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Emerging organic compounds in European groundwater Full text
2021
Bunting, S.Y. | Lapworth, D.J. | Crane, E.J. | Grima-Olmedo, J. | Koroša, A. | Kuczyńska, A. | Mali, N. | Rosenqvist, L. | van Vliet, M.E. | Togola, A. | López, B.
In Europe, emerging organic compounds (EOCs) in groundwater is a growing research area. Prioritisation for monitoring EOCs in Europe was formalised in 2019 through the development of the first voluntary groundwater watch list (GWWL). Despite this, groundwater occurrence data in the peer reviewed literature for Europe has not been reviewed to date. Questions surrounding the effect, toxicity, movement in the subsurface and unsaturated zone make the process of regulating EOC use difficult. The aim in Europe is to develop a unified strategy for the classification, and prioritisation of EOCs to be monitored in groundwater. This paper compiles evidence from the recent published studies from across Europe, since 2012, when the last major literature global review of EOCs in groundwater took place. A total of 39 studies were identified for review based on specific selection criteria (geography, publication date, sample size>10, inclusion of EOCs data). Data on specific compounds, and associated meta-data, are compiled and reviewed. The two most frequently detected EOCs, carbamazepine and caffeine, occurred in groundwater at concentrations of up to 2.3 and 14.8 μg/L, respectively.The most frequently reported category of compounds were ‘Pharmaceuticals’; a highly studied group with 135 compounds identified within 31 of the 39 studies. In Europe, the majority of reviewed studies (23) were at a regional scale, looking specifically at EOCs in a specific city or aquifer. The use of analytical methods is not uniform across Europe, and this inevitably influences the current assessment of EOCs in groundwater. A correlation between the number of compounds analysed for, and the number detected in groundwater highlights the need for further studies, especially larger-scale studies throughout Europe. For the development of EU and national regulation, further work is required to understand the occurrence and impacts of EOCs in groundwater throughout Europe and elsewhere.
Show more [+] Less [-]Environmental concentrations of antifouling paint particles are toxic to sediment-dwelling invertebrates Full text
2021
Muller-Karanassos, Christina | Arundel, William | Lindeque, Penelope K. | Vance, Thomas | Turner, Andrew | Cole, Matthew
Antifouling paint particles (APPs) and associated metals have been identified in sediments around boatyards and marinas globally, but the effects of APPs on benthic organisms are largely unknown. Sub-lethal endpoints were measured following laboratory exposures of the harbour ragworm (Hediste diversicolor) and the common cockle (Cerastoderma edule) to environmentally relevant concentrations of biocidal (‘modern’ and ‘historic’) and biocide-free (‘silicone’) APPs added to clean estuarine sediment. Further, the 5-day median lethal concentrations (LC₅₀) and effects concentrations (EC₅₀) for modern biocidal APPs were calculated. For ragworms, significant decreases in weight (15.7%; p < 0.01) and feeding rate (10.2%; p < 0.05) were observed in the modern biocidal treatment; burrowing behaviour was also reduced by 29% in this treatment, but was not significant. For cockles, the modern biocidal treatment led to 100% mortality of all replicates before endpoints were measured. In cockles, there was elevated levels of metallothionein-like protein (MTLP) in response to both modern and historic biocidal treatments. Ragworms had a higher tolerance to modern APPs (5-day LC₅₀:19.9 APP g L⁻¹; EC₅₀: 14.6 g L⁻¹) compared to cockles (5-day LC₅₀: 2.3 g L⁻¹ and EC₅₀: 1.4 g L⁻¹). The results of this study indicate that modern biocidal APPs, containing high Cu concentrations, have the potential to adversely affect the health of benthic organisms at environmentally relevant concentrations. The findings highlight the need for stricter regulations on the disposal of APP waste originating from boatyards, marinas and abandoned boats.
Show more [+] Less [-]Long-term effects of atmospheric deposition on British plant species richness Full text
2021
Tipping, Edward | Davies, Jessica A.C. | Henrys, Peter A. | Jarvis, Susan G. | Smart, S. M. (Simon M.)
The effects of atmospheric pollution on plant species richness (nₛₚ) are of widespread concern. We carried out a modelling exercise to estimate how nₛₚ in British semi-natural ecosystems responded to atmospheric deposition of nitrogen (Ndₑₚ) and sulphur (Sdₑₚ) between 1800 and 2010. We derived a simple four-parameter equation relating nₛₚ to measured soil pH, and to net primary productivity (NPP), calculated with the N14CP ecosystem model. Parameters were estimated from a large data set (n = 1156) of species richness in four vegetation classes, unimproved grassland, dwarf shrub heath, peatland, and broadleaved woodland, obtained in 2007. The equation performed reasonably well in comparisons with independent observations of nₛₚ. We used the equation, in combination with modelled estimates of NPP (from N14CP) and soil pH (from the CHUM-AM hydrochemical model), to calculate changes in average nₛₚ over time at seven sites across Britain, assuming that variations in nₛₚ were due only to variations in atmospheric deposition. At two of the sites, two vegetation classes were present, making a total of nine site/vegetation combinations. In four cases, nₛₚ was affected about equally by pH and NPP, while in another four the effect of pH was dominant. The ninth site, a chalk grassland, was affected only by NPP, since soil pH was assumed constant. Our analysis suggests that the combination of increased NPP, due to fertilization by Ndₑₚ, and decreased soil pH, primarily due to Sdₑₚ, caused an average species loss of 39% (range 23–100%) between 1800 and the late 20th Century. The modelling suggests that in recent years nₛₚ has begun to increase, almost entirely due to reductions in Sdₑₚ and consequent increases in soil pH, but there are also indications of recent slight recovery from the eutrophying effects of Ndₑₚ.
Show more [+] Less [-]Silica nanoparticles inhibiting the differentiation of round spermatid and chromatin remodeling of haploid period via MIWI in mice Full text
2021
Liu, Jianhui | Li, Xiangyang | Zhou, Guiqing | Zhang, Yue | Sang, Yujian | Wang, Ji | Li, Yanbo | Ge, Wei | Sun, Zhiwei | Zhou, Xianqing
Researches have shown that silica nanoparticles (SiNPs) could reduce both the quantity and quality of sperm. However, the mechanism of toxicity induced by SiNPs in the male reproductive system is still unclear. In this study, male mice were randomly divided into a control group, and SiNPs treated group (20 mg/kg dose; n = 30 per group). Half of the mice per group were sacrificed on 35 days and the remaining on 50 days of the SiNPs exposure. SiNPs were found to decrease sperm count and mobility, increase the sperm abnormality rate, and damage the testes' structure. Furthermore, SiNPs decreased the protein levels of Protamine 1(PRM1) and elevated the histones' levels and suppressed the chromatin condensation of sperm. There was a significant reduction of the ubiquitinated H2A (ubH2A)/H2B (ubH2B) and RING finger protein 8 (RNF8) levels in the spermatid nucleus, while the RNF8 level in the spermatid cytoplasm increased evidently. The protein expression levels of PIWI-like protein 1(MIWI) in the late spermatids significantly increased on day 35 of SiNPs exposure. After 15 days of the withdrawal, the sperm parameters and protamine levels, and histones in the epididymal sperm were unrecovered; however, the changes in testis induced by SiNPs were recovered. Our results suggested that SiNPs could decrease the RNF8 level in the nucleus of spermatid either by upregulating of the expression of MIWI or by inhibiting its degradation. This resulted in the detention of RNF8 in the cytoplasm that maybe inhibited the RNF8-mediated ubiquitination of ubH2A and ubH2B. These events culminated in creating obstacles during the H2A and H2B removal and chromatin condensation, thereby suppressing the differentiation of round spermatids and chromatin remodeling, which compromised the sperm quality and quantity.
Show more [+] Less [-]Temporal variation characteristics and source apportionment of metal elements in PM2.5 in urban Beijing during 2018–2019 Full text
2021
Zhao, Shuang | Tian, Hezhong | Luo, Lining | Liu, Huanjia | Wu, Bobo | Liu, Shuhan | Bai, Xiaoxuan | Liu, Wei | Liu, Xiangyang | Wu, Yiming | Lin, Shumin | Guo, Zhihui | Lv, Yunqian | Xue, Yifeng
To explore high-resolution temporal variation characteristics of atmospheric metal elements concentration and more accurate pollution sources apportionment, online monitoring of metal elements in PM₂.₅ with 1-h time resolution was conducted in Beijing from August 22, 2018 to August 21, 2019. Concentration of 18 elements varied between detection limit (ranging from 0.1 to 100 ng/m³) and nearly 25 μg/m³. Si, Fe, Ca, K and Al represented major elements and accounted for 93.47% of total concentration during the study period. Compared with previous studies, airborne metal pollution in Beijing has improved significantly which thanks to strict comprehensive control measures under the Clean Air Action Plan since 2013. Almost all elements present higher concentrations on weekdays than weekends, while concentrations of elements associated with dust sources during holidays are higher than those in working days after the morning peak, and there is almost no concentration difference in the evening peak period. Soil and dust, vehicle non-exhaust emissions, biomass, industrial processes and fuel combustion were apportioned as main sources of atmospheric metal pollution, accounting for 63.6%, 18.4%, 16.8%, 1.0% and 0.18%, respectively. Furthermore, main occurrence season of metal pollution is judged by characteristic radar chart of varied metal elements proposed for the first time in this study, for example, fuel combustion type pollution mainly occurs in winter and spring. Results of 72-h backward trajectory analysis of air masses showed that, except for local emissions, atmospheric metal pollution in Beijing is also affected by regional transport from Inner Mongolia, Hebei, the Bohai Sea and Heilongjiang.
Show more [+] Less [-]Hollow porous molecularly imprinted polymers as emerging adsorbents Full text
2021
Bhogal, Shikha | Kuldip Kaur, | Mohiuddin, Irshad | Kumar, Sandeep | Lee, Jechan | Brown, Richard J.C. | Kim, Ki Hyun | Malik, Ashok Kumar
Hollow porous molecularly imprinted polymers (HPMIPs) are identified as promising adsorbents with many advantageous properties (e.g., large number of imprinted cavities, highly accessible binding sites, controllable pore structure, and fast mass transfer). Because of such properties, HPMIPs can exhibit improved binding capacity and kinetics to make analyte molecules readily interact with a greater number of recognition sites on the imprinted shell. This review highlights the synthesis and utility of HPMIPs as adsorbents to cover diverse targets of interest (e.g., endocrine disrupting chemicals, pharmaceuticals, pesticides, and heavy metal ions). The overall potential of HPMIPs is thus discussed in the context of analytical chemistry with particular focus on the efficient extraction of trace-level targets from complex matrices.
Show more [+] Less [-]Sensitivity and specificity of macroinvertebrate responses to gradients of multiple agricultural stressors Full text
2021
Brooks, Andrew J. | Bray, Jonathan | Nichols, Susan J. | Shenton, Mark | Kaserzon, Sarit | Nally, Ralph Mac | Kefford, Ben J.
Environmental degradation of rivers in agricultural landscapes is typically caused by multiple co-occurring stressors, but how interactions among stressors affect freshwater ecosystems is poorly understood. Therefore, we investigated the sensitivity and specificity of several measures of benthic macroinvertebrate community response to the individual and combined effects of the pesticide sulfoxaflor (SFX), increased sand sedimentation and elevated nutrients using outdoor recirculating mesocosms. Among the single stressor treatments, nutrients had no observable impact and sand only affected one community response measure compared to controls. High SFX levels had the largest effects on benthic macroinvertebrate communities, negatively affecting six of seven macroinvertebrate response measures. Sulfoxaflor had similar adverse effects on biota when in combination with sand and nutrients in the multi-stressor treatment, suggesting that generally SFX has overwhelming and pervasive effects irrespective of the presence of the other stressors. In contrast to SFX, elevated nutrients had no detectable effect on macroinvertebrate communities, likely as a consequence of nutrients being rapidly taken up by bacteria rather than by benthic algae. Elevated sand sedimentation increased the negative effects of SFX on sediment sensitive taxa, but generally had limited biological effects. This was despite the levels of sedimentation in our treatments being at concentrations that have caused large impacts in other studies. This research points to direct and rapid toxic effects of SFX on stream macroinvertebrates, contrasting with effects of the other stressors. This study emphasises that pesticide effects could be misattributed to other common freshwater stressors, potentially focussing restoration actions on a stressor of lesser importance.
Show more [+] Less [-]Fossil fuels consumption and carbon dioxide emissions in G7 countries: Empirical evidence from ARDL bounds testing approach Full text
2021
Martins, Tailon | Barreto, Alisson Castro | Souza, Francisca Mendonça | Souza, Adriano Mendonça
This research determines the intertemporal relationships caused by the coal, oil, and natural gas consumption in the carbon dioxide emission by the G7 countries from 1965 to 2018. Auto-regressive and Distributed Lags models and Bound test were used to detect cointegration and understand the dynamic effect. Due to structural breaks occurred in the variables, two dummy variables for the periods of breaks, 1978 and 1990 were incorporated respectively. Positive causality was identified, in the sense that the consumption of fossil fuels provides an increase in carbon dioxide emissions. Short-term elasticities indicate that an increase of 1 percentage point in the consumption of oil, coal, and natural gas will cause, respectively, an increase of 0.4823%, 0.3140%, and 0.1717% in carbon dioxide emissions. In the long run, the increase of 1 percentage point in the consumption of oil, coal, and natural gas will cause, respectively, an increase of 0.4924%, 0.2692%, and 0.1829% in carbon dioxide emissions. The error correction model (ECM = −0.4739) indicates that 47.39% of a shock in the carbon dioxide emissions variable is resolved in one year and after 2 years, carbon dioxide emissions return to long term equilibrium.
Show more [+] Less [-]Fe(II) enhances simultaneous phosphorus removal and denitrification in heterotrophic denitrification by chemical precipitation and stimulating denitrifiers activity Full text
2021
Ma, Hang | Gao, Xinlei | Chen, Yihua | Zhu, Jiaxin | Liu, Tongzhou
Using Fe(II) salt as the precipitant in heterotrophic denitrification achieves improved TP removal, and enhancement in denitrification was often observed. This study aimed to obtain a better understanding of Fe(II)-enhanced denitrification with sufficient carbon source supply. Laboratory-scale experiments were conducted in SBRs with or without Fe(II) addition. Remarkably improved TP removal was experienced. TP removal efficiency in Fe(II) adding reactor was 85.8 ± 3.4%; whereas, that in the reactor without Fe(II) addition was 31.1 ± 2.8%. Besides improved TP removal, better TN removal efficiency (94.1 ± 1.1%) were recorded when Fe(II) was added, and that in the reactor without Fe(II) addition was 89 ± 0.8%. The specific denitrification rate were observed increase by 12.6% when Fe(II) was added. Further microbial analyses revealed increases in the abundances of typical denitrifiers (i.e. Niastella, Opitutus, Dechloromonas, Ignavibacterium, Anaeromyxobacter, Pedosphaera, and Myxococcus). Their associated denitrifying genes, narG, nirS, norB, and nosZ, were observed had 14.2%, 19.4%, 21.6%, and 9.9% elevation, respectively. Such enhancement in denitrification shall not be due to nitrate-dependent ferrous oxidation, which prevails in organic-deficient environments. In an environment with a continuous supply of Fe(II) and plenty of carbon sources, a cycle of denitrifying enzyme activity enhancement in the presence of Fe(II) facilitating nitrogen substrate utilization, stimulating denitrifier metabolism and growth, elevating denitrifying genes abundance, and increasing denitrifying enzymes expression were thought to be responsible for the Fe(II)-enhanced heterotrophic denitrification. Fe(II) salt is often a less expensive precipitant and has recently become attractive for TP removal in wastewater. The findings of this study solidify previous observation of enhancement of both TP and TN removal by adding Fe(II) in denitrification, and would be helpful for developing cost-effective pollutant removal processes.
Show more [+] Less [-]Tissue-specific distribution and bioaccumulation of cyclic and linear siloxanes in South Korean crucian carp (carassius carassius) Full text
2021
Wang, Wenting | Cho, Hyeon-Seo | Kim, Kyungtae | Park, Kyunghwa | Oh, Jeong-Eun
The occurrence and distribution of cyclic and linear siloxanes were investigated in South Korean river water and sediment, with a special focus on crucian carp tissues, to evaluate the residual status and potential bioaccumulation of siloxanes. The total siloxanes median concentrations observed in this study were 1495 ng/L in river water, 39.2 ng/g-dry weight [dw] in sediment, and 41.7 ng/g-wet weight [ww] in crucian carp muscle. Cyclic siloxanes (D3–D6) were predominant in all matrices, and D5 (mean: > 81%) was more abundant in biota tissues than in river water (30%) and sediment (26%) samples. Specifically, positive correlations between D5 concentrations and crucian carp sizes (p < 0.01, Spearman) as well as the relatively high estimated biota-sediment accumulation factor value of D5 (D5: 2.31), suggest the high bioaccumulative property of D5 in biota. However, no bioaccumulation potentials were observed for D3, D4, D6, and L3–L17 in this field-scale study. The distributions of major linear siloxanes (L7–L14) in crucian carp gills (17%) and gonads (21%) were higher than in other tissues (brain, 9.6%; liver, 2.6%; muscle, 1.5%). Moreover, relatively high tissue/plasma ratios were observed for linear siloxanes (L7–L10: 1.79–2.12) compared to cyclic siloxanes (D4–D6: 0.829–1.18) (p < 0.01, Mann Whitney U test), which indicated the higher transportability of linear siloxanes to fish tissues than cyclic siloxanes.
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