Heavy metal removal by phytoremediation bears a great potential to decontaminate soils and Brassica juncea L. (Indian mustard) seems to be a possible candidate species for this purpose. A field experiment was conducted to compare the efficiency of eighty Indian mustard cultivars for phytoextraction of cadmium (Cd) and lead (Pb) from bimetal contaminated soil. Our results indicated that total Cd and Pb concentrations in the shoots and roots were in the range of 2.43 ± 0.00 to 0.31 ± 0.02 mg/kg and 2.94 ± 0.05 to 0.44 ± 0.03 mg/kg and 5.33 ± 0.76 to 0.47 ± 0.20 mg/kg and 3.78 ± 0.06 to 0.16 ± 0.08 mg/kg. Significant differences based on the translocation factors indicated that root-to-shoot transfer is higher for Pb (3.87 ± 0.12 to 0.48 ± 0.03) than Cd (3.38 ± 0.05 to 0.22 ± 0.01). Furthermore, significant correlations between dry weights, Cd and Pb concentrations and uptake in both shoots and roots were observed, but translocation factor showed a negative correlation with roots, but not in shoots. Among 80 genotypes of Indian mustard IM-25, IM-13 and IM-65 for Cd and IM-79, IM-24 and IM-32 for Pb seems to perform well for phytoextraction. The results of the field experiment suggest that certain Brassica juncea L. cultivars are suitable for removal of Cd and Pb in low to moderately contaminated soils.

In this paper, the equilibrium and mass transfer kinetics of Sr2+ sorption onto 3 types of microplastics, including polyethylene terephthalate (PET), polyethylene (PE), and polyvinyl chloride (PVC) were investigated. A novel film-pore mass transfer (FPMT) model was developed and used to study the sorption kinetics and mechanisms. This model can be used to describe the external mass transfer (EMT) and the internal mass transfer (IMT) processes and to calculate the diffusion rate. The FPMT model could successfully predict the kinetics data of Sr2+ sorption onto microplastics. The maximum value of the EMT rate achieved at the beginning of sorption was 103 μg g−1·h−1 for PET, 247 μg g−1·h−1for PE, and 854 μg g−1·h−1 for PVC, and then it decreased dramatically with time. The IMT rate was far less than the EMT rate, and decreased slowly with time. The overall sorption rate of Sr2+ onto microplastics was controlled by the external mass transfer step.

The occurrence of environmental antibiotic resistance genes (ARGs) are often attributed to selective pressure from antibiotics from point source pollution. However, the potential effects of natural production of antibiotics, environmental factors, and anthropogenic pressure on the development and spread of ARGs have not been fully investigated. This study evaluated the occurrence and distribution of erythromycin resistance methylase (erm) genes in urban soils. The ermA, ermB, ermC, ermD, ermF, ermG, ermT, and ermY genes were detected with detection frequencies ranging from 20% to 80% and abundances ranging between 5.95 × 101 and 6.94 × 106 copies g−1 dw soil. Both polyketide synthase (PKS) type I and type II biosynthesis genes—which are responsible for biosynthesis of polyketides, such as erythromycin—were detected in all soil samples with a range between 5.77 × 102 and 9.39 × 106 copies g−1 dw soil. The abundances of PKS genes were significantly correlated with 16S rRNA genes (r = 0.487 to 0.741, p < 0.001) and absolute abundances of ermB, ermC, ermD, ermG, and ermY (r = 0.302–0.490, p < 0.05), suggesting that the wide occurrence of ARGs in soils could be potentially driven by naturally produced antibiotics. Erythromycin was strongly correlated with ermB, ermC, ermF and ermY genes (r = 0.462 to 0.667, p < 0.05), but no significant correlation was observed between macrolides and PKS genes, suggesting other environmental factors may have contributed to detected macrolides. The fact that erm gene presented higher extent of variability than PKS genes in different land use types suggests that anthropogenic activity might also influence the occurrence of erm genes in urban soils.

Structural analogues of bisphenol A (BPA) have become widely used as alternatives in BPA-free products. Most toxicological investigations have focused on the estrogenic activities of these analogues, which have been considered as potential environmental estrogens. However, recent studies revealed that certain BPA analogues could dramatically inhibit the proliferation of breast cancer cells, and exhibited strong anti-estrogenic effects compared with the antagonist 4-hydroxytamoxifen (OHT). Thus, we adopted computational models combining molecular dynamics simulations and binding free energy calculations to explore the underlying molecular basis of BPA analogues binding to estrogen receptor α (ERα). We also evaluated ligand-induced structural rearrangements of ERα at the atomic level. Conformational analyses showed that induced-fit H-bonding recognition by Thr347 was an important factor distinguishing antagonist from agonist BPA analogues. Moreover, antagonists of BPA analogues could indirectly induce the structural reposition of key helix 12 and produce an antagonistic conformation of ERα. Compared with OHT, the binding affinity of BPA analogues is stronger for antagonists than agonists. Taken together, we therefore propose computational indicators for screening of anti-estrogenic activities of BPA analogues, which may be beneficial for predicting the estrogenic or anti-estrogenic effects of BPA alternatives.

Increasing interest of seeking substitutable water resources accrues from shortage of freshwater. One of the options considered is reclaimed water (also designated as recycled water) that has been widely used in daily life. Although reclaimed water can serve as a feasible reliever of water pressure, attention about its technologies and potential risks is growing in the meantime. Most established wastewater treatment plants (WWTPs) predate many new contaminants, which means treatment processes cannot ensure to dislodge certain contaminants completely from origin water. Furthermore, a wide range of factors, such as seasons and influent variations, affect occurrence and concentration of reclaimed water-borne contaminants, making research about quality of reclaimed water especially significant. Many reclaimed water-borne contaminants, including biological and chemical contaminants, are toxic to human health, and complex wastewater matrix may aggravate water quality of concern. The widespread use of reclaimed water continues to be a concern on agriculture, ecological environment and human health. This study aims to: 1) provide a critical review about occurrence and profiles of diverse contaminants in the treated reclaimed water, 2) discuss the possibility to avoid the secondary pollution in reuse of reclaimed water, and 3) reveal the prospective consequences of using reclaimed water on agriculture, ecological environment and human health.

Tebuconazole is a widely used fungicide that has been detected in water ecosystems, of which the concentrations may affect the endocrine function of aquatic organisms. At present study, tissue-specific bioaccumulation of tebuconazole was found in ovary of adult zebrafish, indicating a potential risk of endocrine disruption. In order to evaluate the potential endocrine disrupting effects, three life stages (2 hpf (hours post-fertilization) −60 dpf (days post-fertilization), Stage I; 60–120 dpf, Stage II; 180–208 dpf, Stage III) of zebrafish (Danio rerio) were chronically exposed to tebuconazole at the concentrations ranging from 0.05 mg/L to 1.84 mg/L. Result showed that exposed to tebuconazole could lead to a male-biased sex differentiation in juvenile zebrafish and significant decrease of the percentage of germ cells in sexually-mature zebrafish. Egg production was significantly inhibited by 57.8% and 19.2% after Stage II- and Stage III-exposures, respectively. The contents of 17β-estradiol in gonad decreased by 63.5% when exposed to 0.20 mg/L tebuconazole at Stage II and by 49.5% after exposed to 0.18 mg/L tebuconazole at Stage III, respectively. For all stages exposure, reductions in 17β-estradiol/testosterone ratio were observed, indicating an imbalance in steroids synthesis. Additionally, tebuconazole reduced the expression of cyp19a, which was consistent with the decrease of E2 level. In overall, the present findings indicated that, playing as an anti-estrogen-like chemical, tebuconazole inhibited the expression of Cyp19, thereby impairing steroid hormones biosynthesis, leading to a diminished fecundity of zebrafish.

Methane is a potent greenhouse gas whose atmospheric dispersion may have different implications at distinct scales. One significant contributor to methane emissions is sugarcane farming in tropical areas like in Mexico, which has the sixth highest production level in the world. A consequence of the industrial use of this resource is that sugarcane preharvest burning emits large quantities of methane and other pollutants. The objective of this research is to estimate the methane emissions by sugarcane burning and to analyze their atmospheric dispersion under the influence of meteorological parameters, according to different concentration scenarios generated during a period. The methane emissions were investigated using the methodology of Seiler and Crutzen, based on the stage production during the harvest periods of 2011/2012, 2012/2013 and 2013/2014. Average of total emissions (1.4 × 103 Mg) at the national level was comparable in magnitude to those of other relevant sugarcane-producing countries such as India and Brazil. Satellite images and statistical methods were used to validate the spatial distribution of methane, which was obtained with the WRF model. The results show a dominant wind circulation pattern toward the east in the San Luis Potosi area, to the west in Jalisco, and the north in Tabasco. In the first two areas, wind convergence at a certain height causes a downward flow, preventing methane dispersion. The concentrations in these areas varied from 9.22 × 10−5 to 1.22 × 102 ppmv and 32 × 10−5 to 2.36 × 102 ppmv, respectively. Wind conditions in Tabasco contributed to high dispersion and low concentrations of methane, varying from 8.74 × 105 to 0.33 × 102 ppmv. Methane is a potent greenhouse gas for which it is essential to study and understand their dispersion at different geographic locations and atmospheric conditions.

Propyl gallate (propyl 3,4,5-trihydroxybenzoate, PG) is a phenolic antioxidant that has been used for oil-containing foods to prevent acidification. Owing to its antioxidant properties, PG has been applied to various fields and active research is currently underway to prove PG as an anticancer agent. However, there are still concerns about PG as a possible reproductive toxicant. Therefore, we determined whether PG induced male infertility. Our results indicated that PG induced testicular dysfunction in both Leydig and Sertoli cells via suppression of cell viability and steroidogenesis. These normal testis functions were destroyed by PG-induced mitochondrial dysfunction and calcium homeostasis dysregulation. In addition, PG disrupted the expression of several genes associated with the testis function and induced endoplasmic reticulum stress. Furthermore, we verified PG-induced mRNA expression changes in steroidogenesis enzymes and hormone receptors in vitro and in vivo. From the results of the qPCR analysis, we further confirmed the PG-mediated reduction in the mRNA expression of genes related to testis functions by in situ hybridization. Finally, we demonstrated that PG induced testicular toxicity via the disruption of mitochondrial or ER function and the inhibition of testicular development-related genes in mice.

Contamination by plastic debris has been documented in most regions of the world, but their occurrence in high mountain areas has not been investigated to date. Here we present the first report of the occurrence and amount of microplastic in any terrestrial glacier environment. In the supraglacial debris of the Forni Glacier (Italian Alps), we observed the occurrence of (mean ± standard error) 74.4 ± 28.3 items kg⁻¹ of sediment (dry weight). This amount is within the range of variability of microplastic contamination observed in marine and coastal sediments in Europe. Most plastic items were made by polyesters, followed by polyamide, polyethylene and polypropylene. We estimated that the whole ablation area of Forni Glacier should host 131–162 million plastic items. Microplastic can be released directly into high elevation areas by human activities in the mountain or be transported by wind to high altitude. The occurrence of microplastic on Forni Glacier may be due to the gathering of debris coming from the large accumulation area into the relatively smaller ablation area of the glacier, as a consequence of its flow and melting.

Marine mammals in the Barents Sea region have among the highest levels of contaminants recorded in the Arctic and the Atlantic walrus (Odobenus rosmarus rosmarus) is one of the most contaminated species within this region. We therefore investigated the relationships bewteen blubber concentrations of lipophilic persistent organic pollutants (POPs) and plasma concentrations of perfluoroalkyl substances (PFASs) and markers of endocrine and immune functions in adult male Atlantic walruses (n = 38) from Svalbard, Norway. To do so, we assessed plasma concentrations of five forms of thyroid hormones and transcript levels of genes related to the endocrine and immune systems as endpoints; transcript levels of seven genes in blubber and 23 genes in blood cells were studied. Results indicated that plasma total thyroxine (TT4) concentrations and ratio of TT4 and reverse triiodothyronine decreased with increasing blubber concentrations of lipophilic POPs. Blood cell transcript levels of genes involved in the function of T and B cells (FC like receptors 2 and 5, cytotoxic T-lymphocyte associated protein 4 and protein tyrosine phosphatase non-receptor type 22) were increased with plasma PFAS concentrations. These results suggest that changes in thyroid and immune systems in adult male walruses are linked to current levels of contaminant exposure.