Assessment of public exposure to naturally occurring radioactive materials from mining and mineral processing activities of Tarkwa Goldmine in Ghana

Studies have been carried out in a Goldmine in Ghana to determine the exposure of the public to naturally occurring radioactive materials from processing of gold ore. Direct gamma spectrometry and neutron activation analysis techniques were used to analyse soil, rock, water and dust samples from the mining environment. The mean activity concentrations measured for (238)U, (232)Th and (40)K in the soil/rock samples were 15.2, 26.9 and 157.1 Bq kg(?-?1), respectively. For the water samples, the mean activity concentrations were 0.54 and 0.41 Bq l(?-?1)) and 7.76 Bq l(?-?1) for (226)Ra, (232)Th and (40)K, respectively. The mean activity concentrations measured in the dust samples were 4.90 and 2.75 μBq m(?-?3) for (238)U and (232)Th, respectively. The total annual effective dose to the public was estimated to be 0.69 mSv. The results in this study compared well with typical world average values. The results indicate an insignificant exposure of the public from the activities of the Goldmine.     

Review of LCA studies of solid waste management systems – Part I: Lessons learned and perspectives

The continuously increasing solid waste generation worldwide calls for management strategies that integrate concerns for environmental sustainability. By quantifying environmental impacts of systems, life cycle assessment (LCA) is a tool, which can contribute to answer that call. But how, where and to which extent has it been applied to solid waste management systems (SWMSs) until now, and which lessons can be learnt from the findings of these LCA applications? To address these questions, we performed a critical review of 222 published LCA studies of SWMS. We first analysed the geographic distribution and found that the published studies have primarily been concentrated in Europe with little application in developing countries. In terms of technological coverage, they have largely overlooked application of LCA to waste prevention activities and to relevant waste types apart from household waste, e.g. construction and demolition waste. Waste management practitioners are thus encouraged to abridge these gaps in future applications of LCA. In addition to this contextual analysis, we also evaluated the findings of selected studies of good quality and found that there is little agreement in the conclusions among them. The strong dependence of each SWMS on local conditions, such as waste composition or energy system, prevents a meaningful generalisation of the LCA results as we find it in the waste hierarchy. We therefore recommend stakeholders in solid waste management to regard LCA as a tool, which, by its ability of capturing the local specific conditions in the modelling of environmental impacts and benefits of a SWMS, allows identifying critical problems and proposing improvement options adapted to the local specificities.     

Review of LCA studies of solid waste management systems – Part II: Methodological guidance for a better practice

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.     

Models for waste life cycle assessment: Review of technical assumptions

A number of waste life cycle assessment (LCA) models have been gradually developed since the early 1990s, in a number of countries, usually independently from each other. Large discrepancies in results have been observed among different waste LCA models, although it has also been shown that results from different LCA studies can be consistent. This paper is an attempt to identify, review and analyse methodologies and technical assumptions used in various parts of selected waste LCA models. Several criteria were identified, which could have significant impacts on the results, such as the functional unit, system boundaries, waste composition and energy modelling. The modelling assumptions of waste management processes, ranging from collection, transportation, intermediate facilities, recycling, thermal treatment, biological treatment, and landfilling, are obviously critical when comparing waste LCA models.This review infers that some of the differences in waste LCA models are inherent to the time they were developed. It is expected that models developed later, benefit from past modelling assumptions and knowledge and issues. Models developed in different countries furthermore rely on geographic specificities that have an impact on the results of waste LCA models. The review concludes that more effort should be employed to harmonise and validate non-geographic assumptions to strengthen waste LCA modelling.     

Spectroscopic characterization of organic matter of a soil and vinasse mixture during aerobic or anaerobic incubation

Mineralization potentials are often used to classify organic wastes. These methods involve measuring CO₂ production during batch experiments, so variations in chemical compounds are not addressed. Moreover, the physicochemical conditions are not monitored during the reactions. The present study was designed to address these deficiencies. Incubations of a mixture of soil and waste (vinasse at 20% dry matter from a fermentation industry) were conducted in aerobic and anaerobic conditions, and liquid samples obtained by centrifugation were collected at 2 h, 1 d and 28 d. Dissolved organic carbon (DOC) patterns highlighted that: there was a “soil effect” which increased organic matter (OM) degradation in all conditions compared to vinasse incubated alone; and OM degradation was faster under aerobic conditions since 500 mg kg^?1 of C remained after aerobic incubation, as compared to 4000 mg kg^?1 at the end of the anaerobic incubation period. No changes were detected by Fourier transform infrared spectroscopy (FTIR) between 2 h and 1 d incubation. At 28 days incubation, the FTIR signal of the aerobic samples was deeply modified, thus confirming the high OM degradation. Under anaerobic conditions, the main polysaccharide contributions (ν(C–O)) disappeared at 1000 and 1200 cm^?1, as also confirmed by the ¹³C NMR findings. Under aerobic incubation, a 50% decrease in the polysaccharide proportion was observed. Under anaerobic conditions, significant chemical modifications of the organic fraction were detected, namely formation of low molecular weight organic acids.     

Pollution and probabilistic human health risk assessment of potentially toxic elements in the soil-water-plant system in the Bolkar mining district,Niğde,south-central Turkey

Environmental Science and Pollution Research - Globally, potentially toxic elements (PTEs) are regarded as an important group of pollutants for the wider environment because of their intrinsic...     

Re-examining the environmental Kuznets curve (EKC) for India via the multiple threshold NARDL procedure

Environmental Science and Pollution Research - Irrespective of the vast array of empirical evaluations pertaining to the environmental Kuznets curve (EKC) hypothesis, both for India and other...     

Environmental pollution of China to foreign investors: detrimental or beneficial?

Environmental Science and Pollution Research - This study investigates the dynamic linkage among foreign direct investment, energy consumption, and environmental pollution of China spanning from...