Mercury In Surface Waters Research Articles

Mercury in surface waters of a macrotidal urban estuary (River Adour, south-west France)

Surface waters were collected in the River Adour estuary (south-western France) during different sampling periods from 1998 to 2001 in order to investigate the phase distribution and speciation of methylmercury (MeHg+). Although a high variability is observed, significant higher average concentrations of total MeHg+ (dissolved and particulate) are measured during the warm seasons, at 4.40±8.18 pM and 3.90±1.87 pM for July 1998 and September 1999, compared with the winter seasons, with concentrations at 0.99±2.85 pM and 1.00±1.75 pM for February 1998 and February 2001, respectively (one-tailed t-test, P=0.01). The seasonal variations are explained with enhanced bacterial activity during summer and sedimentation/resuspension phenomena. Additionally, signi-ficant longitudinal variations of the MeHg+ concentrations are observed. The highest levels in both dissolved and particulate fractions are found within the downstream urban estuarine area. This can be explained by the high methylation potential of the sediments, but direct anthropogenic inputs of MeHg+ from specific discharge points cannot be neglected. Biogeochemical factors like phytoplankton biomass and salinity also show a relationship with MeHg+ partitioning in the surface waters of the Adour estuary.

Distribution and speciation of mercury in surface water in Wanshan Hg-mined areas, Guizhou Province, China

index of As, Hg, Cd, Cr, Zn, Cu and Pb ranges from 0.119 to 30.967, 0.227 to 5.900, 0.215 to 13.471, 0.111 to 4.773, 0.250 to 63.00, 0.171 to 7.071 and 0.451 to 6.248, respectively. Nemerow synthesis pollution index ranges from 0.511 to 45.459. The results of assessment indicated that there were different extents of contamination of As, Hg, Cd, Zn, Cu and Pb, especially in the Dexing mining area, middle-lower courses of the Le'an River and coal mines in the northwest.

Beyond the Bench: Nurses Adapt to Changing Health Care Climate

Vol. 113, No. 12 EnvironewsOpen AccessBeyond the Bench: Nurses Adapt to Changing Health Care Climate Tanya Tillett Tanya Tillett Search for more papers by this author Published:1 December 2005https://doi.org/10.1289/ehp.113-a814AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit With increased emphasis being placed on the importance of environmental health comes the need for an expanded variety of environmental health care practitioners. Nursing is one of several professions that are augmenting and advancing the capabilities of their practitioners to meet this need. Now the Community Outreach and Education Program (COEP) of the University of New Mexico’s Center for Environmental Health Sciences has partnered with the New Mexico Environment Department to create an environmental health nursing internship as a component of its outreach program.In cooperation with the university College of Nursing, the partners recruit nursing students who are interested in implementing environmental health care initiatives in the surrounding community. For four years, the program has taken nursing students beyond the traditional curriculum and shown them firsthand how interaction with environmental factors affects human health. The program also gives students valuable experience in taking measures to abate hazardous exposures in communities.The interns are currently working on a number of projects that will affect different community members. They are helping to develop surveys and compiling data for a project investigating uranium exposure and subsequent kidney damage among the Navajo Nation, whose members live near and work in uranium mines. They are gathering and assembling materials for a community education and survey project on mercury in surface waters and other environmental health concerns among the Cheyenne River Sioux Tribe. They are helping COEP staff write and field-test an integrated environmental health curriculum on diabetes for middle school students. And in a fourth project, they are helping to develop a best-practices manual for applying farm waste fertilizer to croplands in a way that minimizes human exposure to aerosolized waste.The local ties of some of the nursing interns have enhanced the program’s role as an effective community advocate. Intern Krystyn Yepa is a Native American from the Pueblo of Jemez who became interested in environmental health nursing because she wanted to understand some of the health effects in her tribe resulting from exposure to different pollutants in the environment. “Learning about the different environmental health problems that exist in New Mexico has given me the willpower to finish nursing school to ultimately achieve my goal of improving the health and lifestyles of my people by placing importance on the environment,” she says.Yepa explains further, “As a Native American, I was raised to respect and appreciate the environment, and working at the COEP has only strengthened my values related to the environment.” She also credits the internship with teaching her important assessment tools that lay emphasis on the environment when completing a health history on patients, something a traditional nursing internship would not likely provide.“The nursing interns have been an incredible asset to our COEP,” says staff member Stefani Hines. “It is a mutually beneficial situation on many levels—the student nurses gather valuable real-world experiences in environmental health; the nursing school has access to additional, unique placements for their students; we have additional support for projects, which helps make them better; and the communities we work with benefit from the students’ efforts as well.”Dedicated, enthusiastic environmental health nursing interns will only continue to play an important role in advancing the COEP mission. One project currently in development will help community members get involved in city and county zoning processes, which will both encourage a healthy community mindset and minimize exposures to pollutants.Effecting change in Southwest communities.Krystyn Yepa (right) is one of several nursing interns working with Navajo and Sioux communities to reduce exposures and increase knowledge through a program of the University of New Mexico Center for Environmental Health Sciences.FiguresReferencesRelatedDetails Vol. 113, No. 12 December 2005Metrics About Article Metrics Publication History Originally published1 December 2005Published in print1 December 2005 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. 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Complexation of mercury by dissolved organic matter in surface waters of Galveston Bay, Texas

The chemical speciation of dissolved mercury in surface waters of Galveston Bay was determined using the concentrations of mercury-complexing ligands and conditional stability constants of mercury-ligand complexes. Two classes of natural ligands associated with dissolved organic matter were determined by a competitive ligand exchange-solvent solvent extraction (CLE-SSE) method: a strong class ( L s), ranging from 19 to 93 pM with an average conditional stability constant ( K Hg L s ) of 10 28, and a weak class ( L w) ranging from 1.4 to 9.8 nM with an average K Hg L s of 10 23. The range of conditional stability constants between mercury and natural ligands suggested that sulfides and thiolates are important binding sites for dissolved mercury in estuarine waters. A positive correlation between the estuarine distribution of dissolved glutathione and that of mercury-complexing ligands supported this suggestion. Thermodynamic equilibrium modeling using stability constants for Hg L, HgCl x , Hg(OH) x , and HgCl(OH) and concentrations of each ligand demonstrated that almost all of the dissolved mercury (> 99%) in Galveston Bay was complexed by natural ligands associated with dissolved organic matter. The importance of low concentrations of high-affinity ligands that may originate in the biological system (i.e., glutathione and phytochelatin) suggests that the greater portion of bulk dissolved organic matter may not be important for mercury complexation in estuarine surface waters.

Mercury distribution in Douro estuary (Portugal)

Determinations of dissolved reactive and total dissolved mercury, particulate and sedimentary mercury, dissolved organic carbon (DOC), particulate organic carbon (POC) and suspended particulate matter (SPM) have been made in the estuary of river Douro, in northern Portugal. The estuary was stratified by salinity along most of its length, it had low concentrations of SPM, typically <20 mg dm −3, and concentrations of DOC in the range <1.0–1.8 mg dm −3. The surface waters had a maximum dissolved concentration of reactive mercury of about 10 ng dm −3, whereas for the more saline bottom waters it was about 65 ng dm −3. The surface waters had maximum concentrations of total suspended particulate mercury of ∼7 μg g −1 and the bottom waters were always <1 μg g −1. Concentrations of mercury in sediments was low and in the range from 0.06 to 0.18 μg g −1. The transport of mercury in surface waters was mainly associated with organic-rich particulate matter, while in bottom waters the dissolved phase transport of mercury is more important. Lower particulate organic matter, formation of chlorocomplexes in more saline waters and eventually the presence of colloids appear to explain the difference of mercury partitioning in Douro estuarine waters.

Relationship between DOC photochemistry and mercury redox transformations in temperate lakes and wetlands

We compared diurnal variations in dissolved gaseous mercury (DGM) concentration and in losses of dissolved organic carbon fluorescence (DOCF) in four boreal Canadian Shield lakes, in one beaver pond, and in filtered and unfiltered water from a wetland in Lake St. Pierre, a fluvial lake of the St. Lawrence River. These systems were chosen to represent a spectrum of DOC. We also determined the contribution of UVB, UVA and visible light on DGM photo-induced production in the four lakes. Our results showed a strong relationship between DGM concentrations and light intensity and between DGM production and losses in DOCF, in all study sites. We also observed higher rates of DGM formation and of DOCF bleaching in the presence of UV radiation. Under UVB light, production of DGM was higher in clear lakes than in the humic ones. Inversely, in the UVA range, DGM production tended to be higher in humic lakes. We suggest that DOCF bleaching can be used as a proxy for the rate of formation of reactive species that may alter the redox state of mercury in surface waters. We also have indications that DGM production is more important in clear than in humic waters.

Distribution and speciation of mercury in surface waters in mercury mining areas in Wanshan, Southwestern China

Reactive, dissolved, particulate and total Hg concentrations were measured in surface waters originated from mercury mining areas to evaluate Hg contamination in fluvial systems in Wanshan district, Guizhou, China. Concentrations of total Hg in water samples varied from 17.3 to 585.8 ng/l and were elevated comparing to total mercury concentrations in natural water. The total dissolved Hg concentrations usually ranged from 12.5 to 52.0 ng/l, reactive Hg varied from 1.2 to 5.3 ng/l, and particulate Hg changed between 3.5 and 533.8 ng/l. The highest value of total Hg content occurred in a stream which is contaminated by leachate from the historic abandoned gangue piles was up to 585.75 ng/l. It is suggested that the fluvial systems in Wanshan area were heavy contaminated due to long life of the mining operation and to Hg release from the waste even after the mining activity has been ceased.

Sources of mercury in surface waters of the upper Madeira erosive basins, Bolivia

The human activities impact on the mercury (Hg) distribution in the Amazon waters is still discussed but very few information regarding the Hg sources from the highly turbid Andean headwaters have been published. The annual load of suspended sediments eroded from the Bolivian Andes, averages 300x10 6 tons in the Beni river, of which till 97% is exported during the rainy season. At the edge of the Bolivian Andean piedmont, the total Hg concentration vary from 8 ng/l during the dry season, to 1600 ng/l during the high water period. During this stage, it appears that the maximum concentrations of Hg associated with the fine particles and the highest Hg specific fluxes are observed in the rivers exploited for their alluvial gold during the last century. The black-shales series associated to the gold deposits are characterised by high natural Hg contents, which can be released in the hydrographic system by both chemical and physical weathering. But if we compare two clear water rivers characterised by the same suspended sediment concentrations, the maximum specific Hg flux varies between 126 kg/km 2 .j in the pristine river, to 590 kg/km 2 .j in the river characterised by recent human activities.

The distribution and speciation of mercury in Wujiang river

Concentrations of reactive, dissolved, particulate and total mercury in water samples were determined at 41 locations throughout the Wujiang River Basin, China. The sampling campaign was carried out 15∼30 July 2002. During the collection of water samples for Hg analyses, other parameters were measured in situ (dissolved oxygen, pH, temperature and EC). The average concentration of the reactive mercury in surface water was 1.5 ng/L. The concentration of total mercury ranged from 10.9 to 329.6 ng/L, with a geometric mean of 44.4 ng/L, and the dissolved mercury was from 1.0 to 49.2 ng/L, with a geometric mean of 7.1 ng/L. The proportion of reactive to total mercury was typically less than 5%, and the particulate to total mercury, with 90% of values higher than 50%. The pilot study indicated that Wujiang River is contaminated by mercury in a certain extent.

Mercury in surface waters of three mine-dominated river systems: Idrija River, Slovenia; Carson River, Nevada; and Madeira River, Brazilian Amazon

This paper investigates the aqueous geochemistry of mercury (Hg) in three aquatic systems impacted by either past or present mining activities. The Idrija River in Slovenia flows near the Idrija mercury mine, the second largest mercury mine in the world, with continuous mining and smelting activities for five centuries. During this period, it has been estimated that over 30 000 tonnes of Hg have been released into the mine's surrounding environment, due to inefficient smelting technologies and Hg left behind in mine tailings within the river basin. In contrast to cinnabar mining in the Idrija River Basin, the Carson River in Nevada and the Madeira River in the Brazilian Amazon are impacted by metallic mercury (Hg 0 ) used in the amalgamation process to extract gold (Au) and/or silver (Ag) from crude ores and fine alluvial materials. The Carson River Basin was the site of intensive Au- and Ag-mining for over 50 years in the late 1800s and early 1900s, resulting in an estimated 7000 tonnes of Hg lost to the river and its watershed. The Madeira River is a site of ongoing use of Hg 0 in Au-prospecting. This study reports on the level and speciation of Hg, as well as factors controlling levels of methyl-Hg using aqueous data. Surface water samples collected along longitudinal transects upstream of well-identified point sources of Hg, except for the Madeira River, to river deltas were analysed for Hg and geochemical parameters of interest. Samples from Idrija and Carson rivers show clear evidence of contamination, with Hg levels up to several hundreds of ng l −1 downstream from main point sources. Unlike Idrija and the Carson rivers, water samples collected from the Madeira River exhibited much lower Hg levels (9.51 ng l −1 on average, n = 16). Measured physiochemical parameters are used to determine the fate of Hg in these three river systems.

A comparison of anthropogenic mercury pollution in Kaštela Bay (Croatia) with pristine estuaries in Öre (Sweden) and Krka (Croatia)

Anthropogenic mercury pollution was studied in Kaštela Bay (Croatia), 10 years after chloralkaline plant (PVC) stopped production. The concentration of total mercury determined in sediments which are composed mainly of calcite and quartz, are in the range 14,280–30,400 ng/g. The values are higher than reported in the literature for Elbe and Seine estuaries and also above 25,000 ng/g used for criterion in remediation project in Minamata Bay. The concentration of methylmercury 6.05–36.74 ng/g are typical for slightly to highly contaminated estuarine sediments. The low ratio of methylmercury to total mercury found in sediments of Kaštela Bay is in the range 0.04–0.18%. It can be explained that in this region predominate conditions which do not promote in-situ methylation. Sediments were found to be highly anoxic. Concentrations of total mercury in unfiltered surface waters are in the range 69–145 ng/1 and in unfiltered bottom waters in the range 230–1,418 ng l −1. High concentrations found in bottom waters suggest that either resuspension or partial dissolution of sediments takes place. An experiment performed on filtered and unfiltered waters showed that about 85% of total mercury in surface water and almost 100% in bottom water was retained on 45 μm filters. To demonstrate contrasts, two pristine estuaries from norths and south Europe were studied. Silicious sediments of Öre estuary (Sweden) and calcareous sediments of Krka estuary (Croatia) have total mercury concentrations close to accepted background level. The ratio of methylmercury to total mercury is ⩽1% in all samples with one exception. The highest observed ratio (2.70%) was in the surface sediment from E2 station in Krka estuary measured in March 2000. This location is suitable for studying methylmercury formation in pristine environment.

Distribution of particulate and reactive mercury in surface waters of Swedish forest lakes — an empirically based predictive model

The partition coefficient ( K d) expresses the ratio between particulate bound and dissolved metals. In lake dynamic modelling, it is used to distribute the total load between the dissolved and particulate routes of lake transport. An empirically based model for prediction and evaluation of a modified partition coefficient for mercury (Hg) in lake water has been developed using field data from 25 Swedish lakes. As a substitute for dissolved Hg determined by filtration, this study uses the easy reducible (or reactive) proportion of Hg in water samples and the modified partition coefficient is here denoted K d *. The model relates K d * for Hg to the best correlating of several lake specific environmental variables, resulting in an r 2-value of 0.69. K d * was found to decrease with increasing suspended particulate matter (SPM) concentration, iron concentration (Fe) and ratio of lake to drainage area ( a/ADA). Interpretations of the model parameters were discussed in light of the clusters of statistically and functionally related variables they represent. The negative correlation between K d * and SPM is possibly due to the particle concentration effect, which seems to be valid also for the definition used here for the partition coefficient. For K d the particle concentration effect is often explained by an exponential relationship between colloids and SPM which results in relatively more colloid bound metals at low SPM concentrations. The fraction of colloid bound metals is counted with the ‘dissolved’ fraction which decreases the K d. Influences of spurious correlations on the relationship between K d * and SPM have been assessed and found to contribute to the statistical correlation. The negative correlation with iron can also be accounted for by Hg association with small particles (iron/manganese oxides and hydroxides, possibly in association with humic matter). The influence of the morphometric factor a/ADA is probably due to differences in K d * with different Hg transport paths (direct deposition on the lake surface is believed to decrease K d *). The model was tested using stability tests, which indicated that other related variables could replace the given model parameters. The model parameter interpretations, in terms of clusters of related variables would, however, have been similar.

Monitoring of total Hg in the river Elbe: FIA-device for on-line digestion.

The development of an apparatus for the on-line sampling, digestion and quantification of total mercury in surface water is described. Detection and quantification is done by flow injection cold vapor atomic absorption spectroscopy (FI-CVAAS). Three digestion methods were tested, chemical, microwave and UV. The influence of the digestion parameters (digestion method, digestion time, microwave power, concentration of oxidation solution) on the recovery of mercury in water of the river Elbe have been investigated. Mercury can be determined almost quantitatively (recovery rate > 85%) with some digestion procedures described. The best results were reached by UV digestion. The technique is fast, simple to handle and robust. Each complete analysis only take four minutes. The working range is 10 to 1000 ng/L. The measuring arrangement has been applied successfully in a governmental monitoring station at Schnackenburg/Elbe, Germany.

Microcolumn Field Sampling and Flow Injection-Atomic Fluorescence Spectrometry for Speciation of Mercury in Surface Waters

Abstract A novel approach to mercury speciation in waters based on microcolumn field sampling and flow injection-atomic fluorescence spectrometry is described. Microcolumns of sulphydryl cotton are used as a new sampling tool in order to collect, enrich and immobilise organic mercury species. On return to the laboratory the microcolumns are inserted into the flow injection system for elution/quantitative analysis. The technique, applied to survey analyses of the Manchester Ship Canal, revealed relatively high concentrations of organomercury (0.006–0.058 μg Hg 1−1) and inorganic mercury (0.0038–0.530 μg Hg 1−1). The distribution profiles for the inorganic and organic fractions did not correlate well.

Embryotoxic action of methyl mercury on coho salmon embryos.

Environmental levels of heavy metals like mercury have increased significantly over the last 100 years in response to anthropogenic activities. More recently the increase in acid precipitation may make the situation worse in that it appears to increase the production of methyl mercury (MeHg) in the surface waters and benthic regions. Concentrations of mercury in surface waters are normally relatively low in the ng/L range, yet levels of mercury in fish tissue in the mg/L range are not uncommon. There have been several well-publicized accounts of acute mercury poisoning from consuming highly contaminated fish. Less is known about the health risks associated with consumption of fish with low levels of mercury contamination. Human embryos are especially sensitive to MeHg's teratogenic effects. For example, psychomotor retardation is a common outcome of fetal MeHg exposure. Such neural effects may be the result of abnormal migration of neurons during development. A number of different species have been utilized to investigate the effects of mercury on teleost development. Coho salmon, like all teleostean embryos possess mitotic cells that provide a useful model for the study of MeHg teratogenesis. Due to their large size, coho salmon embryos are easily observed and maintained in the laboratory.more » In addition large numbers of eggs are available from one female thus minimizing effects of variability among individuals. The objective of the present study is to characterize the toxic levels of MeHg and study their uptake. In addition some of the teratogenic effects of MeHg on coho salmon embryos will be described. 16 refs., 3 figs., 1 tab.« less

Determination of Mercury in Surface Waters Using an Optimized Cold Vapor Spectrophotometric Technique

Abstract An analytical method to measure mercury in environmental samples was optimized based upon amalgamation of mercury on gold-coated sand and subsequent ultraviolet absorption measurement of the mercury vapor driven off the sand upon heating. Sample handling and storage methods were employed that were virtually free from mercury loss or contamination. Analytical procedures were tested on standard reference materials obtained from the USEPA and USGS and at concentration levels in the range anticipated for the environmental samples. Stream samples, collected over a seven-month period, were filtered (0.45 μm) in the field, and the mercury in dissolved and particulate fractions was determined. Dissolved mercury concentrations ranged from 24.1 ng/1 to 116.9ng/1 (N = 120) while particulate mercury concentrations ranged from 0.2 μg/g to 33.4 μg/g (N = 120). The method has been found useful for analyzing environmental samples and has been shown to be very sensitive and free of interferences.

Mercury in surface waters of the open ocean

Mercury was determined in samples of surface seawater and rainfall from coastal and open ocean areas of the northwest Atlantic and Pacific Oceans. Mercury concentrations in surface seawater and open ocean rainfall ranged from 0.5 to 11 pM and 6 to 130 pM, respectively. The pluvial flux of Hg to the open ocean was estimated at 1.7 × 109 g/yr, using mean concentrations of Hg in rainfall and annual rainfall volume estimates for the major ocean basins. Fluvial input, while difficult to reliably assess, was a less important (about 0.18 × 109 g/yr) source of Hg to the ocean. The mean residence time of Hg in the surface mixed layer (to 75 m) was calculated at 4–7 years, which is similar to other very reactive elements such as Al, Pb and Bi. Surface seawater Hg distributions are markedly influenced by atmospheric sources. Due to an elevated supply of Hg to the northwest Atlantic by rain, higher Hg values were observed in surface seawater in the northwest Atlantic Ocean (4.0 ± 0.7 pM) than at low latitudes in the central North Pacific Ocean (2.1 ± 0.4 pM). Surface seawater Hg concentrations between coastal New England and the Sargasso Sea do not show the large offshore concentration gradient typical of elements which have relatively large fluvial or coastal sources. Rather, the Hg distribution in this region was similar to that obtained for the atmospherically derived constituents Pb and 210Pb. Surface seawater Hg measurements in the central Pacific Ocean along 160°W between 20°N and 20°S showed a depression (&gt;60%) in the equatorial upwelling area which coincided with the transect region exhibiting low 234Th/238U activity ratios. This relationship implies that Hg has enhanced scavenging and removal from surface seawater in biologically productive oceanic zones. In contrast to the surface distribution in the northwest Atlantic, a pronounced on‐shore gradient in sea surface Hg concentration was observed in the Tasman Sea. This may have resulted from the upwelling of water high in Hg content into the near coastal zone.

Implementation of a sensitive method for determining mercury in surface waters and sediments by cold-vapour atomic-absorption spectrophotometry

The first page of this article is displayed as the abstract.

Mercury levels in water and sediment of Elephant Butte Reservoir, New Mexico

Mercury concentrations from less than 0.1 ppb to 17 ppb are common in surface waters. It is indicated that about 25 ppb represents the likely upper equilibrium limit of mercury in surface waters. The concentration of mercury in water is reduced in the presence of suspended particulate matter which will adsorb many ionic mercury species. This paper discusses whether or not mercury levels found in Elephant Butte Reservoir, New Mexico, represent natural levels compared to levels reported for other parts of the United States.

Mercury in surface waters of seas around the United Kingdom

A SURVEY of the concentration of mercury in the surface waters of the seas around the UK, has been made as part of the Ministry of Agriculture, Fisheries and Food's overall programme of investigation into the distribution of heavy metals in the marine environment. Using a cold vapour–gold trap method on board a research vessel, thus obviating the necessity to store the samples with consequent problems of loss and/or contamination, both ‘reactive’ and ‘total’ mercury concentrations have been measured. The results reported here show clearly the major sources of emission. The possible reasons for differences between these results and those of some other investigators are also discussed.