For further understanding leaching characteristics of heavy metals in tailings and better immobilization on heavy metals against acid rain, batch experiments were conducted. The leaching results of Cu(II), Zn(II), Cd(II) and Mn(II) can be well fit by second-order kinetics equation, and Pb(II) can be well fit by two-constant equation. The leaching intensity of heavy metals in tailings was ranged as: Mn(II)> Cu(II)> Cd(II)> Zn(II)> Pb(II). Triethylenetetramine functioned montmorillonite (TETA-Mt) was successfully synthesized and can obtain simultaneous immobilization effect compared with Mt and TETA, and immobilization rates on Cu(II), Cd(II), Mn(II) and Zn(II) can reach above 90%, the immobilization rate on Pb(II) can reach more than 75%. The mechanisms for efficient immobilization of heavy metals on TETA-Mt included buffering and adsorption abilities. The mechanism for TETA-Mt adsorption of heavy metals included physical absorption, chelation and chemical sedimentation. The results showed that TETA-Mt can be applied to effective immobilization of heavy metals in tailings and efficient remediation of acid mine drainage (AMD) in acid rain area.

The present study describes the physiological and biochemical mechanisms of zinc tolerance in two heterocytous cyanobacteria i.e. Anabaena doliolum and Anabaena oryzae, treated with their respective LC₅₀ concentrations of zinc (3 and 4.5 mg L⁻¹) for eight days. The feedbacks were examined in terms of growth, metabolism, zinc exclusion, zinc accumulation, oxidative stress, antioxidants and metallothionein contents. Although the growth and metabolic activities were reduced in both the cyanobacterium, maximum adversity was noticed in A. doliolum. The higher order of abnormalities in A. doliolum was attributed to excessive accumulation of zinc and enhanced reactive oxygen species (ROS) production. However, the comparatively higher growth and metabolic activities of A. oryzae were ascribed to the lower accumulation of zinc as a result of released polysaccharides mediated zinc exclusion, synthesis of zinc chelating metallothioneins and subsequent less production of ROS. The oxidative stress and macromolecular damages were prominent in both the cyanobacterium but the condition was much harsher in A. doliolum which may be explained by its comparatively low antioxidative enzyme activities (SOD, APX and GR) and smaller amount of ascorbate-glutathione-tocopherol contents than that of A. oryzae. However, sustenance of 50% growth by A. doliolum under zinc stress despite severe cellular damages was attributed to the enhanced synthesis of phenolics, flavonoids, and proline. Thus, differential zinc tolerance in A. doliolum and A. oryzae is possibly the outcome of their distinct mitigation strategies. Although the two test organisms followed pseudo second order kinetics model during zinc biosorption yet they exhibited differential zinc biosorption capacity. The cyanobacterium A. oryzae was found to be more efficient in removing zinc as compared to A. doliolum and this efficiency makes A. oryzae a promising candidate for the phycoremediation of zinc polluted environments.

The trace elements contamination of agricultural soils near petrochemical industry complexes is a concern due to the risk of accumulating in food systems and subsequently affecting human health. We measured representative trace elements (Cu, Ni, Cr, Pb, Zn, Pb, Hg and As) through the soil-plant (maize)-human contamination pathway near a petrochemical industry complexes in an agricultural region from September 20 to 28, 2016. We found that the soil was mildly to moderately polluted by multiple trace elements, which was also confirmed by the contamination factor and enrichment factor values. Cd (enrichment factor = 2.28), Cu (2.75), Zn (1.85) and Pb (1.70) should be given more attention and prioritized over the other trace elements due to their higher potential risks. Furthermore, the trace elements contamination in maize grains was lower than the corresponding limits. The sequence of the transfer coefficient values was Zn > Cd > Cu > Hg > Ni > As > Cr > Pb. Maize grain safety was threatened mainly by Zn, Cd and Cu. There was no risk to humans through soil ingestion, while a potential health risk from maize grain consumption existed. Children were more sensitive than adults to the non-carcinogenic risks of maize grain consumption. Trace element As was found to be the priority metal for risk control. For carcinogenic risk, adults were more sensitive than children; As, Cr and Cd were the priority metals for risk control, with CRₘₐᵢzₑ values exceeding the risk threshold (1 × 10⁻⁴). Overall, strict, intensive monitoring, especially of Cr and Cd, and soil protection measures are needed to prevent any furthertrace elements contamination and to ensure food safety. This study also provides a reference for similar studies worldwide.

Microplastics have become an inevitable component of our environment. Worldwide, free public fountains are common and one of the best sources of drinking water which are being installed with one of the viewpoints of reducing single-use plastics bottle consumption. However, the state of knowledge on how microplastics might be affecting in those free public drinking fountains is unknown. In this study, free drinking water fountains from 42 metro stations in Mexico City were being looked into for the occurrence of microplastics and investigated their shape type, size, abundance, distribution, polymer composition and surface morphology. Microplastics were detected in all the samples analyzed. The results revealed the significant abundance of microplastics ranging from 5 ± 2 to 91 ± 14 L⁻¹ in drinking water with an overall average of 18 ± 7 microplastics L⁻¹. Transparent fibers (69%) were predominant in the identified microplastics followed by blue (24%) and red colored (7%) fibers. The most frequent microplastics dimensions ranged between 0.1 and 1 mm which is approximately 75% of the total microplastics. Micro-Raman spectroscopy analysis indicated that microplastics contained in drinking water were mainly polyesters (poly (trimethylene terephthalate)) and epoxy resin suggesting the possible contribution of wastewater discharges for microplastics contamination. Thus, this study findings show that free public drinking water fountains are potential microplastics hotspot for human consumption and provide useful references for mitigation measures.

Bisphenol S (BPS) is an endocrine disruptor which is widely used in commercial plastic products. Previous studies have shown that exposure to BPS has toxic effects on various aspects of mammalian, but there are few reports about reproductive toxicity. In order to investigate the effects of maternal BPS exposure on the reproductive of F1 and F2 female mice, the pregnant mice were orally administered with different dosages of BPS only once every day from 12.5 to 15.5 days post-coitus (dpc). The results showed that maternal BPS exposure to 2 μg per kg of body weight per day (2 μg/kg) and 10 μg/kg accelerated the meiotic prophase I (MPI) of F1 female mice and the expression of the genes related to meiotic were increased. Further studies showed that maternal BPS exposure resulted in a significant increase in the percentage of oocytes enclosed in primordial follicles in the 3 days post-partum (3 dpp) ovaries of F1 female mice. And at the time of 21 days post-partum (21 dpp) in F1 female mice, the number of antral follicles were significantly lower compare to controls. In the study of five-week female mice of F1, we found that BPS disturbed the folliculogenesis, and the maturation rates and fertilization rates of oocytes were significantly decreased. Of note, maternal BPS exposure disrupted H3K4 and H3K9 tri-methylation levels in F1 ovaries. Maternal BPS exposure only affected the cyst breakdown in F2 female mice. Taken together, our results suggest that, maternal BPS exposure impaired the process of meiosis and oogenesis of F1 and F2 offspring, resulting in abnormal follicular development and serious damage to the reproduction.

Polycyclic aromatic hydrocarbons (PAHs) pollution has become a worldwide environmental problem, and the spread of PAHs can cause carcinogenicity, mutagenicity, and toxicity to humans. However, the transfer and accumulation of PAHs in crop leaves has not been clearly understood. In this study, we first reported that the environmental temperature could induce phenanthrene transfer and accumulation in hydrocultured wheat, corn and soybean leaves via vacuum-infiltration-centrifugation method. Phenanthrene accumulation rises significantly (p < 0.05) in the first 8 h and reaches the maximum accumulation rate at the 4th h. Then the accumulation turns stable in both apoplast and sympalst of wheat, soybean and corn leaves. Temperature is positively correlated with phenanthrene accumulation in apoplast and sympalst of soybean and corn leaves, and phenanthrene accumulation increases under lower temperature in apoplast and sympalst of wheat leaves. Temperature also displays a positive correlation with the phenanthrene accumulation under gradient phenanthrene treatments in both apoplast and sympalst. In addition, the wheat, corn and soybean leaves have the same phenanthrene accumulation pathways and symplast pathway is major for phenanthrene accumulation with the contribution over 55% in total phenanthrene accumulation. Meanwhile, based on the Elovich equation, the symplast and apoplast processes of phenanthrene accumulation are endothermic. In the end, our findings will offer a new understanding for phenanthrene transfer and accumulation pathway in plant leaves and put forward a new biological reference of PAHs transfer in environmental science.

Nicotine (Nic) exposed to the environment which comes from tobacco products is the main addictive agent and specific classes of hazardous compound that merit concern. In this study, we have established a fast and reliable method to achieve specific detection of Nic in natural nicotiana tabacum within 30 s through a miniaturized platform based on screen printed gold electrode (SPE). A simple electrochemical pretreatment mean was employed on gold surface that led to the exposure of Au (111) facet and a convenient sample pretreatment method was adopted to realize the extraction of Nic in tobacco. The present electrochemical sensor exhibits an ample range of sensing from 10 μg/g to 200 μg/g, which is able to compliance with tobacco industry testing standards of actual samples. Over 60 sampling points from different origins in China or other countries were performed with direct analysis using this method and satisfactory results have been obtained. The proposed approach was demonstrated to be a very promising platform for significantly improving analytical efficiency in laboratories as well as for monitoring the source reduction control of Nic in the environment.

Radioactive pollution comes on the top of pollution types that affect human life directly through damaging the human genome or indirectly via his food web. The current study focused on the evaluation of radiation effects of Assiut Thermal Power Plant (ATPP) ashes on two crop plants, potato and squash, in terms of morphological and molecular levels. More particularly, the specific activity concentrations were measured in Bq/kg, of the ²³⁸U (²²⁶Ra) and ²³²Th series, and ⁴⁰K-isotope for the untreated soil sample (control) and ATPP ash sample (represents the radioactive source with 100% concentration). Different concentrations of ATPP ash (0, 2, 4, 6 and 8%) were mixed with soil sample to study the effect of radioactively contaminated soil on potato and squash plants. The results of the present investigation revealed that the morphological characteristics of both potato and squash plants were changed, which reflected a steep regression in the values of all vegetative growth and yield traits. The alterations of the characteristic values were directly proportional to the radioactive ash concentration in the soil. In the same context, the molecular evaluation using PCR-based markers, e.g., ISSR and SCoT helps in understanding and explaining experimental observations at morphological level. ISSR/SCoT bands confirmed the toxicity and mutagenicity of radioactive ash samples at their present dose on both potato and squash plants. The present findings clearly explained the morphometric and genetic abnormalities in two of the main consumed crops by a human. Thus, the green area around the ATPP may disappear in the future due to increasing the pollution in terms of the radioactive component that directly attached to plants or indirectly by mixing with soil.

PM₂.₅ exposure is an emerging environmental concern and severe health insult closely related to psychological conditions such as anxiety and depression in adolescence. Adolescence is a critical period for neural system development characterized by continuous brain maturation, especially in the prefrontal cortex. The etiology of these adolescent conditions may derive from fetal origin, probably attributed to the adverse effects induced by intrauterine environmental exposure. Anxiety- and depression-like behavior can be induced by gestational exposure to PM₂.₅ in mice offspring which act as a useful model system. Recent studies show that B-vitamin may alleviate PM₂.₅-induced hippocampal neuroinflammation- and function-related spatial memory impairment in adolescent mice offspring. However, cortical damage and related neurobehavioral defects induced by gestational PM₂.₅ exposure, as well as the potential reversibility by interventions in mice offspring require to be elucidated. Here, we aimed to investigate whether B-vitamin would protect mice offspring from the adverse effects derived from gestational exposure to urban PM₂.₅ on cortical areas to which anxiety and depression are closely related. Pregnant mice were divided into three groups: control group (treated with PBS alone), model group (treated with both PM₂.₅ and PBS), and intervention group (treated with both PM₂.₅ and B-vitamin), respectively. The mice offspring were then applied to comprehensive neurobehavioral, ultrastructural, biochemical, and molecular biological analyses. Interestingly, we observed that gestational PM₂.₅ exposure led to neurobehavioral defects including anxiety- and depression-like behavior. In addition, neuroinflammation, oxidative damage, increased apoptosis, and caspase-1-mediated inflammasome activation in the prefrontal cortex were observed. Notably, both behavioral and molecular changes could be significantly alleviated by B-vitamin treatment. In summary, our results suggest that the anxiety- and depression-like behavior induced by gestational PM₂.₅ exposure in mice offspring can be ameliorated by B-vitamin supplementation, probably through the suppression of apoptosis, oxidative damage, neuroinflammation, and caspase-1-mediated inflammasome activation.