Street dust forms as a result of the interaction of the atmosphere, lithosphere (pedosphere) and anthroposphere and can be regarded as an index of the condition of the environment in urban areas. At the end of the twentieth century, there was a significant decrease in heavy metal emissions in Europe, but not so intensive in Poland. The question arises: Is the intensity of pollution still decreasing? The study objective was to assess changes in street dust pollution with heavy metals in Lublin (E Poland) in the years 2013 and 2018. The sample collection sites (68) were located within streets with a varying intensity of motor traffic. Cd, Cr, Cu, Ni, Pb and Zn concentrations were determined in two dust fractions, 63–200 μm and < 63 μm, by means of an X-ray fluorescence spectrometer. The levels of street dust pollution with heavy metals, expressed both in absolute concentrations and geochemical indices, were lower in 2018 than those in 2013. The clearest decrease of concentration levels occurred within the main roads, in the 63–200 μm fraction for Cu and Cd, and in both fractions for Pb. The mean concentrations of the investigated metals, normalised to the background values, are in the following order for both fractions in 2013 and 2018: Zn > Cd > Cu > Cr > Pb > Ni. Metals form the following order for Igₑₒ and EF: Zn > Cd > Cu > Pb > Cr > Ni. This order is slightly different for the ecological risk factor: Cd > Cu > Pb > Zn > Cr > Ni. In general, street dust in Lublin does not show contamination with Cr, Ni and Pb. Igₑₒ and EF indices show moderate levels of pollution with Cu, Cd and Zn.

In the present study, a simple, fast, and economical method was introduced to eliminate methylene blue from dye wastewater water using a non-toxic, inexpensive, stable, and efficient adsorbent. The poly (vinyl alcohol) (PVA)/starch hydrogel nanofiber membrane with high surface area and the three-dimensional structure was fabricated in water via electrospinning strategy, and the cross-linking reaction was done by thermal treatment. The characterization of the nanofibers was carried out using Fourier-transform infrared spectrometer (FT-IR) and field-emission scanning electron microscopy (FE-SEM), and the cross-linked PVA/starch nanofiber was applied as a membrane for the removal of methylene blue (MB). The recovery of MB was performed by methanol solution containing 5% (v/v) HCl. Langmuir isotherm model successfully described the adsorption of MB on nanosorbent, and the maximum adsorption capacity (qₘ) was 400 mg g⁻¹. Also, the kinetic of adsorption was well fitted by the pseudo-second-order model. In this study, because of the high stability of fabricated membrane (based on the tensile testing), it can be used as a filter for the fast separation of MB (cationic dye) and methyl orange (MO, anionic dye). Graphical abstract

Ammonia (NH₃) is a highly irritant, alkaline gas. Atmospheric emission of NH₃ was recognized as an environmental challenge. As a global issue, the NH₃ emission survey with spatially detailed information demonstrated that the sources of atmospheric NH₃ include agriculture (livestock wastes, fertilizers) and some industrial activities. As an environmental pollution, excessive NH₃ exposure can induce many bird dysfunction. Neutrophils respond to multiple invading pathogens through different mechanisms. In order to investigate the effect of NH₃ exposure on broilers’ neutrophil, 1-day-old broilers were treated with/without NH₃ for 28 days. We extracted neutrophils from peripheral blood of chicken with/without NH₃ exposure and subsequently stimulated with PMA. Changes of cytokines and inflammatory bodies, heat shock proteins (HSPs), and glucose metabolism of neutrophil were examined in both cases. We not only explored that the index associated with inflammation changed due to NH₃ exposure but also observed the status of neutrophils which was treated with PMA stimulation. After NH₃ exposure, IL-1β and IL-6 were significantly increased on broilers neutrophil. Inflammatory-related factors (NLRP3, ASC, and caspase-1) were significantly elevated. The mRNA expression of HSP70 and HSP90 was increased significantly. All glucose metabolism indicators were reduced. In summary, we concluded that NH₃ enhanced inflammation and disrupted glucose metabolism, and increased the expression of HSPs and inflammatory factors. In addition, the sensitivity of neutrophils to exogenous stimuli was diminished. This information can not only be used to evaluate the damage of NH₃-spiked neutrophils to chickens, but also provide clues for human health pathophysiology caused by excess NH₃, providing valuable information for NH₃ risk management.

There are mounting evidences indicated that maternal exposure to outdoor air pollutants in pregnancy affects children’s neural development, but the researches on children’s behavioral difficulties are seldom. We explored the association between maternal exposure to outdoor air pollution during different trimesters of pregnancy and the prevalence of behavioral difficulties among 657 preschool children aged 3–4 from three kindergartens in Wuhan, China. This is a cross-sectional study. Children’s behavioral difficulties were assessed by the Strengths and Difficulties Questionnaire (SDQ) (reported by parents). Maternal exposure to outdoor air pollutants during pregnancy were estimated based on the daily average measured concentration levels from ground monitoring stations. Potential confounding factors including children-related, maternal, and socio-economic status (SES) were adjusted in the study. We calculated the prevalence of each type of behavioral difficulties and used binary logistic regression method to estimate the crude odds ratio (cOR), adjusted odds ratio (aOR), and corresponding 95% confidence intervals (95% CIs) for 1 μg/m³ increase in each air pollutant during every exposure window in single- and two-pollutant models. The prevalence of participants’ total behavioral difficulties was 9.6%. In single-pollutant models, during full gestation, positive associations were observed between exposure to NO₂ (aOR = 1.204, 95% CI 1.042, 1.392), particle matter (PM)₁₀ (aOR = 1.070, 95% CI 1.018, 1.125), PM₂.₅ (aOR = 1.095, 95% CI 1.021, 1.176) and total difficulties, exposure to PM₁₀ (aOR = 1.040, 95% CI 1.001, 1.081), PM₂.₅ (aOR = 1.053, 95% CI 1.000, 1.109) and prosocial behavior, respectively. In the first trimester, exposure to SO₂ (aOR = 1.047, 95% CI 1.009, 1.086), NO₂ (aOR = 1.039, 95% CI 1.013, 1.066), PM₁₀ (aOR = 1.013, 95% CI 1.004, 1.023), and PM₂.₅ (aOR = 1.016, 95% CI 1.004, 1.028) were all positively associated with total difficulties. The associations between second and third trimesters’ exposure to all pollutants and outcomes were not statistically significant. However, in the two-pollutant models, second trimester exposure to PM₂.₅ (aOR = 1.078, 95%CI 1.023, 1.137) was positively associated with total behavioral difficulties after adjusting for PM₁₀. Exposure to outdoor air pollutants SO₂, NO₂, PM₁₀, and PM₂.₅ during pregnancy may be associated with behavioral difficulties, especially in the first trimester.

The presence of chemical pollutants, especially heavy metals, affects the quality of honey. The objective of this study was to determine the levels of eight heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb, and Zn) in honey samples from Al-Baha region in Saudi Arabia, using inductively coupled plasma with optical emission spectroscopy (ICP-OES). The highest concentration was found for Zn (1707.93 μg kg⁻¹), while the lowest was found for Co (3.04 μg kg⁻¹). Cluster analysis and principal component analysis showed that two groups are recognized indicating two different metal sources. The first group includes only Zn and the second group includes the rest of the metals. In view of the recommended and established heavy metal intakes for humans, consumption of Saudi honey from Al-Baha should not be deemed a matter of concern for human health.

Cadmium and mercury are among the most toxic and dangerous environmental pollutants that may cause fatal implications. Vitamin C is an important chain-breaking antioxidant and enzyme co-factor against heavy metals. The objective of the present study was to evaluate the toxicological effects of cadmium chloride, mercuric chloride, and their co-administration on biochemical parameters of blood serum and metal bioaccumulation in kidneys and also to elucidate the protective effect of vitamin C in rabbits against these metals. In the current research, cadmium chloride (1.5 mg/kg), mercuric chloride(1.2 mg/kg), and vitamin C (150 mg/kg of body weight) were orally administered to eight treatment groups of the rabbits (1, control; 2, vitamin; 3, CdCl₂; 4, HgCl₂; 5, vitamin + CdCl₂; 6, vitamin + HgCl₂; 7, CdCl₂ + HgCl₂, and 8, vitamin + CdCl₂ + HgCl₂). After the biometric measurements of all experimental rabbits, biochemical parameters viz. creatinine, cystatin C, uric acid, and alkaline phosphatase (ALP) and metal bioaccumulation were determined using commercially available kits and atomic absorption spectrophotometer, respectively. The levels of creatinine (28.3 ± 1.1 μmol/l), cystatin C (1932.5 ± 38.5 ηg/ml), uric acid (4.8 ± 0.1 mg/day), and ALP (51.6 ± 1.1 IU/l) were significantly (P < 0.05) increased due to administration of mercuric chloride but in the presence of vitamin C, the effects of mercuric chloride on creatinine (21.9 ± 1.4 μmol/l), cystatin C (1676.2 ± 42.2 ηg/ml), uric acid (3.9 ± 0.1 mg/day), and ALP (43.3 ± 0.8 IU/l) were less as compared to metal-exposed specimens. Similar results were found in rabbits treated with cadmium chloride and vitamin C and also with co-administration of both metals and vitamin C. Because of the bio-accumulative nature of cadmium chloride and mercuric chloride, these metals were accumulated in kidneys of rabbits, which might lead to deleterious effects. The results of the present study provide an insight into the toxicity of the cadmium chloride, mercuric chloride, and/or their combination on biochemical parameters as well as kidneys of the rabbits and the ameliorating potential of vitamin C against these metals is also evaluated.

Greenhouse gas emissions from agricultural soils contribute substantially to global atmospheric composition. Nitrous oxide (N₂O) is one important greenhouse gas induces global warming. Nitrification inhibitors (NI) or biochar can be effective soil N₂O emission mitigation strategies for agricultural soils. However, due to differences in crop physiological traits or agricultural management, the effectiveness of mitigation strategies varies among agricultural systems. Camellia oleifera is a woody oil plant widely grown and requires intensive N input, which will potentially increase N₂O emissions. Thereby, mitigation of N₂O emissions from C. oleifera field soil is vital for sustainable C. oleifera development. Besides NI, incorporation of C. oleifera fruit shell-derived biochar into its soil will benefit waste management and simultaneous mitigation of N₂O emissions but this has not been investigated. Here, we conducted two studies to examine effects of biochar addition and NI (dicyandiamide, DCD) application on N₂O emissions from C. oleifera field soil with different N (urea or NH₄NO₃) and incubation temperatures. Biochar effects on nitrification rates varied among N treatments. Biochar applied in combination with DCD further reduced nitrification rates (for urea treatment, decreased from 1.1 to 0.3 mg kg⁻¹ day⁻¹). Biochar addition consistently increased soil N₂O emissions (for urea treatment, increased from 0.03 to 0.08 ng g⁻¹ h⁻¹) and their temperature sensitivity. DCD application reduced soil N₂O emissions with greater reductions with urea application. In future cultivation of intensively managed C. oleifera gardens, NI should be applied to mitigate N₂O emissions if biochar is added, especially when urea is used.

Uranium-contaminated wastewater associated with uranium (U) mining and processing inevitably releases into soil environment. In order to assess the risk of U wastewater contamination to groundwater through percolation, U adsorption and transport behavior in a typical red soil in South China was investigated through batch adsorption and column experiments, and initial pH and carbonate concentration were considered of the high-sulfate background electrolyte solution. Results demonstrated that U adsorption isotherms followed the Freundlich model. The adsorption of U to red soil significantly decreased with the decrease of the initial pH from 7 to 3 in the absence of carbonate, protonation-deprotonation reactions controlled the adsorption capacity, and lnCₛ had a linear relationship with the equilibrium pH (pHₑq). In the presence of carbonate, the adsorption was much greater than that in the absence of carbonate owing to the pHₑq values buffered by carbonate, but the adsorption decreased with the increase of the carbonate concentration from 3.5 to 6.5 mM. Additionally, the breakthrough curves (BTCs) obtained by column experiments showed that large numbers of H⁺ and CO₃²⁻ competed with the U species for adsorption sites, which resulted in BTC overshoot (C/C₀ > 1). Numerical simulation results indicated that the BTCs at initial pH 4 and 5 could be well simulated by two-site chemical non-equilibrium model (CNEM), whereas the BTCs of varying initial carbonate concentrations were suitable for one-site CNEM. The fractions of equilibrium adsorption sites (f) seemed to correlate with the fractions of positively charged complexes of U species in solution. The values of partition coefficients (kd′) were lower than those measured in batch adsorption experiments, but they had the same variation trend. The values of first-order rate coefficient (ω) for all BTCs were low, representing a relatively slow equilibrium between U in the liquid and solid phases. In conclusion, the mobility of U in the red soil increased with the decrease of the initial pH and with the increase of the initial carbonate concentrations.

Mining is known as one of the primary economic activities where exploitation of minerals and other materials have become essential for human development. However, this activity may represent a risk to the environment, starting from deforestation and ending with production of residues that might contain potentially toxic elements. Tailing deposits from historical mining are an example of waste that may represent an environmental concern when abandoned and exposed to environmental conditions. The town of Nacozari de Garcia, in northwestern Mexico, has three abandoned mine tailings (locally known as tailings I, II, and III) located around the urban area that represent important sources of dust and pollution. Images obtained using unmanned aerial vehicles (UAV) in conjunction with geochemical data are used to assess historic erosion calculation and pollution considering contamination and hazard indexes in tailings II and III. Digital elevation models of abandoned tailings were obtained using photogrammetry with UAV. A total of 37 surficial samples were collected from mine tailings to determine elemental concentrations (As, Cu, Pb, W, Zn) using portable X-ray fluorescence. Higher concentrations were found on samples from mine tailing II. Average concentrations followed the decreasing order of Cu > Zn > W > Pb > As for tailing II, whereas decreasing order of Cu > Zn > W > As > Pb was found for tailing III. Contamination Index (CI) values obtained from tailings II and III represent a low potential of pollution, whereas efflorescent crusts from these tailings represent a high potential of polluting soils and sediments by dust generation. Hazard Average Quotient (HAQ) values on both tailings suggest a very high potential of contamination if fluids infiltrate tailings and interact with surficial water and/or groundwater. Obtained surfaces of mine tailings II and III are 146,216 and 216,689 m², respectively, which represent around 11% of the urbanized area. A loss mass of 321,675 tons was determined for mine tailing II, whereas 634,062 tons for tailing III, accounting for 0.96 million tons of total eroded mass. Since abandonment, calculated erosion rates of 493 t ha⁻¹ year⁻¹ (tailing II) and 232 t ha⁻¹ year⁻¹ (tailing III) are in agreement with those determined in other mining areas. CI and HAQ indexes provide good estimates of pollution associated with abandoned mine tailings from Nacozari de García. Historic erosion determined in these tailings is an environmental concern since eroded material and polluted water have been incorporated into the Moctezuma River, which feeds several villages, whose major activities include agriculture and livestock raising.

TDS is modeled for an aquifer near an unlined landfill in Canada. Canadian Drinking Water Guidelines and other indices are used to evaluate TDS concentrations in 27 monitoring wells surrounding the landfill. This study aims to predict TDS concentrations using three different modeling approaches: dual-step multiple linear regression (MLR), hybrid principal component regression (PCR), and backpropagation neural networks (BPNN). An analysis of the bias and precision of each models follows, using performance evaluation metrics and statistical indices. TDS is one of the most important parameters in assessing suitability of water for irrigation, and for overall groundwater quality assessment. Good agreement was observed between the MLR1 model and field data, although multicollinearity issues exist. Percentage errors of hybrid PCR were comparable to the dual-step MLR method. Percentage error for hybrid PCR was found to be inversely proportional to TDS concentrations, which was not observed for dual-step MLR. Larger errors were obtained from the BPNN models, and higher percentage errors were observed in monitoring wells with lower TDS concentrations. All models in this study adequately describe the data in testing stage (R² > 0.86). Generally, the dual-step MLR and hybrid PCR models fared better (R²ₐᵥg = 0.981 and 0.974, respectively), while BPNN models performed worse (R²ₐᵥg = 0.904). For this dataset, both regression and machine learning models are more suited to predict mid-range data compared to extreme values. Advanced regression methods (hybrid PCR and dual-step MLR) are more advantageous compared to BPNN.