Download or read book Global and Regional Mercury Cycles Sources Fluxes and Mass Balances written by W. Baeyens and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: Essential themes in the biochemical cycling of mercury are the relative importance of anthropogenic versus natural sources, transformation and migration processes at the local, regional and global scale, global emission inventories of different mercury sources (both point and diffuse) of both natural and anthropogenic origin. In this regard, Siberia, with its vast territory and variety of natural zones, is of special interest in the global mercury cycle and in terms of the influence of geographical zones on source and sink terms in regional budgets. Siberia contains large areas of mercuriferous belts; natural deposits that emit mercury into the atmosphere and water. Siberian gold has been mined with the use of mercury since the early 1800s. But there, too, huge forest zones and vast areas of tundra and wetland (bogs) can act as efficient sinks for atmospheric mercury. Audience: Environmental scientists, legislators, politicians and the interested citizen wishing to gain a clear picture of the biogeochemical cycling of mercury.
Download or read book Biogeochemical Cycle of Mercury in Reservoir Systems in Wujiang River Basin Southwest China written by Xinbin Feng and published by Springer. This book was released on 2017-11-09 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an intensive study on the biogeochemical cycle of mercury in a river-reservoir system in Wujiang River Basin, the upper branch of the Yangtze River. Six reservoirs located in the mainstream of the Wujiang River and their corresponding inflow/outflow rivers were selected for inclusion in this study, which was conducted by researchers from the Institute of Geochemistry, Chinese Academy of Sciences. The concentration and distribution of Hg in reservoirs (the water column, sediment, sediment pore water), inflow/outflow rivers of reservoirs, and wet deposition in Wujiang River Basin were systematically investigated, and measurements were taken of the water/air exchange flux of gaseous elemental mercury (GEM). On the basis of the data gathered, a detailed mass balance of total mercury (THg) and methylmercury (MeHg) in the six reservoirs was developed. In addition, the book identifies the primary factors controlling Hg methylation in the river-reservoir system in Wujiang River Basin. The accumulation and bio-magnification of Hg species within food chains in reservoirs and human health risk of MeHg exposure through fish consumption are also included in this book.
Download or read book Mercury in the Biogeochemical Cycle written by Marc Lucotte and published by . This book was released on 1999-05-04 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury in the Biogeochemical Cycle written by Marc Marcotte and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nowadays, major environmental issues are the object of large public debates de spite the fact that scientific knowledge is often insufficient to draw unequivocal conclusions. Such is the case in the ongoing debate regarding the specific contri butions of anthropogenic greenhouse gas emissions and of natural climate changes to global warming. At least 10 to 20 years of additional observations will be re quired, before we will be able to conclude, with certainty, on this subject. In the mean time, and as directed by their immediate interests, people will continue to promote contradictory opinions. The media are, in part, responsible for perpetuat ing such debates in that they convey indiscriminately the opinion of highly credi ble scientists as that of dogmatic researchers, the latter, unfortunately too often expressing working hypotheses as established facts. Naturally, in a similarly mis informed manner, pressure groups tend to support the researcher whose opinions most closely represent either their particular ideological battles or their economic interests and, hence, in their own way, add further to the confusion and obscurity of the debate. Only a few years ago, mercury (Hg)contamination in hydroelectric reservoirs was the object of such media and social biases. At the time, analytical data used to support the discourse were themselves uncertain and numerous hypotheses, often times fanciful, were proposed and hastily "delivered" to the public.
Download or read book Environmental Chemistry and Toxicology of Mercury written by Guangliang Liu and published by John Wiley & Sons. This book was released on 2011-11-07 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the fundamentals, recent developments, and future research needs for critical mercury transformation and transport processes, as well as the experimental methods that have been employed in recent studies. The coverage discusses the environmental behavior and toxicological effects of mercury on organisms, including humans, and provides case studies at the end of each chapter. Bringing together information normally spread across several books, this text is unique in covering the entire mercury cycle and providing a baseline for what is known and what uncertainties remain in respect to mercury cycling.
Download or read book Mercury in the Environment written by Michael S. Bank and published by Univ of California Press. This book was released on 2012-05-31 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury pollution and contamination are widespread, well documented, and continue to pose a public health concern in both developed and developing countries. In response to a growing need for understanding the cycling of this ubiquitous pollutant, the science of mercury has grown rapidly to include the fields of biogeochemistry, economics, sociology, public health, decision sciences, physics, global change, and mathematics. Only recently have scientists begun to establish a holistic approach to studying mercury pollution that integrates chemistry, biology, and human health sciences. Mercury in the Environment follows the process of mercury cycling through the atmosphere, through terrestrial and aquatic food webs, and through human populations to develop a comprehensive perspective on this important environmental problem. This timely reference also provides recommendations on mercury remediation, risk communication, education, and monitoring.
Download or read book Global Biogeochemical Cycling of Mercury written by Noelle Eckley Selin and published by . This book was released on 2009 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury pollution poses global human health and environmental risks. Although mercury is naturally present in the environment, human activities, such as coal burning, have increased the amount of mercury cycling among the land, atmosphere, and ocean by a factor of three to five. Emitted to the atmosphere in its elemental form, mercury travels worldwide before oxidizing to a form that deposits to ecosystems. In aquatic systems, mercury can convert into methylmercury, a potent neurotoxin. People and wildlife are exposed to methylmercury as it bioaccumulates up the food chain. Mercury continues to circulate in the atmosphere, oceans, and terrestrial system for centuries to millennia before it returns to deep-ocean sediments. Areas of uncertainty in the global biogeochemical cycle of mercury include oxidation processes in the atmosphere, land-atmosphere and ocean-atmosphere cycling, and methylation processes in the ocean. National and international policies have addressed direct mercury emissions, but further efforts to reduce risks face numerous political and technical challenges.
Download or read book Global Biogeochemical Cycling of Mercury written by Noelle E. Selin and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury pollution poses global human health and environmental risks. Although mercury is naturally present in the environment, human activities, such as coal burning, have increased the amount of mercury cycling among the land, atmosphere, and ocean by a factor of three to five. Emitted to the atmosphere in its elemental form, mercury travels worldwide before oxidizing to a form that deposits to ecosystems. In aquatic systems, mercury can convert into methylmercury, a potent neurotoxin. People and wildlife are exposed to methylmercury as it bioaccumulates up the food chain. Mercury continues to circulate in the atmosphere, oceans, and terrestrial system for centuries to millennia before it returns to deep-ocean sediments. Areas of uncertainty in the global biogeochemical cycle of mercury include oxidation processes in the atmosphere, land-atmosphere and ocean-atmosphere cycling, and methylation processes in the ocean. National and international policies have addressed direct mercury emissions, but further efforts to reduce risks face numerous political and technical challenges.
Download or read book Mercury Cycling in a Wetland dominated Ecosystem written by Nelson J. O'Driscoll and published by Society of Environmental Toxicology & Chemistry. This book was released on 2005 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global biogeochemical cycles written by Butcher and published by Academic Press. This book was released on 1992-08-12 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global biogeochemical cycles
Download or read book Impacts of Selenium on the Biogeochemical Cycles of Mercury in Terrestrial Ecosystems in Mercury Mining Areas written by Hua Zhang and published by Springer Science & Business. This book was released on 2014-04-17 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: From a new perspective, namely focusing on the interaction of selenium and mercury, this thesis provides new insights into traditional research on biogeochemical cycles of mercury in soil-plant interaction and associated human exposure and risks. The subject of this thesis is both valuable and timely, providing essential information not only on selenium-mercury interaction in the soil-plant system but also on how to assess the combined benefits and risk of co-exposure to mercury and selenium. This work also sheds light on future aspects regarding prevention, remediation and risk management for environmental mercury contamination. Presenting high-quality papers published in leading international SCI journals such as Environmental Health Perspectives and Environmental Science & Technology and having been recognized with the Special Award of Presidential Scholarship Award and Excellent Doctoral Dissertations Prize of the Chinese Academy of Sciences (CAS), this thesis offers a valuable resource for scientific communities, policy-makers and non-experts who are interested in this field. Dr. Hua Zhang works at the Norwegian Institute for Water Research (NIVA), Oslo, Norway.
Download or read book Biogeochemical Cycling of Mercury in the Atmosphere ocean land System written by Yanxu Zhang and published by . This book was released on 2013 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury (Hg) is a ubiquitous trace metal in the environment originating from both natural and anthropogenic sources. It is a pollutant of concern because of the adverse human health effects caused by the consumption of fish and seafood containing methylmercury, which is a neurotoxin. Through development of two transport and chemistry models in the atmosphere and ocean, this dissertation investigates the regional Hg atmospheric transport and wet deposition over North America, and the global ocean Hg cycle as well its perturbation by anthropogenic Hg emissions. Chapter 2 develops a new nested-grid Hg simulation over North America with a 1/2° latitude by 2/3° longitude horizontal resolution employing the GEOS-Chem global chemical transport model. The nested model shows generally improved skill at capturing the high spatial and temporal variability of a variety of observations including wet deposition fluxes, surface concentrations and aircraft measurements of atmospheric Hg. We find that a hypothesized sub-grid rapid in-plume reduction of reactive to elemental Hg improves the model-observation comparison. The nested model suggests that North American anthropogenic emissions account for 10-22% of Hg wet deposition flux over the U.S., depending on whether the in-plume reduction process is included or not. Chapter 3 examines the trends in Hg precipitation concentrations at 47 Mercury Deposition Network (MDN) sites over the United States during 2004 - 2010. We run the model with constant anthropogenic emissions and subtract the model results from the observations in order to remove the influence of meteorological fluctuations. We find significant decreasing trends in the Northeast U.S. ( -4.3±2.2% yr[negative]1) and in the Midwest ( -2.5±1.6% yr[negative]1), but weaker trends over the Southeast ( -0.63±2.5% yr[negative]1) and West (+0.33±7.7% yr[negative]1). Sensitivity simulation with the nested-grid Hg simulation shows that the combination of domestic emission reductions and decreasing background concentrations explains the observed trends over Northeast and Midwest, with domestic emission reductions accounting for 51-33% of the decreasing trends. Chapter 4 implements Hg biogeochemistry in a global 3D offline ocean tracer model, OFFTRAC, and investigate the natural Hg cycle, prior to any anthropogenic input. This model simulates the transformations among different Hg species, and links them to carbon dynamics in the ocean. In the deep ocean, a region which is not expected to be significantly influenced by anthropogenic emissions, the modeled total Hg concentrations (Hg[superscript T], 1.1±0.3 pM) are consistent with observations (1.4±0.9 pM). High concentrations in the mixed layer are modeled at Southern Ocean, coastal regions, closed and shallow water body, western Equatorial Pacific Ocean. The modeled Hg[superscript T] concentrations in the deep old North Pacific waters are a factor of two higher than in the younger the deep North Atlantic because of the longer time to accumulate Hg sinking from the surface. The modeled fraction of elemental Hg (Hg0[subscript aq) is also higher in aged deep waters because of the slow accumulation of Hg0[subscript aq] generated by reduction of oxidized Hg in subsurface waters. Chapter 5 focuses on the perturbation of legacy anthropogenic Hg emissions (1450 - 2008) on oceanic Hg cycle. We couple the OFFTRAC-Hg simulation developed in Chapter 4 with the GEOS-Chem atmospheric Hg simulation. According to the model, the total Hg mass in the global ocean has increased from 1150 Mmol in 1450 to a present-day value of 1640 Mmol. The modeled anthropogenic Hg concentrations peak at a depth of 400-500 m. The model result shows that approximately 43% (210 Mmol) of the anthropogenic Hg resides at depths below the mixed layer and shallower than 1000 m, 55% (270 Mmol) at depths deeper than 1000 m, while only approximately 2% (10 Mmol) in the mixed layer. The model also suggests that sinking with particulate organic carbon is the major pathway for the anthropogenic Hg to penetrate into the deep ocean. The modeled anthropogenic Hg concentrations are higher over the east tropical Pacific Ocean, the east tropical Atlantic Ocean, tropical Indian, west coast of continents, and high-latitude North Pacific and Atlantic Oceans, while being lower over centers of mid-latitude gyres and the Arctic Ocean.
Download or read book Biogeochemistry written by W.H. Schlesinger and published by Academic Press. This book was released on 2013-01-14 with total page 689 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the past 4 billion years, the chemistry of the Earth's surface, where all life exists, has changed remarkably. Historically, these changes have occurred slowly enough to allow life to adapt and evolve. In more recent times, the chemistry of the Earth is being altered at a staggering rate, fueled by industrialization and an ever-growing human population. Human activities, from the rapid consumption of resources to the destruction of the rainforests and the expansion of smog-covered cities, are all leading to rapid changes in the basic chemistry of the Earth. The Third Edition of Biogeochemistry considers the effects of life on the Earth's chemistry on a global level. This expansive text employs current technology to help students extrapolate small-scale examples to the global level, and also discusses the instrumentation being used by NASA and its role in studies of global change. With the Earth's changing chemistry as the focus, this text pulls together the many disparate fields that are encompassed by the broad reach of biogeochemistry. With extensive cross-referencing of chapters, figures, and tables, and an interdisciplinary coverage of the topic at hand, this text will provide an excellent framework for courses examining global change and environmental chemistry, and will also be a useful self-study guide. Emphasizes the effects of life on the basic chemistry of the atmosphere, the soils, and seawaters of the EarthCalculates and compares the effects of industrial emissions, land clearing, agriculture, and rising population on Earth's chemistrySynthesizes the global cycles of carbon, nitrogen, phosphorous, and sulfur, and suggests the best current budgets for atmospheric gases such as ammonia, nitrous oxide, dimethyl sulfide, and carbonyl sulfideIncludes an extensive review and up-to-date synthesis of the current literature on the Earth's biogeochemistry.
Download or read book Toward an Improved Understanding of the Global Biogeochemical Cycle of Mercury written by Helen Marie Amos and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury (Hg) is a potent neurotoxin, has both natural and anthropogenic sources to the environment, and is globally dispersed. Humans have been using Hg since antiquity and continue its use in large quantities, mobilizing Hg from stable long-lived geologic reservoirs to actively cycling surface terrestrial and aquatic ecosystems. Human activities, such as mining and coal combustion, have perturbed the natural biogeochemical cycle of Hg. However, the distribution of natural versus anthropogenic Hg in the environment today and the extent of anthropogenic perturbation (i.e., enrichment) are uncertain. Previous model estimates of anthropogenic enrichment have been limited by a lack of information about historical emissions, examined only near-term effects, or have not accounted for the full coupling between biogeochemical reservoirs. Presented here is a framework that integrates recently available historical emission inventories and overcomes these barriers, providing an improved quantitative understanding of global Hg cycling.
Download or read book Biogeochemical Cycle of Mercury in the Northeastern Mediterranean Southern Coast of Turkey written by I. Salihoglu and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biogeochemical Cycles of Specific Pollutants written by I. H. Elsokkary and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury and the Everglades A Synthesis and Model for Complex Ecosystem Restoration written by Darren G. Rumbold and published by Springer Nature. This book was released on 2019-11-30 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book integrates 30 years of mercury research in the Florida Everglades to inform scientists and policy makers. The Everglades is an iconic ecosystem by virtue of its expanse; diversity of biota; and multiple international designations. Despite this, the Everglades has been subjected to multiple threats including: habitat loss, hydrologic alterations, invasive species and altered water quality. Less well recognized as a threat to Everglades human use and wildlife populations is the toxic metal, mercury. The first half of Volume II focuses on biogeochemistry and factors unique to the Everglades that make it extraordinarily susceptible to mercury methylation following its deposition: warm subtropical climate, shallow depth, high levels of dissolved organic matter, sulfate contamination, nutrient enrichment and sediment redox conditions (for review of atmospheric mercury deposition significance, see Vol. I). The second half of Volume II answers the “so what” question – why biomagnification of the methylmercury produced in the Everglades is a threat to the health of top predators including humans. The results of the synthesis presented in Volume II suggest that the mercury problem in the Florida Everglades is one of the worst in the world due to its areal extent and the degree of risk to ecological receptors and humans.
