Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy may pose adverse health risk to both the mothers and babies. In the present study, 188 pregnant women of different trimesters were recruited in Guangzhou, south China, and nine hydroxyl PAHs (OH-PAHs) and a biomarker of DNA oxidative damage, 8-hydroxy-2′-deoxyguanosine (8-OHdG), were determined in their urine samples. All OH-PAHs except for 4-hydroxyphenanthrene and 6-hydroxychrysene were found in > 90% samples, with total concentration in the range of 0.52 to 42.9 μg/g creatinine. In general, concentration levels of OH-PAHs in pregnant women were lower than those in general population in the same research area but with higher levels in working women than in housewives. The mean daily intakes of PAHs from dietary estimated by urinary OH-PAHs were 0.021, 0.004, 0.047, and 0.030 μg/kg_bw/day for naphthalene, fluorene, phenanthrene, and pyrene, respectively, which were much lower than the reference doses (20, 30, and 40 μg/kg_bw/day for naphthalene, pyrene, and fluorene, respectively) derived from chronic oral exposure data by the United States Environmental Protection Agency. The low exposure levels of PAHs may be attributed to the traditional dietary taboo of Chinese pregnant women, which is to minimize the consumption of “toxic” food. The concentrations of 8-OHdG (4.67–49.4 μg/g creatinine) were significantly positively correlated with concentrations of several OH-PAHs, such as metabolites of naphthalene, fluorene, and phenanthrene (r = 0.3–0.6). In addition, the concentrations of 8-OHdG were higher in working women than in housewives when exposed to the same levels of PAHs, partly indicating the possible relation between work-related pressure for working women and the oxidative stress.

Extensive use of aluminum (Al) in industry, cooking utensils, and wrapping or freezing the food items, due to its cheapness and abundance in the environment, has become a major concern. Growing evidence supports that environmental pollutant Al promotes the aggregation of amyloid beta (Aβ) in the brain, which is the main pathological marker of Alzheimer’s disease (AD). Further, AD- and Al-induced neurotoxic effects are more common among women following reproductive senescence due to decline in estrogen. Though clinically Ginkgo biloba extract (GBE) has been exploited as a memory enhancer, its role in Al-induced neurotoxicity in reproductive senescent female rats needs to be evaluated. Animals were exposed to intraperitoneal dose (10 mg/kg b.wt) of Al and oral dose (100 mg/kg b.wt.) of GBE daily for 6 weeks. A significant decline in the Al-induced Aβ aggregates was observed in hippocampal and cortical regions of the brain with GBE supplementation, as confirmed by thioflavin (ThT) and Congo red staining. GBE administration significantly decreased the reactive oxygen species, lipid peroxidation, nitric oxide, and citrulline levels in comparison to Al-treated rats. On the contrary, a significant increase in the reduced glutathione, GSH/GSSG ratio as well as in the activities of antioxidant enzymes was observed with GBE administration. Based on the above results, GBE prevented the neuronal loss in the hippocampus and cortex, hence caused significant improvement in the learning and memory of the animals in terms of AChE activity, serotonin levels, Morris water maze, and active and passive avoidance tests. In conclusion, GBE has alleviated the behavioral, biochemical, and histopathological alterations due to Al toxicity in rats. However, molecular studies are going on to better understand the mechanism of GBE protection against the environmental toxicant Al exposure. Graphical abstract .

Soybean peroxidase (SBP) has been employed for the treatment of aqueous solutions containing pentachlorophenol (PCP) in the presence of hydrogen peroxide at pH range 5–7. Reaction carried out with 1 mg/L of PCP, 4 mg/L of H₂O₂, and 1.3 × 10⁻⁹ M of SBP showed a fast initial elimination of PCP (ca. 30% in 20 min), but the reaction does not go beyond the removal of 50% of the initial concentration of PCP. Modification in SBP and PCP amounts did not change the reaction profile and higher amounts of H₂O₂ were detrimental for the reaction. Addition of Fe(II) to the system resulted in an acceleration of the process to reach nearly complete PCP removal at pH 5 or 6; this is more probably due to a synergetic effect of the enzymatic process and Fenton reaction. However, experiments developed in tap water resulted in a lower PCP elimination, but this inconvenience can be partly overcome by leaving the tap water overnight in an open vessel before reaction.

Renewable fuels are desirable as alternate fuels with ignition quality equivalent to diesel and its combustion parameters, but unsuitable for direct operation in diesel engines as fuel because of their higher viscosity. Hence, fuel and engine-based modifications are being developed to improve the performance, emission and combustion behaviour of the compression ignition engines. The higher viscosity of fuel oil does not let it vaporize even after it is being injected into the combustion chamber. Therefore, converting the higher viscosity of vegetable oil into biodiesel improves the atomization resulting in better combustion. Issues related to the use of biodiesel as working fuel are its oxidation stability and performance. In this study, safflower oil, neem oil and corn oil are used as fuel oils. The experimental results displayed a significant increase in the brake thermal efficiency of 28.25% for corn oil methyl ester (COME). HC and CO emissions are lower with corn oil methyl ester. At full load, the smoke emission reduces slightly with corn oil methyl ester about 58% opacity respectively, but it is still lower than diesel having 66.2% opacity.

Evaluation of 50 nm zinc oxide nanoparticles’ (ZnO-NPs) effects on the microalgae Chlorococcum sp. growing in high salt growth medium (HSM) was investigated by using flow cytometry parameters (cell size (FSC), granularity (SSC), chlorophyll a fluorescence (FL3), and formation of reactive oxygen species (ROS)). Algal cells in exponential growth were exposed to 0–100 mg/L of ZnO-NPs and their physiological responses were measured after 24 and 96 h of treatment. Behavior of ZnO-NPs was analyzed in HSM and results indicated that ZnO-NPs formed agglomeration with a large distribution. Total soluble Zn concentration increased when initial ZnO-NP concentration increased. Significant negative effect on algal cells was observed after 96 h exposition and at high ZnO-NP concentration. This negative impact was evaluated by the significant increase in ROS production, inhibition in the photosynthetic electron transport, and reduction in cell growth. In this study, using flow cytometry multi-parameters might help to prevent and evaluate inhibitory effect of oxide nanoparticles on aquatic photosynthetic microorganisms.

This research project explores the performance of soils intended to support ornamental plants serving an ecological benefit within bioremediating rain gardens. Three plots of identical plantings were installed in autumn of 2015 into three different planting media in Northeast Ohio, USA. A control soil blend was tested against two experimental soil blends in the field under natural conditions for 3 years to explore any potential differences in overall plant performance. The control planting soil was created following current Ohio Department of Natural Resources specifications for rain garden planting soils which consist of no less than 80% sand and no more than 10% clay by volume. Test soil blends incorporated lightweight expanded shale to combat the potential negative effects of high sand soils for plants (i.e., high matric potential) while maintaining required engineering benefits (i.e., fast infiltration rate coupled with good physical, chemical, and biological filtration). Our analysis suggests that incorporating expanded shales into bioremediating gardens as a replacement to high sand content can maintain all engineering specifications and may increase survival rates of plant life beyond rates currently found in high sand content rain gardens. Survival rate for plants in the control plot was at 48.3% while experimental plots one and two were 96.5% and 75.8% respectively. The research team suggests that these increased survival rates could contribute to more widespread adoption and implementation of stormwater management practices, especially small-scale, interconnected rain gardens in the urban environment as designated by low-impact development standards.

Phosphorus-rich sludge is one of most suitable raw materials for phosphorus recovery as slow release fertilizers by struvite crystallization. However, alginic acid as a surrogate for extracellular polymeric substances in the sludge has been proved to adversely inhibit struvite crystallization. To quantitatively evaluate the inhibitory effect, the study aimed to investigate the influence of the concentration of alginic acid (0–250 mg/L), reactant concentration (2.5–3.5 mmol/L), pH (8.0–9.5), and ionic strength (0.01–0.2 mol/L NaCl), on the inhibition of the growth rate of struvite crystals, which was accurately determined by constant composition technique. The results indicated that the growth rate of struvite crystals substantially decreased with increasing the concentration of alginic acid, thereby adversely affecting the quantity and quality of struvite crystals. Moreover, as reactant concentration or pH increased, the growth rate of struvite crystals showed a considerable increase, whereas the weaker inhibitory effect of alginic acid was observed. Conversely, the increase of ionic strength drastically reduced the growth rate of struvite crystals, but moderately enhanced the inhibitory effect. Our study provides an effective theoretical foundation for deriving high-quality struvite crystals as slow release fertilizers from the phosphorus-rich sludge commonly containing a considerable number of organic pollutants.

An acquisition of metal tolerance in cladocerans related to the historical exposure has been well documented for the genera Daphnia and Ceriodaphnia, which are frequently used in ecotoxicological studies. However, small-sized cladocerans are rarely investigated for the inter-clonal variation in metal sensitivity, whereas they often dominate zooplankton community in many lakes and ponds, and even in eutrophicated rivers. We investigated the influence of historical copper exposure on the copper sensitivity of Bosmina longirostris. Copper sensitivity was compared among three clones originating from a site (Lake Yanaka), which located at downstream of historically contaminated river (Watarase River) and clones from five different reservoirs. For reference, the background copper concentration (as Cu²⁺ activity) at each site and its toxicity to Daphnia magna were estimated by metal speciation and the biotic ligand model (BLM), respectively. Less copper-sensitive Bosmina clones were obtained only from Lake Yanaka, although the background copper concentrations were far below the lethal levels. The results suggested the variability in copper-sensitivity in B. longirostris and its association with historical copper contamination.

Numerous uncertainty factors in dispersion models should be taken into account in order to improve the reliability of predictions. The ability of a mesoscale meteorological model to assimilate observational data is an efficient way to improve operational air quality model forecasts. In this study, local weather data assimilation based on a flux-adjusting surface data assimilation system (FASDAS) is introduced to a Gaussian atmospheric dispersion model for a period with reported stable meteorological conditions. After evaluating the vulnerabilities of FASDAS, a combined data assimilation method is proposed to simultaneously improve the model weather prediction and retrieve the representation of accurate concentration distributions for short-range dispersion modeling against a control run. The two main uncertainty parameters considered are the wind speed and direction. A twin experiment demonstrates that the combined technique effectively improves the distribution of simulated concentrations. Comparison between results before and after the implement of data assimilation demonstrates that discrepancies between the reference simulation and the model forecast are mitigated after introducing the combined method, with more than 70 % of the predictions within a factor of two of the measurements. The errors in wind predictions in the FASDAS influenced the dispersion calculations, and the implementation of wind data assimilation in conjunction with the FASDAS has an indirect effect on further alleviating pollutant transport modeling errors.

Mine waste contaminated soils are classified as degraded soils with poor conditions such as low soil pH, low organic matter and high metal concentrations. This study evaluated the potential of fly ash enriched vermicompost in improving poor soil conditions in mine waste affected soils. The soils were amended with the vermicompost to supply 0, 10, 20, 40 and 80 mg of phosphorus per kg and incubated for 8 weeks. The soil pH increased from the original acidic range of 3.7–5.3 to 6.8–7.6. Available P significantly improved (P < 0.001) to yield the target P levels; however, at the end of incubation period, 80 mg-P/kg treatment had lower Olsen P relative to the 40 mg-P/kg treatment. Nitrogen mineralisation was enhanced with addition of the vermicompost as reflected by an average increase of 51% in NO₂/NO₃⁻-N while NH₄⁺-N decreased over time. The Mn, Zn and Pb solubility was reduced with addition of the vermicompost, with 20 mg-P/kg resulting in the most reduced solubility. However, concentrations at 20 mg-P/kg treatment were generally not different to 40 mg-P/kg. Solubility of Cu significantly increased in proportion to increase in amendment rate but did not exceed maximum permissible limits. Solubility of Cd and Cr also increased during the incubation study; however, this could not be attributed to the different vermicompost treatments but the soil properties. Therefore, in conclusion, application of fly ash enriched vermicompost at 40 mg-P/kg was found to be optimum for a balanced supply of essential nutrients and reduced metal solubility.