Asian Journal of Environment & Ecology

This study intends to assess the current water quality of the Surma River alongside Sylhet City and its impacts on urban residents. The water quality has been assessed by laboratory analysis considering a total of seven water quality parameters, viz. pH, DO, BOD, COD, TS, TSS and TDS and water samples were collected from four stations. The impacts of water quality on human health, fishing, the soil, agriculture and the surrounding environment are analyzed based on primary data collected through questionnaire survey covering a total of 200 respondents who resides at the bank of the river. The average values of parameters are DO 11.15 mg/l, BOD 1.77 mg/l, COD 25.27 mg/l, pH 7.2, TSS 131.5 mg/l, TDS 26.47 mg/l and TS 158 mg/l. Among of them only pH is within standard value. Respondent of the study area opined that they have no waste dumping station where they can put their waste. For that reason they compelled to dump waste into the river.Inadequate waste management system and lack of proper waste management initiatives accelerating the pollution exponentially. The scenario can be improved by implementing the recommendations made by the study, which can have the positive changes in the human and aquatic life, environment and ecosystem of the river area.

Azadirachtin (C₃₅H₄₄O₁₆/AZT) develops antifeedancy/growth-regulation/fecundity-suppression/ sterilization/oviposition/repellence and deformity in insect via biochemical/cellular changes and causes their death. Agricultural productivity/quality/eco-sustainability is concerned to this issue. ROS are cytotoxic-factors generated in invertebrates in stress-conditions. The present in-vivo/in-vitro study aimed to investigate the impact of dose dependant AZT toxicity on oxidative-stress-marker (alkaline-phosphatise/ALP; thiobarbituric-acid-reactive-substances/TBARS; non-protein-soluble-thiols/NPSH; acetyl-cholinesterase/AChE) and antioxidant-enzyme activity (superoxide-dismutase/SOD; catalase/CAT; glutathione-peroxidise/GPx; amylase) in brain/hemolymph of Spathosternum prasiniferum prasiniferum (Walker,1871) (Orthoptera:Acridoidea). Acridids are highly abundant and bio-indicator of grassland-ecosystem. During cultivation, insects are exposed (dose/time dependant) to AZT. AZT developed restlessness, jerky-movements and swarming-movements in the insects. It promoted oxidative-stress-marker in brain/hemolymphin both sexes but female had significantly stimulated antioxidant-enzymes to overcome cellular-stress. Increase of brain TBARS, antioxidant-enzymes and decrease in NPSH by AZT indicates oxidative-stress induction in this species. In several instances damage to the brain DNA was noticed. In general female insect responded more intensely with some prominent adaptive strategies.

The study investigate a series of selected heavy metal pollution of soil, the extent of their uptake by Telfairia occidentalis and Amaranthus cruentus as well as their ecological risk around dumpsite in Chanchaga Minna, Niger State, Nigeria. Soil samples were collected at 15 cm depth with the aid of soil auger and vegetable samples were collected from dumpsite and other samples with no activities served as control. The soil samples were collected at random and their physicochemical parameters such as pH, total nitrogen, total phosphorus, organic matter, total carbon and exchangeable cations (i.e., K+, Mg2+ and Na+) using a standard method and concentrations of the heavy metals in soils and vegetables, As, Cd, Cr, Cu, Hg and Pb were analyzed using flame Atomic Absorption Spectrometer (AAS). The ecological health risk assessment from the consumption of these vegetables was calculated using standard methods. The result showed a significant (p-value) increase of AC and TO in test soil samples relative to the control soils. The pH of the soil in dumpsite and control site was 5.93, and 7.35 respectively. Mean concentrations of As, Cd, Cr, Cu, Hg and Pb in the dump site were 6.35, 4.84, 6.67, 7.35, 5.72 and 4.96 mg/kg while the control site were 1.18, 0.28, 1.26, 6.83, 1.19 and 3.54 mg/kg respectively which was below the WHO/FAO limits of As (20), Cd (3.0), Cr (100), Cu (100), Hg (2.00) and Pb (50 mg/kg) for soil. The concentrations of As, Cd, Cr, Cu, Hg and Pb recorded in AC dump site were As (6.13), Cd (3.67), Cr (5.37), Cu (4.28), Hg (3.46), and Pb (4.52) and in TO As (5.67), Cd (3.13), Cr (4.67), Cu (3.65), Hg (3.19) and Pb (4.27 mg/kg) which were above the WHO/FAO permissible limits (0.5, 0.20, 0.3, 3.0, 0.1 and 0.3 mg/kg) respectively for edible vegetable. The concentrations of heavy metals in soils and vegetables from the dumpsite soil were significant (p < 0.05) from the controls. The bioaccumulation factor (BAF) for the vegetable showed that they exclude the element from soil. The Hazard Quotient (HQ) and Hazard index (HI) show that there is no harmful effect since the values obtain were not greater than >1. But continuous consumption can accumulate in the food chain especially for children. This study showed that the soils and vegetables within the vicinity of the dumpsites were polluted by heavy metals which can pose health risk. The study also calls for proper waste management practices and policy implementation.

Background: Environmental issues have gained widespread attention from all around the world and most of them originate from the root cause of climate change. Climate change occurs when there is increased concentrations of greenhouse gases in the environment, reflecting less heat back to space. In view of extreme weather and consequences, afforestation is now seen as one of the most effective methods in mitigating the effects of climate change. Increasing popularity of using forests as mitigation methods, however, does not translate to forests being effective solutions in all situations. Being part of our ecosystem, processes of forests are easily altered by climate change itself.

Aims: To ascertain if afforestation can effectively mitigate the effects of climate change in consideration that the processes of trees are affected by climate change itself.

Study Design:  Literature review.

Methods: Data sources include Nature, Science Direct and environmental journals.

Results: Climate change currently increases the ability of forests to mitigate climate change but long-term exposure to increased temperatures and carbon dioxide (CO₂) levels reduce their abilities to do so. Location of where afforestation is carried out also affects the extent of effectiveness in reducing CO₂ levels and climate change.

Conclusion: Afforestation can mitigate climate change if implemented appropriately, especially where it is effective. However, the primary solution will still be cutting carbon emissions since trees have a biological limit in response to climate change.

Water is an important medium for many activities including water for consumptive and non-consumptive purposes. Lack of water quality and quantity does not only hampers socio-economic development but affects agricultural productivity, sustainable development, sanitation, health, industrial development and the ecosystem. The advent of climate change is known to affect water flow, increases dry season spells and drought, and influences reservoirs or deep groundwater wells thus worsening the precarious water situation in Africa.  About 1.7 billion of the world population lives in water scarce regions and this is projected to grow to about 300% or 5 billion by 2025 especially in Africa.  In Ghana, population growth, pollution of river bodies, high evapotranspiration, erratic rainfall pattern and environmental degradation among others have affected water availability and use.  These challenges will therefore require a deliberate water harvesting, integrated water management and conservation, water use efficiency and capacity building to withstand the dwindling trend of water resources in the country. This paper therefore seeks to inform policy makers, stakeholders, institutions responsible for water resources management among others to consider water harvesting as a potential solution to the many challenges including water shortages, floods, and land degradation. The article was carried out through extensive review of literature, official reports and policy documents. It shows the need to adopt appropriate techniques for rainwater harvesting to address the perennial water scarcity in the country.