Release of phosphorus (P) from sediment is a major source of P in many freshwater lakes. Currently, assessing the ability of sediment to release P, which is valuable to the management of water eutrophication, remains a challenge. Thus, the purpose of this study was to find effective indexes for predicting the release potential of internal-P. In this study, high-resolution diffusive gradients in thin films (DGT) and conventional sequential extraction were used to characterize the distribution and speciation of P, iron (Fe), and sulfur (S) in the surface sediment of a mildly eutrophic reservoir in southwestern China. Sediment samples exhibited large variations in Fe, S, and P, thereby providing favorable conditions for investigating the effects of Fe and S on sediment P mobilization. In contrast to traditional knowledge, our results show that total P (TP) and redox-sensitive P(BD-P) are poorly correlated with releasable P(DGT-P). This implies that high levels of sedimentary TP and BD-P do not necessarily result in an elevated release of internal-P under anaerobic conditions. Sedimentary P release was greatly suppressed at ratios of Fe/P > 30 and Fe/S > 6. Significant positive correlations between DGT-P and DGT-Fe or DGT-S suggest that Fe and S play an important role in governing the mobility of sedimentary P. These results support the combined Fe/P and Fe/S ratios as an effective and practicable index for assessing the ability of sediment to release P. Thus, our study provides a new and simple method for assessing sedimentary P pollution in freshwater ecosystems.

Limited information about the sludge quality is a major constraint for its usage and proper disposal. This study investigated the occurrence of 49 elements in sludge from 11 wastewater treatment plants (WWTPs) in Chongqing and Xiamen cities of China. The concentration of 46-detected elements ranged from 16.2 μg kg⁻¹ (Pt) to 55.0 g kg⁻¹ (Al) on dry solid basis in the sludge. The enrichment factor of most of the elements was > 1.5, indicating their possible anthropogenic origin. The precious metals had considerably higher enrichment factor ranging from 56.3 to 200,000. Principal component analysis clustered the samples from Chongqing and Xiamen separately to suggest strong spatial variations. Contamination factor, pollution loading index, and integrated pollution degree were calculated to evaluate the elemental pollution risk. The pollution loading index indicated unpolluted to highly polluted levels of the elements in the sludge. In addition, results from the ecotoxicological risk index showed an individual low to very high ecotoxicological risk posed by eight metal(loid)s (As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) in the WWTPs.

According to global estimates, at least 107,000 people die each year from asbestos-related lung cancer, mesothelioma, and asbestosis resulting from occupational exposure. Chrysotile accounts for approximately 90% of asbestos used worldwide. Artificial substitutes can also be cytotoxic to the same degree as chrysotile. But only a few researchers focused on their genetic effects and mutagenicity information which is useful in evaluating the carcinogenicity of chemicals. In this study, chrysotile from Mangnai, Qinghai, China, and an artificial substitute, rock wool fiber were prepared as suspensions and were tested at concentrations of 50, 100, and 200 μg/ml in V79 lung fibroblasts. Chromosome aberrations were detected by micronucleus assay after exposure for 24 h, and DNA damage were estimated by single cell gel electrophoresis after exposure for 12, 24, or 48 h. According to the results, chrysotile and rock wool fibers caused micronuclei to form in a dose-dependent manner in V79 cells; olive tail moment values increased in a dose- and time-dependent manner. When V79 cells were exposed to a concentration of 200 μg/ml, the degree of DNA damage induced by chrysotile fibers was greater than rock wool fibers. Our study suggests that both chrysotile and rock wool fibers could induce chromosome aberrations and DNA damage. These materials are worthy of further study.

Plant leaves play a key role in the accumulation of PAHs, as they are able to capture PAHs from the air. In this paper, the mechanism, including absorption and adsorption, for plants to scavenge PAHs from the air was reviewed. Moreover, the differences of PAHs accumulating capability are mainly compared among three representative plant species, including pine needles, Holm oak leaves, and moss. On the whole, it is shown that oak leaves present the strongest PAHs accumulating capability for total PAHs among three plants species. Oak leaves and pine needles show higher accumulating tendency for light and medium molecular weight PAHs, whereas moss presents stronger accumulating tendency for heavy molecular weight PAHs. Environmental factors (i.e., temperature, seasonality, and photolysis) also account for the process of PAHs transferred from air to plants. With the temperature climbing, the concentration of PAHs in the air will increase. Due to the meteorological conditions and the human activities changed with seasons, it was shown that the PAHs were greatly accumulated in leaf surface in winter than in summer. Photolysis was also able to influence the PAHs on leaf surface, which are significant to this process. In conclusion, oak, pine, and moss can be used to filter PAHs when considering urban landscaping. Besides combining the traditional analytical methods with in situ determination, there might be able to provide a novel method to further study the specific absorption mechanisms. The accumulation of PAHs in crop leaf surface related to the application of surfactants is also worth studying.

The study evaluated the effect of oral intoxication of cadmium and the possible causes of oxidative stress and its preferential accumulation in different organs as well as sub-sequential effects in mice. Twenty-four Swiss albino male mice were divided into three groups viz., normal control group without cadmium chloride (CdCl₂), whereas a daily dose of 0.5 and 1.2 mg of CdCl₂ was orally administered for a period of a week to dose group 1 (DG-1) and dose group 2 (DG-2), respectively. A significant increase in the severity of cadmium toxicity was observed in animals as evidenced by aggravation in liver enzymes viz., serum alanine aminotransferase and aspartate transaminase, whereas lower levels of antioxidative stress markers in liver and kidney tissues of treated mice were observed as compared to normal control group. A significant depletion of calcium levels in liver tissues of DG-1 (217.36 ± 1.73 μg/g of wet tissues) and DG-2 (186.41 ± 1.56 μg/g of wet tissues) groups, along with Cd accumulation, was observed. To summarize, the current study would increase our understanding with respect to dose-dependent absorption of Cd and its toxicity led to mortality as well as adverse health effects in the body of mice. Graphical abstract ᅟ

Influent river carrying cumulative watershed load plays a significant role in promoting nuisance algal bloom in river-fed lake. It is most relevant to discern in-stream water quality exceedance and evaluate the spatial relationship between risk location and potential pollution sources. However, no comprehensive studies of source tracking in watershed based on management grid have been conducted for refined water quality management, particularly for plain terrain with complex river network. In this study, field investigations were implemented during 2014 in Taige Canal watershed of Taihu Lake Basin. A Geographical Information System (GIS)-based spatial relationship model was established to characterize the spatial relationships of “point (point-source location and monitoring site)-line (river segment)-plane (catchment).” As a practical exemplification, in-time source tracking was triggered on April 15, 2015 at Huangnianqiao station, where TN and TP concentration violated the water quality standard (TN 4.0 mg/L, TP 0.15 mg/L). Of the target grid cells, 53 and 46 were identified as crucial areas having high pollution intensity for TN and TP pollution, respectively. The estimated non-point source load in each grid cell could be apportioned into different source types based on spatial pollution-related entity objects. We found that the non-point source load derived from rural sewage and livestock and poultry breeding accounted for more than 80% of total TN or TP load than another source type of crop farming. The approach in this study would be of great benefit to local authorities for identifying the serious polluted regions and efficiently making environmental policies to reduce watershed load.

The purpose of this study was to identify the concentrations, sources, and potential ecological and health risks of heavy metals in soils from a typical industrial area in Shanghai, China. A total of 28 surface soil samples were collected and analyzed for As, Cd, Cr, Cu, Pb, Ni, Zn, and Hg from the BAO steel industry in June and July 2016. Classic multivariate statistical and geostatistical analysis methods were used to detect the sources of heavy metals, and the ecological risk index (RI) and hazard index (HI) were calculated to assess the potential ecological and health risks. The results showed significant pollution levels, which were derived from the industrial production process and closely related to the spatial layout of the functional areas of the industry. The ecological risk assessment indicated that a very high concentration zone with values ranging from 2045 to 3417 mg kg⁻¹ represented considerable ecological risk in the range of 300 to 600. The main dominant factor affecting the ecological risk is toxicity rather than concentration. The health risk assessment indicated that noncarcinogenic risk was mainly caused by Cr, and the average HI value for adults was 6.48, while it was 39.01 for children. Thus, children face higher threats to heavy metals in soils. The average carcinogenic risk values for Ni, Cr, Cd, and As were 7.97E-09, 5.2E-07, 2.1E-10, and 2.1E-09, respectively, all of which were below the threshold values (1.0E − 04). These results provide basic information for the control and environmental management of heavy metal pollution in steel industrial regions.

The environmental degradation, because of various factors, such as climate change, human activities, increase of population globally, etc. have brought on pressures on the fresh water supplies that vary on time and space. Consequently, economic, environmental, and social tools have emerged known as footprints, in an effort to examine and measure the needs and consequences of humanity on the Earth’s life support systems and take measures towards sustainable development. Furthermore, the constantly worsening environmental conditions have resulted in the cultivation of a green culture among society stakeholders that brought on terms such as green marketing and green products. This paper deals with the water footprint (WF) concept and an effort is performed, to explore through a literature review, in which ways it can contribute to the sustainable development of water use, in the context of green marketing (GM) strategies. The approach of the analysis is based on the discrimination to the following aspects: international scale, national and subnational scale, farmers, business, and consumers, in order to track the affection of each part in water issues. The main findings of the literature review showed that the aforementioned factors are playing a key role in protecting water recourses, by the way they formulate their water use and they are interrelated and interdependent. WFs can be useful in the context of GM, by providing helpful information about direct and indirect water consumption, to every contributor factor in supply chains, to consumers, governments, and water managers.

The removal of emergent contaminants via adsorption on granular activated carbon, prepared from Macauba palm, has been studied, contributing to the recovery of the residual biomass, endocarp, obtained in the Macauba palm oil extraction process. The material was characterized by different techniques, such as Raman spectroscopy, thermal analysis, adsorption/desorption of N₂, zeta potential, and scanning electron microscopy. The N₂ adsorption studies showed that the material presents wide micropores and narrow mesopores, and has a surface area of 907.0 m² g⁻¹. Its maximum adsorption capacity towards the three main emerging contaminants (bisphenol A, ethinylestradiol, and amoxicillin) is much higher than that obtained with benchmark adsorbents (0.148, 0.104, and 0.072 mmol g⁻¹, respectively). The influence of temperature and pH on the adsorption was also analyzed, allowing an improved description of the adsorption mechanism and showing very promising results.