speed of 3 m/s, with an emission rate of 10 g/s. The contribution of AMF emissions was explained by contribution factor analysis. During the study period of December 2014-December 2015, the incoming contribution of PM2.5 at the LRV measurement station was approximately 47.6%. These results suggest that the proposed method can be useful for understanding adverse air quality conditions and estimating the emissions of air pollutants from primary sources for local environmental and public health authorities.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente , Sistemas de Información Geográfica , Material Particulado/análisis
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