Five-wheel framework for system-based monitoring of heavy metal pollution in rivers

Sectorial approach for monitoring heavy metal pollution in rivers has failed to report realistic pollution status and associated ecological and human health risks. The increasing spread of heavy metals from different sources and emerging risks to human and environmental health call for reexamining heavy metal pollution monitoring frameworks. Also, the sources, spread, and load of heavy metals in the environment have changed significantly over time, requiring consequent modification in the monitoring frameworks. Therefore, studies on heavy metal monitoring in rivers conducted in the last decade were evaluated for experimental designs, research frameworks, and data presentations. Most studies (∼99%) (i) lacked inclusiveness of all environmental compartments; (ii) focused on “one pollutant – one/two compartment” or sometimes “one pollutant – one compartment – one effect” approach; and (iii) remained “data-rich but information poor.” An ecological approach with integrative system thinking is proposed to develop a holistic approach for monitoring river pollution. It is visualized that heavy metal monitoring, risk analyses, and water management must incorporate tracking pollutants in different environmental compartments of a river (water, sediment, and floodplain/bank soil) and consider correlating it with riverbank land use. The systems-based pollution monitoring and assessment studies will reveal the critical factors that drive heavy metals pollutant movement in ecosystems and associated potential risks to the environment, wildlife, and humans. Also, water quality and pollution indexing tools would help better communicate complex pollution data and associated risks among all stakeholders. Therefore, integrating systems approaches in scientific- and policy-based tools would help sustainably manage the health of rivers, wildlife, and humans.     

Improvement in rice straw pulp bleaching effluent quality by incorporating oxygen delignification stage prior to elemental chlorine-free bleaching

Environmental degradation by industrial and other developmental activities is alarming for imperative environmental management by process advancements of production. Pulp and paper mills are now focusing on using nonwood-based raw materials to protect forest resources. In present study, rice straw was utilized for pulp production as it is easily and abundantly available as well as rich in carbohydrates (cellulose and hemicelluloses). Soda-anthraquinone method was used for pulp production as it is widely accepted for agro residues. Bleaching process during paper production is the chief source of wastewater generation. The chlorophenolic compounds generated during bleaching are highly toxic, mutagenic, and bioaccumulative in nature. The objectives of study were to use oxygen delignification (ODL) stage prior to elemental chlorine-free (ECF) bleaching to reduce wastewater load and to study its impact on bleached pulp characteristics. ODL stage prior to ECF bleaching improved the optical properties of pulp in comparison to only ECF bleaching. When ODL stage was incorporated prior to bleaching, the tensile index and folding endurance of the pulp were found to be 56.6 ± 1.5 Nm/g and 140, respectively, very high in comparison to ECF alone. A potential reduction of 51, 57, 43, and 53% in BOD₃, COD, color, and AOX, respectively was observed on adding the ODL stage compared to ECF only. Generation of chlorophenolic compounds was reduced significantly. Incorporation of ODL stage prior to bleaching was found to be highly promising for reducing the toxicity of bleaching effluents and may lead to better management of nearby water resources.

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Plant steroid hormones produced under Ni stress are involved in the regulation of metal uptake and oxidative stress in Brassica juncea L

Brassinosteroids (BRs) are involved in the amelioration of various biotic and abiotic stresses. With an aim to explore the role of BRs under heavy metal stress, plants of Brassica juncea L. were grown in pots. The plants were subjected to various concentrations of Nickel metal (0.0, 0.2, 0.4 and 0.6 mM) and harvested on 60th day in order to observe the expression of these hormones. The isolated BRs from the leaves of Brassica plants characterized by GC-MS include 24-Epibrassinolide (24-EBL), Castasterone, Dolicholide and Typhasterole. The effect of isolated 24-EBL was studied on Ni metal uptake and antioxidative defense system in 60 d old plants of Brassica. It was observed that 24-EBL significantly increased the activities of stress ameliorating enzymes and lowered the metal uptake in plants. This is the first report in B. juncea L. plants showing the expression of BRs under metal treatments and effect of the isolated 24-EBL on metal uptake and in oxidative stress management.     

Effect of marble dust on plants around Vishwakarma Industrial Area (VKIA) in Jaipur, India

The paper describes the effect of marble dust on plants in and around Vishwakarma Industrial Area (VKIA) Jaipur, Rajasthan (India). Trees species growing in and around VKIA area were selected and various morphological characteristics were studied such as leaf area dry weight ratio (LADWR), Dust retaining capacity (DRC) and Chlorophyll content. In the study the effects of marble dust on selected tree species was observed. LADWR was recorded maximunm 217.90 cm2 g(-1) dry wt. in Polyalthia longifolia in VKIA and minimum 98.74 cm2 g(-1) dry wt. in Ficus religiosa in Nindar whereas The DRC was observed maximum 178.51 mg cm(-2) in Azadirachta indica in VKIA as well as minimum recorded 66.41 mg cm(-2) in Thevetie pervvianain in Vidyadher Nagar. However the Total Chlorophyll Content was also determined and it was found maximum in Bougainvillea i.e. 2.949 mg g(-1) (fresh wt.) in VKIA whereas minimum for Nindar i.e. 0.784 mg g(-1) (fresh wt.) in Ficus religiosa.     

Biodiversity of earthworm resources of arid environment

Biodiversity of earthworms was studied in arid zone of Jodhpur district of Rajasthan. A total nine species of earthworms were recorded from different pedoecosystems of desert environment. These species were Pontoscolex corethrurus, Amynthas morrisi, Metaphire posthuma, Lampito mauritii, Perionyx sansibaricus, Ocnerodrilus occidentalis, Dichogaster bolaui, Octochaetona paliensis and Ramiella bishambari. They belonged to the families Glossoscolicidae, Megascolicidae, Ocnerodrilidae and Octochaetidae. The species P. sansibaricus, O. paliensis and P. corethrurus were reported for the first time from Rajasthan. The earthworm fauna of Jodhpur district were either exotic peregrine or native peregrine. Exotic species like A. morrisi and M. posthuma, and native peregrine species like L. mauritii were widely distributed in arid region. They appear to be better adapted to withstand drought conditions, as they have enteronephric meronephridia and excrete their urine into the guts for conservation of water in their bodies.     

Penetration of herbicides to groundwater in an unconfined chalk aquifer following normal soil applications

The persistence and penetration of the herbicides isoproturon and chlorotoluron in an unconfined chalk aquifer has been monitored over a 4-year period through soil sampling, shallow coring and groundwater monitoring. Chlorotoluron was applied on plots as a marker compound, having never been used previously on that, or surrounding fields. The fieldsite had a 5 degree slope with soil depths of 0.5 to 1.5 m and a water table between 20 and 5 m from the soil surface. Where the water table was deepest (9-20 m below surface (mbs)) little or no positive herbicide detections were made. However, where the water table was at only 4-5 mbs, a regular pesticide signal of around 0.1 microg/l for isoproturon and chlorotoluron could be distinguished. Over the winter recharge period automatic borehole samplers revealed a series of short-lived peaks of isoproturon and chlorotoluron reaching up to 0.8 microg/l. This is consistent with a preferential flow mechanism operating at this particular part of the field. Such peaks were occurring over 2 years after the last application of these compounds. Shallow coring failed to uncover any significant pesticide pulse moving through the deep unsaturated zone matrix at the fieldsite.     

Non-powered hand tool improvement research for prevention of work-related problems: a review

Purpose. In lower-middle-income countries, most of the work is performed manually using non-ergonomic hand tools which results in work-related health problems. Using hand tools designed in line with ergonomic principles may play an important role in reducing work-related health concerns significantly. Methods. Scientific databases (PubMed, EBSCOhost) and e-publishers were searched for articles from 1985 to 2015 using the following keywords: ‘hand tool’, ‘ergonomics’, ‘usability’ and ‘design’. After applying selection criteria to 614 articles, 58 articles related to the physical design of hand tools were selected. Results. Seventeen articles were related to hand tool improvement in the manufacturing sector. Musculoskeletal disorders were found to be the most frequently occurring work-related health problems. Most of the articles focused on product and qualitative variables for improvement in hand tools, while few articles considered human and task variables. Conclusions. Literature shows that hand tool improvement studies have been given less importance in low-income and lower-middle-income countries. However, some work of significance is reported in the agriculture sectors of these countries. Hence, it is concluded that ergonomic intervention in hand tools is much needed for those industries which employ traditional methods of working.     

Assessment of habitat quality with relation to fish assemblages in an impacted river of the Ganges basin, northern India

In this work, we examined water-quality assessment in relation to fish assemblage of Gomti River, a large tributary of the Ganges River basin in northern India. Principal component analysis was performed for 18 environmental variables which produced three axes that cumulatively explained 60.23% of the environmental variation in sites. Fifteen variables (fine substrate fine gravel, coarse gravel, cobble, sand substrate water flow, conductivity, TDS, total hardness, temperature, dissolved oxygen, pH, and overhanging vegetation) had high loadings on at least one of the principal component axes interpreted. The canonical correspondence analysis was used to establish the relationship between important fish species and environmental variables. Species were distributed within four groups with respect to the significant habitat characteristics. The Pearson correlation coefficient was calculated between the water-quality parameters. We concluded that the level of species richness is mostly dependent on abiotic factors like temperature, dissolved oxygen, TDS, conductivity, depth, pH, and water current in the Gomti River, of the Ganges basin.