Gemstone mining as a development cluster: A study of Brazil’s emerald mines

For many centuries, emeralds have bejeweled the rich and famous all over the world. Emeralds have also made many millionaires overnight, sometimes by chance, as in some of the cases reported in this study. On the other hand, even though emerald mining has brought some economic benefits, many of these have remained at the top of the production chain. In many cases mining activities have caused a number of negative social and environmental impacts locally. Working conditions in small mines are very poor in general: with bad ventilation, high temperatures, long working hours, lack of safety, informal working contracts and no health or life insurance. Environmental impacts can be significant, such as widespread deforestation, erosion of abandoned mines, and soil and water pollution in streams. The economic and social public benefits can be minimal. Even when taxes on gem mining are relatively low, much of the mining local activity is informal and the high value-added formal activities take place outside the mining regions. This study aims to understand the dynamics of emerald mining and its impact on local development using the concept of clusters. The research analyzes three case studies in Brazil: Campos Verdes/Santa Terezinha (Goias state), Nova Era/Itabira (Minas Gerais state) and Carnaiba/Campo Formoso (Bahia state). Emerald mining regions attract many migrants, increasing the demand for public services (infrastructure, health, education, etc.), but local governments are unable to provide for them because the activity produces little tax revenue. In the end, there is a growing mismatch between demand and supply of public services, leading to a series of social and environmental problems. However, working with the concept of cluster can help to shed light on policies to improve the local benefits of gem mining, by organizing the miners and their supporting organizations to allow investments that bring long term benefits locally.     

Unrevealing arsenic and lead toxicity and antioxidant response in spinach: a human health perspective

Environmental Geochemistry and Health - Arsenic (As) and lead (Pb) are highly toxic and carcinogenic metal(loid)s. The present study evaluated the human exposure risk via estimating As and Pb...     

Property rights and grassland degradation: a study of the Xilingol pasture, Inner Mongolia, China

The semi-private property rights arrangement called the Household Production Responsibility System (HPRS) was started in the early 1980s in Xilingol pasture of Inner Mongolia (China), and stimulated the development of stockbreeding. The grassland has been degrading severely with increasing numbers of livestock. Based on a historical review of property rights regimes in Inner Mongolia and empirical surveys in Xilingol pasture during 2001-2003, this paper assesses the implementation of HPRS and its impacts on incomes of households as well as the environmental impact on the grassland. It was found that HPRS does not mitigate the "Tragedy of the Commons", instead it has exacerbated the situation. It was also found that co-management of grassland and livestock among a few households presents a sustainable use of grassland to develop livestock breeding. We conclude with the recommendation that small-scale collective property rights systems should be encouraged in Xilingol pasture of Inner Mongolia.     

Association of textile industry effluent with mutagenicity and its toxic health implications upon acute and sub-chronic exposure

Complex industrial discharges pose certain risks to the ecosystem. This study was aimed at identifying acute and sub-chronic toxicological effects of the textile industry wastewater. The textile wastewater was evaluated for the metals and organic pollutants by atomic absorption spectrophotometer and GC-MS respectively. In vitro genotoxicity and mutagenicity were assessed by Comet assay in peripheral lymphocytes isolated from Ovis aries and Ames test in Salmonella typhimurium strains TA-100 and 102 respectively. Physiological and behavioral changes along with systemic toxicity were determined in Rattus norvegicus albinus following acute and sub-chronic exposure. High amount of heavy metals such as Cr, Pb, Hg, As, and Cd were detected in textile wastewater. Organic pollutants such as 25-deacetoxy cucurbitacin-b, E-14-Hexadecenal, 11-Tricosene, and phthalates were also found. In vitro genotoxicity assessment in lymphocytes showed statistically significant DNA damaging potential of textile wastewater. Textile wastewater also showed significantly higher (p? 0.05) mutagenic potential in Salmonella TA-100 and TA-102 strains than sodium azide and 2-amino anthracycline. Acute exposure of textile wastewater to Rattus norvegicus was associated with several physiological changes and behavioral symptoms. Sub-chronic exposure of textile wastewater in Rattus norvegicus instigated the degeneration and necrosis of epithelial cells in renal tubules, hydropic degeneration and necrosis of hepatocytes, peri-bronchiolar infiltration and emphysema of the alveoli, and the degradation of myocardial cells. This study concludes that the textile wastewater may cause genotoxicity and mutagenicity, result in physiological and behavioral changes upon acute exposure, and inflict various pathological lesions upon sub-chronic exposure.     

Carbon and polymer-based magnetic nanocomposites for oil-spill remediation—a comprehensive review

Environmental Science and Pollution Research - Oil spills are a major contributor to water contamination, which sets off a significant impact on the environment, biodiversity, and economy....     

Nitrogen and plant population change radiation capture and utilization capacity of sunflower in semi-arid environment

The combination of nitrogen and plant population expresses the spatial distribution of crop plants. The spatial distribution influences canopy structure and development, radiation capture, accumulated intercepted radiation (Sa), radiation use efficiency (RUE), and subsequently dry matter production. We hypothesized that the sunflower crop at higher plant populations and nitrogen (N) rates would achieve early canopy cover, capture more radiant energy, utilize radiation energy more efficiently, and ultimately increase economic yield. To investigate the above hypothesis, we examined the influences of leaf area index (LAI) at different plant populations (83,333, 66,666, and 55,555 plants ha^?1) and N rates (90, 120, and 150 kg ha^?1) on radiation interception (Fi), photosynthetically active radiation (PAR) accumulation (Sa), total dry matter (TDM), achene yield (AY), and RUE of sunflower. The experimental work was conducted during 2012 and 2013 on sandy loam soil in Punjab, Pakistan. The sunflower crop captured more than 96% of incident radiant energy (mean of all treatments), 98% with a higher plant population (83,333 plants ha^?1), and 97% with higher N application (150 kg ha^?1) at the fifth harvest (60 days after sowing) during both study years. The plant population of 83,333 plants ha^?1 with 150 kg N ha^?1 ominously promoted crop, RUE, and finally productivity of sunflower (AY and TDM). Sunflower canopy (LAI) showed a very close and strong association with Fi (R ² = 0.99 in both years), PAR (R ² = 0.74 and 0.79 in 2012 and 2013, respectively), TDM (R ² = 0.97 in 2012 and 0.91 in 2013), AY (R ² = 0.95 in both years), RUE for TDM (RUE_TDM) (R ² = 0.63 and 0.71 in 2012 and 2013, respectively), and RUE for AY (RUE_AY) (R ² = 0.88 and 0.87 in 2012 and 2013, respectively). Similarly, AY (R ² = 0.73 in 2012 and 0.79 in 2013) and TDM (R ² = 0.75 in 2012 and 0.84 in 2013) indicated significant dependence on PAR accumulation of sunflower. High temperature during the flowering stage in 2013 shortened the crop maturity duration, which reduced the LAI, leaf area duration (LAD), crop growth rate (CGR), TDM, AY, Fi, Sa, and RUE of sunflower. Our results clearly revealed that RUE was enhanced as plant population and N application rates were increased and biomass assimilation in semi-arid environments varied with radiation capture capacity of sunflower.     

Magnetic nanocomposites for sustainable water purification—a comprehensive review

Numerous contaminants in huge amounts are discharged to the environment from various anthropogenic activities. Waterbodies are one of the major receivers of these contaminants. The contaminated water can pose serious threats to humans and animals, by distrubing the ecosystem. In treating the contaminated water, adsorption processes have attained significant maturity due to lower cost, easy operation and environmental friendliness. The adsorption process uses various adsorbent materials and some of emerging adsorbent materials include carbon- and polymer-based magnetic nanocomposites. These hybrid magnetic nanocomposites have attained extensive applications in water treatment technologies due to their magnetic properties as well as combination of unique characteristics of organic and inorganic elements. Carbon- and polymer-related magnetic nanocomposites are more adapted materials for the removal of various kinds of contaminants from waterbodies. These nanocomposites can be produced via different approaches such as filling, pulse-laser irradiation, ball milling, and electro-spinning. This comprehensive review is compiled by reviewing published work of last the latest recent 3 years. The review article extensively focuses on different approaches for producing various carbon- and polymer-based magnetic nanocomposites, their merits and demerits and applications for sustainable water purification. More specifically, use of carbon- and polymer-based magnetic nanocomposites for removal of heavy metal ions and dyes is discussed in detail, critically analyzed and compared with other technologies. In addition, commercial viability in terms of regeneration of adsorbents is also reviewed. Furthermore, the future challenges and prospects in employing magnetic nanocomposites for contaminant removal from various water sources are presented.

     

Status of Cadmium Concentration in Soil and Vegetable Irrigated with City Effluent

Cadmium is a toxic and carcinogenic element[1].In the1950s and 1960s,cadmium intoxication was considered to bestrictly an occupational disease.It was not until recognition of thecontribution of cadmium exposure to the etiology of Itai-itai dis-ease.It is …     

Spatial modeling of rat bites and prediction of rat infestation in Peshawar valley using binomial kriging with logistic regression

In this study, we propose to develop a geostatistical computational framework to model the distribution of rat bite infestation of epidemic proportion in Peshawar valley, Pakistan. Two species Rattus norvegicus and Rattus rattus are suspected to spread the infestation. The framework combines strengths of maximum entropy algorithm and binomial kriging with logistic regression to spatially model the distribution of infestation and to determine the individual role of environmental predictors in modeling the distribution trends. Our results demonstrate the significance of a number of social and environmental factors in rat infestations such as (I) high human population density; (II) greater dispersal ability of rodents due to the availability of better connectivity routes such as roads, and (III) temperature and precipitation influencing rodent fecundity and life cycle.