A full-factorial test design was applied to systematically investigate the contribution and significance of water chemistry parameters (pH, divalent cations and dissolved organic carbon (DOC) concentration) and their interactions on the behavior and fate of copper nanoparticles (CuNPs). The total amount of Cu remaining in the water column after 48 h of incubation was mostly influenced by divalent cation content, DOC concentration and the interaction of divalent cations and DOC. DOC concentration was the predominant factor influencing the dissolution of CuNPs, which was far more important than the effect of pH in the range from 6 to 9 on the dissolution of the CuNPs. The addition of DOC at concentrations ranging from 5 to 50 mg C/L resulted in a 3–5 fold reduction of dissolution of CuNPs after 48 h of incubation, as compared to the case without addition of DOC. Divalent cation content was found to be the most influential factor regarding aggregation behavior of the particles, followed by DOC concentration and the interaction of divalent cations and DOC. In addition, the aggregation behavior of CuNPs rather than particulate dissolution explained most of the variance in the sedimentation profiles of CuNPs. These results are meaningful for improved understanding and prediction of the behavior and fate of metallic NPs in aqueous environments.

Indo-Pacific humpback dolphin (Sousa chinensis) are chronically exposed to organic pollutants since they inhabit shallow coastal waters that are often impacted by anthropogenic activities. The aim of this review was to evaluate existing knowledge on the occurrence of organic pollutants in Indo-Pacific humpback dolphins, identify knowledge gaps, and offer recommendations for future research directions. We discussed the trends in the bioaccumulation of organic pollutants in Indo-Pacific humpback dolphins focusing on sources, physicochemical properties, and usage patterns. Furthermore, we examined factors that influence bioaccumulation such as gender, age, dietary intake and tissue-specific distribution. Studies on bioaccumulation in Indo-Pacific humpback dolphin remain scarce, despite high concentrations above 13,000 ng/g lw we previously detected for PFOS, ∑PBDE and chlorinated paraffins. The maximum concentration of organochlorines detected was 157,000 ng/g wt. Furthermore, variations in bioaccumulation were shown to be caused by factors such as usage patterns and physicochemical properties of the pollutant. However, restrictions in sampling inhibit investigations on exposure pathway and toxicity of organic pollutants in Indo-Pacific humpback dolphin. We proposed the use of biopsy sampling, predictive bioaccumulation and toxicity modeling, and monitoring other emerging contaminants such as microplastics and pharmaceuticals for future health risk assessment on this critically endangered marine mammal species.

Emission of hazardous trace elements (HTEs) from energy production is receiving much attention due to concerns about the toxicity to the ecosystem and human health. This study presented new field measurement data on the HTEs partitioning behavior and size-segregated elemental compositions of gaseous particular matter (PM) generated from a commercial circulating fluidized bed (CFB) power plant. Mineralogical and morphological characteristics of combustion ash and PM2.5 (particle diameter less than 2.5 μm) were determined by X-ray diffractometer (XRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). Functional groups alteration during CFB combustion was characterized by Fourier transform infrared spectroscopy (FTIR). The presence of aliphatic hydrogen at 2910 cm−1 and 2847 cm−1 in the PM2.5 suggested that the aliphatic carbon-rich volatiles were absorbed on the fine particles with large surface area. Fine fly ash (PM2.5) occurred as irregular glass particles or/and as unburned carbon. The typical irregular particles were mainly composed of Al-Si-Ca or Al-Si-Fe phases. The enrichment behavior of HTEs was determined for the airborne size-segregated particular matter. Elemental occurrences, combustion temperature, unburnt carbon, and limestone additives during CFB combustion were critical in the transformation behavior of HTEs. The total potentially mobile pollutants that exit the CFB power plant every year were estimated as follows: 0.22 tons of Cr, 0.12 tons of Co, 0.73 tons of Ni, 0.04 tons of As, 0.07 tons of Se, 3.95 kg of Cd, and 3.34 kg of Sb.

An experiment was performed to explore the interactive impacts of zinc oxide nanoparticles (ZnO NPs) and cadmium (Cd) on growth, yield, antioxidant enzymes, Cd and zinc (Zn) concentrations in wheat (Triticum aestivum). The ZnO NPs were applied both in Cd-contaminated soil and foliar spray (in separate studies) on wheat at different intervals and plants were harvested after physiological maturity. Results depicted that ZnO NPs enhanced the growth, photosynthesis, and grain yield, whereas Cd and Zn concentrations decreased and increased respectively in wheat shoots, roots and grains. The Cd concentrations in the grains were decreased by 30–77%, and 16–78% with foliar and soil application of NPs as compared to the control, respectively. The ZnO NPs reduced the electrolyte leakage while increased SOD and POD activities in leaves of wheat. It can be concluded that ZnO NPs (levels used in the study) could effectively reduce the toxicity and concentration of Cd in wheat whereas increase the Zn concentration in wheat. Thus, ZnO NPs might be helpful in decreasing Cd and increasing Zn biofortification in cereals which might be effective to reduce the hidden hunger in humans owing the deficiency of Zn in cereals.

Several monitoring studies have shown that benzoylecgonine (BE) is the main illicit drug residue commonly measured in the aquatic system worldwide. Few studies have investigated the potential toxicity of this molecule towards invertebrate and vertebrate aquatic non-target organisms focusing on effects at low levels of the biological organization, but no one has assessed the consequences at higher ones. Thus, the present study was aimed at investigating the toxicity of a 48-h exposure to two concentrations of BE, similar to those found in aquatic ecosystems (0.5 μg/L and 1.0 μg/L), on the cladoceran Daphnia magna at different levels of the ecological hierarchy. We relied on a multi-level approach focusing on the effects at biochemical/biomolecular (biomarkers), individual (swimming activity) and population (reproduction) levels. We measured the amount of reactive oxygen species and of the activity of antioxidant (SOD, CAT, and GPx) and detoxifying (GST) enzymes to assess if BE exposure can alter the oxidative status of D. magna specimens, while the lipid peroxidation (TBARS) was measured as a marker of oxidative damage. Moreover, we also measured the acetylcholinesterase (AChE) activity because it is strictly related to behavioral changes in aquatic organisms. Changes in swimming behavior were investigated by a video tracking analysis, while the consequences on reproduction were assessed by a chronic toxicity test. Our results showed that BE concentrations similar to those found in aquatic ecosystems induced oxidative stress and inhibited AChE activity, affecting swimming behavior and the reproduction of Daphnia magna individuals.

Because most chickens are reared in intensive farms, where a range of feed additives are used routinely, concerns have been raised on the potential public health risk of chicken product consumption. This study was conducted to characterize the contents of trace metals in fresh chicken tissues (354 samples) on the food markets in Guangdong province of southern China, a major region of chicken production with heavy per capita chicken consumption, and to assess the public health risk from chronic dietary exposure to the trace metals through chicken consumption. With the exception of Cr, Ni, and Pb, the contents of trace metals were generally higher in the chicken giblets (livers, gizzards, hearts, and kidneys) compared to muscles (breasts and drumsticks). Chicken tissues from the urban markets generally contained higher levels of As, Cu, Mn, and Zn than those from the rural markets, while the contents of Pb were typically higher in the chicken muscles from the rural markets. Results of statistical analyses indicate that Cu, Zn, and As in the chicken tissues derived mainly from the feeds, which is consistent with the widespread use of Cu, Zn, and phenylarsenic compounds as feed supplements/additives in intensive poultry farming. No non-carcinogenic risk is found with the consumption of fresh chicken meat products on the food markets, while approximately 70% of the adult population in Guangzhou and 30% of those in Lianzhou have bladder and lung cancer risk above the serious or priority level (10⁻⁴), which arises from the inorganic arsenic contained in the chicken tissues. These findings indicate that the occurrence of inorganic arsenic at elevated levels in chicken tissues on the food markets in Guangdong province poses a significant public health risk, thus the use of phenylarsenic feed additives in China's poultry farming should be significantly reduced and eventually phased out.

Wind induced flow velocity patterns and associated thermal destratification can drive to hypoxia reduction in large shallow lakes. The effects of wind induced hydrodynamic changes on destratification and hypoxia reduction were investigated at the Meiling bay (N 31° 22′ 56.4″, E 120° 9′ 38.3″) of Lake Taihu, China. Vertical flow velocity profile analysis showed surface flow velocities consistency with the wind field and lower flow velocity profiles were also consistent (but with delay response time) when the wind speed was higher than 6.2 m/s. Wind field and temperature found the control parameters for hypoxia reduction and for water quality conditions at the surface and bottom profiles of lake. The critical temperature for hypoxia reduction at the surface and the bottom profile was ≤24.1C° (below which hypoxic conditions were found reduced). Strong prevailing wind field (onshore wind directions ESE, SE, SSE and E, wind speed ranges of 2.4–9.1 m/s) reduced the temperature (22C° to 24.1C°) caused reduction of hypoxia at the near surface with a rise in water levels whereas, low to medium prevailing wind field did not supported destratification which increased temperature resulting in increased hypoxia. Non-prevailing wind directions (offshore) were not found supportive for the reduction of hypoxia in study area due to less variable wind field. Daytime wind field found more variable (as compared to night time) which increased the thermal destratification during daytime and found supportive for destratification and hypoxia reduction. The second order exponential correlation found between surface temperature and Chlorophyll-a (R²: 0.2858, Adjusted R-square: 0.2144 RMSE: 4.395), Dissolved Oxygen (R²: 0.596, Adjusted R-square: 0.5942, RMSE: 0.3042) concentrations. The findings of the present study reveal the driving mechanism of wind induced thermal destratification and hypoxic conditions, which may further help to evaluate the wind role in eutrophication process and algal blooms formation in shallow water environments.Wind field is the key control factor for thermal destratification and hypoxia reduction. 24.1C° is the critical/threshold temperature for hypoxia, Chlorophyll-a and NH3-N concentrations of the shallow freshwater lake.

Particulate matter with diameters <2.5 μm (i.e., PM₂.₅) has multiple natural and anthropological sources. The association between PM₂.₅ and the exacerbation of respiratory allergy and asthma has been well studied, but the components of PM₂.₅ that are responsible for allergies have not yet been determined. Here, we elucidated the effects of aqueous and organic extract of PM₂.₅ collected during four seasons in November 2014–December 2015 in two cities (Kawasaki, an industrial area and Fukuoka, an urban area affected by transboundary pollution matter) of Japan on respiratory health. Ambient PM₂.₅ was collected by high-volume air samplers and extracted into water soluble and lipid soluble components. Human airway epithelial cells, murine bone marrow-derived antigen-presenting cells (APC) and splenocytes were exposed to PM₂.₅ extracts. We measured the cell viability and release of interleukin (IL)-6 and IL-8 from airway epithelial cells, the DEC205 and CD86 expressions on APCs and cell proliferation, and TCR and CD19 expression on splenocytes. The water-soluble or aqueous extracts, especially those from Kawasaki in fall, had a greater cytotoxic effect than the lipid-soluble or organic extracts in airway epithelial cells, but they caused almost no pro-inflammatory response. Extract of fall, especially the aqueous extract from Fukuoka, increased the DEC205 and CD86 expressions on APC. Moreover, aqueous extracts of fall, summer, and spring from Fukuoka significantly increased proliferation of splenocytes. Organic extract of spring and summer from Kawasaki significantly elevated the TCR expression, and organic extract of summer from Kawasaki decreased the CD19 expression. These results suggest that PM₂.₅ extract samples are responsible for cytotoxicity in airway epithelial cells and for activating APCs and T-cells, which can contribute to the exacerbation of respiratory diseases such as asthma. These effects can differ by PM₂.₅ components, collection areas and seasons.

The main purpose of this study is to develop accurate equation for predicting methane emission into the environment during natural gas (NG) purging process. The process is carried out regularly in NG pressure reducing stations. For this purpose, a numerical investigation has been carried out to simulate NG exit flow from a purging valve during opening time. The simulation has been carried out using Ansys-Fluent code. To make the solution and results more similar to actual scenario, the valve is continuously opened in a transient turbulent flow. Initial condition, is assumed steady flow in the pipeline. Three-dimensional modeling is used to simulate the valve and connected pipe, and all of the effective parameters including, inlet pressure, pipeline diameter, valve diameter and purging process time (including the time which valve needs to get completely opened and also purging time) are investigated. For simplicity and also as the main component of NG is methane, methane is considered as working fluid (a real compressible gas). The numerical results show that discharging gas velocity is reached to a supersonic velocity at outlet section of valve. As the highest expected exit velocity is sonic velocity, the supersonic velocity is a surprised result. Looking at the streamlines show that this is due to a convergent-divergent nozzle occurrence (due to re-circulation zone near junction) in discharging pipe. Also results show that discharged mass flow rate has liner relation with pipeline pressure, second degree relation with valve diameter and has fourth-degree relation with valve to pipeline diameter ratio. To make the results more applicable for NG industry, two correlations have been developed for calculating the amount of released gas in steady state and unsteady state condition. Unsteady state correlation is valid for valve opening time and steady state correlation could be used while the valve is completely opened.

Perfluoroalkyl substances (PFAS) are a diverse class of manufactured compounds used in a wide range of industrial processes and consumer products and have been detected in human serum worldwide. Previous cross-sectional and cohort studies in humans have suggested exposure to PFAS is associated with a wide array of chronic diseases, including endocrine disruption, developmental health effects, cancer and metabolic changes. We examined the associations between a panel of eight PFAS and indicators of thyroid disruption, kidney function, and body mass index (BMI), all of which were measured at repeated time points (1990–2008) over the course of the study. Participants (N = 210) were selected from the Fernald Community Cohort based on household water supply from a PFAS-contaminated aquifer. In adjusted repeated measures models, we observed several notable associations between serum PFAS and thyroid hormones as well as kidney function as measured by estimated glomerular filtration rate (eGFR). An interquartile (IQR) increase in serum PFOS was associated with a 9.75% (95% CI = 1.72, 18.4) increase in thyroid stimulating hormone. An IQR increase in serum PFNA, PFHxS, and PFDeA was associated with a −1.61% (95% CI = −3.53, −0.59), −2.06% (95% CI = −3.53, −0.59), and −2.20% (95% CI = −4.25, −0.14) change in eGFR, respectively. On the other hand, an IQR increase in serum Me-PFOSA was associated with a 1.53% (95% CI = 0.34, 2.73) increase in eGFR. No significant associations with BMI and serum PFAS were noted. Our findings are in agreement with previous reports that serum PFAS are associated with altered kidney and thyroid function.