Contaminated area instability along Ångermanälven River,northern Sweden

Industrially utilized river basins are frequently exposed to contaminants originating from polluting activities. However, the physical instability and probability of mass movement mobilization of contaminated soil into rivers have only received little attention. In this study, we present a GIS-based method to produce a regional overview of where and how contaminated areas are potentially exposed to slope instability. A landslide susceptibility-index was used to study the degree and distribution of overlap between contaminated sites and unstable ground. A contaminated area instability hazard classification was produced integrating slope instability and contamination risk classification. Our results indicate that mass movement can be tied mainly to a slope gradient ≥16°, a proximity to the river that is <500 m, a distance of <500 m from roads, concave surface curvature, and sand- and silt soils. Forty-six (22%) of all considered contaminated sites are located within areas with a non-negligible slope instability, of which a majority, 30 sites (14%) are situated on ground with a low or moderate instability. Three sites with a class 2 contamination risk (the 2nd highest class) are located on ground with a very high slope instability.     

Variability in the phytoplankton community of Kavaratti reef ecosystem (northern Indian Ocean) during peak and waning periods of El Niño 2016

El Niño, an interannual climate event characterized by elevated oceanic temperature, is a prime threat for coral reef ecosystems worldwide, owing to their thermal threshold sensitivity. Phytoplankton plays a crucial role in the sustenance of reef trophodynamics. The cell size of the phytoplankton forms the “master morphological trait” with implications for growth, resource acquisition, and adaptability to nutrients. In the context of a strong El Niño prediction for 2015–2016, the present study was undertaken to evaluate the variations in the size-structured phytoplankton of Kavaratti reef waters, a major coral atoll along the southeast coast of India. The present study witnessed a remarkable change in the physicochemical environment of the reef water and massive coral bleaching with the progression of El Niño 2015–2016 from its peak to waning phase. The fluctuations observed in sea surface temperature, pH, and nutrient concentration of the reef water with the El Niño progression resulted in a remarkable shift in phytoplankton size structure, abundance, and community composition of the reef waters. Though low nutrient concentration of the waning phase resulted in lower phytoplankton biomass and abundance, the diazotroph Trichodesmium erythraeum predominated the reef waters, owing to its capability of the atmospheric nitrogen fixation and dissolved organic phosphate utilization.     

Analysis of some heavy metals in the riverine water, sediments and fish from river Ganges at Allahabad

The river Ganges has been one of the major recipients of industrial effluents in India. The present paper deals with the study related to occurrence and bioaccumulation of heavy metals (Cu, Cr, Cd, Pb, Zn) in the riverine water, sediment, and the muscles of two cat fish species, Channa punctatus (C. punctatus) and Aorichthys aor (A. aor) procured from the river Ganges at Allahabad. The data obtained after water analysis reflected the order of occurrence of heavy metals to be Zn > Pb > Cu > Cr > Cd, respectively. The analysis of heavy metals in sediment indicated that among the five heavy metals tested; Zn was maximally accumulated followed by Pb, Cr, Cu and Cd. The trend of heavy metals accumulation in fish muscles was found to be similar to that observed in sediment and water such as Zn > Pb > Cu > Cr > Cd. Data indicated that Zn accumulated maximally in the sediment as well as muscles of both of the fish species in comparison to other metals.     

An assessment of fluoride in the coastal aquifer of the Bara tract in Bharuch district, Gujarat (India)

The fluoride (F) concentration in the coastal aquifers of Bara tract in Bharuch district, Gujarat was determined by potentiometric method using an ion-selective electrode. The fluoride concentration in these aquifers varies between 0.060 to 3.51 mg/L. It was also found that F has a positive correlation with pH and HCO(3)(-) whereas negatively correlated with Ca(2+), indicating that high fluoride in ground water is associated with low calcium content. This suggests that the higher pH of water promotes the leaching of fluoride and thus affects the concentration of fluoride in the ground water. It was also found that there exists no relationship between F, EC, and ground water table from surface in the ground water.     

Mathematical models for accurate prediction of atmospheric visibility with particular reference to the seasonal and environmental patterns in Hong Kong

Atmospheric visibility impairment has gained increasing concern as it is associated with the existence of a number of aerosols as well as common air pollutants and produces unfavorable conditions for observation, dispersion, and transportation. This study analyzed the atmospheric visibility data measured in urban and suburban Hong Kong (two selected stations) with respect to time-matched mass concentrations of common air pollutants including nitrogen dioxide (NO(2)), nitrogen monoxide (NO), respirable suspended particulates (PM(10)), sulfur dioxide (SO(2)), carbon monoxide (CO), and meteorological parameters including air temperature, relative humidity, and wind speed. No significant difference in atmospheric visibility was reported between the two measurement locations (p > or = 0.6, t test); and good atmospheric visibility was observed more frequently in summer and autumn than in winter and spring (p < 0.01, t test). It was also found that atmospheric visibility increased with temperature but decreased with the concentrations of SO(2), CO, PM(10), NO, and NO(2). The results showed that atmospheric visibility was season dependent and would have significant correlations with temperature, the mass concentrations of PM(10) and NO(2), and the air pollution index API (correlation coefficients mid R: R mid R: > or = 0.7, p < or = 0.0001, t test). Mathematical expressions catering to the seasonal variations of atmospheric visibility were thus proposed. By comparison, the proposed visibility prediction models were more accurate than some existing regional models. In addition to improving visibility prediction accuracy, this study would be useful for understanding the context of low atmospheric visibility, exploring possible remedial measures, and evaluating the impact of air pollution and atmospheric visibility impairment in this region.     

Recent biosensing developments in environmental security

Environmental security is one of the fundamental requirements of our well being. However, it still remains a major global challenge. Therefore, in addition to reducing and/or eliminating the amounts of toxic discharges into the environment, there is need to develop techniques that can detect and monitor these environmental pollutants in a sensitive and selective manner to enable effective remediation. Because of their integrated nature, biosensors are ideal for environmental monitoring and detection as they can be portable and provide selective and sensitive rapid responses in real time. In this review we discuss the main concepts behind the development of biosensors that have most relevant applications in the field of environmental monitoring and detection. We also review and document recent trends and challenges in biosensor research and development particularly in the detection of species of environmental significance such as organophosphate nerve agents, heavy metals, organic contaminants, pathogenic microorganisms and their toxins. Special focus will be given to the trends that have the most promising applications in environmental security. We conclude by highlighting the directions towards which future biosensors research in environmental security sector might proceed.     

Origin and characterisation of microparticles in an ice core from the Central Dronning Maud Land, East Antarctica

The scanning electron microscopy-energy dispersive spectroscopic (SEM-EDS) study of selected samples from an ice core collected from Central Dronning Maud Land (CDML), East Antarctica, revealed several microparticles. They are mainly siliceous and carbonaceous particles and have distinct variations in their shape and composition. The morphology and major element chemistry of the particles suggest their origin from either volcanic eruptions or continental dust. The EDS analysis revealed that the volcanic particles are enriched in silica (average SiO2 62%), compared to the continental dust particle (average SiO2 56%). We found that the tephra relating to Agung (1963) and Karkatau (1883) volcanic eruptions, as recorded, in the ice core harbored microbial cells (both coocoid and rods). The occurrence of organic and inorganic particles which bear relation to volcanic eruption and continental dust implies significant environmental changes in the recent past.