Challenges to measuring,monitoring, and addressing the cumulative impacts of artisanal and small-scale gold mining in Ecuador

Portovelo-Zaruma, Ecuador is an artisanal and small-scale gold mining (ASGM) region with approximately 6000 gold miners working with mercury and cyanide. Although artisanal gold mining (AGM) has taken place in Portovelo-Zaruma for centuries, highly mechanized small-scale gold mining (SGM) processing plants capable of increased throughput began being built in the 1990s. While there are benefits associated with ASGM, there are also negative impacts experienced by the miners and the surrounding communities. To take advantage of ASGM as a poverty-alleviating mechanism while reducing unwanted externalities, the cumulative impacts must be understood. Numerous challenges to measuring, monitoring, and addressing ASGM impacts result from the complexity of the impacts themselves, the nature of the gold mining as an informal industry, and the shortfalls in the current regulatory framework. These are discussed in the context of ongoing, unresolved issues including efforts to address trans-boundary water pollution, management of mining waste, and conflicts regarding priorities, ambiguities, and enforcement of existing regulations and policies. Internationally, interventions to address both AGM and SGM impacts have typically focused almost exclusively on technological changes through the elimination of mercury use. Our analysis suggests that to better address ASGM and their cumulative impacts in Ecuador, it will be beneficial to revisit the legal definitions of AGM and SGM. Additionally, promotion of information-based strategies including educational outreach programs and cross-scale and cross-level mitigation methods may also be beneficial. The success of these strategies to reduce ASGM-related cumulative impacts will depend on sufficient funding and the commitment of stakeholders.     

Quantification of Human Adenoviruses in European Recreational Waters

The presence of human adenoviruses (HAdV) in recreational water might cause disease in the population upon exposure. HAdV detected by PCR could also serve as indicators of the virological water quality. In order to assess the applicability of HAdV to the evaluation of the faecal contamination in European bathing waters, a real-time quantitative PCR assay was used for the quantification of HAdV in 132 samples collected from 24 different recreational marine and freshwater sites in nine European countries. Selected samples presenting positive nested PCR results for HAdV were analyzed using quantitative PCR and 80 samples from a total of 132 produced quantitative results with mean values of 3.2 × 10² per 100 ml of water, being human adenovirus 41 the most prevalent serotype between the samples where adenovirus was typified. HAdV were quantified in samples from all 15 surveillance laboratories. Statistical analysis showed no homogeneous linear relation between HAdV and E. coli, intestinal enterococci or somatic coliphages concentrations in the tested samples when considering all the data together. Significant correlations between HAdV and at least one of the other indicators were observed only when data from individual laboratories were considered. The quantification of HAdV may provide complementary information in relation to the use of bacterial standards in the control of water quality in bathing water.     

Plant cell death and cellular alterations induced by ozone: key studies in Mediterranean conditions

An account of histo-cytological and ultrastructural studies on ozone effect on crop and forest species in Italy is given, with emphasis on induced cell death and the underlying mechanisms. Cell death phenomena possibly due to ambient O₃ were recorded in crop and forest species. In contrast, visible O₃ effects on Mediterranean vegetation are often unclear. Microscopy is thus suggested as an effective tool to validate and evaluate O₃ injury to Mediterranean vegetation. A DAB-Evans blue staining was proposed to validate O₃ symptoms at the microscopic level and for a pre-visual diagnosis of O₃ injury. The method has been positively tested in some of the most important crop species, such as wheat, tomato, bean and onion and, with some restriction, in forest species, and it also allows one to gain some very useful insights into the mechanisms at the base of O₃ sensitivity or tolerance.     

Environmental and lifestyle factors affect benzene uptake biomonitoring of residents near a petrochemical plant

Background

We monitored urinary benzene excretion to examine factors affecting benzene uptake in a sample of the general population living near a petrochemical plant.

Methods

Our study population included 143 subjects: 33 petrochemical plant workers (W) with low level occupational benzene exposure; 30 residents in a small town 2 km from the plant (2kmR); 26 residents in a second small town located 2 to 4 km from the plant (4kmR); and 54 urban residents 25 km from the plant (25kmR). Exposure to benzene was evaluated by personal air sampling during one work-shift for the W group, and from 8.00 to 20:00 for general population subgroups, and by urinary benzene (BEN-U).

Results

Median airborne benzene exposure was 25, 9, 7 and 6 μg/m³ benzene among the W, 2kmR, 4kmR, and 25kmR subgroups, respectively; the highest level was found among the workers, while there was no significant difference among the other groups. Median BEN-U was 2 to 14-fold higher in smokers compared to non-smokers; among non-smokers BEN-U was the highest in W (median 236 ng/L), and lower in the 2kmR (48 ng/L) and 4kmR (63 ng/L) subgroups than in the 25kmR (120 ng/L) subgroup. A multiple linear regression analysis, explaining up to 73% of BEN-U variability, confirmed that active smoking and airborne benzene most strongly affected BEN-U. Among the non-smoking, non-occupationally exposed study subjects, a positive association was found between BEN-U and the distance of residence from the plant. This association was explained by increased exposure to urban traffic emissions in the study group residing at a greater distance from the plant. Environmental tobacco smoke had a marginally positive role.

Conclusion

Among factors affecting benzene uptake in non-occupationally exposed individuals, urban residence contributes to benzene exposure more than residing in close proximity to a petrochemical plant.     

Socioeconomic consequences of mercury use and pollution

In the past, human activities often resulted in mercury releases to the biosphere with little consideration of undesirable consequences for the health of humans and wildlife. This paper outlines the pathways through which humans and wildlife are exposed to mercury. Fish consumption is the major route of exposure to methylmercury. Humans can also receive toxic doses of mercury through inhalation of elevated concentrations of gaseous elemental mercury. We propose that any effective strategy for reducing mercury exposures requires an examination of the complete life cycle of mercury. This paper examines the life cycle of mercury from a global perspective and then identifies several approaches to measuring the benefits of reducing mercury exposure, policy options for reducing Hg emissions, possible exposure reduction mechanisms, and issues associated with mercury risk assessment and communication for different populations.     

Biosemiotics: a new understanding of life

Biosemiotics is the idea that life is based on semiosis, i.e., on signs and codes. This idea has been strongly suggested by the discovery of the genetic code, but so far it has made little impact in the scientific world and is largely regarded as a philosophy rather than a science. The main reason for this is that modern biology assumes that signs and meanings do not exist at the molecular level, and that the genetic code was not followed by any other organic code for almost four billion years, which implies that it was an utterly isolated exception in the history of life. These ideas have effectively ruled out the existence of semiosis in the organic world, and yet there are experimental facts against all of them. If we look at the evidence of life without the preconditions of the present paradigm, we discover that semiosis is there, in every single cell, and that it has been there since the very beginning. This is what biosemiotics is really about. It is not a philosophy. It is a new scientific paradigm that is rigorously based on experimental facts. Biosemiotics claims that the genetic code (1) is a real code and (2) has been the first of a long series of organic codes that have shaped the history of life on our planet. The reality of the genetic code and the existence of other organic codes imply that life is based on two fundamental processes--copying and coding--and this in turn implies that evolution took place by two distinct mechanisms, i.e., by natural selection (based on copying) and by natural conventions (based on coding). It also implies that the copying of genes works on individual molecules, whereas the coding of proteins operates on collections of molecules, which means that different mechanisms of evolution exist at different levels of organization. This review intends to underline the scientific nature of biosemiotics, and to this purpose, it aims to prove (1) that the cell is a real semiotic system, (2) that the genetic code is a real code, (3) that evolution took place by natural selection and by natural conventions, and (4) that it was natural conventions, i.e., organic codes, that gave origin to the great novelties of macroevolution. Biological semiosis, in other words, is a scientific reality because the codes of life are experimental realities. The time has come, therefore, to acknowledge this fact of life, even if that means abandoning the present theoretical framework in favor of a more general one where biology and semiotics finally come together and become biosemiotics.     

Reducing mine water network energy requirements

Increasing energy efficiency and reducing water consumption are two of the key requirements in moving toward a more sustainable mining industry. This paper demonstrates a method of determining the lowest energy option for a mine/mill water system network. The method uses a linear programming algorithm to compare different possible combinations of supplying water to mine and mill consumers. First, a site water balance is determined and then every major water consumer and source is specified. Water sources may require pumping, cooling and/or treatment before the water meets the specifications of the water consumer. The amount of energy required for each water source to supply each consumer is calculated and then the model is solved to minimize power consumption. An example is used to illustrate the method.     

Effects of floaters on the free surface profiles of river flows

Environmental Fluid Mechanics - The presence of floaters should be taken into account when dealing with hydraulic analyses, e.g. when boats are moored along the river banks or large wood is...     

A simplified matrix of environmental impacts to support an intervention program in a small-scale mining site

This paper describes a tool developed to evaluate environmental risks at a Brazilian artisanal small-scale gold mining site. The tool consists of a matrix used to determine the relevance of such risks through the classification of mining activities according to the likelihood that they may cause environmental impacts. The language and method are very simple, and thus appropriate for local stakeholders. It ensures their participation when developing a plan of action for intervention and training. When applied to a pilot site in the Brazilian Amazon, the matrix revealed the variables that pose higher environmental risks. These activities were subsequently addressed in a training program to promote better practices. As a result, the mining activities were improved by 28.8% when comparing compliance to environmental requisites before and after the training program. Specifically, the training program resulted in improved gold recovery, and reduced environmental and health impacts.     

International guidelines on mercury management in small-scale gold mining

This article reports on a stakeholder engagement process to develop the International Guidelines on Mercury Management in Small-Scale Gold Mining. Commissioned by the United Nations Global Mercury Project, the purpose of the guidelines is to assist policymakers, practitioners, researchers, miners and the public in developing strategies for reducing mercury use, eliminating major pollution point sources and reducing risks. The guidelines are proposed with the view of supporting miners and their communities by promoting safer, more efficient practices that improve environmental and human health. The paper discusses challenges in addressing mercury issues and technical measures in the guidelines. The paper also highlights the need for interactive engagement in communities to discuss and adapt the guidelines as appropriate, in order to create technology transfer strategies, regulatory measures and strategic priorities that are suitable to the local context.