Toxicity and genotoxic evaluations in African catfish Clarias gariepinus (Burchell 1822) exposed to Act Force Gold®, Butaforce®, and Atraforce®

Act Force Gold^®, Butaforce^®, and Atraforce^® are among the most commonly used pesticides in Nigeria. The lethal concentrations and the respective toxic units for the three pesticides were determined. The genotoxic effects of the three pesticides were investigated in the red blood cells of Clarias gariepinus using micronucleus (MN) assay. The 96 h LC₅₀ was 4.75, 4.84, and 54.74 mg L⁻¹ for Act Force Gold^®, Butaforce^®, and Atraforce^®, respectively. The toxic units in ascending order of toxicity were 1.83, 20.66, and 21.05 for Act Force Gold^®, Butaforce^®, and Atraforce^® respectively. The estimated safe levels based on NAS/NAE varied from 4.75 × 10⁻¹–4.75 × 10⁻⁵ in Act Force Gold^® through 4.64 × 10⁻¹–4.85 × 10⁻⁵ in Butaforce^® to 5.74–5.74 × 10⁻⁵ in Atraforce^®. Fish specimens were exposed to the pesticides and sampling was done at regular intervals at days 1, 7, 14, and 21 and after another 7-day recovery period. The results obtained indicated concentration- and duration-dependent increase in % MN formation with maximum values of 3.40 ± 0.25 for Act Force Gold^® on day 14 and 3.05 ± 0.36 and 2.35 ± 0.14 for Butaforce^® and Atraforce^® respectively on day 7 of exposure. The 7-day recovery period could not reverse the trend as the % MN values obtained were significantly different from the control. The results further support the use of MN assay in assessing the toxicity of aquatic pollutants and can be used in the monitoring of aquatic ecosystems.

     

The environmental impacts of regional disparity in population and wealth distribution in Nigeria

The disparity in both population and wealth distribution in Nigeria by geo-political zones is well recognized. There is also the recognition that some of the environmental problems in certain sections of the country can be attributed to the imbalance in both population and wealth distribution. Hence the various agitations for environmental resource control in the country. What is lacking however is the research that shows the magnitude of the linkages between the disparity and the environmental degradation in regional context. This provides the basis for this research. To achieve the aim of the research, a STIRPAT model was employed as an analytical tool. The findings show that the southern geopolitical zones are generally more densely populated and wealthier than the northern zones. The south is also experiencing a higher degree of environmental resource degradation attributable to anthropogenic factors. Thus, there is congruence between population density, wealth distribution and environmental degradation in Nigeria. Therefore the achievement of sustainable environment and development in Nigeria requires deliberate policies to mitigate the impact of population concentration and wealth creation on the environment. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

A hierarchic metric approach for integration of green issues in manufacturing: a paper recycling application

This paper presents a hierarchic framework for environmentally conscious design. The framework integrates both product designers and stakeholders to evaluate not only the product features but also its environmental burden. In evaluating the product's burden, a life cycle assessment of the product is conducted through input-output analysis so that a comprehensive inventory of the product's actions and reactions to the environment could be documented. The analytic hierarchy procedure (AHP) is used to develop priority indices for customer requirements to highlight key features that must be present in the product. Subsequently, the quality function deployment is used to match design requirements to customer requirements. A cost-effective design plan is then finally developed. This framework adopts a systemic approach and ensures that environmentally conscious products are designed and manufactured.     

The impacts of anthropogenic factors on the environment in Nigeria

Generally speaking, there has been a consensus on the primary drivers of anthropogenic induced environmental degradation. However, little progress has been made in determining the magnitude of the impacts, particularly in developing countries. This creates a lacuna that needs to be filled up. The purpose of this study therefore is to ascertain the degree of anthropogenic induced environmental impacts in Nigeria. To achieve the aim, fossil fuel consumption was used as a surrogate for carbon dioxide emissions while the magnitude of the impacts was determined by regression statistics and the STIRPAT model. The results show that only three variables, namely population, affluence and urbanization, were statistically significant and that the regression model accounts for 60% of the variation in the environmental impacts. However, population and affluence, which have ecological elasticities of 1.699 and 2.709, respectively, are the most important anthropogenic drivers of environmental impacts in Nigeria while urbanization, with an elasticity of -0.570, reduces the effect of the impacts. This implies that modernization brings about a reduction in environmental impacts. The paper therefore makes a significant contribution to knowledge by successfully testing the STIRPAT model in this part of the world and by being the first application of the model at political units below the regional or nation states.     

A Decision Support Framework for Environmental Planning in Developing Countries

This paper presents a decision support framework for environmental planning in developing countries. The interest in protecting the natural environment from pollution gained increased importance in the 1990s with a push by world communities for sustainable development. Developing countries as well as the industrialized nations are expected to cut down on pollution and control the use of non-renewable natural resources. Although the concept of sustainable development sounds plausible, it is difficult to implement in many countries due to their conflicting goals. The world-wide targets on emissions, use of fossil fuels, reduction in water and atmospheric pollution require the participation of every nation. These goals are not easily achievable by some of the poorer developing countries partly because of their economic dependence on natural resources and partly because of their inability to afford more modern and efficient technologies. Thus, environmental planning goals are often in conflict with the development,social and economic needs of a country. In this paper, we develop a decision support framework that utilizes multicriteria and optimization models to address environmental planning problems. This framework is based on identifying the priorities of conflicting goals by working through and reducing the conflicts. A strategic planning framework is introduced into the decision support system since national planning is a strategic issue and these goals can only be achieved by adopting a systemic view.