Eutrophication and warming lead to frequent occurrence of cyanobacterial blooms, which significantly impact on zooplankton. Freshwater zooplankton Daphnia adopts two distinct ways of reproduction: asexual (parthenogenetic) reproduction for rapidly reproducing many offspring in favorable environment and sexual reproduction for producing resting eggs as seed bank to survive in harsh environments. Daphnia pulex has worse performance in growth and reproduction under the exposure to toxic cyanobacteria Microcystis aeruginosa and tends to allocate less energy to reproduction in the case of insufficient food. However, the relative reproductive allocation strategy (energy allocation) of D. pulex individuals exposed to toxic M. aeruginosa is still unclear. Here we tested the relative reproductive performance of D. pulex fed on solely Chlorella pyrenoidosa (high quality food) or Chlorella mixed with toxic M. aeruginosa (low quality food), based on the parthenogenetic reproduction (life-history experiments) and sexual reproduction (population experiments). The results showed that under low quality food conditions, D. pulex reproduced fewer offspring which were also smaller and thus led to a reduced absolute output in parthenogenetic reproduction, but produced ephippia in the same size and quantity compared to those cultured under high quality food conditions. However, as the body size of maternal D. pulex cultured under low quality food conditions decreased, the relative reproductive allocation significantly increased in both parthenogenetic and sexual reproduction, compared to those cultured under high quality food conditions. In conclusion, D. pulex tend to allocate relatively more energy to reproduction under Microcystis conditions, which is a reasonable strategy for it to decentralize the risks from low-quality food.

Soil anthropogenic contaminants can limit enzymatic nutrient mineralization, either by direct regulation or via impacts on the microbial community, thus affecting plant growth in agricultural and non-agricultural soils. The impact on phosphatase activity of mixing two contaminated, post-industrial rail yard soils was investigated; one was vegetated and had high phosphatase function, the other was barren and had low enzymatic function. The two soils had different abiotic properties, including contaminant load, vegetation cover, soil aggregate size distribution, and phosphatase potential. An experimental gradient was established between the two soils to systematically vary the abiotic properties and microbial community composition of the two soils, creating a gradient of novel ecosystems. The time dependence of extracellular phosphatase activity, soil moisture, and organic matter content was assessed along this gradient in the presence and absence of plants. Initially, mixtures with higher percentages of functional, vegetated soil had higher phosphatase activities. Phosphatase activity remained unchanged through time (65 days) in all soil mixtures in unplanted pots, but it increased in planted pots. For example, in the presence of plants, phosphatase activity increased from 0.6 ± 0.1 to 2.4 ± 0.3 μmol•h⁻¹•gdᵣy ₛₒᵢₗ⁻¹ from day one to day 65 in the 1:1 functional:barren soil mixture. The presence of plants also promoted moisture retention. Inoculation of poorly functioning soil with 10% of the functional soil with its microbial community did not, over 65 days, revitalize the poorly functioning soil. The findings showed that abiotic limitations to enzymatic activity in barren brownfield soils could be mitigated by establishing primary production but not by the addition of enzymatically active microbial communities alone.

The study objective is to contemplate the effectiveness of COVID-19 on the air pollution of Indian territory from January 2020 to April 2020. We have executed data from European Space Agency (ESA) and CPCB online portal for air quality data dissemination. The Sentinel – 5 P satellite images elucidate that the Air quality of Indian territory has been improved significantly during COVID-19. Mumbai and Delhi are one of the most populated cities. These two cities have observed a substantial decrease in Nitrogen Dioxide (40–50%) compared to the same period last year. It suggests that the emergence of COVID-19 has been proved to a necessary evil as being advantageous for mitigating air pollution on Indian territory during the lock-down. The study found a significant decline in Nitrogen Dioxide in reputed states of India, i.e., Delhi and Mumbai. Moreover, a faded track of Nitrogen Dioxide can be seen at the Maritime route in the Indian Ocean. An upsurge in the environmental quality of India will also be beneficial for its neighbor countries, i.e., China, Pakistan, Iran, and Afghanistan.

Triclosan (TCS) and its two derivatives (2,4-dichlorophenol and 2,4,6-trichlorophenol) are priority pollutants that coexist in aquatic environments. Joint exposure of TCS, 2,4-dichlorophenol and 2,4,6-trichlorophenol, hereafter referred to as TCS-DT, contributes severe toxicity to aquatic organisms. There is currently a paucity of data regarding TCS-DT molecular toxicity, especially on cardiac diseases. We used zebrafish (Danio rerio) as a model organism, and evaluated the molecular-level cardiotoxicity induced by TCS-DT from embryonic to adult stages. TCS-DT exposure prominently led to phenotypic malformations, such as pericardial cysts, cardiac bleeding, increased SV-BA distance, decreased heart rate and reduced ejection fraction, as well as abnormal swimming behavior. Analyses of the GO and KEGG pathways revealed enrichment pathways related to cardiac development and screened for significantly down-regulated adrenaline signaling in cardiomyocytes. The cardiac marker genes (amhc, cmlc2, vmhc, and nkx2.5) were obtained through protein-protein interaction (PPI) networks, and expressed as down-regulation by WISH. After chronic exposure to TCS-DT from 30 to 90-dpf, both body mass and heart indexes prominently increased, showing myocardial hypertrophy, abnormal heart rate and histopathological injury. Heart tissue damage included disordered and ruptured myocardial fibers, broken and dissolved myofilaments, nuclear pyknosis, mitochondrial injury and inflammatory cell infiltration. Further, abnormal changes in a series of cardiac functions-related biomarkers, including superoxide dismutase, triglyceride, lactate dehydrogenase and creatinine kinase MB, provided evidence for cardiac pathological responses. These results highlight the molecular mechanisms involving TCS-DT induced cardiac toxicity, and provide theoretical data to guide prevention and treatment of pollutant-induced cardiac diseases.

Hypoxia is a major stressor in aquatic environments and it is frequently linked with excess nutrients resulting from sewage effluent discharges and agricultural runoff, which often also contain complex mixtures of chemicals. Despite this, interactions between hypoxia and chemical toxicity are poorly understood. We exposed male three-spined stickleback during the onset of sexual maturation to a model anti-androgen (flutamide; 250 μg/L) and a pesticide with anti-androgenic activity (linuron; 250 μg/L), under either 97% or 56% air saturation (AS). We assessed the effects of each chemical, alone and in combination with reduced oxygen concentration, by measuring the transcription of spiggin in the kidney, as a marker of androgen signalling, and 11 genes in the liver involved in some of the molecular pathways hypothesised to be affected by the exposures. Spiggin transcription was strongly inhibited by flutamide under both AS conditions. In contrast, for linuron, a strong inhibition of spiggin was observed under 97% AS, but this effect was supressed under reduced air saturation, likely due to interactions between the hypoxia inducible factor and the aryl hydrocarbon receptor (AhR) pathways. In the liver, hypoxia inducible factor 1α was induced following exposure to both flutamide and linuron, however this was independent of the level of air saturation. This work illustrates the potential for interactions between hypoxia and pollutants with endocrine or AhR agonist activity to occur, with implications for risk assessment and management.

Hydroquinone (HQ), one of the main metabolites of benzene, is a well-known human leukemogen. However, the specific mechanism of how benzene or HQ contributes to the development of leukemia is unknown. In a previous study, we demonstrated the upregulation of DNA methyltransferase (DNMT) expression in HQ-induced malignant transformed TK6 (HQ-TK6) cells. Here, we investigated whether a regulatory loop between the long noncoding RNA FAS-AS1 and DNMT3b exists in HQ-TK6 cells and benzene-exposed workers. We found that the expression of FAS-AS1 was downregulated in HQ-TK6 cells and workers exposed to benzene longer than 1.5 years via histone acetylation, and FAS-AS1 expression was negatively correlated with the time of benzene exposure. Restoration of FAS-AS1 in HQ-TK6 cells promoted apoptosis and inhibited tumorigenicity in female nude mice. Interestingly, treatment with a DNMT inhibitor (5-aza-2-deoxycytidine), histone deacetylase inhibitor (trichostatin A), or DNMT3b knockout led to increased FAS-AS1 through increased H3K27ac protein expression in HQ-TK6 cells, and DNMT3b knockout decreased H3K27ac and DNMT3b enrichment to the FAS-AS1 promoter region, which suggested that DNMT3b and/or histone acetylation involve FAS-AS1 expression. Importantly, restoration of FAS-AS1 resulted in reduced expression of DNMT3b and SIRT1 and increased expression of FAS in both HQ-TK6 cells and xenograft tissues. Moreover, the average DNMT3b expression in 17 paired workers exposed to benzene within 1.5 years was decreased, but that of the remaining 103 paired workers with longer exposure times was increased. Conversely, DNMT3b was negatively correlated with FAS-AS1 expression. Both FAS-AS1 and DNMT3b influenced the enrichment of H3K27ac in the FAS promoter region by regulating the expression of SIRT1, consequently upregulating FAS expression. Taken together, these observations demonstrate crosstalk between FAS-AS1 and DNMT3b via a mutual inhibition loop and indicate a new mechanism by which FAS-AS1 regulates the expression of FAS in benzene-related carcinogenesis.

Wastewater effluents released in surface water provides suitable nutrient rich environment for the growth and proliferation of antibiotic resistant bacteria (ARB) and genes (ARG). Consequently, bacterial resistance has highly evolved over the recent years and diversified that each antibiotic class is inhibited by a distinct mechanism. In the present study, the prevalence of Multidrug resistant (MDR), extended spectrum β-lactamases (ESBL) and plasmid mediated Amp-C producing strains was analyzed in 28 surface water samples collected near domestic effluent discharge sites in river Ganga located across 11 different geographical indices of Uttar Pradesh, India. A total of 243 bacterial strains with different phenotypes were isolated. Among 243 isolates, 206 (84.77%) exhibited MDR trait displaying maximum resistance towards β-lactams (P = 78.19%; AMX = 72.84%), glycopeptides (VAN = 32.92%; TEI = 79.42%), cephalosporins (CF = 67.90%; CFX = 38.27%), and lincosamides (CD = 78.18%) followed by sulfonamide, macrolide and tetracycline. ESBL production was confirmed in 126 (51.85%) isolates that harbored the genes: blaTEM (95.24%), blaSHV (22.22%), blaOXA (11.90%) and blaCTX-M group (14.28%). The presence of plasmid mediated AmpC was detected only in 6.17% of isolates. The existence of such pathogenic strains in the open environment generates an urgent need for incorporating stringent measures to reduce the antibiotic consumption and hence its release.

The present study attempts to explore and compare the seasonal variability in chemical composition and contributions of different sources of fine and coarse fractions of aerosols (PM₂.₅ and PM₁₀) in Delhi, India from January 2013 to December 2016. The annual average concentrations of PM₂.₅ and PM₁₀ were 131 ± 79 μg m⁻³ (range: 17–417 μg m⁻³) and 238 ± 106 μg m⁻³ (range: 34–537 μg m⁻³), respectively. PM₂.₅ and PM₁₀ samples were chemically characterized to assess their chemical components [i.e. organic carbon (OC), elemental carbon (EC), water soluble inorganic ionic components (WSICs) and heavy and trace elements] and then used for estimation of enrichment factors (EFs) and applied positive matrix factorization (PMF5) model to evaluate their prominent sources on seasonal basis in Delhi. PMF identified eight major sources i.e. Secondary nitrate (SN), secondary sulphate (SS), vehicular emissions (VE), biomass burning (BB), soil dust (SD), fossil fuel combustion (FFC), sodium and magnesium salts (SMS) and industrial emissions (IE). Total carbon contributes ∼28% to the total PM₂.₅ concentration and 24% to the total PM₁₀ concentration and followed the similar seasonality pattern. SN and SS followed opposite seasonal pattern, where SN was higher during colder seasons while SS was greater during warm seasons. The seasonal differences in VE contributions were not very striking as it prevails evidently most of year. Emissions from BB is one of the major sources in Delhi with larger contribution during winter and post monsoon seasons due to stable meteorological conditions and aggrandized biomass burning (agriculture residue burning in and around the regions; mainly Punjab and Haryana) and domestic heating during the season. Conditional Bivariate Probability Function (CBPF) plots revealed that the maximum concentrations of PM₂.₅ and PM₁₀ were carried by north westerly winds (north-western Indo Gangetic Plains of India).

Whereas the adverse effects of vanadium released from smelting activities on soil microbial ecology have been widely recognized, little is known about spatiotemporal vanadium distribution and microbial community dynamics in typical contaminated sites. This study describes vanadium contents associated with health risk and microbial responses in both topsoil and subsoil during four consecutive seasons around an ongoing-production smelter in Panzhihua, China. Higher levels of vanadium concentration exceeding soil background value in China (82 mg/kg) were found close to the smelter. Vanadium concentrations decreased generally with the increase in distance to the smelter and depth below surface, as soil vanadium pollution is induced mainly by atmospheric deposition of vanadium bearing dust during smelting. Residual fraction was the predominated vanadium form in soils, with pronounced increase in bioavailable vanadium during rainfall period due to frequent drought-rewetting process. Topsoil close to the smelter exhibited significant contamination, inducing high probability of adverse health effects. Spatiotemporal vanadium distribution creates filtering effects on soil microorganisms, promoting metal tolerant genera in topsoil (e.g. Microvirga) and subsoil (e.g. Bacillus, Geobacter), which is the key in maintaining the community structure by promoting cooperative relation with other taxa. Our results reveal spatiotemporal vanadium distribution in soils at site scale with potential health risk and microbial responses, which is helpful in identifying severe contamination and implementing bioremediation.

Municipal waste incineration plants (MWIPs) are a source of emission of diverse pollutants that have been associated with environmental and health effects, mainly in relation to premises that are old and not well equipped or maintained. As a result, the public usually holds a negative view of such plants and tends to react adversely to construction of new plants. Understanding a population’s perceptions is key to ensuring the correct development of such infrastructure and adequately managing population health concerns and behaviours. In this study, we surveyed 173 residents living close (≤ 10 km) to an MWIP being built in San Sebastian (Gipuzkoa, Spain) and 164 living further away (>10 km). The questionnaire included sociodemographic and psycho-environmental measures. Answers to the questionnaire revealed a fairly low acceptance rate and the perception of a high risk for human health and the environment (average scores of 0.57, 3.07 and 2.89 respectively in a 0 to 4 scale), with no statistically significant differences between people living nearby and further afield. A hierarchical regression model built to explore the public’s acceptance of the MWIP explained 59% of the variance. Dominance and relative weight analyses revealed that the most important predictors of acceptance were trust in the information provided by the local government and perceived risk for human health, which accounted for 33.7% and 27.4% of the variance explained by the model respectively. Preference for landfilling and MWIP acceptance in a farther location made a less relevant contribution.