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.

Estuaries are often considered to be the filters of pollutants from the land-derived outflows of freshwater to open seawater. Oysters are efficient bioaccumulators of metals in the estuarine environment, however, little information is available on the long-term tissue variability of metals in a large dynamic estuary under complex urbanized and anthropogenic impacts. Thus, an eight-year biomonitoring study of metals (Ag, Cd, Cr, Cu, Ni, Pb, and Zn) in the oysters from 10 sites were carried out to reveal the highly spatial-temporal variations in the Pearl River Estuary (PRE) of China during 2011–2018. Cd, Cu, and Zn in oysters were significantly correlated with the dissolved metals in seawater. Geographically, Ag, Cd, and Cr were higher in the western sites, and Cu, Ni, and Zn were higher in the eastern sites. High seasonal variations of Ag, Cu, and Zn were found in the wet season. The calculated annual change rates (vc) of Cd, Cu, Zn, Ag, Pb, Ni, and Cr in the oysters were −1.1, −45, −48, 0.338, −0.216, −2.2, and −2.8 μg/g/y, respectively. If such decreasing rates of vc (or natural logarithm rates v) were maintained, Cd, Cu, Zn, Pb, and Ni in oysters from PRE would be expected to recover to the national 50% concentrations in years 2022 (2024), 2045 (2079), 2073 (2110), 2021 (2023), and 2019 (2020), respectively. Long-term series observations of metals in organisms reflected the real bioavailability of metals, pollution status, and trends for environmental management and control in a large dynamic and contaminated estuary.

Hypoxia off the Changjiang Estuary (CE) and its adjacent waters is purported to be the most severe in China, attracting considerable concern from both the scientific community and the general public. Currently, continuous observations of dissolved oxygen (DO) levels covering hypoxia from its appearance to disappearance are lacking. In this study, twelve consecutive monthly cruises (from February 2015 to January 2016) were conducted. The consecutive spatiotemporal variations in hypoxia throughout the annual cycle were elucidated in detail, and the responses of annual variations in hypoxia to the different influential factors were explored. Overall, hypoxia experienced a consecutive process of expanding from south to north, then disappearing from north to south. The annual variations in hypoxia were mainly contingent on stratification variations. Among different stages, there was significant heterogeneity in the dominant factors. Specifically, low-DO waters initially appeared from the intrusion of nearshore Kuroshio branch current (NKBC), as NKBC intrusion provided a low-DO background and triggered stratification. Thereafter, stratification was enhanced and gradually expanded northward, which promoted the extension of low-DO areas. The formation of hypoxia was regionally selective, and more intense organic matter decomposition at local regions facilitated the occurrence and discontinuous distribution of hypoxia. Hypoxic zones were observed at the Changjiang bank and Zhejiang coastal region from August (most extensively at 14,800 km²) to October. Thereafter, increased vertical mixing facilitated the dissipation of hypoxia from north to south.

This study investigated the seasonal characterization of dissolved organic matter (DOM) in reclaimed wastewater (RW) with a special focus on dissolved organic nitrogen (DON) from two full-scale municipal wastewater reclamation plants (WRPs) where the produced RW was used to augment urban rivers. Results showed that the concentrations of DON in RW ranged from 0.32 mg/L to 1.21 mg/L. A higher seasonal mean value of DON in RW from both of the WRPs was observed in winter (p < 0.05, ANOVA). DON chemical characteristics analysis, including ultrahigh-resolution mass spectrometry and ultrafiltration fractionation, showed that DON in RW exhibits more lability during winter than during the other three seasons. This finding was also supported by the results of an algal bioassay experiment, in which DON bioavailabilities were 63.7 ± 3.0%, 53.0 ± 5.3%, 49.5 ± 0.5%, and 49.8 ± 0.2% for WRP-A and were 60.8 ± 2.4%, 43.7 ± 2.2%, 41.2 ± 1.7%, and 43.1 ± 1.1% for WRP-B in winter, spring, summer, and autumn, respectively. Accordingly, DON in RW during winter is more prone to stimulate natural algae and microorganisms, which gives rise to eutrophication in urban rivers. At the molecular level, the seasonal changes in DON are not coupled with those of DOC, which highlights the necessity of DON measurement to obtain a comprehensive understanding of the seasonal characteristics of DOM in RW and its effect on wastewater reuse in urban rivers.

In vitro bioassays have been used as a bioanalytical means of detecting dioxin-like compounds (DLCs) in environmental matrices and have been suggested as a tool for quantifying DLCs in sediments. The present study evaluated the relationship between bioanalytical results from the micro-7-ethoxyresorufin-O-deethylase (EROD) bioassay and chemical analytical results in 25 sediment samples collected from rivers across Germany. Sediments were collected, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were extracted from the sediments, biological toxicity equivalent quotients (BEQs) were determined by micro-EROD assay and toxicity equivalent quotients (TEQs) were calculated from chemical analysis. Correlations between BEQs and TEQs were evaluated, and linear regression modeling was performed, excluding 6 samples as validation data, to derive equations for predicting TEQs from BEQs. Validation data was tested to evaluate predictive capabilities of the models. Correlations were observed between BEQ and TEQ for PCDD/Fs (r=0.987), PCBs (r=0.623), measured sum of PCDD/F and PCBs (r = 0.975) and calculated sum of PCDD/F and PCBs (r = 0.971). The modeling equations provided low variances as evaluated by mean absolute error (MAE) (≤10.3 pg/g) and root mean square error (RMSE) (≤15.8 pg/g) indicating that expected TEQs could be reasonably well calculated from BEQs. Predicted TEQs from validation data fell within the 95% probability intervals of the test data and had low variances (MAE≤6.5 pg/g) and (RMSE≤10.7 pg/g). Our results indicate that the micro-EROD bioassay can be used as a screening tool for DLCs in sediment and has the capability to be used as an alternate method to chemical analysis for quantifying dioxin-like potential of sediments.

Data (N = 11251) from National Health and Nutrition Examination Survey (NHANES) for 2003–2016 for US adults aged ≥20 years were stratified by gender and anemia and analyzed to evaluate the associations between the concentrations of whole blood hemoglobin (WBHGB) and selected perfluoroalkyl acids (PFAAs) in serum by stages of glomerular filtration (GF). Investigated PFAAs were perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). Females with whole blood hemoglobin concentrations <12 g/dL and males with whole blood hemoglobin concentrations <13 g/dL were classified as being anemic. Regression models with log10 transformed concentrations of whole blood hemoglobin as dependent variable and age, poverty income ratio, body mass index, serum cotinine, daily alcohol intake, survey year, and log10 concentrations of one of the PFAA as independent variables were fitted. For anemic females, association between WBHGB and PFAA concentrations were uniformly positive across worsening stages of renal failure and percent increases for 10% increases in PFAAs varied between 0.03% and 0.39%. For anemic males, association between WBHGB and PFAA concentrations were positive except at GF-3A (45 ≤ eGFR<60 mL/min/1.73 m²) and percent increases for 10% increases in PFAAs varied between 0.02% and 0.53%. Thus, more often than not, presence of positive associations between WBHGB and PFAA among anemics imply elevated levels of PFAA are associated with higher levels of WBHGB. Similar results were observed for non-anemic males and females, however strengths of associations between whole blood hemoglobin and PFAAs were several fold higher among anemic compared to non-anemic participants. Hemoglobin is consistently associated with serum PFAAs.

Because pollution is predicted to worsen and sources of quality water for agriculture and other human activities are limited, many countries have been motivated to seek novel water sources. Qatar relies on groundwater and water desalinization to meet its water needs, and additional water resources will be needed to avoid unexpected crises in the future. Industrial wastewater (IWW) is an alternative water source, and much research activities should be focused on developing innovative and contemporary approaches to removing pollutants from IWW. Phytoremediation methods, shown to be efficient methods of removing and degrading contaminants of various kinds from polluted waters and soils, require knowledge of the native plants and associated microorganisms. In Qatar, many native plants (monocot and dicot, indigenous or introduced) have been shown to be greatly effective in remediating polluted areas. This article is a guide for Qatari scientists aiming to identify promising native plants and associated microbes for IWW phytoremediation. In it, we review the basic components of bioremediation and summarize the principle phytoremediation approaches and preferred recycling options. The multiple mechanisms and methods of phytoremediation for cleansing polluted soils and waters are also discussed as are details of the metabolic reactions degrading the organic components of oil and gas. Finally, heavy metal accumulation is addressed. Wastewater from industrial and domestic activities is currently being used to create green areas around Doha, Qatar, and such areas could be at risk of contamination. Many native Qatari plants and soil-dwelling microbes are efficient at removing organic and inorganic contaminants from polluted soils and waters, and some are promising candidates for achieving a clean environment free of contaminants.

Ny-Ålesund, one of four permanent settlements on Spitsbergen in Svalbard, is a research town that includes scientific institutes from many countries. Because of daily-used chemicals (e.g., pharmaceutical and personal care products (PPCPs)) used by residents in the area, generated sewage is considered as a point source in the Kongsfjorden. The aim of the present study was to identify and quantify organic pollutants in the effluent and along the shoreline and offshore via target, suspect, and non-target screening using liquid chromatography–high-resolution mass spectrometry. We tentatively identified 30 compounds using the suspect and non-target screening methods in effluent samples from our first visit to the settlement in 2016. Among these, 3 were false positive, 24 were confirmed, and the 3 remaining compounds were not confirmed because of a lack of reference standards. Of the confirmed, 21 were quantifiable and considered target compounds for the 2nd year study. The quantified compounds in the effluent samples in 2017 totaled 17, including PPCPs, pesticides, perfluorinated compounds, and their metabolites. Some of the compounds, such as caffeine, paraxanthine/theophylline, acetaminophen, cetirizine, diethyl toluamide (DEET), and icaridin, were also detected in the receiving seawater. The concentration range was from 4 to 280,000 ng/L in the effluent and 2–98 ng/L in the seawater. Other 24 compounds were tentatively identified in the second-year effluent samples. Five were further confirmed using reference standards. Prioritization was performed on the 47 substances screened in Ny-Ålesund using the exposure and toxicity index. As the result, the top seven substances of concern present were perfluorooctanesulfonic acid (PFOS), triphenyl phosphate (TPHP), irbesartan, DEET, acetaminophen, caffeine, and paraxanthine/theophylline. As the effluent was identified as a source of the concerned organic pollutants, an emission reduction strategy should take place for protection of Arctic Fjorden environment.

This work evaluated the debromination and uptake of ¹⁴C-labeled BDE-209 in rice cultivars grown in anoxic soil for 120 days (d) followed by cultivation of vegetables (peanut, eggplant and pepper) in oxic soil (120 d). Degradation of BDE-209 to lower polybrominated diphenyl ethers (PBDEs) occurred in cultivated soils, and more metabolites were released in oxic soil than in anoxic soil. The crop rotation from anoxic to oxic greatly enhanced the dissipation of BDE-209 in the soil (P < 0.05), in which the dissipation in anoxic soil planted with Huanghuazhan (HHZ, indica) and Yudao 1 (YD1, indica) were 6.8% and 2.4%, respectively, while in oxic soil with peanut and pepper were increased to 25.8% and 21.7%, respectively. The crop rotation also enhanced the degradation of BDE-209 in the soil, the recovered BDE-209 in soil after 120 d anoxic incubation with YD1 was 81.1%, but it decreased to 47.8% and 45.8% after another 120 d oxic incubation. Bioconcentration factors were between 0.23 and 0.36 for rice, eggplant and pepper but reached to 0.5 in peanut, which contains more lipids in the edible portion than the other test crops. The estimated daily intake for vegetables was 0.01–0.07 μg BDE-209-equivalent kg⁻¹ bw day⁻¹, which is at least two orders of magnitude below the maximum acceptable oral dose (7 μg kg⁻¹ bw day⁻¹). Our work confirms that crop rotation from rice to vegetable enhanced the dissipation and debromination of BDE-209 in the soil, and indicate that sequential anoxic-oxic rotation practice is considered to be effective in remediation of environmental pollutants.

Recently, we reported that hypoxia disrupts the endocrine system and causes metabolic abnormalities in prawns. Although transgenerational impairment effects of hypoxia have become a hot topic in vertebrate, it is unknown whether hypoxia could exert cross-generational effects on testicular function crustaceans. The present study aimed to investigate hypoxia’s toxic effects on the testicular function of oriental river prawns (Macrobrachium nipponense) and offspring development. Hypoxia disrupted testicular germ cells quality, caused sex hormone imbalance (testosterone and estradiol), and delayed testicular development. The F1 generation derived from male prawns exposed to hypoxia showed retarded embryonic development, and reduced hatching success and larval development, despite not being exposed to hypoxia. Analysis of the transcriptome the F0 generation (exposed to hypoxia) showed that the impaired testicular functions were associated with changes to mitochondrial oxidative phosphorylation, apoptosis, and steroid biosynthesis. Interestingly, quantitative real-time PCR confirmed that hypoxia could significantly suppress the expression of antioxidant and gonad development-related genes in the testis of the F1 generations, with and without continued hypoxia exposures. In addition, paternal exposure to hypoxia could result in a higher production of reactive oxygen species in offspring testis tissue compared with those without hypoxia exposure. The cross-generational effects of testicular function implied that the sustainability of natural freshwater prawn populations would be threatened by chronic hypoxia.