Influence of small-scale gold mining on French Guiana streams: Are diatom assemblages valid disturbance sensors?

The ongoing gold-rush in French Guiana could cause severe disturbance to ecosystems. Although illegal, small gold mining sites are rapidly expanding. Few studies have attempted to measure the consequences of the increased gold mining on the biota of small forest streams, and to date no study has dealt with primary producers. Here we measured the response of diatom assemblages to gold mining in ten sites differently affected by the mining activity (i.e., reference, formerly gold-mined and currently exploited). Our results showed that both taxonomic and functional structure of the diatom assemblages were influenced by the intensity of gold mining activity. A significant relationship between soil erosion and diatom motility ability has been demonstrated. These findings show that diatom assemblages are sensitive to gold mining disturbance and suggest that diatom communities may be used as sensors of the environmental stress caused by small-scale gold mining activities.     

Risks and costs to human health of sulfide-ore mining near the Boundary Waters Canoe Area Wilderness

Abstract

Sulfide-ore copper nickel (SOCN) mining is being considered in water-rich Minnesota. Given pollution resulting from SOCN mining elsewhere, careful scrutiny is necessary examining the risks associated. Health considerations of mining within the Rainy River Watershed, the geographic region at the headwaters of the Boundary Waters Canoe Area Wilderness (BWCAW), Ontario’s Quetico Park (Quetico), and Voyageurs National Park (VNP) are examined. This discussion considers toxins released from SOCN mining, examines data regarding degradation of water quality and deleterious environmental impact from SOCN mining elsewhere, considers the most vulnerable populations, and recognizes the broader effects to public health as well as benefits of existing wilderness. Recent federal decisions to reinstate mineral leases and abort the environmental assessment process have placed this unique and irreplaceable region of our country at substantial risk. The overall health and wellness of this region will very likely be negatively affected by SOCN mining, and economic costs will predictably outweigh benefits. In addition, negative impacts on water, fish and wild rice will likely degrade nutritional and tribal resources resulting in violation of usufructuary rights of tribal communities.     

Assessment of Carcinogenic Risk and Non-Carcinogenic Health Hazard from Exposure to Toxicants in Water from the Southwestern Coastal River System in Ghana

This study evaluated cancer risk and non-cancer human health hazard from exposure to the toxicants such as As, Cu, Pb, Zn, Mn, and CN in water from a southwestern river system in Ghana that drains through gold mining areas, using 108 water samples collected with random sampling techniques and analyzed in accordance with standard methods of chemical analysis outlined by the U.S. Environmental Protection Agency (USEPA). The concentrations of Cu and Zn were within World Health Organization and USEPA guideline values; Mn, free cyanide, As, and Pb values in most cases either exceeded USEPA and WHO values or both. The concentrations of the toxicants were used as input parameters in the cancer and non-cancer study that was conducted in line with USEPA risk assessment guidelines. The results of As cancer health risk revealed higher risk cases in two locations (Potroase and Dominase); non-cancer health risk for As was higher in 10 of the 14 locations, with other metals being of health concern at few locations in the study area. In conclusion, the findings of this study hold several policy implications as residents of mining communities still depend on these water bodies as their source of drinking water.     

Heavy Metals in Sediments of the Gold Mining Impacted Pra River Basin,Ghana, West Africa

Total concentrations of Hg, Al, Fe, As, Pb, Cu, Cr, Ni, Mn, Co, V, and Zn were determined in surface sediments collected from 21 locations within the gold mining impacted Pra River basin in southwestern Ghana. Samples were collected during both the rainy and dry seasons. We hypothesized that in the rural southwestern portion of Ghana, the lack of industrial activities makes artisanal gold mining (AGM) by Hg amalgamation the main source of water resource contamination with heavy metals. Therefore, metals showing concentration trends similar to that of Hg in the studied system are likely impacted by AGM. We found that total-Hg (THg) concentrations in riverine sediments are rather low as compared to other aquatic systems that are impacted by similar mining activities. Measured THg concentrations ranged from 0.018 to 2.917 mg/kg in samples collected in the rainy season and from about 0.01 to 0.043 mg/kg in those collected during the dry season. However, the determination of the enrichment factor (EF) calculated using shale data as reference background values showed signs of severe contamination in most of the sampled sites. In the dry season, THg concentrations correlated positively and significantly to the concentrations of As (r = 0.864, p < 0.01), Cu (r = 0.691, p < 0.05), and Ni (r = 0.579, p < 0.05). Based on our previously stated hypothesis, this could then be an indication of the impact of AGM on ambient levels of these 3 elements. However, the determined concentrations of Cu, and Ni co-varied significantly with Al, suggesting that natural sources do account for the observed levels. Accordingly, both AGM and metal inputs from weathered natural deposits are likely co-responsible for the observed levels of Cu and Ni. In contrast, the lack of correlation between As and Al tends to suggest an impact of AGM on As levels. Overall, our data suggest that besides Hg and to some extent As, the impact of AGM on ambient levels of investigated metals in the gold mining impacted Pra River remains negligible. Finally, the increase in metal concentrations from the dry to the rainy season underlines the impact of changes in hydrologic conditions on levels and fate of metals in this tropical aquatic system.     

Population monitoring: experience with residents exposed to uranium mining/milling waste

More emphasis should be placed upon using biomarkers to address potential health risk among populations exposed to high concentrations of environmental toxicants. Among these studies, those which integrate exposure measurements with analyses of validated biomarkers may provide more reliable information for risk assessment and disease prevention. We have used a multidisciplinary approach to elucidate potential health hazards in a population living around uranium mining/milling facilities. The study included 24 target and 24 control residents who were matched for age and gender and selected based on time of residence in the study areas and proximity to mining/milling sites. Environmental samples were analyzed for uranium-238 concentrations and lead isotope ratios using inductively coupled plasma-mass spectrometry (ICP-MS) procedures, and blood samples were collected for cytogenetic analysis. We found that the concentrations in soil samples were significantly higher than those in the control areas. In addition, the concentrations in the surface soil were significantly higher than in the subsurface soil (p<0.05) from target areas indicating environmental contamination by the mining/milling activities. Lead isotope data from soil samples taken near a railroad transfer location was significantly different from those of other sites, indicating contamination by non-native ore transported from sources outside of the region to local milling facilities for processing. Therefore, local residents have been exposed to low levels of radioactive contamination from the mining/milling activities on a daily basis for many years. From our cytogenetic analysis, the target population had more chromosome aberrations than the controls, although the differences were not significant (p<0.05). However, using our challenge assay, cells from the target population had a significantly abnormal DNA repair response, compared to cells from the same control population. In conclusion, the observed environmental contamination by uranium is consistent with the observed genotoxic effects in the target residents. Therefore, the residents have increased health risk and some of the health problems will most likely be related to exposure to the radioactive contaminants. Since the chromosome aberration frequency revealed increased, but not significant differences between the exposed and the control populations, we conclude that the health risk among the exposed residents is similar to those among nuclear workers.     

Gender-Differentiated Impacts of the Belo Monte Hydroelectric Dam on Downstream Fishers in the Brazilian Amazon

The Belo Monte Hydroelectric dam on the Xingu River in the Brazilian Amazon will be the third largest dam in the world in power generating capacity (11 GW). Its construction has brought negative socioeconomic and environmental impacts for local fishers that far outweigh the benefits. We used a qualitative case study approach to explore perceptions among fishers in a community downstream from the dam of the impact of Belo Monte on their livelihoods and their fisheries. We found that fishers, who, although they were not displaced were neither consulted nor compensated, have been severely impacted by the dam, and that fishermen and fisherwomen are differentially affected. More attention needs to be given to downstream communities and the impacts they experience.     

Environmental impacts of gold mining in Essakane site of Burkina Faso

In this study, environmental impacts on air, water, and soil pollution caused by the exploit of Essakane gold mine, which is located in North Eastern part of Burkina Faso were investigated. Analyses on drinking water were made in the laboratory to determine the concentration of essential chemicals used in gold mining. Dust fallouts have been measured to assess the level of air pollution. The results showed that exploiting of gold mine directly or indirectly contributes to air pollution in Essakane district. The use of chemicals such as cyanide (industrial gold mining) and mercury (artisanal gold mining) to obtain the gold from the ore constitutes a potential risk for the ecosystem, the local population's health, and livestock production. The results also showed that there is a significant degradation of natural landscape and topography of the soil by open-pits mining (industrial mine) and holes dug by artisanal miners.     

Acceptability of Rapid Diagnostic Test-Based Management of Malaria among Caregivers of Under-Five Children in Rural Ghana

Introduction

WHO now recommends test-based management of malaria (TBMM) across all age-groups. This implies artemisinin-based combination treatment (ACT) should be restricted to rapid diagnostic test (RDT)-positive cases. This is a departure from what caregivers in rural communities have been used to for many years.

Methods

We conducted a survey among caregivers living close to 32 health centres in six districts in rural Ghana and used logistic regression to explore factors likely to influence caregiver acceptability of RDT based case management and concern about the denial of ACT on account of negative RDT results. Focus group discussions were conducted to explain the quantitative findings and to elicit further factors.

Results

A total of 3047 caregivers were interviewed. Nearly all (98%) reported a preference for TBMM over presumptive treatment. Caregivers who preferred TBMM were less likely to be concerned about the denial of ACT to their test-negative children (O.R. 0.57, 95%C.I. 0.33–0.98). Compared with caregivers who had never secured national health insurance cover, caregivers who had valid (adjusted O.R. 1.30, 95% CI 1.07–1.61) or expired (adjusted O.R. 1.38, 95% CI 1.12–1.73) insurance cover were more likely to be concerned about the denial of ACT to their RDT-negative children. Major factors that promote TBMM acceptability include the perception that a blood test at health centre level represents improvement in the quality of care, leads to improvement in treatment outcomes, and offers opportunity for better communication between health workers and caregivers. Acceptability is also enhanced by engaging caregivers in the procedures of the test. Apprehensions about negative health worker attitude could however undermine acceptance.

Conclusion

Test (RDT)-based management of malaria in under-five children is likely to be acceptable to caregivers in rural Ghana. The quality of caregiver-health worker interaction needs to be improved if acceptability is to be sustained.     

Gold mining in the Peruvian Amazon: global prices, deforestation, and mercury imports

Many factors such as poverty, ineffective institutions and environmental regulations may prevent developing countries from managing how natural resources are extracted to meet a strong market demand. Extraction for some resources has reached such proportions that evidence is measurable from space. We present recent evidence of the global demand for a single commodity and the ecosystem destruction resulting from commodity extraction, recorded by satellites for one of the most biodiverse areas of the world. We find that since 2003, recent mining deforestation in Madre de Dios, Peru is increasing nonlinearly alongside a constant annual rate of increase in international gold price (∼18%/yr). We detect that the new pattern of mining deforestation (1915 ha/year, 2006–2009) is outpacing that of nearby settlement deforestation. We show that gold price is linked with exponential increases in Peruvian national mercury imports over time (R² = 0.93, p = 0.04, 2003–2009). Given the past rates of increase we predict that mercury imports may more than double for 2011 (∼500 t/year). Virtually all of Peru''s mercury imports are used in artisanal gold mining. Much of the mining increase is unregulated/artisanal in nature, lacking environmental impact analysis or miner education. As a result, large quantities of mercury are being released into the atmosphere, sediments and waterways. Other developing countries endowed with gold deposits are likely experiencing similar environmental destruction in response to recent record high gold prices. The increasing availability of satellite imagery ought to evoke further studies linking economic variables with land use and cover changes on the ground.     

汞矿山环境汞污染研究进展

汞矿山开采对周边环境的汞污染一直受到关注,尽管全球多数汞矿山已经相继停产、闭坑,但这些废弃的汞矿山仍然通过采矿所遗留的尾矿等固体废弃物、坑道废水和污染的土壤等对当地的环境和居民健康产生着持续的影响和危害.本文总结了环境样品中各形态汞的分析方法,评述了全球范围内汞矿的分布以及汞矿山开采和冶炼过程所造成的环境影响,提出了对于污染治理和风险评价的展望.     

Ecosystem Approach to Community Health Planning in Ghana

An ecosystem approach to community health seeks to investigate human health concerns from an ecological perspective. The goal is to improve the health of community members by instituting sustainable ecosystem management strategies that will preserve the health of both the ecosystem and its inhabitants. This article reports on a study in a rural community in Ghana that employed an ecosystem approach to community health planning. Adopting a participatory action research approach, a research team comprised of representatives from various local government departments collaborated with local residents to identify major community health problems, their underlying causes, and possible intervention strategies. The findings illustrate the usefulness of the ecosystem approach to mobilizing community-based interventions to addressing environmental determinants of human health.     

Image analysis of aerial photography to quantify changes in channel morphology and instream habitat following placer mining in interior Alaska

1. ‘Placer’ mining for alluvial deposits of gold in a number of stream systems in interior Alaska represents a major disturbance to the stream bed and affects habitat for biotic communities. 2. The potential of analysing aerial photographs to map changes in channel habitat and morphology within gravel-bed rivers is outlined with reference to the impact and recovery of Faith Creek, a second-order stream with a history of placer mining. 3. A strong correlation between the reflectance of the channel bed and water depth is necessary to use the technique succesfully, together with a knowledge of the effects of ‘broken’water on the spectral characteristics of rivers. 4. Image analysis demonstrated that a wide range of water depths and instream mesoscale habitats existed prior to mining. During mining, the stream was confined to a channellized reach with negligible deep water or habitat diversity. 5. Since mining ceased the stream has abandoned its channellized course and formed a new channel with few deep pools. It is suggested that geomorphological recovery and associated habitat recovery takes a number of large flood events and is likely to require more than 10 years.     

Can we make participatory NTFP monitoring work? Lessons learnt from the development of a multi-stakeholder system in Northern Laos

Monitoring natural resources is essential for their successful and sustainable management. Community participation should enable local people to take ownership of the monitoring and ensure that it is cost-effective. But even then, success is often elusive. We developed a participatory Non Timber Forest Product (NTFP) monitoring system in 6 upland villages of Luang Prabang Province, Lao PDR, using focus group discussions, interviews, village meetings and direct observations. We used simple approaches to select resources, discuss issues, and develop a cost-effective NTFP monitoring system. Communities usually relied on shifting cultivation, fishing and collection of NTFPs. Gold mining activities affected livelihoods in three villages, which had better access to markets. Participatory monitoring looks less successful when external economic pressures or a major environmental threat disturbs local livelihoods. In the case of gold mining, we observed the prioritization of villagers’ activities towards this sudden new economic opportunity. In contrast, communities not impacted by mining participated more actively in data collection. They understood how the data could be used to influence the local government, to achieve more beneficial land management for all stakeholders concerned. We believe that participatory NTFP monitoring can work and is an important tool for decision-making and economic empowerment for local communities. We identified the conditions under which participatory NTFP monitoring could work: reaching a shared understanding of what needs to be monitored and how; testing and refining a simple monitoring system; and integrating local government concerns with those of other stakeholders.     

The trans-national gold curse of Papua New Guinea

This paper reviews gold and copper mining in Papua New Guinea (PNG) along the “triad stakeholder model” (Ballard and Banks 2003) proposing a triad relationship between (1) trans-national mining corporations, (2) the nation-state of Papua New Guinea, and (3) indigenous local communities, their socio-ecological environment and claims. Gold mining could be a huge asset, but turns out to be a curse to the independent part of the world’s second largest island known as “a mountain of gold in a sea of oil.” Our paper is based on research that began during our year-long residency at the country’s only Technical University in Lae. We are discussing several issues related to the nation’s gold resources and their exploitation: varied mining technologies and locations, the environmental impact, economics, human cost and gender issues, indigenous culture versus international corporate culture, state interferences, and urban development. One example is the industrial port city of Lae, founded during the gold rush of the 1920s that inaugurated rapid urban development. Once gloriously known as the “Pearl of the Pacific,” the town experienced administrative expansion and suffered from the subsequent exhaustion of nearby gold mines entailing a reverse development.     

Factors affecting the choice of cooking fuel, cooking place and respiratory health in the Accra metropolitan area, Ghana

Indoor air pollution resulting from the combustion of solid fuels has been identified as a major health threat in the developing world. This study examines how the choice of cooking fuel, place of cooking and behavioural risk factors affect respiratory health infections in Accra, Ghana. About 65.3% of respondents use charcoal and 4.2% use unprocessed wood. A total of 241 (25.4%) respondents who cook had had respiratory health symptoms in the two weeks preceding the study. Household socioeconomic status and educational attainment of respondents were found to have a significant impact on respiratory health through their particular influence on the choice of cooking fuel. Households that use wood and charcoal have a high incidence of respiratory health symptoms. The poor are more affected by respiratory health problems due to their heavy dependence on solid fuels as compared with their wealthy counterparts. Households that cook in multiple purpose rooms are more affected by respiratory health problems than those that cook outdoors. There is a positive correlation between the presence of children in the kitchen during cooking and the incidence of respiratory health symptoms among children (r=0.31, p<0.0001). Poverty and lack of education and awareness are the major factors affecting the choice of cooking fuel, place of cooking and respiratory health in Accra.     

Poor maternal environment enhances offspring disease resistance in an invertebrate

Natural populations vary tremendously in their susceptibility to infectious disease agents. The factors (environmental or genetic) that underlie this variation determine the impact of disease on host population dynamics and evolution, and affect our capacity to contain disease outbreaks and to enhance resistance in agricultural animals and disease vectors. Here, we show that changes in the environmental conditions under which female Daphnia magna are kept can more than halve the susceptibility of their offspring to bacterial infection. Counter-intuitively, and unlike the effects typically observed in vertebrates for transfer of immunity, mothers producing offspring under poor conditions produced more resistant offspring than did mothers producing offspring in favourable conditions. This effect occurred when mothers who were well provisioned during their own development then found themselves reproducing in poor conditions. These effects likely reflect adaptive optimal resource allocation where better quality offspring are produced in poor environments to enhance survival. Maternal exposure to parasites also reduced offspring susceptibility, depending on host genotype and offspring food levels. These maternal responses to environmental conditions mean that studies focused on a single generation, and those in which environmental variation is experimentally minimized, may fail to describe the crucial parameters that influence the spread of disease. The large maternal effects we report here will, if they are widespread in nature, affect disease dynamics, the level of genetic polymorphism in populations, and likely weaken the evolutionary response to parasite-mediated selection.     

安太堡矿区人工植被在恢复过程中的生态关系

采用TWINSPAN、DCA和DCCA,从植物种、植物群落与环境因子关系方面对平朔安太堡矿区的人工植被在恢复过程中的生态关系进行了研究.结果表明,将63个样方划分为12个群落类型,反映了植物群落与环境梯度之间的关系,并列举了各群落的特征.DCA排序图明显反映出排序轴的生态意义,随着复垦时间的增加,土壤含水量也不断升高.DCCA排序进一步表明了土壤有机质含量是所有因子中对植物群落发展起决定性作用的主要环境因素.     

Climate change is not just global warming: Multidimensional impacts on animal gut microbiota

Climate change has rapidly altered many ecosystems, with detrimental effects for biodiversity across the globe. In recent years, it has become increasingly apparent that the microorganisms that live in and on animals can substantially affect host health and physiology, and the structure and function of these microbial communities can be highly sensitive to environmental variables. To date, most studies have focused on the effects of increasing mean temperature on gut microbiota, yet other aspects of climate are also shifting, including temperature variation, seasonal dynamics, precipitation and the frequency of severe weather events. This array of environmental pressures might interact in complex and non-intuitive ways to impact gut microbiota and consequently alter animal fitness. Therefore, understanding the impacts of climate change on animals requires a consideration of multiple types of environmental stressors and their interactive effects on gut microbiota. Here, we present an overview of some of the major findings in research on climatic effects on microbial communities in the animal gut. Although ample evidence has now accumulated that shifts in mean temperature can have important effects on gut microbiota and their hosts, much less work has been conducted on the effects of other climatic variables and their interactions. We provide recommendations for additional research needed to mechanistically link climate change with shifts in animal gut microbiota and host fitness.     

Sustainability in metal mining: from exploration, over processing to mine waste management

Metal mining or more general mineral mining, is the base industry of the economic wealth and development of numerous countries. However, mining has a negative reputation due to the complex problems of environmental contamination like SO₂ and CO₂ emissions and acid mine drainage (AMD) formation, which endangers vital limited resources, like air, water, and soils. This view paper highlights the environmental problems of todays metal mining operations and explores possibilities of future more sustainable mining operations with focus on enhanced and optimized metal recovery systems in combination with a minimization of the environmental impact. These changes depend on a change in mentality and in the mining operation process, which can nowadays yet be observed in some modern mining operations. The goal for the future will be to implement these changes as standard for all future mining operations.