Background. Occupational exposures to chromium (Cr), which can have adverse effects on immune function, have not yet been extensively investigated. Hexavalent chromium (Cr (VI)), used in mineral tanning processes, poses a threat to the health of workers in the leather tanning industry. Objectives. The aim of the present study was to evaluate the effects of long-term Cr exposure on the physical health and immunological parameters of male tannery workers in Bangladesh compared with a control group. Methods. A health examination was performed with tannery workers (N=195) and control subjects (N=125) by physicians, demographic data were recorded in questionnaires and peripheral blood samples were collected. Serum Cr levels were analyzed by an atomic absorption spectrophotometer (AAS), immunoglobulin (Ig)G, IgA, and complement components C3 and C4 were determined by nephelometry, IgE was measured by sandwich enzyme-linked immunosorbent assay and complement function was assayed by bactericidal activity. Results. The mean duration of work exposure for the tanners was 9.4±7.1 years. Their body mass index (21.8±3.0 kg/m2), was not significantly different from the controls (22.7±3.2 kg/m2). The mean serum level of Cr in 30 long-term exposed tannery workers (26.97±21.11 μg/dL) was significantly higher than that of 30 randomly selected control subjects (7.38±6.81 μg/dL). The tannery workers had rough skin, rashes, itchy and decolorized skin, allergic diseases and respiratory illness, and had significantly lower levels of serum IgG, IgA, C3 and C4, but significantly higher levels of IgE than the controls. IgG, IgA and C3 levels were all inversely associated with Cr, while IgG, IgE and bactericidal activity showed an inverse correlation with duration of exposure. Conclusions. The results of the present study suggest that chronic exposure to Cr is associated with impaired immune function in male tannery workers. Participant Consent. Obtained Ethics Approval. The present study was approved by the Ethical Review Committee of the faculty of Biological Sciences, University of Dhaka, Bangladesh. Competing Interests. The authors declare no competing financial interests.

Background. In parts of Cambodia, irrigation of rice with groundwater results in arsenic accumulation in soils and rice, leading to health concerns associated with rice consumption. In Bangladesh and China, low zinc levels in rice have been found in regions where arsenic levels in rice are high. Furthermore, there have been claims that zinc deficiency is responsible for stunting of children in Cambodia. There are limited data on zinc in Cambodian rice, but in rural Asia, rice is the major source of zinc. Objectives. To provide a preliminary evaluation of the zinc content in rice grain in Preak Russey, an area with elevated levels of arsenic. The importance of zinc in rice for infants was also assessed. Methods. Rice cultivation was evaluated in sixty farms along the Mekong River in Cambodia. Analyses for metals, total arsenic, and arsenic species in the water and rice were conducted at the University of Ottawa, Canada by inductively coupled plasma – mass spectrometry. Analysis of total zinc and arsenic in soils were analyzed in Phnom Penh using X-ray fluorescence spectrometry (XRF). Total zinc in rice was also measured by XRF analysis. Results. Rice in the Preak Russey area contained zinc with ½ to ¼ of the 1987 Codex standard for rice in Infant Formula. Moreover, our average zinc concentration in rice samples was less than a third that recommended for zinc fortification in rice by the United Nations World Food Programme. There was a significant (α=0.05) negative correlation between the arsenic and zinc content of rice with the lowest zinc levels occurring near the irrigation wells, the source of arsenic. There was a significantly higher content of zinc in rice from farms that fertilized with cow manure. Conclusions. Handheld XRF spectrometers are useful tools for detection of zinc levels in rice. The potential for zinc deficiency in farmers in areas of Cambodia with arsenic toxicity is high. Competing Interests. The authors declare no competing financial interests.

The present study was aimed to reveal the effect of cadmium (Cd)-polluted soil on the activation of antioxidant enzymes, photosynthesis, pigments, water relation, and other biochemical traits and comparative effect of synthetic and organic chelators. A pot experiment was conducted using two maize varieties grown in Cd-contaminated (15 and 30 mg kg⁻¹) soil and chelators (1 mM EDTA, and 1 mM citric acid). Cd decreased biomass and photosynthetic traits while increased malondialdehyde (MDA) contents, total proteins, and antioxidant enzyme activities. Addition of EDTA enhanced Cd uptake, antioxidative enzyme, and total proteins; however, it reduced the water, osmotic, and turgor potential as compared to Cd alone. Addition of citric acid has lessened the antioxidant enzyme activities and MDA contents and enhanced the plant biomass as compared to Cd alone. Increases in antioxidants and MDA content were found to be positively related to the Cd contents in shoot and root. The application of citric acid significantly alleviated the Cd-induced toxic effects, showing remarkable improvement in biomass. These results indicated that EDTA was more effective for mobilizing Cd from soil to the root and shoot than citric acid; however, the physiological traits and plant biomass were more strongly inhibited by EDTA than by the Cd. Our study implies that citric acid ameliorated the negative effect of Cd on physiological traits and biomass, and hence could be used effectively for Cd phytoextraction.

Phytoplankton assemblages were investigated in 2015 along the seasonal changes of the Genhe River in the Greater Hinggan Mountains. The survey was performed in June (spring), August (summer), and October (autumn) at nine sampling stations to study the community composition, abundance, and biodiversity. The results showed that 61 species belonging to 16 genera were identified, including Bacillariophyta of 31 species, Dinophyta 2 species, Cyanophyta 2 species, Chlorophyta 20 species, Chrysophyta 2 species, and Cryptophyta 1 species; Besides, Bacillariophyta are dominant species. Shannon-Wiener (H′) and Pielou (J′) indices indicated that phytoplankton community was stable. And these two indices were significantly lower in summer than in spring and autumn. Phytoplankton abundance and biomass show significant differences in each season. The total phytoplankton abundance (1122.3 × 104 ind/L) and biomass (6.5709 mg/L) in summer are much higher than that in spring and autumn. There were few species and low abundance and biomass in the upper reaches of Genhe River; this fact can be explained by the cold climate in the Greater Higgnan Mountains region. Canonical correspondence analysis (CCA) was used to analyze the data. It revealed that Fe³⁺, Cu²⁺, pH, and water temperature (WT) were responsible for most of the variation in space in the phytoplankton community. These environmental parameters play an essential role in the community structure variation of phytoplankton in the upper reaches of Genhe River, the strong association between phytoplankton community structure and ecological factors is varied in each season.

In this study, some different selected plant leaves grown in Jordan such as Citrus limon (Rutaceae), Ceratonia siliqua L., Olea europaea (Oleaceae), Washingtonia filifera, and Myoporum (Myoporaceae) were examined for removal of copper (Cu) and zinc (Zn) ions from aqueous solutions. Cu and Zn were analyzed by atomic absorption spectrometry. A pH S-2 acidometer was used for determining the acidity of leaves solution system. Our findings showed the plants leaves were relatively efficient for removal of Cu and Zn compared to activated carbon. Removal of a 5 mg/L aqueous metal solution of Cu and Zn was treated with 2.5 g oven-dried plant in a 50 mL deionized water. The removal of Cu and Zn was expressed in terms of a time function ranged between 0 and 192 hours of contact time. The uptake of Cu and Zn by plant leaves was arranged in the following order:(i)Cu: Activated carbon > Washingtonia filifera > Ceratonia siliqua L. > Olea europaea (Oleaceae) > Myoporum (Myoporaceae) > Citrus limon (Rutaceae)(ii)Zn: Activated carbon > Olea europaea (Oleaceae) > Citrus limon (Rutaceae) > Ceratonia siliqua L. > Washingtonia filifera > Myoporum (Myoporaceae)

Fluorene-9-bisphenol (BHPF), a new derivative of bisphenol A (BPA), has been introduced for treatment with estrogen-related tumors, such as endometrial cancer. This study investigated the potential mechanism underlying the action of BHPF against endometrial cancer in vitro. We used the cell counting kit-8 (CCK8) method on Ishikawa cells to screen sub-lethal doses of BHPF and established the optimal concentration at which BHPF influenced the proliferation of Ishikawa cells. Effect of BHPF on cell migration and invasion was investigated by cell scratch assay and transwell assay, respectively. Expression levels of epithelial-mesenchymal transition (EMT)–related proteins were detected by Western blot analysis. BHPF was found to inhibit the proliferation of Ishikawa cells, whose migration and invasion abilities were also reduced. Western blot indicated that BHPF can significantly inhibit the EMT process of Ishikawa cells by blocking transforming growth factor-β (TGF-β) signaling pathway. This is the first report of the effect of BHPF on the biological behavior of endometrial cancer cells and its inhibition of endometrial cancer progression by repressing both endometrial cell proliferation and epithelial-mesenchymal transition, hence suggesting it as a novel anti-cancer drug. Graphical abstract Schematic representation of the molecular basis underlying BHPF treatment. BHPF repressed the EMT process by regulating EMT-related genes, such as E-cadherin, N-cadherin, and vimentin as well as the TGF-β signaling pathway–related genes, including p-Smad2/3 and slug, in a BHPF-dependent manner.

Among the different contaminants, detergent as an important pollutant has serious risks to natural ecosystems. Furthermore, detergents can pass into the wastewater treatment plants and have bad effect on their performance. They are part of human life and consumed for different aims especially hygienic purposes. Therefore, detergent components can enter to soil and water bodies from different sources. Detergents affect fauna and flora, and they have direct and indirect effects on ecosystems. Eutrophication, foaming, and altering parameters such as temperature, salinity, turbidity, and pH are more important, and their effects need to be managed and controlled. Researchers confirmed that aerobic processes are able to degrade the most of detergents but anaerobic degradation is not possible because of restricted metabolic pathways and toxicity of them. Therefore, production of environment-friendly detergent is an important issue around the world. Graphical abstract

The most commonly used solution in chrome plating bath is chromic acid (hexavalent Cr), and a considerable amount of mists is released into the air and consequently produce hazards to workers. Thus, the aim of this study was to evaluate whether the biomarker of exposure to metals, specially Cr levels, presents associations with hematological and biochemical parameters and if they can alter the activity of enzymes that contain thiol groups such as pyruvate kinase, creatine kinase, adenylate kinase, and δ-aminolevulinate dehydratase. Fifty male chrome plating workers were used for exposed group and 50 male non-exposed workers for control group. For that, biological monitoring was performed through quantification of metals on total blood and urine by inductively coupled plasma mass spectrometry (ICP-MS) and enzyme activity was performed by spectrometry in erythrocytes. In addition, chromium levels in water was quantified and ecotoxicology assay was performed with Allium cepa test. The results demonstrated that blood and urinary chromium levels in exposed group were higher than the control group (p < 0.0001). Furthermore, decreased activity of enzymes was found in those that contain thiol groups from exposed group when compared with the control group (p < 0.001). The water analysis did not present a statistical difference between control and exposed groups (p > 0.05), demonstrating that water did not seem to be the source of contamination. In summary, our findings indicated some toxicology effects observed in the exposed group, such as thiol enzyme inhibition, mainly associated with occupational exposure in chrome plating and besides the presence of other metals, and Cr demonstrated to influence the activity of the enzymes analyzed in this research.

Bisphenol A (BPA) and bisphenol S (BPS) are frequently detected in soils and groundwater, which may pose threats to public health and the environment. However, the fate and transport of BPA/BPS in the subsurface media are still not clear. In this study, the retention and transport of BPA/BPS in three different natural soils were investigated with column experiments and mathematical modeling. The results showed that both BPA and BPS had high mobility in saturated soil A (Xinjiang soil), medium mobility in soil B (Changshu soil) media, and no mobility in the soil C (Jilin soil). There was a negative correlation between the mobility of BPA/BPS and soil organic matter (SOM) content because of the strong sorption of BPA/BPS on SOM. BPS showed higher mobility than BPA in the three soils. In addition, with the reduction of SOM of the soil B and C (after H₂O₂-treatment), the mobility of BPA/BPS enhanced dramatically. All these suggest that SOM played a significant role in controlling the retention and transport of BPA/BPS in the soil. Furthermore, the two-site kinetic model simulated the BPA/BPS transport experiment results very well.

Three representative earthen canals from urban, peri-urban, and rural-urban fringe of Sri Lanka were studied for a 2-year period against different seasons to capture insights important in ecological rehabilitation. Only the canal from rural-urban fringe showed a better water quality in wet season; elucidating, the impact of contaminated catchment runoff in the other canals. At a given sampling session, one or two peaks (relative maxima) were observed in urban and peri-urban canals for pollution representative parameters such as nitrate nitrogen and soluble reactive phosphorus. Those peaks were highly localised, an indication of poor advection. In general, two-dimensional variations of electrical conductivity and turbidity in dry season were uniform in urban and peri-urban canals, an indication of dominant molecular diffusion. This was further evidenced via physical models for different flow stages (low, high, and bankfull). Therefore, fate of contaminants had to be mainly governed by assimilation via sediments. However, grey water footprint analyses showed urban and peri-urban canals have over utilised the natural assimilation capacity of many water quality parameters by several folds. This study proved the importance of inducing attenuation by instream physical heterogeneity similar to natural streams or naturalised canals such as the canal from the rural-urban fringe of this study.