The concentration characteristics, sources, and potential ecological risk assessment of 16 PAHs were investigated in the surface water from the Songhua River Basin, Northeast China. A total of 48 river water samples, including 16 from the main streams and 32 from the tributaries, were collected. Samples were separated into dissolved phases and suspended particle matter (SPM) via filtration with 0.47 μm glass fiber filters. Each phase was analyzed for PAHs. The total PAH concentration in the dissolved phase in the water ranged from 32.5 to 108 ng L⁻¹ and from 0.3 to 62.3 μg g⁻¹ (dry weight) in the suspended particle matter (SPM). The total PAH concentration in the main stream was lower than in the tributaries; the volume of annual runoff of rivers had a significant effect on the ƩPAH in the rivers. The 2- and 3-ring PAHs dominated in both the dissolved phase and SPM, indicating a relatively recent local source of PAHs in the study area. The concentrations of PAHs in the Songhua River Basin are lower when compared with the values previously reported in the literature from other rivers around the world. The sources of PAHs were assessed by diagnostic ratios and principal component analysis (PCA), and the ecological risk of the PAHs was assessed based on the risk quotient (RQ). The diagnostic ratios and PCA indicated that the main sources of PAHs originated from pyrogenic and petrogenic sources, and pyrogenic sources had a greater impact. The ecological risk assessment indicated that the PAHs presented low ecosystem risk in the Songhua River Basin.

Lead (Pb) bioaccessibility measurements have been the subject of much research in recent years, given the desire to develop a cost-effective and reliable alternative method to estimate its bioavailability from soils and dusts. This study investigates the relationship between Pb bioaccessibility estimated using the Relative Bioavailability Leaching Procedure (RBALP) and solid phase speciation of Pb using mining impacted soils and associated dusts. Solid phase speciation was conducted prior to and after RBALP extractions. The average Pb concentrations were 59, 67, and 385 mg/kg for top soil, sub-soil, and house dust samples, respectively. Lead bioaccessibility in selected top soils and dusts ranged from 16.7 to 57.3% and 8.9 to 98.1%, respectively. Solid phase speciation of Pb in <250 μm residues prior to and after RBALP extraction revealed 83% decrease in Pb bound to carbonate fraction after RBALP extraction. This accounts for 69% of RBALP-extractable Pb. Besides contribution from carbonate bound Pb, 76.6 and 53.2% of Pb bound to Mn oxyhydroxides and amorphous Fe and Al oxyhydroxides contributed to bioaccessible Pb, respectively. However, Pb bound to Mn oxyhydroxides and amorphous Fe and Al oxyhydroxides account for only 13.8 and 20.0% of total RBALP-extractable Pb, respectively. Both non-specifically bound and easily exchangeable fractions and strongly bound inner-sphere complexes were also part of bioaccessible Pb. The present study demonstrates that bioaccessible Pb is released from both soil solution phase Pb as well as that from all soil solid phase with the most contribution being from Pb bound to carbonate mineral phase.

Mosquitoes (Diptera: Culicidae) are vectors of important parasites and pathogens causing death, poverty and social disability worldwide. The overuse of synthetic insecticides to control mosquito vectors lead to resistance, adverse environmental effects and high operational costs. Therefore, the development of eco-friendly control tools is an important public health challenge. In this study, two different essential oils (EO) (geranium, Geranium maculatum, and bergamot, Citrus bergamia) loaded polymeric nanoparticle (PN) were elaborated using polyethylene glycol (PEG) and chitosan (Qx) as the polymeric matrix/coating. In addition, the mosquito larvicidal acute and residual activity of the PN was evaluated on Culex pipiens pipiens. The physicochemical characterization of PN revealed that PEG-PN had sizes <255 nm and encapsulation efficiency between 68 and 77%; Qx-PN showed sizes <535 nm and encapsulation efficiency between 22 and 38%. From the toxicological test, it was observed that Qx-PN produced higher acute and residual activity than PEG-PN. Overall, this study highlights that polymer nanoparticles containing essential oil are a promising source of eco-friendly mosquito larvicidal products.

The biological quality of secondary treated sewage effluent was evaluated using a toolbox approach, which combined a larval developmental bioassay and measurement of fecal indicator organisms. The zoea developmental toxicity of Scylla serrata from stage I to stage II was determined by exposing to a range of secondary treated sewage concentrations. Results indicated that the relative progress of zoea stage I to zoea stage II negatively correlated with increasing sewage concentrations. Data was analyzed statistically to determine lethal, median lethal, sublethal, low observed effect, and no observed effect concentrations. Water samples collected along the Buckingham canal discharge zone were also analyzed for its toxicity to the larval development. Fecal indicator organisms chosen to determine the water quality were E. coli, enterococci, C. perfrigens, and F+ coliphages. Concentrations of these fecal markers were determined in the raw influent, primary treated effluent, secondary treated effluent, and in four discharge zone sites. Data showed that this biological toolbox is helpful for providing baseline information on the effectiveness of the wastewater treatment and environmental health of the discharge zone.

In this study, an attempt has been made to develop inventory of greenhouse gas (GHG) emissions for Pakistan at the national and sectoral level. The emission profile includes carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). In 2012, GHG emissions from different sectors of economy are estimated at 367 Tg CO₂eq. Out of this, CO₂ emissions were 179 Tg; CH₄ emissions were 107 Tg CO₂eq; and N₂O emissions were 81 Tg CO₂eq. Energy and agriculture sectors contribute approximately 89% of national GHG emissions. Industrial processes, waste, and land use change and forestry (LUCF) sectors contribute the remaining 11% GHG emissions. A comparison with the 1994 GHG emission inventory of Pakistan shows that GHG emissions in Pakistan from 1994 to 2012 have increased at an annual growth rate of 4.1% and yet anticipated to increase further for meeting the national developmental goals; however, the per capita emissions in Pakistan will remain low when compared with the global average.

The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in 8 passive air samples (PAS) and 6 lichen transplants (Ramalina fastigiata) deployed for a period of 2 months in different zones of Tarragona County (Catalonia, Spain), an area with an important number of chemical and petrochemical industries. The accumulated amount of the sum of the 16 PAHs ranged between 1363 to 7866 ng/sample in air samples. The highest concentration was found in the neighborhood of Puigdelfí (village of Perafort), in the vicinity of a big oil refinery and well under the potential influence of the petrochemical emissions. In lichen samples, the sum of the 16 PAHs ranged between 247 and 841 ng/g (dry weight), being the greatest value also observed in Puigdelfí. Data on the levels and profiles of PAHs in both passive monitoring methods were compared. A significant positive linear correlation was found between the concentrations of low molecular weight PAHs in lichens and the amounts accumulated in passive air samples (R = 0.827, P < 0.05), being especially significant the correlation of 4-ring PAHs (R = 0.941, P < 0.05). These results strongly suggest that lichens can be used to monitor gas-phase PAHs, providing data that can be quantitatively translated into equivalents for air.

Measuring the content of hydrogen chloride (HCl) in exhaust gas used to take time and energy. In this paper, we introduce a new online monitoring system which can output real-time data to the monitoring center. The system samples and cools exhaust gas, and after a series of processing, it will be analyzed by a specific instrument. The core part of this system is remote terminal unit (RTU) which is designed on Cortex-A8 embedded architecture. RTU runs a scaled-down version of Linux which is a good choice of OS for embedded applications. It controls the whole processes, does data acquisition and data analysis, and communicates with monitoring center through Ethernet. In addition, through a software developed for windows, the monitoring process can be remotely controlled. The new system is quite beneficial for steel industry to do environment monitoring.

In the current study, we used micromodel experiments to study three-phase fluid flow in porous media. In contrast to previous studies, we simultaneously observed and measured pore-scale fluid behavior and three-phase constitutive relationships with digital image acquisition/analysis, fluid pressure control, and permeability assays. Our results showed that the fluid layers significantly influenced pore-scale, three-phase fluid displacement as well as water relative permeability. At low water saturation, water relative permeability not only depended on water saturation but also on the distributions of air and diesel. The results also indicate that the relative permeability–saturation model proposed by Parker et al. (1987) could not completely describe the experimental data from our three-phase flow experiments because these models ignore the effects of phase distribution. A simple bundle-of-tubes model shows that the water relative permeability was proportional to the number of apparently continuous water paths before the critical stage in which no apparently continuous water flow path could be found. Our findings constitute additional information about the essential constitutive relationships involved in both the understanding and the modeling of three-phase flows in porous media.

Abamectin is one of the most used pesticides worldwide. However, investigations about its effects on amphibian populations are rare. Thus, the present study sought to investigate possible cytotoxic effects on Lithobates catesbeianus tadpoles exposed to low abamectin concentrations diluted in water. Accordingly, four experimental groups were set: negative control, positive control (cyclophosphamide—40 mL L⁻¹), abamectin at concentrations 36 μg a.i./L (ABA36 group), and 72 μg a.i./L (ABA72 group), applied as Kraft® 36EC. The micronucleus test was conducted and other nuclear abnormalities in peripheral blood erythrocytes were checked after 24, 48, and 72 h of exposure to the treatments. The total of other nuclear abnormalities was influenced by the treatments, whereas the frequency of micronuclei was influenced by the exposure time. Such frequency was higher in the animals comprising the ABA72 group, which was assessed 72 h after the exposure had begun. The total of other nuclear abnormalities was influenced by the treatments. Animals in the positive control, ABA36, and ABA72 groups showed similar frequency of these abnormalities at 48 and 72 h. However, this frequency was statistically higher than that of animals in their respective negative control groups. Thus, the present study confirmed the hypothesis that the exposure of L. catesbeianus tadpoles to abamectin caused cytotoxic effects on them, although this exposure lasted short and the concentrations were low. It disclosed prospects for variations in the nucleus of erythrocytes circulating in amphibians, a fact that may provide an important/complementary approach for the detection of cytotoxicity caused by abamectin exposure.

In the recent years, the use of sewage water for irrigation has attracted the attention of arid and semi-arid countries where the availability of fresh water is poor. Despite the potential use of sewage water in crop irrigation as effective and sustainable strategy, the environmental and human risks behind this use need to be deeply investigated. In this regard, an experiment was carried out under field conditions in Nursery, University College of Agriculture Sargodha, to evaluate the possible health risks of undesirable metals in wheat grains. Wheat variety Sarang was cultivated and irrigated with different combinations of ground (GW) and sewage water (SW). The concentrations of heavy metals (Cr, Cd, Ni, and Pb) and trace elements (Cu, Zn, and Fe) in wheat grains as well as in soil were determined. Moreover, the pollution load index (PLI), accumulation factor (AF), daily intake of metals (DIM), and health risk index (HRI) were calculated. Results showed that the concentration trend of heavy metals was Pb<Cr<Cu<Ni<Cd<Zn<Fe and Cr<Cu<Pb<Cd<Ni<Fe<Zn in soil and wheat, respectively. Among metals, Cd concentration in wheat exceeded the permissible limits regardless water quality, whereas Pb concentration in grain was within the acceptable levels as suggested by World Health Organization, when 100 % of SW was used for irrigation. Similar observation was reported for Cd concentration in the soil when wheat was irrigated with 100 % SW. In comparison to soil, the edible part of wheat presented lower concentration of all studied metals, except for Zn which was much higher compared to the tested soil samples. The higher concentration of Zn was responsible for increasing the DIM of Zn where, in average, the highest value was reported, particularly in 75 % SW treatment. This was reflected also in HRI where the maximum value was reported for Zinc under the same treatment. Higher value of HRI for wheat cultivated on polluted soils suggested that appropriate management of cultivated area is necessary for food safety and thus for public health. The results are expected to create awareness among the public on the safety of consuming food products grown in particular areas.