Download or read book Assessment of Total Mercury and Methyl Mercury in Selected Subsistence Fish in Western Alaska written by Xiaoming Zhang and published by . This book was released on 2001 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Total Hg (THg) and methylmercury (MeHg) were examined in muscle and liver samples of salmon species (Chinook: Oncorhynchus tshawytscha; Chum: O. keta; Sockeye: O. nerka; Coho: O. kisutch) and freshwater fish species (Pike: Esox lucius; Grayling: Thymallus arcticus; Whitefish: Caregonus nelsoni) collected in 1999 and 2000 from the Western Alaska rivers (Yukon, Kuskokwim, Nushagak and Kvichak). The THg in salmon muscles has a mean value of 62 ng/g (ww). In Pike muscles, THg has a mean value of 879 ng/g. The mean concentrations of THg in Grayling and Whitefish muscle are 153 ng/g and 32 ng/g respectively. In salmon muscle and liver the MeHg levels constitute 77% and 62% of the THg levels, respectively. In Pike muscle the MeHg levels constitute 100% of the THg levels. A significant correlation between Hg levels and fish length was found. Calculated consumption limits indicate that children may consume 0.05-1.5 kg of fish per month, depending on the species consumed. The study suggests that, from 1979 to 1998, nearly 21 kg of MeHg was transported by Sockeye salmon to the Alaskan rivers of the Bering Sea east coast"--Leaf 3.
Download or read book Index Medicus written by and published by . This book was released on 2004 with total page 2098 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1963- include as pt. 2 of the Jan. issue: Medical subject headings.
Download or read book Heavy Metal Tissue Distributions in Southwestern Alaskan Waterfowl written by Roger F. N. Rothschild and published by . This book was released on 2005 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Food containing mercury has been identified as a possible health risk. Total mercury (THg), which is inorganic (Hg2), and methylmercury (MeHg) species, has been found in the arctic food web. In Alaska, birds are an important seasonal component of the diet, but have not been studied extensively and characterized for the presence of mercury. Birds are good subjects for examination because they feed at different trophic levels, can be long-lived, and are both abundant and widely distributed. Not only can birds monitor local Alaskan food webs, but, if they are migratory, can be used to compare exposure in different regions. Mercury levels in muscle, brain, and bone tissue of 140 birds taken by subsistence hunters across southwestern Alaska were determined. I tested the null hypothesis of no interspecific differences in total mercury levels in the 18 species of Alaska birds surveyed. There were interspecific differences with the Lesser Scaup (Aythyra marila mariloides), and the Black Scoter (Melanita nigra Americana), having the highest levels of mercury. In general, mercury levels were higher in muscle than in brain or bone. The mean values for mercury in the species studied were lower than the levels known to cause adverse reproductive or behavioral effects"--Leaf iii.
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 Compound specific Stable Isotopes of Amino Acids Reveal the Influence of Trophic Level and Primary Production Sources on Mercury Concentrations in Fishes from the Aleutian Islands Alaska written by Michelle Trifari and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Total mercury (THg) concentrations exceed thresholds of concern in some Steller sea lion (Eumetopias jubatus; SSL) tissues from certain portions of the Aleutian Islands, Alaska. Here, compound-specific stable isotope analyses (CSIA) of carbon in essential amino acids ([delta]13CEAA values) and nitrogen in AAs ([delta]15NAA values) in fish muscle tissue was applied to quantify the proportional contributions of primary production sources and trophic positions of eight prey species (n = 474 total) that are part of SSL diets. Previous THg analyses of fish muscle, coupled with additional monomethylmercury (MMHg) analyses of a subset of samples, substantiated previous findings that fishes from the west of Amchitka Pass, a discrete oceanographic boundary of the Aleutian Archipelago, have higher muscle THg concentrations relative to fishes from east of the pass. All fish muscle samples were analyzed separately for, both, CSIA-AA of carbon and nitrogen. The [delta]13CEAA values in fish muscle demonstrated that although most fishes obtained their EAAs primarily from algae, some species varied in the extent to which they relied on this primary production source. Certain [delta]15NAA values of the same fish samples indicated that trophic positions of fishes were higher from the west relative to the east of the pass for some species. Total Hg was positively correlated with bulk [delta]15N values, [delta]15N values of glutamic acid ([delta]15NGlu), and trophic positions. However, only trophic magnification slopes using [delta]15NGlu values indicated a higher rate of Hg biomagnification to the west of Amchitka Pass. Broad and species-level multiple linear regression models revealed that trophic position was the most important driver of fish muscle THg with a smaller amount of variation explained by other parameters, such as proportional contributions of primary production sources, fish body condition, and catch location. Collectively, results indicate that differences in fish trophic positions were the most consistent determinants of the higher fish THg concentrations to the west of Amchitka Pass. However, a higher rate of THg biomagnification to the west of Amchitka Pass may also play a role in the regional differences in fish muscle THg.
Download or read book Mercury study report to Congress written by and published by DIANE Publishing. This book was released on with total page 1811 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Total Mercury and Methyl Mercury in Marine Water and Fresh Water Fish Species written by Nazirah Ariffin and published by . This book was released on 2014 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury study report to Congress Vol 4 written by and published by DIANE Publishing. This book was released on with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Total Mercury and Methylmercury in Fish Fillets Water and Bed Sediments from Selected Streams in the Delaware River Basin New Jersey New York and Pennsylvania 1998 2001 written by and published by . This book was released on 2004 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluating the Public Health Risks of Methylmercury Exposure and Benefits from Omega 3 Fatty Acids and Selenium from Fish Consumption written by Leanne K. Cusack and published by . This book was released on 2014 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although fish are a nutritious food source, they also are the main source of methylmercury exposure in U.S. populations. This research examined the risks from methylmercury and benefits from omega-3 fatty acids and selenium from fish consumption. The first study provided the first region-specific quantitative risk/benefit analysis for nine commonly consumed freshwater fish species in the Columbia River Basin; which is home to many Native American Tribes and subsistence fishermen who consume large quantities of locally caught fish. (Donatuto and Harper 2008; Harper and Harris 2008)(Donatuto and Harper 2008; Harper and Harris 2008) My results showed that mountain whitefish and rainbow trout provided a net benefit for cardiovascular risk and improved infant visual response memory scores across all consumption rates in all subregions in which they were sampled. The second study examined the associations between region of residence, demographic characteristics and total blood mercury concentrations in a nationally representative sample of women of childbearing age, using the 1999-2010 NHANES database. Women who live in the Atlantic and Pacific coastal regions have the highest, and women in the Midwest have the lowest, methymercury concentrations in their blood. The third study analyzed intra-and inter-specific variability in selenium: mercury molar ratios in ten species of freshwater fish from the Columbia River Basin to determine the potential application for fish consumption guidelines. Variability in selenium:mercury molar ratios was high within the fish species regardless of fish size. This variability within fish species warrants caution in using selenium:mercury ratios in risk assessment calculations. Overall, this research demonstrates the complexities involved in crafting guidelines that consider both the risks and benefits of fish consumption.
Download or read book Advances in Geochemistry Analytical Chemistry and Planetary Sciences written by Vladimir P. Kolotov and published by Springer Nature. This book was released on 2023-02-28 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents 41 selected articles written by leading researchers from the Vernadsky Institute of Geochemistry and Analytical Chemistry, part of the Russian Academy of Sciences. The articles are grouped by the following topics: (1) Geochemistry, (2) Meteoritics, Cosmochemistry, Lunar and Planetary Sciences, (3) Biogeochemistry and Ecology, and (4) Analytical Chemistry, Radiochemistry, and Radioecology. The articles present recent experimental data, theoretical investigations, critical reviews, the results of computer modeling in the above-mentioned fields. Intended to provide a scientific “snapshot” of the institute, the book also includes content on its history, main scientific achievements and current goals, together with detailed descriptions of its 25 laboratories and three museums so as to promote new international collaborations. Given its scope, the book will be of interest to all scientists and graduate students working in the areas of geochemistry, analytical chemistry and radiochemistry, earth and environmental sciences, biogeosciences, meteoritics and planetary science, and to those seeking new collaboration opportunities in these areas in Russia.
Download or read book A Human Health Risk Assessment of Mercury in Fish from the San Diego River written by and published by . This book was released on 2015 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methylmercury is the most toxic organic form of mercury in the environment and humans are exposed mainly from the consumption of contaminated fish and shellfish. Methylmercury poisoning can cause adverse health effects including muscle weakness, disrupted motor function, and memory loss, and prenatal exposure can lead to problems with mental and motor development once a child is born. The utilization of the San Diego River in San Diego, CA for recreational and subsistence fishing has created a need for updated information on the human health risk posed by consumption of fish from the river. This study quantified the levels of Methylmercury found in four fish species (Micropterus salmoides or largemouth bass, n=20; Lepomis macrochirus or bluegill, n=11; Lepomis cyanellus, or green sunfish, n=4; and Ameiurus nebulosus or brown bullhead, n=3) from three locations on San Diego River. Muscle tissue analysis was carried out with a DMA-80 Direct Mercury Analyzer. Mercury levels from existing data for largemouth bass from El Capitan Reservoir was also used. A human health risk assessment was completed with data from this study and the El Capitan data set to calculate hazard quotients for 11 different scenarios for recreational and subsistence fishers in the San Diego River. Adverse health effects are likely to occur for recreational fishers who catch and consume maximally contaminated largemouth bass from El Capitan Reservoir, or all study species from the river at the rate of 17.5 g/day. Adverse health effects are also likely to occur for subsistence fishers who catch and consume only large mouth bass, a combination of large mouth bass and bluegill, or all study species from the river at the rate of 142.4 g/day. Additionally, adverse health effects were shown likely to occur for subsistence fishers who catch and consume largemouth bass from El Capitan Reservoir, however these risks are rare due to the financial burden associated with fishing at the reservoir. Overall, consuming fish caught from the San Diego River can be considered safe for recreational fishers, however subsistence fishers should limit their consumption to four 8-ounce servings of any species per week, or target only bluegill.
Download or read book A Comparative Analysis of Arctic Risk Assessment of Methylmercury in Fish written by Sandra C. Almeida and published by . This book was released on 2014 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is a critical examination of official public health advice on fish consumption in one of the most contaminated regions on the planet, the Arctic. This thesis compares the bureaucratic strategies to minimize methylmercury exposure among residents in three northern regions, Alaska, Canada, and Greenland, with special attention paid to risk reduction among the Inuit. The two primary questions informing this work are 1) How have public health officials assessed the health risks from methylmercury exposure in Arctic residents? and 2) How have these assessments shaped advisories and advice about fish consumption? The research methodology involved content analysis of state health bulletins, public health announcements, federal agency fact sheets, international organization publications, and scholarly articles in the disciplines of environmental science, anthropology, and toxicology. The research findings suggest that fish consumption advice among government officials in Alaska, Canada, and Greenland are astonishingly similar. In short, fish consumption guidelines in these countries are almost completely absent in Inuit communities. Moreover, government entities maintain that despite toxic contaminants, fish is still an ideal food for Inuit health and cultural livelihood. There are no official advisories targeting the consumption of marine mammals, and in cost-benefit calculations, the benefits of fish are considered to outweigh the risks from methylmercury exposure. I argue that the public health advice is seemingly holistic in its concern for chronic disease prevention, cultural survival, and reduction in toxic exposure; however, these conventional assessments of risk are not protective enough against methylmercury toxicity.
Download or read book A Framework for Assessing Effects of the Food System written by National Research Council and published by National Academies Press. This book was released on 2015-06-17 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: How we produce and consume food has a bigger impact on Americans' well-being than any other human activity. The food industry is the largest sector of our economy; food touches everything from our health to the environment, climate change, economic inequality, and the federal budget. From the earliest developments of agriculture, a major goal has been to attain sufficient foods that provide the energy and the nutrients needed for a healthy, active life. Over time, food production, processing, marketing, and consumption have evolved and become highly complex. The challenges of improving the food system in the 21st century will require systemic approaches that take full account of social, economic, ecological, and evolutionary factors. Policy or business interventions involving a segment of the food system often have consequences beyond the original issue the intervention was meant to address. A Framework for Assessing Effects of the Food System develops an analytical framework for assessing effects associated with the ways in which food is grown, processed, distributed, marketed, retailed, and consumed in the United States. The framework will allow users to recognize effects across the full food system, consider all domains and dimensions of effects, account for systems dynamics and complexities, and choose appropriate methods for analysis. This report provides example applications of the framework based on complex questions that are currently under debate: consumption of a healthy and safe diet, food security, animal welfare, and preserving the environment and its resources. A Framework for Assessing Effects of the Food System describes the U.S. food system and provides a brief history of its evolution into the current system. This report identifies some of the real and potential implications of the current system in terms of its health, environmental, and socioeconomic effects along with a sense for the complexities of the system, potential metrics, and some of the data needs that are required to assess the effects. The overview of the food system and the framework described in this report will be an essential resource for decision makers, researchers, and others to examine the possible impacts of alternative policies or agricultural or food processing practices.
Download or read book Cumulated Index Medicus written by and published by . This book was released on 2000 with total page 1840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mercury Study Report to Congress Executive summary written by and published by . This book was released on 1997 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Metabolism in Aquatic Environments written by William J. Langston and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Metabolism in Aquatic Environments is a synthesis of recent developments in the field of metal ecotoxicology and features a number of contemporary issues arising from the interaction of metals and biota, such as pathways of assimilation and food chain transfer, metal accumulation and detoxification in humans and biotransformation of elements such as mercury and arsenic.
