Upon screening for novel and potential biocompounds with larvicidal activities, we successfully isolated hamisonine (HMSN) a limonoid compound from endophytic fungi Penicillium oxalicum LA-1 of Limonia acidissima. The extracted compound structure was elucidated by spectral studies such as UV-vis spectroscopy, thin-layer chromatography, FTIR, LC-ESI-MS, ¹H NMR, and ¹³C NMR upon comparing with the spectral data available in the literature. Further, the isolated HMSN was tested against III and IV instar Culex quinquefasciatus larvae. The outcome of this study clearly emphasize that the extracted compound HMSN possesses a stupendous larvicidal activity in a dose-dependent manner with the LC₅₀ and LC₉₀ values of 1.779 and 7.685 ppm against III instar larvae and 3.031 and 28.498 ppm against IV instar larvae of C. quinquefasciatus, respectively. Interestingly, the histological studies evidently showing the damage of peritrophic membrane and epithelial cells of testing mosquito larvae.

Brown carbon (BrC) has recently received much attention because of its light absorption features. The chemical compositions, optical properties, and sources of fine aerosol at a high-elevation mountain observatory (4730 m a.s.l.) in the central Tibetan Plateau were measured between 31 May and 1 July 2015. A low flow-rate sampler was used to collect 24-h average fine particulate matter (PM₂.₅) filter samples. Water-soluble ions, organic carbon (OC), elemental carbon, water-soluble organic carbon (WSOC), and light absorption by water-soluble BrC were determined for 26 filter samples. The mean (± 1σ) OC and WSOC concentrations were 0.76 ± 0.43 and 0.39 ± 0.15 μgC/m³, respectively, and the mean WSOC/OC mass ratio was 0.59 ± 0.22. The OC and WSOC concentrations were relatively higher (0.59–1.80 and 0.33–0.83 μgC/m³, respectively) during the pre-monsoon period (2–13 June) and were relatively lower (0.27–0.77 and 0.12–0.50 μgC/m³, respectively) during the monsoon period (14 June to 1 July), probably because of wet scavenging of aerosols during long-range transport and the presence of cleaner marine air masses during the monsoon period. The absorption spectra of PM₂.₅ water extracts smoothly increase from visible range to ultraviolet range. The absorption Ångström exponent, which describes the wavelength dependence of water-soluble BrC, was 2.74–10.61 (mean 6.19 ± 1.70), and its value was similar in the pre-monsoon period (6.57 ± 0.56) to that in the monsoon period (5.91 ± 2.14). The water-soluble BrC mass absorption efficiency, 0.38 ± 0.16 m²/(g C), was much lower than those observed in most urban areas but similar to those in other remote sites. Absorption coefficient at 365 nm, typically used as a proxy for water-soluble BrC, correlated well with the WSOC concentration (R ² = 0.57), K⁺ concentration (R ² = 0.75), and organic aerosol biomass burning markers characterized by an Aerodyne aerosol mass spectrometer (C₂H₄O₂⁺ + C₃H₅O₂⁺, R ² = 0.60). It can be inferred that biomass burning was an important source of water-soluble BrC in the study area combined with air mass back trajectory analysis using the NOAA HYSPLIT as well as MODIS data of fire dots and aerosol optical depths. The water-soluble BrC to BC light absorption (at 365 nm) coefficient ratios were 9–27%.

Assessment and monitoring of microbial community dynamics is useful when tracking the progress of vinyl chloride (VC) bioremediation strategies, particularly in dilute plumes where apparent VC attenuation rates are low. In a long-term field study, the abundance and the activity of microbial VC degraders were tracked in three monitoring wells (MW05, MW25, and MW19) along a dilute VC plume at Naval Air Station (NAS) Oceana. High-throughput sequencing of partial 16S ribosomal RNA (rRNA) genes and transcripts revealed diverse groundwater microbial communities and showed that methanotrophs and anaerobic respirers (e.g., methanogens, sulfate reducers, and iron reducers) were among the most active and abundant guilds. Quantitative PCR analysis showed that among bacterial guilds with a potential to contribute to VC biodegradation, methanotrophs were the most abundant and active microbial group. Ethene-oxidizing bacterial populations were less abundant and relatively inactive compared to methanotrophs. In MW19, expression of functional genes associated with both aerobic VC oxidation and anaerobic VC reduction was observed. Overall, our results reveal that the groundwater community contains various active bacterial guilds previously associated with metabolic and cometabolic VC degradation processes either under aerobic and anaerobic conditions that might have contributed to the slowly decreasing VC concentrations at the NAS Oceana site over the 6-year study period.

Electrokinetic remediation (EKR) is the most efficient technique for remediation of fine-grained soil. The primary removal mechanisms of heavy metal in EKR are the electromigration and electroosmosis flow under appropriate electric gradients. Most EKR studies have researched the variation according to the electrolyte and electric voltage. Also, EKR could be influenced by the migration velocity of ions, while few studies have investigated the effect of moisture content. In this study, soil moisture was controlled by using tap water and NaOH as electrolytes to enhance electromigration and electroosmosis flow. In both electrolytes, the higher moisture content led to the more As removal efficiency, but there were no differences between tap water and NaOH. Therefore, tap water was the most cost-effective electrolyte to remove As from fine-grained soil.

This is the first study from Pakistan to report the exposure of petrol filling workers (n = 120) to naphthalene (Nap) and pyrene (Pyr) in relation to their functional capacities and health outcome. A group of non-exposed subjects (controls n = 46) was also recruited for comparison. The perceived health risk of the exposed workers was monitored using a questionnaire based on the self-reporting survey. The observed physical anomalies related to the health disorder included the acidity after meals, eye redness, appetite loss, skin lesions, and dryness of oral cavity, while those related to neurasthenic symptoms included the body aches, energy loss, twitching, fatigue, sleeplessness, fainting, and irritability. Mean Nap level observed in the exposed group (106 μg L⁻¹) was significantly correlated (r = 0.49; p < 0.01) with cigarette smoking, while the average Pyr concentration (19.18 μg L⁻¹) was associated with job duration. Workers exposed for 6 h per day or more had significantly high prevalence of physical disorders (OR = 2.79, 95% CI = 1.28–6.09). Neurasthenic symptoms were found in 65% of the subjects and were associated with years of involvement in job. Ten years or more work duration at petrol pumps could be associated with a substantial development of neurasthenic effects (OR = 2.80, 95% CI = 1.23–6.34). In conclusion, the subjects ascribed the disturbances in physical and neurological behavior to their occupation (petrol filling) and also rated their overall health and functional capacity as poor. To promote health of petrol pump workers, reduction in work hours and provision of masks and gloves could be introduced as occupational health interventions.

Nitric oxide (NO) is a free radical molecule involved in an array of functions under physiological and adverse environmental conditions. As other free radical molecules, NO biological action depends on its cellular concentration, acting as a signal molecule when produced at low concentration or resulting in cellular damage when produced at sufficiently high levels to trigger nitro-oxidative stress. Over the last decade, significant progress has been made in characterizing NO metabolism and action mechanism, revealing that diverse biosynthetic routes can generate this free radical in plants and its action mainly occurs through posttranslational modification (nitration and S-nitrosylation) of target proteins. Intricate crosstalk networks between NO and other signaling molecules have been described involving phytohormones, other second messengers, and key transcription factors. This review will focus on our current understanding of NO interplay with phytohormones and other plant growth regulators under abiotic stress conditions.

The use of sewage sludge in agricultural soils can improve soil physical and chemical properties and soil fertility by increasing organic materials; however, the presence of heavy metals in sewage sludge is a significant problem for the quality of agricultural products and the environment. Most heavy metals, due to their inactive nature, are stable and can affect human health. This study investigates the effect of sewage sludge on the concentration of copper, zinc, cadmium, lead, iron, and manganese in two varieties of wheat, i.e., Sivand (Triticum aestivum cv. Sivand) and Roshan (Triticum aestivum cv. Roshan). Results were obtained from a factorial experiment in a completely randomized design with three replications and at three levels (0, 60, and 120 kg soil) and were carried out in a research greenhouse. This research concluded that in the treated seed and stem of Sivand variety, concentrations of Zn, Cd, Fe, and Mn were below the standard toxicity limit, and concentrations of Cu and Pb were above the standard limit. In the Roshan variety, the concentrations of Zn, Cd, Pb, Fe, and Mn were below the standard limit, and Cu concentration was above the standard. The results of this study lead to the recommendation that farmers avoid using sewage sludge in farming, as much as possible. Instead, it is far more appropriately employed as a fertilizer for green space, ornamental trees, and parks, where edible products for human consumption are not grown.

Groundwater quality in bone-dry and semiarid areas of Iran is decreasing because of contaminants from natural origins and anthropogenic sources. Among many harmful contaminants, nitrate and fluoride ions are more common. This study was carried out with the aim of determining geochemical processes controlling chemistry of groundwater with special reference to nitrate and fluoride enrichment in groundwater in Lar plain aquifer, south of Iran. Groundwater samples were collected from 17 sites and analyzed for main constituents (Na, K, Ca, Mg, Cl, SO₄ ²⁻, HCO₃ ⁻, F⁻, and NO₃ ⁻). Composite diagram, saturation indices calculation, and multivariate analysis techniques including cluster and factor analyses were employed in evaluating groundwater quality. The EC ranges from 8793.87 to 13,345.00 μS/cm in wet season and from 9621.59 to 12,640.00 μS/cm in dry season. Fluoride amounts range between 0.59 and 3.92 mg/L. Nitrate concentrations range between 1.47 and 70.66 mg/L. Results indicate that dissolution–precipitation of carbonate and evaporate minerals, evaporation (in terms of agricultural water return), and opposite ion interchange are the main processes that determine groundwater chemistry. It seems that fluoride has a natural origin and the equilibrium reaction between fluorite and calcite is very significant to control fluoride concentration level in water. Vertical variation of nitrate concentration and distribution of agricultural areas have indicated that nitrate originated from nitrogenous inorganic fertilizers used during irrigation periods. The results also indicate that denitrification takes place in the aquifer and that nitrate decline is not only a function of dilution but also a process of denitrification.

As a result of great increases in CO₂ emissions in the last few decades, many papers have examined the relationship between renewable energy and CO₂ emissions in the energy economics literature, because as a clean energy source, renewable energy can reduce CO₂ emissions and solve environmental problems stemming from increases in CO₂ emissions. When one analyses these papers, he/she will observe that they employ fixed parameter estimation methods, and time-varying effects of non-renewable and renewable energy consumption/production on greenhouse gas emissions are ignored. In order to fulfil this gap in the literature, this paper examines the effects of non-renewable and renewable energy on CO₂ emissions in Turkey over the period 1970–2013 by employing fixed parameter and time-varying parameter estimation methods. Estimation methods reveal that CO₂ emissions are positively related to non-renewable energy and renewable energy in Turkey. Since policy makers expect renewable energy to decrease CO₂ emissions, this paper argues that renewable energy is not able to satisfy the expectations of policy makers though fewer CO₂ emissions arise through production of electricity using renewable sources. In conclusion, the paper argues that policy makers should implement long-term energy policies in Turkey.

A robust risk assessment of Mehmood Booting Open Dumping (MBOD) site has been carried out by developing holistic risk assessment framework. Framework mainly comprises on baseline study, hazard identification, and risk quantification and evaluation. Physico-chemical analysis of groundwater and leachate, health risk assessment, and estimation of gas emissions from the site were carried out for risk evaluation. LandGEM 3.02 modelling software was used to measure the gas emissions. Analysis of leachate showed that all parameters were exceeding the WHO standard limit. Water samples were found polluted with heavy metals and total coliform contamination. Health survey inferred that problems which were faced by the majority of respondents were respiratory problems (80%). LandGEM model estimated that total landfill gas (TLG) emitted from the site for the year 2014 was 1.760E+05 Mg/year, CH₄ emission was 5.445E+06 Mg/year, CO₂ emission was 1.290E+05 Mg/year and for non-methane organic compound emission was 2.021E+03 Mg/year. It can be concluded that in the near future, almost all the water locations are possibly threatened with leachate contamination due to the continued accumulation of solid waste at MBOD site. The study recommends that new sanitary landfill sites should be designed to minimize the adverse effects associated with solid waste disposal and to preclude further pollution to surface water, groundwater, soil, and air.