Average Mercury Concentration Research Articles

The content of mercury in sediments around Artisanal Small-scale Gold Mining (ASGM) Bumela district, Gorontalo Regency, Gorontalo Province, Indonesia

Artisanal Small-scale Gold Mining (ASGM) in Gorontalo spread across several regions. One is located in the village Bumela, District Bilato, Gorontalo regency. The processing of gold at the mine site Bumela do with the amalgamation method. The purpose of this study is to assess the content of mercury in sediments around the ASGM Bumela. Sediment sampling sites in Totopo River, Motebo River and ASGM Bumela tailings. The number of sampling point sediment in the river are 15 points. The number of sampling point sediment in tailings location is 2 points. Sampling was done by varying the depth of 0-20 cm and 20-40 cm. To determine the concentration of mercury in the sediment used Atomic Absorption Spectroscopy (AAS) without a flame in LPPMHP Gorontalo Province. The quality standard levels of mercury in the sediment used European Safety Standard. The average content of mercury in the sediment was 71.36 mg/kg. The average content of mercury in the tailings is 31.95 mg/kg. The content of mercury in Totopo River, Motebo River and the tailings are exceeding the quality standard of European Safety Standard.

Geochemical processes of mercury transformation in the river-sea system

In this paper, the average concentrations of mercury in river water and suspension in seawater were presented. The authors gave the spatial distribution of mercury in the dissolved and suspended forms and in the bottom sediments. The studies were carried out at 30 stations twice a year (in the period of high water and low water) in the period 2014 – 2016. Samples of the bottom sediments were collected in the surface layer. The spatial distribution of mercury was performed by Kriging interpolation in ArcGIS 10.2.2. It was shown that the river flow is dominated by dissolved forms of mercury at the top and suspended forms in the mouths of watercourses, while the sea is dominated by dissolved forms. The geochemical transformation processes of the river sedimentary substance (dissolved and suspended forms of mercury) in the mixing zone of the river and sea waters (in the area of the so-called marginal ocean filter) have been studied in detail. It has been shown that, the marginal filter is characterized by flocculation of inorganic and organic dissolved substances with concomitant capture of dissolved forms of metals, which can lead to an increase in the proportion of mercury carried on the suspended substance. The content of suspended forms of metal was reduced due to the self-purification of the water system from the river material and the transition to marine conditions.

Environmentally significant shifts in trace element emissions from coal plants complying with the 1990 Clean Air Act Amendments

The Clean Air Act Amendments of 1990 (CAAAs) reduced criteria air pollution from coal-fired power plants (CFPPs) in the United States, but compliance strategies also altered the magnitude and phase of environmentally significant trace element emissions. The present work quantitatively assesses changes in trace element emissions stemming from CAAAs compliance, attributes these changes to specific CAAAs compliance strategies, and discusses implications for future environmental regulatory design. We combine plant-level coal purchase and installed air pollution control device data with a trace element partitioning model to approximate changes in trace element mass entering and exiting CFPPs in the solid, liquid, and gas phase between 1993 and 2017. Though US coal combustion decreased by 2% during this period, the vast majority of trace element emissions reductions stem from the 18-64% reductions in the fleet-wide average concentrations of arsenic, bromine, chloride, lead, mercury, and selenium in the combusted coal. Combined with the installation of air pollution control technologies, these shifts resulted in nationwide reductions of gas phase trace element emissions by between 49 and 68% for the elements included in this study. In contrast, installation of flue gas desulfurization devices increased the mass of trace elements discharged in wastewater. This work reinforces the value of multi-phase emissions regulations in ensuring that contaminants are not shunted from regulated to unregulated phases.

Timber harvest alters mercury bioaccumulation and food web structure in headwater streams

Timber harvest has many effects on aquatic ecosystems, including changes in hydrological, biogeochemical, and ecological processes that can influence mercury (Hg) cycling. Although timber harvest's influence on aqueous Hg transformation and transport are well studied, the effects on Hg bioaccumulation are not. We evaluated Hg bioaccumulation, biomagnification, and food web structure in 10 paired catchments that were either clear-cut in their entirety, clear-cut except for an 8-m wide riparian buffer, or left unharvested. Average mercury concentrations in aquatic biota from clear-cut catchments were 50% higher than in reference catchments and 165% higher than in catchments with a riparian buffer. Mercury concentrations in aquatic invertebrates and salamanders were not correlated with aqueous THg or MeHg concentrations, but rather treatment effects appeared to correspond with differences in the utilization of terrestrial and aquatic basal resources in the stream food webs. Carbon and nitrogen isotope data suggest that a diminished shredder niche in the clear-cut catchments contributed to lower basal resource diversity compared with the reference of buffered treatments, and that elevated Hg concentrations in the clear-cut catchments reflect an increased reliance on aquatic resources in clear-cut catchments. In contrast, catchments with riparian buffers had higher basal resource diversity than the reference catchments, indicative of more balanced utilization of terrestrial and aquatic resources. Further, following timber harvest THg concentrations in riparian songbirds were elevated, suggesting an influence of timber harvest on Hg export to riparian food webs. These data, coupled with comparisons of individual feeding guilds, indicate that changes in organic matter sources and associated effects on stream food web structure are important mechanisms by which timber harvest modifies Hg bioaccumulation in headwater streams and riparian consumers.

Mercury Concentrations Vary Within and Among Individual Bird Feathers: A Critical Evaluation and Guidelines for Feather Use in Mercury Monitoring Programs.

Feathers are widely used to represent mercury contamination in birds. Yet, few recommendations exist that provide guidance for using bird feathers in mercury monitoring programs. We conducted a literature review and 5 experiments to show that mercury concentrations vary substantially within (vane >100% higher than calamus) and among (>1000%) individual feathers from the same bird. We developed a research tool and guidelines for using bird feathers for mercury studies based on 3 components: 1) variability of feather mercury concentrations within an individual bird (coefficient of variation), 2) desired accuracy of the measured mercury concentration, and 3) feather and bird mass. Our results suggest a general rule that if the goal is to limit analytical and processing costs by using whole feathers in only one sample boat, then to achieve an accuracy within 10% of a bird's overall average feather mercury concentration a bird with a coefficient of variation ≤10% must be <190 g (size of a large shorebird). To achieve an accuracy within 20%, a bird with a coefficient of variation ≤10% must be <920 g (a large duck). When more than one sample boat is needed to fit the required number of feathers to achieve the desired accuracy, the results suggest homogenizing feathers and analyzing an aliquot of ≥20 mg for mercury. The present study suggests increasing the number of feathers typically used per bird to assess mercury concentrations. Environ Toxicol Chem 2019;38:1164-1187. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Long-term study of atmospheric mercury deposition at monitoring stations in Lithuania

The results of the long-term study of atmospheric mercury concentrations in the rain water carried out at the Aukštaitija and Žemaitija integrated monitoring stations are presented in this work. The bulk precipitation samples at both stations were collected every week during the 2007–2017 period. The mercury measurement method is based on the absorption of radiation by mercury vapour at the 253.7 nm line. The monthly samples of precipitation after preparation were analysed using a mercury analyzer ‘Gardis’ developed at our institution. The average annual concentrations, deposition amounts and trends of mercury in the precipitation over the period of 2007–2017 were analysed. The tendency of average monthly mercury concentrations in the precipitation at the Žemaitija station was continuously increasing before 2011, however, after 2012 it has a decreasing tendency which was contrary to that at the Aukštaitija station. At the same time, the tendencies of average monthly amounts of mercury deposited with precipitation showed decreasing amounts, especially at the Žemaitija station. Explanation of the above-mentioned phenomenon is complicated and the main reason is very changeable air mass trajectories and irregularity of precipitation.

Species and correlations between selenium and mercury in fishpond ecosystems.

The chemical species and contents of selenium and mercury in water, sediments, and crucian carps collected from three wild and three aquaculture fishponds in Tianjin, China, were determined, and the interaction between selenium and mercury in water was also investigated by the calorimetry method. The results revealed that the average contents of total selenium (TSe) and total mercury (THg) in each item of the wild areas were higher than in those of the aquaculture areas, and significant differences (95% confidence) were presented for THg both in the sediments and crucian carps. The molar ratios between TSe and THg in all investigated fishponds were far higher than 1, indicating good protective effects of selenium on mercury toxicity. Obviously, negative correlations (r>0.9993) were found between TSe and THg in water. The antagonism of selenium on mercury in water was confirmed to mainly result from the reaction between selenate and Hg2+ to form an insoluble selenium-mercury oxygenated compound, by which the addition of selenate into the water of fishponds would reduce the environmental risk of mercury. PRACTITIONER POINTS: Se and Hg in different fishpond ecosystems were investigated and compared. Direct evidence was provided for the interaction between Se and Hg in water. The addition of Se(VI) into fishpond ecosystems would reduce the environmental risk of Hg.

A comparison of fish tissue mercury concentrations from homogenized fillet and nonlethal biopsy plugs

The use of biopsy plugs to sample fish muscle tissue for mercury analyses is a viable alternative to lethal sampling; however, the practice has yet to be widely implemented in routine monitoring due to concerns about variability of mercury concentrations in fish muscle tissues. Here we examine distribution of mercury in fillets of four fish species (Walleye, Northern Pike, Smallmouth Bass and Lake Trout), suitability of left/right side of fillet for biopsy sampling, and appropriateness of re-using a biopsy punch. The results showed that average mercury concentrations in left and right fillets of fish are similar. Mercury concentrations in biopsy plug samples, taken from the anterior dorsal area of the fish fillet, were statistically equivalent to the mercury concentrations in homogenized fillets. There was no discernible cross contamination between samples when a biopsy punch was reused after washing in hot soapy water, and as such, biopsy punches can be recycled during sampling to reduce the sampling cost. If a tissue mass collected from a specific site on the fillet is insufficient, then we suggest sampling corresponding locations on the other fillet rather than sampling two adjacent sites on one fillet to obtain more tissue. The results presented here can improve the accuracy of fillet biopsy plug sampling, minimize fish mortality for mercury monitoring, and reduce labor and material costs in monitoring programs.

Combining flux monitoring and data reconstruction to establish annual budgets of suspended particulate matter, mercury and PCB in the Rhône River from Lake Geneva to the Mediterranean Sea

Long term and high resolution data on water discharge, suspended particulate matter (SPM) and contaminant concentrations in rivers are required for a better understanding of particulate transfers from the continental areas to the seas. The aim of this study was to provide a novel estimation of annual fluxes of SPM and related pollutants in the Rhône River from Lake Geneva to the Mediterranean Sea by combining high frequency or time-integrative monitoring and novel relations between SPM concentration (Cs) and water discharge (Q). At six stations of the Rhône Sediment Observatory (OSR), SPM fluxes were calculated over the 2000–2016 period by combining observational data and Cs-Q relations. Monthly average concentrations of mercury (Hg) and PCB 180 were obtained by analysis of SPM samples collected in time integrative particle traps between 2011 and 2016. These pollutants were selected because of the well documented contamination of the Rhône watershed by these substances. Inter-annual fluxes at the Rhône River outlet averaged 6.6 Mt. yr−1 for SPM, 572 kg yr−1 for Hg and 14 kg yr−1 for PCB 180. The Isère and Durance tributaries were found to be the main contributors of SPM fluxes. Annual SPM budgets were not balanced, suggesting deposition, remobilization of bottom sediments and/or contributions from non-monitored tributaries. The SPM sampled at the outlet was more contaminated than the combined SPM inputs from the monitored tributaries, suggesting that intermediate sources of contamination were not captured in the budget.

Mercury in Poplar Leaves in the Urbanized Areas of Southern Siberia and the Far East

The problem of technogenic contamination by mercury of urbanized territories of the southern part of Siberia and the Far East in the regional and sectoral aspects according to sampling of poplar leaves is considered. The study was conducted according to a single methodology in 35 localities. Quantitative estimates of the distribution of mercury in the leaves of poplar in individual cities and the region as a whole were obtained. The dependence of the growth of the average mercury content in the cities on their population has been established. Revealed are significant in terms of area and length, technogenic biogeochemical aureoles, and mercury dispersion streams that are stable in time in the city of Novosibirsk, in the villages of Aktash and Shelekhov, as well as sources of mercury emissions into the environment located on their territory. Recommendations are made for further research.

Source Attribution for Mercury Deposition with an Updated Atmospheric Mercury Emission Inventory in the Pearl River Delta Region, China.

We used CMAQ-Hg to simulate mercury pollution and identify main sources in the Pearl River Delta (PRD) with updated local emission inventory and latest regional and global emissions. The total anthropogenic mercury emissions in the PRD for 2014 were 11,939.6 kg. Power plants and industrial boilers were dominant sectors, responsible for 29.4 and 22.7%. We first compared model predictions and observations and the results showed a good performance. Then five scenarios with power plants (PP), municipal solid waste incineration (MSWI), industrial point sources (IP), natural sources (NAT), and boundary conditions (BCs) zeroed out separately were simulated and compared with the base case. BCs was responsible for over 30% of annual average mercury concentration and total deposition while NAT contributed around 15%. Among the anthropogenic sources, IP (22.9%) was dominant with a contribution over 20.0% and PP (18.9%) and MSWI (11.2%) ranked second and third. Results also showed that power plants were the most important emission sources in the central PRD, where the ultra-low emission for thermal power units need to be strengthened. In the northern and western PRD, cement and metal productions were priorities for mercury control. The fast growth of municipal solid waste incineration were also a key factor in the core areas. In addition, a coordinated regional mercury emission control was important for effectively controlling pollution. In the future, mercury emissions will decrease as control measures are strengthened, more attention should be paid to mercury deposition around the large point sources as high levels of pollution are observed.

Bioaccumulation of mercury and other trace elements in bottom-dwelling omnivorous fishes: The case of Diplodus sargus (L.) (Osteichthyes: Sparidae)

The presence of toxic elements in fish represents a hazard for human health, especially in Mediterranean countries and other regions with high per-capita fish consumption. The present research, carried out along the northern Catalan coast (NW Mediterranean), aimed to determine the levels of trace metals and arsenic in the muscle of white seabream Diplodus sargus (L.), a common demersal species of growing interest for fisheries and aquaculture. Average mercury concentrations widely exceeded the limits imposed by EU despite the low contamination levels previously reported for the study area, stressing the potential risk associated to the consumption of medium-sized, non-predatory fishes. The other analyzed elements fell within the recommended limits. Preliminary results about the feeding habits of D. sargus are reported, in order to determine feeding habitat and items of the analyzed specimens.

Factors affecting the concentration and distribution of gaseous elemental mercury in the urban atmosphere of downtown Toronto

Atmospheric gaseous elemental mercury (GEM) and meteorological parameters were simultaneously monitored at two building rooftops in downtown Toronto, Canada from Oct. 2015 to Oct. 2016. The two buildings are ∼136 m apart, one is an office building (60 m tall) and the other (30 m tall) mainly contains chemistry and biology laboratories, offices and classrooms. The average mercury concentrations were found to be 1.46 ± 0.54 ng/m3 and 1.78 ± 0.89 ng/m3 for the 60 m and 30 m sites, respectively. Analysis of the data reveals that sporadic events of high mercury concentration are related to local sources; that the higher level of GEM at the 30 m site resulted from a combination of local sources and weaker mixing of air at lower height; regional sources contributed to the loading of GEM in urban atmosphere.Comparing the data set with a data set collected in 2004 from the same location revealed that the average atmospheric GEM concentration in downtown Toronto dropped from 4.5 ng/m3 to 1.78 ng/m3 (60% decrease). Decreases in GEM were also observed in the data reported by CAMNet over the same period in rural and remote areas but to a lesser extent (10.5 and 13.9% respectively). The decrease is in line with the key national and provincial policies on mercury use, emission control and management that have been enacted since 2004.

Understanding the antagonism of Hg and Se in two shark species from Baja California South, México

Mercury and Selenium concentrations were determined in the muscle and liver tissues of Silky shark (Carcharhinus falciformis) and Smooth Hammerhead shark (Sphyrna zygaena) caught off Todos Santos, Southern Baja California, Mexico during August–December 2014. The average mercury concentrations in C. falciformis [(mg/kg) muscle: 3.04; liver: 3.95] and S. zygaena (muscle: 5.23; liver: 3.39) exceeded the permissible limit of 1.0 mg/kg established by the Mexican government. Biomagnification Factors (BMF) to understand the prey-predator relations were also calculated and it was observed that all BMFs were >1 indicating absolute biomagnification of Hg. Additional Se concentrations were found in C. falciformis: 5.34 mg/kg and S. zygaena: 3.29 mg/kg resulting in a molar excess of Se over Hg. Thus, our results prove to offer the basic strategies of Hg-Se biogeochemical processes in marine sharks.

Экогеохимия ртути в почвах и углях юга Кузбасса

Assessment for content of mercury as a toxic component of coal combustion by-product in rocks and deposit environments is aimed at identification of risks caused by impact of hazardous activities on the environment in full concordance with green chemistry concept. In this paper have been presented results of mercury content determination for the South Kuzbass coals and soils of the coal-mining area. The mercury contents in soils (30 samples) and coals (30 samples) were determined by atomic absorption method on the RA‑915+ mercury analyzer with pyrolytic attachment. The mercury content in Mezhdurechensk strip mines’ coals varies from 0.13 to 2.46 mg/kg with the average concentration of 0.57±0.10 mg/kg. The determined content exceeds the Clarke of mercury in coals by factor of 1.3 to 24.6. The mercury content in soil samples varies from 0.012 to 0.173 mg/kg with the average value of 0.057±0.007 mg/kg, which is by 1.7 times more than the average mercury content in the Earth crust. There are five locations within Mezhdurechensk city area where the mercury content in the soil exceeds 3.1–5.3 times the Clark value. During past 25 years the average mercury content in the soil has been decreased by 2.8 times. The solubility of mercury from technogenic landscapes’ soils has been studied by methods of successive acetate-ammonium and hydrochloric acid extracts. The solubility of mercury in aqueous extracts from Mezhdurechensk soils is by 2.2–2.9 times higher than the ones taken from undisturbed landscapes, in acetate-hydrochloric acid and alkaline extracts it is within the limits of content in natural soils; in strongly acidic extracts has been found the maximum solubility of mercury (30.6–84.8% from the total amount). Based on the major contribution of coal dust in the gross input of mercury into the environment of Mezhdurechensk, it is possible to expect the increasing of mercury background in and around the city caused by the growth of coal mining in the area without implementation of modern and effective methods for dust suppression.

KONSENTRASI MERKURI PADA RAMBUT KEPALA DAN KESEHATAN MASYARAKAT PADA LOKASI PENAMBANGAN EMAS TRADISIONAL BULADU KABUPATEN GORONTALO UTARA

This study aims to identify mercury concentrations in head hair and its effect on public health at the traditional gold mining. The study was conducted at the gold mining, Buladu Village, North Gorontalo Regency. Samples were taken randomly from human head hair. Samples of public health condition were taken from respondents who served as the samples of mercury concentrations in the head hair. The number of respondents was 20 people. The samples of mercury in the head hair were analyzed at the Integrated Research and Testing Laboratory of UGM by using mercury analyzer. The quality standard used as a reference to the mercury concentrations in the head hair was the recommendation of the National Research Council (NCR), i.e. 12 ppm. The results of the analysis of the public health were tabulated and then interpreted. The results of the analysis indicated that the highest mercury concentration in the head hair was 952.85 mg/kg and the lowest was 0.03 mg/kg with an average mercury concentration of 55.09 mg/kg. This result was above the threshold quality standards established by NCR, i.e. 12 ppm. Many factors affect the mercury concentrations in humans, including education, income, environmental sanitation and food consumption. Waste dumped directly into the river will affect river water and marine aquatic animals. The consumption of food taken from the waters of Sulawesi Sea affects influence the mercury concentrations in the head hair.

Evaluating Total Mercury and Methyl Mercury Contents in Canned Tuna Fish of the Persian Gulf.

Due to hygienic risks of mercury residues in food and marine originated supplements, measuring total mercury and methyl mercury contents of canned tuna as a highly consumable marine food product is essential. In this study, 40 canned Tuna fish (from Persian Gulf) were collected in 2015 and then flame atomic absorption spectrometer (FAAS) and thermo gas chromatography mass spectrophotometry were used to measure total mercury and methyl mercury, respectively. The results indicated that the average contents of total mercury and methyl mercury of the canned tunas, with 34.2 and 29.5 ppb decrements compared with 2009's measurement, were 177.4 and 143.7 ppb respectively. The highest concentration of the total mercury was 315.2 while it was 267.9 ppb for methyl mercury. This study showed that the content of the mercury in canned tunas of the Persian Gulf was less than the Maximum Residue Limit (MRL).

Method development and validation for total mercury determination in coke oven gas combining a trap sampling method with CVAAS detection

Coke oven gas is one of the by-products of the coal coking process. It is used as a fuel in the coking plant, but also as a raw material in the chemical industry to produce methanol, syngas or environment-friendly, low-CO2 hydrogen fuel. Due to the reasons mentioned above, the knowledge of coke oven gas pollutants such as mercury is a key issue. To determine the mercury in the cleaned coke oven gas a trap sampling method combined with CVAAS mercury detection was developed, optimized and validated. In order to perform the sampling process the traps filled with activated carbon were used. The determination of mercury in the traps material was performed by means of an MA-2 mercury analyzer. During the optimization of the method one selected the trap material, sample volume and flow rate. The optimal volume of the coke oven gas sample was 3 dm3 and the flow rate was 18 dm3/h (per one trap). The developed method was validated according to the Eurachem recommendation and was applied to determine mercury in the clean coke oven gas. The coke oven gas sampling was performed in a coking plant in Poland. The average concentration of mercury in the clean coke oven gas was 3.2 ± 0.3 μg/m3N (k = 2) for n = 18.

Transport of mercury on the finest particles results in high sediment concentrations in the absence of significant ongoing sources

The mercury contaminated upper Penobscot Estuary in Maine provided a unique opportunity to rigorously examine the effect of sediment type and particle size on mercury concentrations in sediments, and to explain why sediments at different locations in the estuary had different mercury concentrations. This is because the Penobscot Estuary contains a large, well-mixed pool of mobile sediments of many different types (muds, sand, gravel, wood chips), which are the source of material for the permanently deposited surface sediments. Despite this mixing, average surface sediment mercury concentrations were very different in different locations, ranging from 238 ng/gdw to 1032 ng/gdw in the 11 subareas studied. Average total mercury concentrations were highly related to the type of sediment (wood chips > muds > sands) regardless of location in the estuary. The characteristics in both mobile and surface sediments that were positively related to total mercury concentrations were % organic matter (measured as loss on ignition) and %fines (measured usually as <62.5 μ). Also, in a subset of samples it was shown that mercury was positively associated only with the very finest (<44 μ) particles. Thus, side embayments of the estuary such as the Orland River and Mendall Marsh, which experience lower velocity currents and so accumulate more fine particles, tended to be much higher in mercury concentrations. This knowledge will be important in managing remediation of this system, as fine particles can be the most difficult to trap or to retain if dredging is employed. Methyl mercury was well correlated with total mercury and so its distribution would also be affected by transport characteristics. This was the case even in the mobile sediments, which were more oxic and not expected to provide a good habitat for methylation.

Mercury health risk assessment among petrochemical workers in Rayong Province, Thailand

ABSTRACTBackground: Mercury occurs naturally in environment; thus, retention of fossil fuels used as feedstock in petrochemical plants is commonly found. The purpose of this study was to assess mercury health risks among petrochemical workers.Methods: In all, 188 operators and 30 office workers were recruited from 3 petrochemical plants. A total of 83 and 56 air samples were collected during normal working days and turnaround (TA) periods, respectively. Three main meals over 5 consecutive days, drinking water and spot urine samples were collected. Demographics and lifestyle data were collected using questionnaires. USEPA guidelines for mercury health risks were applied.Results: The inhalation exposure during normal working days of the two groups was lower than 5% of the Threshold Limit Value (TLV), but during TA some operators’ exposure exceeded the TLV. The average urinary mercury concentrations of the two groups did not significantly differ. The mercury concentration in the water samples was undetected and did not differ in the food samples of the two groups. Sixty-six operators presented a hazard quotient, HQinh greater than 0.2, but none of office staff, and 98 of 218 participants had hazard index, HI >1.Conclusion: Unacceptable mercury health risk among the petrochemical worker mostly cause by mercury in cooked food.