Bulletin of Environmental Contamination and Toxicology

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Izmir Bay Sampling Location
  • Selma KatalaySelma Katalay
  • Melike Merve AyhanMelike Merve Ayhan
  • Cem GulerCem Guler
  • [...]
  • N. Ulku Karabay YavasogluN. Ulku Karabay Yavasoglu
In this study, cellular biomarkers and heavy metal concentration in the Mytilus galloprovincialis L. (Mediterranean mussels) collected from eight sites of Izmir Bay (Turkey) were determined to reveal water pollution for the first time in these stations. Results show that heavy metals (As, Cu, Hg, Zn, Cd, Sn, Pb) have been specified in mussels’ tissues collected from all stations. According to GST, SOD, CAT activities, and TBARS contents, mussels in the outer bay have exposed more oxidative stress than the ones in the inner bay. Digestive gland tissues of them were showed more inhibition at AChE levels than gills. Also, abnormal nucleus rates and micronucleus frequencies (MN) were found to be higher in the inner bay than in the outer bay. This study showed that heavy metal pollution in different levels is an environmental issue on the Izmir Bay. Especially the coastal regions of the bay have been extremely affected by anthropogenic effects due to growing population.
Map of the study area showing sampling sites. S1: sampling site located in the northern Tunisian coasts (Rades harbor). S2: sampling site located in the southern Tunisian coasts (Zarzis harbor)
Biomarker responses in the soft tissues of Brachidontes pharaonis collected at two sites along the Tunisian coasts, the Rades harbor in the North (N) and the Zarzis harbor in the South (S). a Malondialdehyde (MDA); b metallothionein (MT); c reduced glutathione (GSH); d glutathione peroxidase (GPx); e superoxide dismutase (SOD); f Catalase (CAT). *Statistically different (p < 0.05)
  • Khaoula TelahigueKhaoula Telahigue
  • Mouna AntitMouna Antit
  • Imen RabehImen Rabeh
  • [...]
  • Lazhar MhadhbiLazhar Mhadhbi
This study aims to verify the relevance of Brachidontes pharaonis to assess the ecotoxicological status of polluted sites. For this, the levels of some heavy metals (i.e. Zn, Cu, Pb, and Cd) and a battery of biomarkers including metallothionein (MT), malondialdehyde (MDA), reduced glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) were assessed in mussels collected from the harbor of Rades (North), and the harbor of Zarzis (South). Moreover, abiotic parameters including temperature, salinity, pH, and dissolved oxygen were assessed. Results from the ICP-OES showed that the southern population exhibited a higher metal pollution index with significantly higher Zn, Cu, and Pb concentrations. Moreover, the specimens from Zarzis displayed significantly higher levels of MDA, MT, GSH, GPx, SOD, and CAT reflecting higher levels of oxidative and chemical stress. These results emphasize the potential utility of B. pharaonis for the monitoring of heavily impacted sites.
Geographical data of the selected study sites of both Vellar and Kollidam Rivers
Shape distribution of MPs in the fish species collected from the Kollidam and Vellar
Colour distribution of MPs in the fish species collected from the Kollidam and Vellar
Microplastics (MPs) in the gastrointestinal (GI) tracts of the five fish species from the Kollidam and Vellar rivers of Tamil Nadu, Southern India were evaluated. A total of 315 MPs were isolated from GI tracts of 23 fishes (Chanos chanos, Chanda nama, Chelon macrolepis, Carangoides malabaricus and Gerrus filamentosus) sampled from both rivers. MPs ranged from 109 to 129 μm (119 ± 79.7) and 181 to 284 μm (122 ± 92.6) in size, with fibres (85.7%) and fragments (14.3%) being the most common ones in the fishes from Kollidam and Vellar river, respectively. The colour pattern of ingested MPs was dominated by blue, transparent, red, yellow and black in collected fishes from both rivers. In this study, MPs were higher in fishes with omnivore feeding habits due to their broad diet habits. Moreover, urban wastes, fishing and agricultural activities are the possible primary sources of MPs in both rivers.
Life expectancy at hatching, net reproductive rate, intrinsic rate of increase, and proportion of mictic offspring of B. calyciflorus exposed to different temperatures and imidacloprid concentrations relative to controls (mean ± standard error). The dotted line indicates the response of control. Asterisks (*) indicate means that are different from the control at each temperature, and the same lowercase letter means that are similar between two temperatures for the same IMI concentration (P > 0.05)
Global warming and pesticide contamination are two stressors of high concern, but their combined effects on freshwater biota are controversial. This study investigated the combined effects of warming and imidacloprid (IMI) on survival (measured as life expectancy at hatching), reproduction (net reproductive rate), population growth (intrinsic rate of population increase) and sexual reproduction (proportion of sexual offspring) of Brachionus calyciflorus using a life table experiment. The results showed that compared with controls, treatments with IMI at 50–100 mg/L significantly decreased survival, reproduction and population growth of the rotifers at 20℃. The inhibiting effect at higher IMI concentrations on survival increased with increasing temperatures, but those on reproduction and population growth increased only when the temperature increased from 25℃ to 30℃. The proportion of sexual offspring decreased with increasing temperatures. When monitoring the ecological effects of pollutants, environmental temperature and the possible adaptation of rotifers to it should be taken into consideration.
The Nile River islands are recognized as the most productive lands in Egypt. Although, these islands are vulnerable to several natural and man-made crises. The present study was aimed to evaluate the consequences of different anthropogenic activities on the heavy metals load and histological alterations in O. niloticus and S. galilaeus collected from four different Nile River islands along the Great Cairo sector (Egypt), and the possible health risks for human consumers. Metals were accumulated in both fish muscles in the following order: Fe > Zn > Cu > Mn > Pb. S. galilaeus was recorded higher metal pollution index than O. niloticus, while El-Warrak Island was documented the highest MPI and hazard quotient among all sampling sites. All sampled tissues were recorded histopathological lesions in both fish. The present study may be considered as an early alert for habitual consumers, particularly at high consumption rates of some fish species.
a) Study area b) Sampling locations for river sediments and top soil samples
Microplastic fiber obtained from the field after processing (a-Fibre;b-fragment;c-Film)
The study focuses on analyzing the presence and quantity of microplastics near an unscientific solid waste dumping site located at Kochi city in India and thereby assessing the contribution of massive open dumping towards microplastic pollution in the river. Two sets of sampling with three sediment samples from nearby Kadambrayar river and five topsoil samples from various parts of the Brahmapuram waste dumping yard were carried out during January – February 2019. The samples were analyzed as per the US National Oceanic and Atmospheric Administration (US NOAA) protocol. ATR-FTIR and DSC analysis based characterization indicated that polyethylene dominated the micro plastics followed by polypropylene and polystyrene. The size distribution of particles showed that comparatively larger particles of size range between 2.36 − 4.75 mm were present in the topsoil than that in river sediments which had more number of particles in size range below 2.36 mm. The study confirmed the presence of an average of 100 microplastic pieces per 100 gram of sediments of Kadambrayar river bordering the waste dumping yard at Brahmapuram. The topsoil of Brahmapuram waste dumping yard was found to contain 178 pieces of microplastics per 100 gm of soil. Microplastics are found to be high in the river stretch near the open dumping site which has a significant role in the pollution, causing a major threat to the entire ecosystem.
Cd concentration in roots and stems of L. leucocephala exposed at different treatments. Results show the average value of three replicates ± standard error. Same lowercase letters and uppercase letters represent no significant difference between treatments at p < 0.05
A K, B Ca, and C Mg concentrations in roots, stem, and leaves of L. leucocephala plants exposed to different Cd concentrations. Results represent the average value of three replicates ± standard error. Same lowercase letters, uppercase letters, and Greek letters represent no significant differences between treatments at p < 0.05
A Mn and B Zn concentrations in roots, stem and leaves of L. leucocephala exposed at different Cd concentrations. Results indicate the average value of three replicates ± standard error. Same lowercase letters, uppercase letters, and Greek letters represent no significant differences between treatments at p< 0.05
Enzymatic activity in roots and leaves of L. leucocephala exposed at different Cd concentrations. Results show the average value of three replicates ± standard error. Same lowercase letters and uppercase letters indicate no significant differences between treatments at p < 0.05
Environmental contamination with Cadmium (Cd) is of great concern due to its hazardous effects on living organisms.Query In the present research, Leucaena leucocephala plants were exposed to Cd concentrations of 5, 10, and 15 mg/L to determine their potential use in Cd remediation. Different parameters including Cd uptake, macro/micronutrient content, chlorophyl, and catalase production were determined. Results indicated that Cd uptake by L. leucocephala roots did not show a significant difference between treatments. However, a significant increase in Cd content (Tukey´s HSD) was observed in stems as Cd levels in the media augmented. The highest Cd content (830 ± 20 mg/kg) was determined in stems of plants exposed to 15 mg/L Cd, and no Cd was detected in leaves. Data showed that as Cd concentration increased in the media, Ca, Mg, K, Zn, and Mn decreased. Moreover, while the presence of Cd reduced catalase activity in roots, chlorophyll production was not affected.
Scanning electron microscopy (SEM) images of polystyrene and polyethylene particles before and after 3-month seawater exposure
(A) Surface roughness, (B) adhesion, and (C) Young’s modulus of polystyrene (PS) and polyethylene (PE) particles. (A1, B1, C1) pristine PS; (A2, B2, C2) aged PS; (A3, B3, C3) pristine PE; (A4, B4, C4) aged PE
Adsorption isotherms of DEHP on microplastic particles
Microplastics (MPs) are a widely distributed pollutant and have been attracting global attention. The increasing abundance of MPs in marine environments has raised concern about their adverse effects on marine organisms and influence on the fate of contaminants in seawater. In this study, we investigated the effects of natural aging on the adsorption of di (2-ethylhexyl) phthalate (DEHP), one of the most widely used phthalic acid esters (PAEs), in two types of MPs (polyethylene and polystyrene). Biofilm was observed on the surface of MPs after 3-month exposure in seawater. Atomic force microscopy revealed there were significant physical changes in the MPs after aging. Aging in coastal seawater for 3 months significantly reduced the MPs’ surface roughness and adhesion, and increased the Young’s modulus at the same time. Adsorption isotherms of DEHP indicated that aged MPs had stronger binding capacity of the organic contaminant than pristine MPs. Our data shed some light on the biogeochemical role of MPs in marine environments.
There are increasingly attentions on the pollution from microplastics, especially the impact on human health. This work focuses on one hand the effect of digestion system on the surface microstructures of microplastics from the most popular sources such as polypropylene, polyethylene, polyethylene terephthalate, polystyrene and polyvinyl chloride. On the other hand, how these microplastic affect probiotics in digestion system was also investigated to evaluate their toxicity on health. All the samples were treated by in vitro simulating digestion consisting of three phases: oral, gastric and intestinal. There were no physical differences observed by both Scanning Electronic Microscopy and Atomic Force Microscopy, and no significant chemical changes detected by both Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy after digestion treatment. The effect of these microplastics on tested strains were investigated by in vitro culture method and results showed that polystyrene microplastics could inhibit the growth of the Lactobacillus significantly. The results indicated that the digestion system could not decompose microplastics, even on the surfaces, since plastics are inert due to their low chemical reactivity, but the microplastics might lead to imbalance of intestinal microbiota.
Temporal variations of MeHg in sediments during the period of incubation with (a) A. philoxeroides (b) C. dactylon and (c) D. pyramidalis
Variations of %MeHg in sediments during the period of incubation
Variations of MeHg in overlying water during the period of incubation
To explore the effects of herbaceous plants on mercury (Hg) behaviors after flooding in the water-level fluctuation zone (WLFZ) of Jialing River, three typical local plants (D. pyramidalis, A. philoxeroides and C. dactylon) and their in-situ sediments were collected for flooding experiments to study the Hg dynamics of water and sediment in different treatments. The results showed that flooding increased sediment MeHg concentrations and flooded plants (especially for the D. pyramidalis) promoted this process. Similarly, the highest dissolved MeHg level and proportion of MeHg to total Hg (%MeHg) were observed in plant-water treatments in the presence of D. pyramidalis, indicating the potential for the methylation of Hg in the water body influenced by the decay process of herbaceous plants. These results suggest that the herbaceous plant D. pyramidalis contributes more to Hg methylation and release in the WLFZ of the Jialing River than other plants studied.
Content of total vitellogenic proteins in the ovary of females exposed to ibuprofen (IBU) or diclofenac (DCF), during the first (A) assay and second (B) in vivo assays. Mean ± standard error is indicated. Asterisks indicate significant differences (p < 0.05) compared to the control group.
Proportion of the different oocyte types in the ovary of females exposed to ibuprofen or diclofenac (5 mg/L each), during the second (A), and the third (B) in vivo assay. Means ± standard error is indicated. Asterisks indicate significant differences (p < 0.05) compared to the control) group.
Histological sections of ovaries from control (A), and diclofenac (B), showing normal vitellogenic (VO) and pre-vitellogenic (PO) oocytes. Reabsorbed oocytes are indicated by the asterisk. Ovaries were dissected from females exposed to 5 mg/L of diclofenac for 90 d (second in vivo assay). Scale bars: 50 μm.
The drugs ibuprofen and diclofenac were assessed in vivo on adult females of the estuarine crab Neohelice granulata. In a first, preliminary assay comprising 60-d, a significant (p < 0.05) lower content of total vitellogenic proteins was detected in the ovary at 10 mg/L of each drug. In a second 90-d assay, comprising the exposure of crabs to 5 mg/L of each drug during the entire pre-reproductive period, a significant (p < 0.05) decrease in the proportion of vitellogenic oocytes was observed by effect of diclofenac. The same effect was also observed in a third assay only comprising the last month of the pre-reproductive period, at 5 mg/L of diclofenac, and also at a mixture of both drugs; besides, this mixture significantly (p < 0.05) increased the proportion of reabsorbed vitellogenic oocytes. The obtained results indicate that the effect of diclofenac is critical at the final stage of ovarian maturation, when the participation of prostaglandins is relevant.
To determine whether the national soil heavy metal standards (GB 15618-2018) are applicable to some carbonate and non-carbonate zones in Southwest China, rice and rhizosphere soil samples were collected in Chongqing and analyzed for heavy metal contents, pH, and other chemical parameters. In addition, regression analysis was also used to predict the risk threshold of soil heavy metals. The Cd risk screening value in GB 15618-2018 was strict for alkaline soils (pH > 7.5) as compared to those revealed in carbonate and non-carbonate areas, while the calculated pollution threshold for Cd in acidic soils (pH ≤ 5.5) in the non-carbonate area was lower than that in GB 15618-2018. Therefore, to improve the applicability of the evaluation results, a soil-crop system evaluation is recommended.
Map showing location and sample collection points.
Source: Arc-GIS software
ANOVA analysis mean plot of heavy metals in different environmental compartments
The mean values of trace heavy metals
The mean values of major elements
The aim of the study was to assess the distribution of heavy metals in the environmental compartments from artisanal and small-scale gold mining (ASGM) activities from Lolgorian, Kenya. The investigation was carried out using Inductively-Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Mercury (p > 0.05) (p = 0.755), arsenic (p = 0.182), and lead (p = 0.430) mean concentrations in soil, water, sediments, and ore were not significantly different. The mean mercury, lead, and arsenic concentrations in the water were 0.66 mg/L, 0.46 mg/L, and 1.25 mg/L, respectively. In sediments, the mean values of Cr (66.65 mg/kg), Zn (45.62 mg/kg), Hg (24.63 mg/kg), Pb (22.35 mg/kg), Cd (0.90 mg/kg), and Mn (613.10 mg/kg) were found to be significantly higher. A positive correlation between ore-tailings (r = 0.971109), tailings-sediment (r = 0.9441036), and ore-sediment (r = 0.9441036), was observed indicating the presence of harmful heavy metals in the environment in excess of national and World Health Organization (WHO) recommended threshold, posing a high risk of multiple human exposure pathways.
Statistical data of the tested microplastics (a type, b shape, c particle size) and plant species (d)
Inhibitory mechanisms of microplastics on plants. The solid arrows refer to the direct influencing mechanism; the dotted arrows refer to the indirect influencing mechanism
Microplastics pose great risks to terrestrial systems owing to their large quantity and strong persistence. Higher plants, an irreplaceable part of the terrestrial ecosystem, are inevitably exposed to microplastics. This review highlights the effects of microplastics on higher plant growth and performance. The tested microplastics, plant species, and cultural methods used in existing studies were summarized. We discussed the reasons why these microplastics, plants, and methods were selected. The various responses of higher plants to microplastics in both soils and waters were critically reviewed. We also highlighted the influencing mechanisms of microplastics on higher plants. Conclusively, more than 13 types of common microplastics and more than 30 species of higher plants have been selected and studied by the published literatures. Soil culture tests and hydroponic experiments are almost equally divided. The effects of microplastics on higher plants varied among microplastic properties, plant species, and environmental factors. Microplastics had no or positive effects on higher plants under certain experimental conditions. However, more studies showed that microplastics can inhibit higher plant growth and performance. We reduced the inhibitory mechanisms into direct and indirect mechanisms. The direct mechanisms include blocking pores or light, causing mechanical damage to roots, hindering genes expression, and releasing additives. The indirect mechanisms contain changing soil properties, affecting soil microbes or soil animals, and affecting bioavailability of other pollutants. This review improves the understanding of effects and influencing mechanisms of microplastics on higher plants.
Map showing the 28 sampling sites located in 11 provinces, China
Map showing the distributions of selected heavy metals using Kriging interpolation method
We investigated the occurrence of Cd, Cr, Cu, Ni, Pb and Zn in 28 road dust samples collected across China from June to August, 2020. The mean concentrations of Cd, Cr, Cu, Ni, Pb and Zn were 3.16, 24.2, 27.4, 10.4, 49.8 and 608 mg·kg− 1, respectively. The mean levels of Cd and Zn exceeded the Chinese background values by 32.6- and 8.2- fold. Cd, Ni mainly distributed in southern China, whereas Cu, Pb and Zn mainly distributed in central China. Higher concentrations of Cd, Cr, Cu and Pb were found in road dusts from urban areas than those from rural areas. Cu and Ni mainly came from natural sources; Pb and Cd mainly originated from industrial emissions and vehicle exhaust. Hand-mouth ingestion was the most common exposure pathway for both adults and children, followed by dermal contact and inhalation. Pb was found to be the highest risk element via ingestion. No significant non-carcinogenic risks and carcinogenic risks were found for local residents.
Microfluidic paper-based analytical devices (μ-PADs) are a new technology platform for the development of extremely low-cost sensing applications. In this study, μ-PADs has been developed for quantitative determination of carbamate pesticides. Key experimental parameters including concentration and volume of acetylcholinesterase, acetylthiocholine iodide and 5,5′-dithiobis-(2-nitrobenzoic acid), incubation time and image capturing time were systematically optimized. Under optimal conditions, the method showed wide range of linearity (0.25–16 mg/L), repeatability (4%–5% RSD) and intermediate precision (7%–10% RSD). Limit of detection was observed to be 0.4, 0.24 and 0.46 mg/L for carbaryl, carbosulfan and furathiocarb, respectively. An acceptable mean recovery (87% to 94%) was observed for the three pesticides at 1 mg/L fortification level. The results reveal that the developed method requires minimal reagents, simple and is easy to handle. It can be used for the quantification of carbamate pesticides in resource limited laboratories without the need for the conventional analytical instruments.
Microbiota in paddy soil slurry systems successfully dechlorinated Aroclor1260, and the concentration of Cl⁻ significantly raised. (a) Residues of PCB congeners in group B and (b) the concentration of Cl⁻ in three groups at the end of the experiment. Group A went without the addition of Aroclor1260 and sterilization; group B was added with Aroclor1260 to a final concentration of 40 mg/kg; the control group CK was added with the same amount of Aroclor1260 but sterilized
Resides of PCB116 (a) and PCB153 (b) with or without the addition of organic matters. (c) Changes in the concentration of Cl⁻ under natural or enhanced conditions. Changes in Eh (d), pH (e) and concentrations of H2 (f). OM: organic matters
The IR spectra of the groups PCBs-OM and PCBs + OM at day 0 and day 124, respectively. OM: organic matters
Relative abundance of enrichment cultures at the second generation (G-II), the third generation (G-III) as well as the control group (CK) in the phylum level
The toxicity of high-chlorinated polychlorinated biphenyls (PCBs) can be efficiently reduced through anaerobic dechlorination. However, this approach suffers a lot in face of in situ microbial remediations, like a shortage of biomass. In this study, we showed that the amendment of organic matters could help microbiota in paddy soil with anaerobic dechlorination and greatly shortened the lag period. The presence of organic matters offered a better environment for dechlorinating bacteria. They provided not only a more strictly anaerobic milieu but also copious carbon sources. By using high-throughput 16S rRNA gene sequencing, genera Dehalobacter, Dehalobacterium, and Desulfitobacterium capable of dechlorination were identified in enriched cultures. Taken together, this study proved that extra organic matters can promote anaerobic dechlorination in paddy soil slurry microcosm systems, which provides new insights into the bioremediation of PCB-contaminated soils.
Bioremoval efficiency of linear alkylbenzene sulfonate (LAS) by L. minor (a) at various LAS concentrations (T = 25°C, Treatment period = 1, 3, 7 days, pH 7, L. minor biomass = 4 g), b at different plant biomass [Treatment period = 7 days, (LAS)0 = 20 mg L⁻¹, T = 25°C, pH 7], c at various temperatures (pH 7, L. minor biomass = 4 g, [LAS]0 = 20 mg L⁻¹, Treatment period = 7 days) and d at different pH (Treatment period = 7 days, L. minor biomass = 4 g, [LAS]0 = 20 mg L⁻¹). Values are mean ± SE of three replicates. Different letters indicate a statistical difference between treatments at p ≤ 0.01
(-)-LC–ESI–MS spectra during bioremediation of linear alkylbenzene sulfonate (LAS) surfactant after 7 days
Duckweed (Lemna minor L.) has a high potential for wastewater treatment. Here, its capability for bioremoval of linear alkylbenzene sulfonate (LAS) as one of the primary contaminants of water resources was evaluated. The effect of some operational parameters on surfactant removal efficiency was determined. Also, the impact of LAS on several physiological responses of Lemna was investigated. LAS remediation efficiency of L. minor was elevated with increasing LAS concentration, duckweed weight, and temperature. Furthermore, the optimal pH for removal was 7–8.5. The benzenesulfonate ring and five homologs of sulfophenyl carboxylate were identified as intermediates in the LAS degradation pathway. A decrease in relative growth rate and pigment contents was observed by increasing LAS concentration. In contrast, an increase in hydrogen peroxide content and electrolyte leakage indicated oxidative stress by LAS. Induction of enzymatic/non-enzymatic antioxidants was observed during the surfactant remediation process, indicating their role in overcoming free radicals generated under surfactant stress.
Adsorption isotherms of azoxystrobin by 5 different soils. Error bars represent the standard deviation (n = 3)
Accumulation amount of azoxystrobin in the whole plant of pakchoi (A) and its relationship with Freundlich adsorption coefficient (B). Values with different letters (a-e) differ significantly (p < 0.05). Error bars represent the standard deviation (n = 5)
Relationship between soil total concentration (A), pore water concentration (B) and CaCl2 extraction concentration (C) of azoxystrobin and the accumulation amount of azoxystrobin in pakchoi. Error bars represent the standard deviation (n = 5)
Correlations of root lipid content with root concentration of azoxystrobin (A) and translocation factor (B) for the tested plant species. Error bars represent the standard deviation (n = 5)
Although azoxystrobin has been widely applied on various crops, little is known about the bioavailability of azoxystrobin in the soil-vegetable system. In this study, the uptake, accumulation and translocation of azoxystrobin as affected by soil characteristics and plant species were respectively investigated. The accumulation amount of azoxystrobin in pakchoi increased as soil adsorption decreased and was positively associated with its concentration in pore water (Cpw), which was mainly affected by soil organic matter content. Therefore, Cpw could be a candidate for the estimation of azoxystrobin accumulation in pakchoi. In all the tested vegetables, azoxystrobin was mainly accumulated in roots, and its upward translocation was limited. Root lipid content was a major factor affecting the uptake and translocation of azoxystrobin in different vegetables.
The silver contents in nematodes treated with 0.01, 0.1 and 1 µM Ag2Se QDs for 24 and 72 h, respectively (n = 100). Data are presented as the mean ± SE of experiments performed independently three times (*P < 0.05)
The lifespan of nematodes treated with 0.01, 0.1 and 1 µM Ag2Se QDs for 24 and 72 h, respectively (n = 50)
The neurobehavior changes in nematodes treated with 0.01, 0.1 and 1 µM Ag2Se QDs for 24 and 72 h, respectively (n = 30). (A, B) The quantity of head thrashes and body bends in nematodes. Data are presented as the mean ± SE of experiments performed independently three times (*P < 0.05)
The expression changes of genes lys-7, dod-6 and spp-1 relevant to neurological functions in nematodes treated with 0.01, 0.1 and 1 µM Ag2Se QDs for 24 and 72 h, respectively (n = 100). Data are presented as the mean ± SE of experiments performed independently three times (*P < 0.05)
The expression changes of genes sod-3 and cst-2 relevant to oxidative stress in nematodes treated with 0.01, 0.1 and 1 µM Ag2Se QDs for 24 and 72 h, respectively (n = 100). Data are presented as the mean ± SE of experiments performed independently three times (*P < 0.05)
Silver selenide quantum dots (Ag2Se QDs), as a novel type of QDs, are valuable in the biomedical application due to their low-toxic and excellent optical property in near infrared region, but the biosafety assessment of Ag2Se QDs is rare. In this study, the findings suggested that the accumulation of Ag2Se QDs in the body of nematodes decreased the lifespan and damaged normal neurobehaviors of Caenorhabditis elegan (C. elegans). Furthermore, Ag2Se QDs caused excessive reactive oxygen species (ROS) productions and altered expressions of several genes associated with redox equilibrium, which might contribute to neurotoxic outcomes in nematode C. elegans. According to this study, it is necessary and important for researchers to pay attention to the biosafety assessment of presumed low-toxic nanomaterials, like Ag2Se QDs, especially on sensitively toxic targets, i.e. the nervous system.
Heavy metals distribution in different size fractions of soil samples
Heavy metals distribution in different size fractions of road dust samples
Principle component analysis results for soil (A) and road dust (B) samples
Soil and road dust are important receptors of heavy metals in the environment. Meanwhile, heavy metal could transfer to the atmosphere through resuspension. Due to the serious consequences and atmospheric haze in Jing-Jin-Ji area, it’s important to evaluate the pollution level, particle size distribution and sources of heavy metals. For heavy metals in soil samples, similar concentrations to the background values and no obvious pollution or low-level pollution was presented. Higher concentration of Cu (78.9 mg/kg) and Zn (261 mg/kg) were found in road dust. The source appointment results showed that Mn, Co, Cr, Ni, Zn and Pb in soils and Cr, Co and Mn in road dust were mainly from the natural sources, while traffic source contributed to most of Cu, Zn and Pb in road dust. Different particle size distribution patterns were found in soils and road dusts, and the finest particles presented the highest heavy metal concentrations.
Contents of labile SOC fractions of a DOC (dissolved organic carbon), b MBC (microbial biomass carbon), and c EOC (easily oxidizable carbon) under different long-term fertilization treatments. Vertical bars denote the standard errors of the mean values (n = 4). Different letters indicate significant differences among treatments at p < 0.05 (Duncan’s test)
Concentrations of a total Cd and b BCR fractions of Cd under different long-term fertilization treatments. Vertical bars denote the standard errors of the mean values (n = 4). Different letters indicate significant differences among treatments at p < 0.05 (Duncan’s test). The blue dot line in a is the soil environmental quality risk screening standard (0.3 mg kg⁻¹, 5.5 < pH ≤ 7.5) for soil contamination of agricultural land in China (GB 15618–2018)
Long-term pig manure addition has been widely applied in red soil to improve soil fertility. However, the influence of combined utilization of pig manure and effective microbes (EM) on soil organic carbon (SOC) and Cd are not well understood. This study conducted a 23-year (1996–2019) long-term fertilization field trial to investigate the changes of different fractions of SOC and Cd under chemical fertilization (CF), pig manure (PM), and pig manure with effective microbes (PM + EM) treatments in an agricultural soil of Jiangxi Province, South China. The results showed that the pig manure addition significantly enhanced the contents of SOC and Cd in the soils compared with the CF treatments. Furthermore, with the increment of SOC, the PM + EM treatment significantly increased the contents of soil microbial biomass carbon, dissolved organic carbon and easily oxidizable carbon compared with the pig manure application alone. Meanwhile, compared with the CF treatments, the EM addition significantly enhanced the exchangeable and oxidizable fractions of Cd, thus the potential Cd environment risk due to pig manure application should be carefully assessed.
Collection sites (filled circle) of thornback guitarfish Platyrhinoidis triseriata in the Eastern Pacific Ocean
Variation of Hg (a) and Se (b) concentrations (µg g⁻¹ wet weight) in muscle of female (open circle) and male (filled circle) thornback guitarfish Platyrhinoidis triseriata with total specimen length (cm)
Variation of Hg (a) and Se (b) concentrations (µg g⁻¹ wet weight) in liver of female (open circle) and male (filled circle) thornback guitarfish Platyrhinoidis triseriata with total length (cm) of specimens
Human consumption of the thornback guitarfish (Platyrhinoidis triseriata) is concentrated in coastal populations of the Pacific coast of Mexico as its meat is prized for its high quality. This study analyzes the distribution of mercury and selenium in the muscle and liver of Platyrhinoidis triseriata and the risk to human health associated with its consumption. In order to conduct these estimates, specimens were collected from the Eastern Pacific Ocean in 2015 and 2016 and found mean concentrations (µg g⁻¹ wet weight) of mercury ranging from 0.02 to 0.58 in muscle and 0.10 to 0.31 in liver. Selenium ranged from 0.14 to 1.31 in muscle and from 0.93 to 4.52 in liver. Mercury levels in the muscle of P. triseriata were significantly correlated (positive correlation) with the total length of the specimens. The predominant prey of P. triseriata was the shrimp Pleuroncodes planipes and according to the biomagnification factor, only mercury was biomagnified. The risk to consumers associated with the simultaneous presence of mercury and selenium in the muscle and liver of rays under the selenium health benefit value approach indicated that consumption of P. triseriata from this area is beneficial to human health.
The organic carbon content normalized partition coefficient for HHCB (A) and AHTN (B) in bulk soil and different sized soil aggregate fractions
Koc variation of HHCB before and after HF-treatment among selected bulk soils and their different aggregate fractions. The gray bar indicates the change in Koc before and after HF-treatment. ∆ Koc = Koc (after the HF-treatment)—Koc (before the HF-treatment). ∆ Koc > 0 after HF-treatment indicates an increase of Koc; and ∆ Koc < 0 after HF-treatment indicates a decrease of Koc
Polycyclic musks (PCMs) in soils have been of increasing concern because of their potential characteristics of persistence, bioaccumulation, and ecological risk. However, little is known about their fate process in soil environment. Here, two PCMs namely galaxolide (HHCB) and tonalide (AHTN) were selected as sorbates to explore their sorption process in soils. Sorption batch experiments with six soils and their different aggregate fractions were carried out to elucidate the effect of organic matter–mineral interactions in different aggregate fractions on sorption of these two PCMs. The possible causes of variation in the organic carbon-normalized partition coefficient (Koc) for HHCB and AHTN have been investigated. The strong influence of organic matter–mineral interactions on Koc was evidenced by the large variation in Koc on HF-treatment for both bulk soils and their different aggregate fractions. This study verified the dual effect of organic matter–mineral interactions among selected soils, and in promoting or inhibiting sorption may be related to the types of organic matter–mineral interactions. There were also interactions between soil components with different aggregate sizes, which affected the variation of Koc in the bulk soil. This study represents a valuable contribution to the understanding of the fate processes and behaviors of HHCB and AHTN in soils and its implication on the risk assessment.
FT-IR spectra before (a) and after (b) of the MB adsorption of the lignocellulosic biosorbent
SEM images and EDX spectra: a lignocellulosic biosorbent (I, II); b MB adsorbed lignocellulosic biosorbent (I, II)
The effect of different parameters on the recovery of MB by the SPE method: A varying adsorbent masses, B different ratio of wash solvents, C numune volumes and D effect of different eluent solvents
The recent introduction of a large number of synthetic dyes, which are toxic, mutagenic, and carcinogenic, has made the situation worse by disrupting normal aquatic life. For this reason, the detection and removal of dyestuffs in wastewater become important. In this study, for the extraction of methylene blue, used as solid phase extraction adsorbent, lignocellulosic biosorbent of tea waste activated with ZnCl2 was prepared. The factors affecting its extraction were studied in detail. To determine the sensitivity and certainty of the solid phase extraction process; optimized to have an adsorbent amount (75 mg), wash solvent (3 mL water), loading volume (20 mL), elution solvent methanol/acetic acid (80:20, v/v), and eluent volume (8 mL). As a result of the optimization processes, rates ranging from 94.4% to 98.9% recovery were obtained in methylene blue extraction in aqueous solutions. According to the results obtained, this method can be extensively applied in the efficient removal of colored contaminants.
Extracted quantitative ion (m/z 294) chromatogram obtained using GC-MSD analysis. a JLK-1 and b JSO-1 extracts spiked with 20 ng/g MeHg. c 3 ng/mL standard MeHg solution. d JLK-1 and e JSO-1 extracts spiked with blank solution
Typical six-point calibration curves of the phenyl derivative MeHg for quantification at m/z 294, at a range of 1–50 ng/mL
A simple, universal method to quantify soil methylmercury (MeHg) is not available. Here, we developed a solid-phase extraction-based method using gas chromatography mass spectrometry. MeHg was purified from the soil matrix using an optimized solid-phase extraction method, which reduced the use of organic solvents and eliminated the requirement for harmful reagents. The sample limit of quantification was 7.5 ng/g. MeHg recovery in the reference samples was 96.2%–102.6%; the intra- and inter-assay coefficients of variation were 3.4%–7.1% and 4.3%–7.1%, respectively, indicating high validation performance. This analysis method is simple as it can be performed using general-purpose reagents and instruments; has a high degree of trueness and accuracy; could be useful for soil MeHg quantification with improved sensitivity; and can provide reliable data to prevent MeHg contamination and improve food safety.
Dissipation of halauxifen-methyl in soils Soil A, Soil B and Soil C incubated at 20, 30 and 40° C temperature fortified at T1 (a) and T2 (b)
Dissipation of pyroxsulam in soils Soil A, Soil B and Soil C incubated at 20, 30 and 40° C temperature fortified at T1 (a) and T2 (b)
Physico-chemical properties of the experimental soils
Dissipation kinetics and persistence data of halauxifen-methyl and pyroxsulam in Soil A, Soil B and Soil C at 20, 30 and 40° C
The persistence and dissipation of a new readymix formulation of halauxifen-methyl + pyroxsulam was investigated in three soils viz. red lateritic (Soil A), coastal saline (Soil B) and black soil (Soil C) under three incubation temperatures (20, 30 and 40° C). Soil samples were fortified at 1.0 (T1) and 2.0 (T2) mg kg− 1 doses separately for both compounds. The analytical methods showed satisfactory mean recovery, precision and linearity and therefore accepted for analysis. Both molecules followed single first-order kinetics. A significant influence of soil type on the persistence of both herbicides was observed. The order of stability of halauxifen-methyl was Soil A > B > C and for pyroxsulam was Soil B > C > A. Besides, a faster rate of dissipation of halauxifen-methyl and pyroxsulam was recorded at elevated temperatures, regardless of soil type. This research will help to understand the effect of temperature on the fate of the herbicide mixture in soils of diverse agro-climatic regions.
It is crucial that a highly effective adsorbent can be used to simultaneously remove the composite pollution including both inorganic and organic arsenic from wastewater. In this work, the iron modified corncob biochar (MCCB), prepared via the co-precipitation of ferric chloride hexahydrate (FeCl3⋅6H2O) with sodium hydroxide (NaOH) on corncob biochar, was studied for the high efficiency removal of arsenilic acid (ASA) and arsenate [As(V)] in wastewater. X-ray diffraction, scanning electron microscopy, and fourier transform infrared spectroscopy were carried out to characterize the MCCB. At pH of 4.0–5.0, initial concentration of 10 mg/L ASA and 1 mg/L As(V), adsorbent dose of 0.4 g/L, the maximum adsorption capacities of ASA and As(V) were 49.20 and 4.89 mg/g, respectively. The adsorption performance of MCCB for ASA and As(V) was fitted well to the pseudo-second-order kinetic model. Results from this study indicate the promise of MCCB as an efficient, low-cost and environmentally friendly adsorbent for composite arsenic pollution.
Effects of biochar and compost on the soil properties: (a) TOC, (b) pH, (c) EC
Effects of biochar and compost on the soil AP (a) and TP (b)
Effects of biochar and compost on ALP activity (a) and the abundance of phoD gene (b)
Relationship between the phoD gene abundance and AP (a), ALP (b), EC (c), and relationship between ALP and EC (d) in samples during the experiment
Heatmap of four treatments applied to soil, each with three plot replicates, based on the relative abundances of the 30 most abundant microbial genera in the soils (a). The phoD gene RDA plots (b) with significant physicochemical parameters were shown by red solid lines with filled arrows
This research was carried out to determine the influence of biochar and compost addition on the characteristics of potential alkaline phosphatase (ALP) activity and phoD gene community in heavy metal polluted soils. The ALP activity, the abundance and structure of phoD gene were systematically determined. Results showed that biochar and compost significantly changed soil properties, and promoted the microbial transformation of phosphorus. Compost addition significantly increased the ALP activity. Biochar and compost addition markedly increased the phoD gene abundance. The addition of biochar increased the proportion of Actinobacteria, Euryarchaeota, and Proteobacteria. By contrast, Betaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria were the dominant taxa in soils with compost addition. Electrical conductivity critically controlled the expression of phoD and changed the structure of phoD-coding microbial communities in heavy-metal polluted soils that remediated by biochar and compost.
In this study, a composite algaecide containing flocculants and Cinnamomum. camphora leaves extracts (CCCLE) were synthesized. The inhibition and flocculation effects on Microcystis aeruginosa (M. aeruginosa) were investigated, and the release of microcystin-LR (MC-LR) was determined. Results showed that the CCLEC composite algaecide was effective for the inhibition and flocculation of M. aeruginosa, and the optimal dose of CCLEC composite algaecide was 1.8%, which resulted in an algae inhibition ratio of 98.00% and a flocculation efficiency of 99.44% within 5 days of M. aeruginosa culturing. Besides, the total amount of MC-LR decreased by 80.04% on day 20 compared with the control group, while the concentration of intracellular MC-LR on day 5 was 36.69 μg L⁻¹, which was related to a portion of cells underwent apoptosis-like cell death under CCLEC composite algaecide stress. The results of this study may improve our understanding of the M. aeruginosa control by CCCLE composite algaecide.
Stereoscopic MPs photographs illustrating shapes: a fiber, b fragment, and d film
a Metals concentration and overall metal contamination (Pb, Cr, Co, Ni, and Cd) in four regions (FSD-S; FSD-W; FSD-N; FSD-E); b metals contamination and overall metal contamination (Pb, Cr, Co, Ni, and Cd) in different sample sources (water, soil, root, and leaves); c overall Pb, Cr, Cd, Ni, and Co contamination in different sample sources relation to location; d HMTF of the Pb, Cr, Cd, Ni, and Co from soil to plant concerning different locations. The caps represent standard errors (n = 3 replicates)
A case study was conducted to evaluate the microplastics and heavy metals distribution in Pakistani farmland. Wastewater, soil, and vegetable samples were collected from four locations that received raw effluents for irrigation in the Faisalabad district. The average MPs abundances found in soil was 2790.75 items/kg, FSD-S has higher MPs (3865 items/kg) which is almost 34.62% from the total. However, the highest metal pollution (3.666 mg/kg) was recorded in the FSD-E zone, Cr showed the highest transfer factor about 34.24% in FSD-N in comparison with other sites. This research establishes a benchmark for estimating the environmental harm posed by microplastics and heavy metals in this rapidly emerging field of study.
Textile dyes are becoming a growing threat to the environment. This report presents the findings of the study on the toxicity of the textile dye Alizarin Red S on two freshwater microalgae. The acute toxicity assay revealed that 96-h EC50 values of Chlorella vulgaris and Spirulina platensis were 29.81 mg/L and 18.94 mg/L respectively. The pigments chlorophyll-a, b and carotenoids in C. vulgaris on 96-h exposure to the dye were 2.91, 3.29 and 3.01 times lower in analogy to control whereas Spirulina platensis showed 2.89and 2.56 fold decrease in chlorophyll-a and carotenoid content than control. After the test period of 96-h with dye, the protein content of C. vulgaris and S. platensis were 2.33 and 1.77 times lower compared to the control. The growth inhibition rate, pigment as well as the protein content declined in compliance with the rise in dye concentration, which anticipate paradigm about the toxic effects of the textile dye. Inhibition of growth rate and changes in the biochemical composition reveals the toxicity of the textile dye.ARS can be considered as harmful to the aquatic organism according to the EU-Directive 93/67/EEC.Dye toxicity to microalgae varies depending on the dose and exposure period. Inhibition of growth rate and changes in the biochemical composition reveals the toxicity of the textile dye. ARS can be considered as harmful to the aquatic organism according to the EU-Directive 93/67/EEC. Dye toxicity to microalgae varies depending on the dose and exposure period.
This study investigated the effects of different types of saline stress on the availability of cadmium (Cd) and bacterial growth. Changes in soil physicochemical properties and DTPA-Cd content as well as microbial responses after the addition of salts were measured. The addition of 18 g kg⁻¹ of salts with NaCl and Na2SO4 increased the available Cd content by up to 17.80%–29.79%. Respiration rate, biomass, and relative bacterial growth decreased with increasing salt concentrations. Estimated salinity tolerance of bacterial communities based on pollution-induced community tolerance. The salinity tolerance index EC50 of the bacterial community was estimated by logistic equation and ranged from 4.32–12.63 g kg⁻¹. Structural equation modeling showed that soil salinity stress significantly affected Cd availability and bacterial community, while bacterial growth characteristics also contributed to reducing available Cd. We conclude that saline stress can alter soil Cd availability in soils by affecting the growth characteristics of soil bacterial communities.
Relationships between the hydraulic conductivity of montmorillonite and the composition of exchangeable cations in the montmorillonite: (A) Na/K-montmorillonite, (B) Na/Ca-montmorillonite, (C) Na/Zn-montmorillonite, and (D) Na/Al-montmorillonite
The hydraulic conductivity of Na-montmorillonite in dual-cation solutions of Na⁺ and Mⁿ⁺ (Mⁿ⁺ = K⁺, Ca²⁺, Zn²⁺ and Al³⁺) with a constant ionic strength of 0.1 mol/L was determined. The focus of this study was on the influence of Mⁿ⁺ on the grain-size distribution of montmorillonite and hence its hydraulic conductivity. All the tested cations showed a high affinity towards montmorillonite, and the high valency favored the exchange between Mⁿ⁺ and Na⁺. The hydraulic conductivity of montmorillonite increased to the maxima and then decreased in a left-skewed log-normal shape as the cation exchange progressed. The grain size of montmorillonite concurrently decreased monotonically with the cation exchange. The XRD patterns of montmorillonite confirmed the occurrence of demixing of Na⁺ and K⁺ in the interlayers. It is proposed that the rearrangement and reaggregation of grains during cation exchange occurred, leading to variations in the hydraulic conductivity of montmorillonite.
The structural chemical formula of four TSILs
HPLC–MS/MS Chromatogram of the four TSILs ([C2NH2MIm]BF4, [HOEMIm]BF4, [HOEMIm]NO3, [MOEMIm]BF4). The concentration of the TSILs was 0.1 ng mL⁻¹, and the injection volume was 2 µL
Recovery of four TSILs in water (A), soil (B), cucumber (C) and wheat (D) under different extraction conditions. The concentration of TSILs was 0.1 µg mL⁻¹. Each bar is the mean of six replicates, and the error lines represent the standard deviation. The different letters (a, b, c) are the results of significant differences (p < 0.05) between different treatments
With the extensive application of task-specific ionic liquids (TSILs), their environmental impact has attracted increasing attention. However, no studies involving residue analyses of TSILs have been reported in the literature thus far. In the present study, residues of four TSILs ([C2NH2MIm]BF4, [HOEMIm]BF4, [HOEMIm]NO3, [MOEMIm]BF4) were analyzed by high-performance liquid chromatography–tandem mass spectrometry. The limit of detection of instrument was approximately 10⁻¹⁵ g. Residual TSILs were extracted from soil and plant samples by the accelerated solvent extraction method. In water, soil and plants, the coefficient of variation was 0.38%–4.43%, and the method detection limits of the four TSILs were lower than 1.40 ng g⁻¹. These results meet the standards of residue analysis. The present study can provide an analysis method for studying TSIL residues and toxicity in the environment.
Peaks obtained for the CRM materials SRM 2976 and DORM-3 spiked with 3 µg L− 1 of either Ag⁺ or Ag NPs of different sizes
Peaks obtained for mussel specimens (n = 5) spiked with3 µg L− 1 Ag⁺, Ag NPs 10 and 60 nm. The analyses were performed directly on the solid samples. The represented tad is calculated as average (n = 5 specimens) and presented with respective standard deviation. The Δtad were calculated using the respective average values of tad: the resulting combined uncertainty did not exceed 5%
Peaks obtained for sponge specimens (n = 5) exposed in the aquarium to 5 µg L− 1 Ag⁺, Ag NPs 10 and 60 nm. Due to the high Ag amount present in control samples, these analyses were performed on slurries, to reduce the Ag amount introduced in the furnace and to be able to highlight the differences in tad. The represented tad is calculated as average (n=5 specimens) and presented with respective standard deviation. The Δtad were calculated using the respective average values of tad: the resulting combined uncertainty didn’t exceed 5%
The present study describes the development of a fit-for-purpose analytical procedure for the detection of Ag NPs in different marine organisms by Solid Sampling Continuous Source High Resolution Atomic Absorption Spectrometry (SS-CS-HR-AAS). The detection is based on the observation of the Ag absorption peak and its atomization delay tad which is different for ionic Ag and Ag NPs. The temperature program was optimized in order to achieve the maximum difference between the t ad (Δtad ). The method was first developed using biota CRMs spiked with different Ag NPs standard solutions or Ag⁺ , at the same concentration. Then, laboratory exposure experiments were performed on mussels and marine sponges. The results showed that the developed methodology is suitable for the detection of Ag NPs for both groups of organisms, showing Δtad up to 3.1 s. The developed method is therefore a promising tool to assess the presence of AgNPs in marine invertebrates.
Mechanism schematic of soil washing technology
Main methods for the recycling of washing effluents
Main remediation technologies combined with soil washing
Contaminated soils have caused serious harm to human health and the ecological environment due to the high toxicity of organic and inorganic pollutants, which has attracted extensive attention in recent years. Because of its low cost, simple operation and high efficiency, soil washing technology is widely used to permanently remove various pollutants in contaminated soils and is considered to be the most promising remediation technology. This review summarized the recent developments in the field of soil washing technology and discusses the application of conventional washing agents, advanced emerging washing agents, the recycling of washing effluents and the combination of soil washing and other remediation technologies. Overall, the findings provide a comprehensive understanding of soil washing technology and suggest some potential improvements from a scientific and practical point of view.
Effects of single or combined exposure of MPs and Cu on the copper accumulation (dry weight basis) in the goldfish hepatopancreas and intestine. Values are presented as mean ± SD (n = 3). Significant differences are indicated by different letters (p < 0.05)
Effects of single or combined exposure of MPs and Cu on the MDA content and the activity of SOD and CAT in the goldfish hepatopancreas and intestine. Values are presented as mean ± SD (n = 3). Significant differences are indicated by different letters (p < 0.05)
The histological changes induced by the single or combined exposure of MPs and Cu in the goldfish hepatopancreas (HE, ×40). A Control group; B: Cu group; C: MPs group; D: MPs + Cu group; Black circle: bilirubin
The changes histological and the ratio of villus height to crypt depth induced by the single or combined exposure of MPs and Cu in the goldfish intestine (HE, × 40). A Control group; B Cu group; C MPs group; D MPs + Cu group; Black circle: the junction of the lamina propria cells was loose; Black arrow: the intestinal mucosa exhibited partial shedding; VH villus height, CD crypt depth
Effects of single or combined exposure of MPs and Cu on the expression of functional genes in the hepatopancreas and intestine of goldfish. Values are presented as mean ± SD (n = 3). Significant differences are indicated by different letters (p < 0.05). The differences between the groups were considered to be statistically significant if the number of "*" is different
The enhancement of the toxic effect of microplastics (MPs) on heavy metals and its mechanism needs more in-depth and systematic research. In this study, the copper (Cu) accumulation, histological injury, and expression of genes involved in oxidative stress, inflammation, apoptosis, and autophagy of goldfish after single or combined exposure of MPs (1 mg/L) and Cu²⁺ (0.1 mg/L) for 7 days were determined. The results demonstrated that MPs enhanced the Cu accumulation in hepatopancreas and intestine of goldfish and induced more severe oxidative stress in the hepatopancreas and intestine of goldfish. Additionally, combined exposure of MPs and Cu induced inflammation, excessive apoptosis and insufficient autophagy in the hepatopancreas. Contrary, the inflammation and apoptosis were depressed in the intestine after combined exposure of MPs and Cu, which still requires further exploration. Hence, these findings provide further evidence for the threat of MPs and its adsorbed heavy metals.
Concentrations of fluridone in the water column and pore water in microcosms to which commercially available granular and liquid formulations were applied. Microcosm sediments contained 0, 0.2 (sand only), 5.9, 18.6, and 41.6% organic matter. Bars represent standard deviation (n = 2). Target dosing concentration: 600 ng/mL
Concentrations of penoxsulam in the water column and pore water in microcosms to which commercially available granular and liquid formulations were applied. Microcosm sediments contained 0, 0.2 (sand only), 5.9, 18.6, and 41.6% organic matter. Bars represent standard deviation (n = 2). Target dosing concentration: 390 ng/mL
Control of invasive aquatic plants is crucial for the maintenance of chemical, biological and ecological balances in many fresh water systems. Exposure of invasive plants to herbicides used for their control may be reduced by sorption to organic matter in sediments. Since granular herbicide formulations have closer contact with sediments (compared to liquid formulations), concentrations in the water column may be much lower. To test this hypothesis, microcosms containing sediments with < 1%, 6.4%, 19.7%, and 44% organic matter were treated with liquid and granular formulations of fluridone and penoxsulam. Herbicide concentrations in the water column and sediment pore water were monitored over 40 days. The presence of sediments (regardless of organic carbon content) significantly reduced concentrations of fluridone in the water column from the granular formulations relative to the liquid formulation. A similar, though less extreme, pattern was observed for penoxsulam in most of the organic carbon treatments.
According to careful estimations, open burning of plastic waste affects app. 2 billion people worldwide. While human health risks have become more and more obvious, much less information is available on the phytotoxicity of these emissions. In our study phytotoxicity of particulate matter samples generated during controlled combustion of different plastic waste types such as polyvinyl chloride (PVC), polyurethane (PUR), polypropylene (PP), polystyrene (PS) and polyethylene (PE) was evaluated based on peroxidase levels. While different samples showed different concentration-effect relationship patterns, higher concentration(s) caused decreased peroxidase activities in each sample indicating serious damage.
To investigate the dynamic effects of organic fertilizer application on the agronomic traits of rice (Oryza sativa L.), soil physicochemical properties and soil Cd activity under excess cadmium (Cd) exposure, this study was conducted to simulate a paddy system under different organic fertilizer application rates using exogenous spiked Cd soil as the test soil and conducting a rice pot experiment. The obtained results showed that the application of organic fertilizer increased the number of rice tillers, rice plant height, total grain number and total grain weight at maturity in all treated soils, while it decreased the concentration of Cd in brown rice. The application of organic fertilizer increased the organic matter (OM), redox potential and electrical conductivity of all treated soils but decreased the pH and TCLP-extractable Cd of all treated soils. There was a significant or highly significant negative correlation (p < 0.05 or p < 0.01) between soil TCLP-extractable Cd and soil OM throughout the experimental period, implying that soil OM may be an important factor influencing the changes in Cd activity in soil. In addition, our experiment also examined in detail the dynamic change process of the abovementioned indicators throughout the experimental period and observed that the dynamic change process of soil Cd activity could be described as a trend of first decreasing and then gradually increasing throughout the rice reproductive period.
Oreochromis niloticus gills, liver, and muscle concentrations throughout time after being exposed to Cd (A) and Zn (B) for 14 days, followed by a depuration period of 7 days. During the accumulation trial, lowercase letters showed that there were differences at different time intervals (p < 0.05, a < b < c < d < e < f). During a depuration experiment, capital letters revealed a significant difference at different exposure intervals (p < 0.05, A > B > C > D > E)
Oreochromis niloticus was subjected to sub-lethal Cd and Zn concentrations for 14 days in order to evaluate their accumulation in the gills, liver, and muscle. Following that, the fish were placed to uncontaminated water for 7 days to allow the metals to be removed from the tissues. The gills had the highest bio-concentration factor for Cd and Zn. The gills showed the highest Cd accumulation rate, and the muscle showed the lowest. The muscle had the highest Cd depuration rate, while the liver had the lowest. The liver exhibited the highest Zn accumulation rate, while the gills and muscle had nearly similar values. Zn depuration rates were very consistent across all tissues.
Sampling Location map
Dinual variation of Meteorological conditions of Delhi in the year 2017
Diurnal and monthly variation of a PM10, b SO2, c NO2 and d NH3 in Delhi (2017)
The diurnal and seasonal variation of PM10, SO2, NO2, NH3 and water-soluble compounds were studied in Naraina industrial area; Delhi from January to December, 2017. It was observed that annual average concentrations of PM10, SO2, NO2, NH3, SO4²⁻, NO3⁻, NH4⁺,Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻ and F⁻ in the day time were 227 ± 91, 9 ± 5, 59 ± 22, 65 ± 15, 17.45 ± 5.14, 17.60 ± 4.94, 8.66 ± 2.94, 4.05 ± 1.08, 3.46 ± 0.91, 10.38 ± 4.48, 3.15 ± 0.99, 43.06 ± 5.20 and 0.50 ± 0.12 µg m⁻³, respectively and night time were 320 ± 127, 14 ± 7, 82 ± 25, 83 ± 20, 22.64 ± 5.22, 21.66 ± 5.0, 11.81 ± 3.47, 3.29 ± 0.87, 3.02 ± 1.19, 7.55 ± 3.16, 2.49 ± 0.95, 31.86 ± 4.70 and 0.37 ± 0.12 µg m⁻³, respectively. PM10 and sometimes NO2 concentrations exceeded the Indian National Ambient Air Quality Standards. SO2, and NH3 concentrations were within the standard. The selected parameters varied from season to season. In the night time, selected parameters concentrations were high in comparison to day time might be due to formation of inorganic secondary particulate matters and low wind speed in the ambient air.
Spatial distributions of the study sites
Principal coordinates analysis (PCoA) results of gut microbial communities from YT versus WS (A) and YT versus ZC (B)
Relative abundance (phylum level) of gut microbiota from WS, YT and ZC
Gut microbiota abundance comparison (phylum level) of YT versus WS (A) and YT versus ZC (B)
MeHg demethylation efficiency of gut microbiota form three sites. The X axis represents the reaction time (h), and the Y axis represents the MeHg residue (%)
This study aims to investigate methylmercury (MeHg) demethylation processes in human gut. Here, we determined the compositions and MeHg demethylation rates of gut microbiota in residents from different Hg exposure levels (Wanshan (WS) town and Yangtou (YT) town) and different Hg exposure sources (Zhuchang (ZC) town and YT town) regions. MeHg and inorganic Hg exposure levels in residents of WS town were significantly higher than those of YT and ZC town. Desulfovibrio and Methanogens, which related to Hg methylation/demethylation, showed significantly higher abundance in WS and ZC, comparing with YT. In vitro experiments demonstrated that human intestinal microbiota could degrade MeHg directly. Besides, gut microbiota in WS and ZC exhibited significantly higher demethylation rates than YT, suggesting Desulfovibrio and Methanogens may play important roles in intestinal MeHg demethylation. This study highlights Hg exposure levels and sources may affect demethylation efficiency of gut microbiota, which provides new insights for MeHg demethylation processes in human body.
Concentration (ng g⁻¹) of 16 organochlorine pesticides (OCP) in barn owl primary feathers (A) and liver (B). Box and whisker plots show the median, 25% quartiles and range. Outliers not represented. * OCP not detected in Tagus area; **OCP not detected in Évora area
Relative concentrations of 16 organochlorine pesticides (OCP) expressed as percentage of total concentrations of OCP groups (ΣHCH, Σheptachlor, Σdrins, Σendosulfan and ΣDDT) in barn owl primary feathers and liver from Portugal in 2009–2012. Whiskers represent standard error
We evaluated feathers as a non-destructive biomonitoring tool documenting organochlorine pesticides (OCP) in liver and checked possible trends in pesticide use in two areas based on OCP concentrations in barn owls (Tyto alba). We measured the concentrations of 16 OCP in 15 primary feathers and 15 livers from barn owl carcasses collected on roadsides in Tagus Valley and Évora regions, south Portugal. Total OCP mean concentration was 8 120 ng g⁻¹ in feathers and 178 ng g⁻¹ in livers. All compounds were detected in feathers while in livers δ-HCH, endosulfan sulphate, p,p′-DDT and p,p′-DDD were not detected. The high β-HCH and heptachlor concentrations in feathers most likely derived from external endogenous contamination. P,p′-DDE was the OCP with the highest hepatic concentration. Both matrices indicated an exposure to recently released heptachlor. The differing OCP concentrations between Tagus Valley and Évora seem to reflect differences in land-use and pesticide use histories of the two locations, and/or faster degradation of OCP in the Tagus area.
The purpose of this research was to evaluate the concentrations, sources and ecological risk assessment of sixteen polycyclic aromatic hydrocarbons (PAHs) present in water from the La Fe reservoir, Colombia in the months of October and November of 2017 and 2018. Concentrations of PAHs in water were measured with semipermeable membrane devices (SPMD) which allow obtaining the dissolved concentrations of the PAHs in the reservoir, emphasizing the reactivity and bioavailability in the environment. The PAHs analyses were carried out by means of gas chromatography, coupled with tandem mass spectrometry (GC/MS–MS) with triple quadrupole (QqQ). The environmental risk assessment using the estimation of risk quotient with deterministic and probabilistic method, the predictive no-effect concentration (PNEC) and environmental exposure concentration (EEC) in water indicate a negligibe risk for probabilistic method for all PAHs evaluated (RQ < 0.1).
Sampling sites map. Cities from Colombia where were collected samples
Total PCBs concentration in breast milk by cities in ng g⁻¹ extractable lipids
Log EDI = Logarithm of the estimated daily intake (EDI) results of the 68 samples by cities. EDI = Estimated daily intake, TDI = Tolerable daily intake
Polychlorinated biphenyls (PCBs) are persistent in the environment, bioaccumulate and biomagnify throughout the food chain, and may have adverse effects on human health and wildlife. PCB indicator (PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153, and PCB 180) were monitored in human milk using 68 samples from healthy and primiparous mothers from seven cities in Colombia, and the estimated daily intake (EDI) of infants was calculated. The PCB indicator with the highest concentration was PCB 153 with a value of 7.30 ng g⁻¹ lipids. The maximum EDI was calculated as 0.257 μg kg⁻¹ bw⁻¹ day⁻¹. In general, the PCB levels found in the 68 samples were low and did not represent a risk to breastfed infants. Additionally, these results could strengthen Colombia’s efforts to increase the practice of breastfeeding. Finally, the results establish a general overview of population exposure and can be a scientific tool to improve environmental health policies in the country.
Adsorption isotherm of quinclorac on MWCNTs
Growth status of tomato with MWCNTs added to alleviate the damage of quinclorac. Concentration of quinclorac from left to right: 0, 0.025, 0.05, 0.1, 0.2, 0.4 mg/kg. MWCNTs content from top to bottom: 0, 0.25%, 0.5%, 1%
Remediating effect of MWCNTs to quinclorac, determined by a tomato plant height and b fresh weight
In order to remediate the phytotoxicity of quinclorac to tomato by multi-walled carbon nanotubes (MWCNTs), the adsorption of quinclorac to MWCNTs was monitored and the effect of MWCNTs on the phytotoxicity of quinclorac to tomato in soil were studied. The results showed that the Linear equation and Freundlich equation can well fit the adsorption isotherm of quinclorac in the soil containing MWCNTs. The adsorption of quinclorac in soil was significantly enhanced by the addition of MWCNTs; the Kd of soil (1% MWCNTs) was 28.7 times of pure soil. The quinclorac had an obvious inhibitory effect on the growth of tomatoes; serious phytotoxicity was also induced even at the lowest concentration of 0.025 mg/kg. With the MWCNTs content in soil increased to 0.5% and 1%, the phytotoxicity of quinclorac to tomatoes decreased significantly, and the height and fresh weight of tomatoes were even higher than those of the control group, indicating that MWCNTs can promote the growth of tomato. These results provide a reference for resolving the problem of phytotoxicity induced by residual herbicides in farmland.
TEM image of diluted TiO2 NPs in distilled water
TEM image of diluted ZnO NPs in distilled water
The glutathione reductase (GR) of baker's yeast (Saccharomyces cerevisiae) was exposed to titanium dioxide nanoparticles (TiO2 NPs) and zinc oxide nanoparticles (ZnO NPs) at concentrations of 0, 25, 50, 100, 250, and 500 mg/L (ppm) in vitro. According to the calculations, the effect of 25, 50, 100, 250, and 500 mg/L TiO2 NPs on GR enzyme activities resulted in percentage changes of - 3.12; - 0.87; - 2.12; - 2.12, and - 1.50, respectively. Percentage changes in GR enzyme activities with the effect of 25, 50, 100, 250, and 500 mg/L ZnO NPs were calculated as - 2.01; + 1.88; + 0.38; - 2.51, and + 0.75, respectively. It can be deduced from this research that the change in concentrations of TiO2 NPs and ZnO NPs has no statistically significant effect on GR enzyme activities in comparison with the control groups (p > 0.05, N = 3).
Overview on cell layer and targeted cell selection. The coccus (fig. a) and rod cells (fig. c) labeled with red circles are the targeted cells for ejection, the black points in fig. b and d labeled with red circle are the location where the targeted cells were ejected with laser
Experimental process of this study
The relative abundance of genera in different samples (FS: fresh paddy soil; DS: dry paddy soil; FSE1 to FSE3: the fourth generation of bacterial enrichment from fresh paddy soil; DSE: the fourth generation of bacterial enrichment from dry paddy soil.)
The number of isolates from single cell sorting (left figure) and single colony sorting (right figure). The y axis is the number of isolates in different genera (shown in x axis) isolated from samples FSE1, FSE2, FSE3 and DSE
Growth of the isolated strains with biphenyl as the carbon source, the growth is quantified with OD600 (y axis), the culture duration is 270 h (x axis). The figure a shows the two slow-growing strains belonging to genera Macrococcus and Achromobacter, and figure b presents the four fast-growing strains belonging to Aerococcus, Acinetobacter, Metabacillus, Paenibacillus
In this work, biphenyl was used as carbon source to enrich microorganisms from polychlorinated biphenyls (PCBs)-contaminated paddy soil samples, and the taxonomic structures in both of the soil samples and the fourth-generation enrichments were examined with high-throughput sequencing. Single cells were isolated from the enrichments via single cell sorting technology named Laser Induced Visualized Ejection Separation Technology (LIVEST) and also traditional single colony sorting, and the genera of the isolates were identified using 16S rRNA sequencing. The results from high-throughput sequencing present that enrichment from generation to generation can considerably change the microbial community. Comparing the two sorting methods, the LIVEST is more time-saving and cell-targeted for microbial resource exploration. Based on the further verification of biphenyl degradation, it was found that some strains belonging to genera Macrococcus, Aerococcus and Metabacillus are capable in degrading biphenyl, which have not been reported yet.
Top-cited authors
Balwinder Singh
  • Apple Inc.
Irani Mukherjee
  • Indian Agricultural Research Institute
Chiara Copat
  • University of Catania
Margherita Ferrante
  • University of Catania
Mohammad Yusuf
  • United Arab Emirates University