Mercury Hg Research Articles

Determination of Mercury (Hg) in Sediment by a Sequential Injection (SI) System With Cold Vapor Generation Atomic Fluorescence Spectrometry (CVAFS) Detection After a Rapid and Mild Microwave-Assisted Digestion

A simple and rapid method has been developed for the determination of total Hg in drainage sediment. The method is performed by using a sequential injection (SI) system with cold vapor generation atomic fluorescence spectrometry (CVAFS) after a closed microwave assisted digestion. Digestion was carried out at a temperature of 140°C for 5 minutes using a mixture of 10% HCl + 50% HNO3 +40% H2O as digestion acid media. Stability experiment revealed that the extracted samples were stable in 24 hours. The SI–CVAFS system was well optimized. At optimized conditions, the detection limit of the method was 0.5 ng/g−1. Relative standard deviation (RSD) for the complete procedure by the analysis of the 10 digestions was 3.7%. The method was validated against 3 drainage sediment certified reference materials: GSD-2, GSD-9, and GSD-10 and successfully applied to the determination of Hg in the sediment of Pi River, China.

834: Seafood in pregnancy and mercury levels in umbilical cord blood

levels in umbilical cord blood Reni Soon, Timothy Dye, Nicholas Ralston, Marla Berry, Lynnae Sauvage University of Hawaii, Obstetrics & Gynecology, Honolulu, HI, University of North Dakota, Energy & Environmental Research Center, Grand Forks, ND, University of Hawaii, Cell & Molecular Biology, Honolulu, HI OBJECTIVE: The purpose of this study was to examine the influence of maternal fish consumption during pregnancy on umbilical cord mercury (Hg) concentrations in a multiethnic cohort of US women. STUDY DESIGN: This was a secondary analysis of a prospective cohort pilot study examining antenatal fish consumption and neonatal outcomes in Hawaii. The first 100 women who met eligibility criteria and consented were enrolled. After delivery umbilical cord blood was collected and women completed a dietary survey of their last month of pregnancy. RESULTS: 86% of women reported eating fish during the previous month, with 9% eating more than the recommended limit of 12 oz per week. 75% of Filipina ate fish, which was significantly less than nonFilipina (p .05). Women of most ethnicities consumed similar quantities of fish, with the exception of Japanese women, who consumed significantly less fish than non-Japanese, and Pacific Islander women, who consumed significantly more. Fish consumption varied significantly by income status, with 30% of poor women averaging more than 12 oz per week. Fish consumption did not vary by women’s age, or education. 44% of all women had 5 g Hg/L or more. Filipina were significantly less likely to have elevated Hg levels when compared with non-Filipina ( .05). Mercury levels did not vary by other demographic characteristics. Women who reported eating more than 12 oz of fish per week were significantly more likely to have 5 g Hg/L or more, but mean Hg levels were not significantly higher (6.1 3.3 v 5.0 3.7). The odds ratio for elevated Hg, however, was significant among fish-consumers compared with non-consumers (5.7; 95% confidence interval: 1.2, 27.1). CONCLUSION: Despite variation by ethnicity and income status in fish consumption during pregnancy, there exists a strong correlation between fish consumption and mercury levels. Almost half of the women in this study had elevated mercury levels. This project was supported by grants NCRR U54RR026136 and NIMHD U54MD007584 from the National Institutes of Health.

Assessing the fish consumption beneficial use impairment in the Bay of Quinte

The state of contamination in Bay of Quinte fish was assessed to determine whether delisting criteria have been met, and to recommend further studies/actions to be undertaken. We examined fish contaminant data collected by the Ontario Ministry of the Environment between 1975 and 2008 for seven sites in Lake Ontario including the Bay of Quinte. Where sufficient data was available, we tested for differences in recent years by examining the post-1998 data for Walleye, Smallmouth Bass, Yellow Perch and Brown Bullhead. Our analysis specifically focused on known contaminants of concern within the Bay of Quinte: polychlorinated biphenyls (PCBs), mercury (Hg), as well as Mirex which is known to originate from Lake Ontario. Insufficient data was available for the examination of total TEQs (dioxins, furans and dioxin-like PCBs). When appropriate, we used the general linear model (GLM) to compare contaminant concentrations among sites as a function of fish length. When no significant relationship between contaminant concentration and fish length was found, mean values among sites were compared using analysis of variance. While there were no significant differences for the majority of contaminants among sites, some species and contaminant combinations at one or more of the Bay of Quinte sites had elevated fish concentrations compared to some reference sites. For instance, mercury concentrations in Yellow Perch and Brown Bullhead at Quinte sites exceeded those from some reference sites. Current consumption restrictions for Brown Bullhead and Yellow Perch are more severe in the Upper Bay of Quinte compared to the other sites, indicating impacts of local sources. As a result, the fish consumption beneficial use impairment continues to be classified as impaired for the Bay of Quinte. As many sport fish such as Walleye and Smallmouth Bass are large, long-lived and potentially wide-ranging species, it is difficult to link contaminant concentrations to local sources. To investigate the impact of sources within the Upper Bay of Quinte, comparison of contaminants in sentinel fish collected on the same scale as the source of the contamination is recommended.

Phenological development stages variation versus mercury tolerance, accumulation, and allocation in salt marsh macrophytes Triglochin maritima and Scirpus maritimus prevalent in Ria de Aveiro coastal lagoon (Portugal)

Efficient and sustainable management of rapidly mounting environmental issues has been the focus of current intensive research. The present study aimed to investigate the impact of plant phenological development stage variation on mercury (Hg) tolerance, accumulation, and allocation in two salt marsh macrophytes Triglochin maritima and Scirpus maritimus prevalent in historically Hg-contaminated Ria de Aveiro coastal lagoon (Portugal). Both plant samples and the sediments vegetated by monospecific stands of T. maritima and S. maritimus were collected from reference (R) and sites with moderate (M) and high (H) Hg contamination in Laranjo bay within Ria de Aveiro lagoon. Hg tolerance, uptake, and allocation in T. maritima and S. maritimus, physico-chemical traits (pH, redox potential, and organic matter content) and Hg concentrations in sediments vegetated by these species were impacted differentially by phenological development stages variation irrespective of the Hg contamination level. In T. maritima, Hg concentration increased with increase in Hg contamination gradient where root displayed significantly higher Hg followed by rhizome and leaf maximally at H. However, in S. maritimus, the highest Hg concentration was perceptible in rhizome followed by root maximally at M. Between the two studied plant species, S. maritimus displayed higher Hg tolerance index (depicted by higher plant dry mass allocated to reproductive stage) and higher available Hg at M (during all growth stages) and H (during senescent stage) when compared to T. maritimus. Both plant species proved to be Hg excluder (low root/rhizome-leaf Hg translocation). Additionally, T. maritima also acted as Hg stabilizer while, S. maritimus as Hg accumulator. It can be inferred from the study that (a) the plant phenological development stage variations significantly influenced plant Hg sensitivity by impacting sediment chemistry, plant growth (in terms of plant dry mass), Hg accumulation, and its subsequent allocation capacity, contingent to Hg contamination gradient; (b) S. maritimus accumulated higher Hg but restricted its translocation to above-ground part using exclusion process at both M and H due to its accelerated growth during Hg-tolerant reproductive/metabolically active phenological development stage greater than its counterpart T. maritima; and (c) the studied salt marsh plants although hailed from the same C3 and monocot group did not necessarily display similar phenotypic plasticity and behavior towards Hg-contaminated scenario during their life cycle.

Effect of Pregnancy on the Levels of Blood Cadmium, Lead, and Mercury for Females Aged 17–39 Years Old: Data from National Health and Nutrition Examination Survey 2003–2010

Data from the National Health and Nutrition Examination survey for the years 2003–2010 were used (n = 4700) to evaluate the effect of age, parity, body mass index (BMI), race/ethnicity, pregnancy, iron (Fe) storage status, smoking status, and fish/shellfish consumption on the levels of blood cadmium (Cd), lead (Pb), and total mercury (Hg)for females aged 17–39yr old. Regression analysis was used to fit models for each of the three metals. For all three metals, age was positively and BMI was negatively associated with levels of these metals in blood. Smokers had statistically significantly higher levels of Cd and Pb irrespective of race/ethnicity and Fe storage status as compared to nonsmokers. Novel to this study, pregnancy was found to be associated with significantly lower levels of Cd, Pb, and Hg irrespective of race/ethnicity and Fe storage status as compared to nonpregnant females. It is conceivable that pregnancy may thus accelerate clearance of these metals from blood. Fish/shellfish consumption was associated with higher levels of Hg but not with Cd levels.

Heavy Metal Contents in Registered Dietary Supplements in Malaysia: A Pilot Study from the Drug Safety Perspective

Objectives: In Malaysia dietary supplements are ram- pantly consumed for general health and well-being and therefore, available in community pharmacies, health food stores, night markets, grocery stores and even obtained via internet. However, gap in the level of Malaysian consumer’s awareness regarding the toxicity of dietary supplements is a major issue, which needs to be addressed by the analysis of their constituents. This study was aimed to evaluate and analyze the heavy metal contents such as lead (Pb), cadmium (Cd), arsenic (As) and mercury (Hg) in registered dietary supplements available in community pharmacies in Malaysia Methods: This study was focused on Eurycoma longifolia (Tongkat Ali), glucosamine, Allium sativum (garlic) and Zingiber officinale (ginger) products. A total of twenty registered single ingredient dosage form dietary supple- ments from different brands were purchased from com- munity pharmacies located in Penang. The samples were then evaluated and subjected to analysis by atomic absorption spectrometry. Results: The study showed that variable amounts of lead have been quantified as 0.29 -0.47 ppm (Tongkat Ali), 0.19 – 0.27 ppm (glucosamine), 0.01 – 0.38 ppm (garlic) and 0.26 – 0.74 ppm (ginger) products. While for cad- mium detection, the amounts indicated 0.02 – 0.24 ppm (Tongkat Ali), 0.03 – 0.22 ppm (glucosamine), 0.06 ppm (ginger) and was absent in garlic No traces of arsenic and mercury were found in all four product samples. The regression linear coefficients (r2) for Pb, Cd, As and Hg standards were 0.9990, 0.9958, 0.9960 and 0.9989, respectively. Conclusions: The amount of Pb, Cd, As and Hg in all the products were found within the limits as per the re- quirement stated by National Pharmaceutical Control Bureau (NPCB). Thus, in order to ensure the safety and quality of dietary supplements, the analysis of heavy metals must be carried out on routine basis using simple and robust atomic absorption spectrometry (AAS) technique

Decreased Bioelements Content in the Hair of Patients with Fahr’s Disease (Idiopathic Bilateral Calcification in the Brain)

The remarkable calcification of the basal ganglia and cerebellum has been traditionally called Fahr's disease, but this nomenclature is criticized for including heterogeneous diseases. To determine the pattern of some biological metals in the hair of patients with Fahr's disease, we investigated the levels of 24 bioelements in the hair of 28 patients (17 males and 11 females) with Fahr's disease and compared them with those of three age-, sex-, and living region-matched controls (84 controls in total). Interestingly, we found decreases in the levels of several bioelements [calcium (Ca), copper (Cu), iron (Fe), mercury (Hg), iodine (I), nickel (Ni), phosphate (P), lead (Pb), and selenium (Se)] in the hair of patients. This is in contrast to our previous finding of increases of Cu, Fe, zinc (Zn), and magnesium (Mg) in the cerebrospinal fluid (CSF) of patients. The decreased level of Cu in the hair was the most prominent and pathognomonic, while the increased level of Cu in the CSF had been found to be the most significant in patients. More significant correlations between two bioelements in the hair were recognized in patients than controls. Although Fahr's disease has been considered to be a heterogenous entity, the significant tendencies of several bioelements in the hair of patients in this study suggest metabolic disorders of bioelements, especially biometals, on the background. Some transporters, especially P transporter such as PiT2, of bioelements will be involved in the different distribution of bioelements in the body of patients.

Heavy Metals accumulation in fish species of Savitri River in Raigad district of Maharashtra

A study was carried out to investigate the contamination of heavy metals in muscle and intestine tissue in 7 fish species and 1 prawn species, caught at upstream and downstream points along the Savitri River in the Raigad district of Maharashtra. The river course has a discharge point in which the Common Effluent Treatment Plant (CETP) discharges its treated effluent. Water analysis was carried out from 10 different locations in the upstream and downstream of the river from the discharge point. The common fish species available in the river course were collected and toxicity tests were carried out for the muscle and intestine samples for 3 metals: lead (Pb), cadmium (Cd) and mercury (Hg) by Atomic Absorption Spectroscopy (AAS). The results showed that lower metal values were recorded in the water than fish organs. The concentrations of metals (mg lt -1 ) in water were below the levels recommended by the Maharashtra Pollution Control Board for drinking, except for Pb (0.31±0.02). The highest concentration (mg lit -1 ) of all heavy metals was recorded upstream, in the intestine of Etroplus suratensis (3.42±0.07 for Pb) while the lowest was recorded downstream, in the muscle of Cynoglossus macrolepidotus (0.07±0.01 for Hg). There were significant differences (P0.05) were recorded in mean concentrations between muscle and intestine in species, except for Cd and Hg levels in Liza tade, caught upstream and Cd level in Machrobrachium malcolmsonni , caught downstream (P<0.05). Overall results indicated that fish organs were slightly contaminated by heavy metals, mainly by Pb, but did not exceed the levels recommended by the Indian Food Safety&Standards regulation (FSSAI), 2011.

Mercury release flux and its influencing factors at the air-water interface in paddy field in Chongqing, China

The exchange of mercury (Hg) across the air-water interface is an important part of Hg biogeochemical cycle. Mercury fluxes across the air-water interface in paddy fields were measured by a Dynamic Flux Chamber (DFC) coupled with a Lumex® multifunctional mercury analyzer RA-915+ at two sites (Chengjiang (CJ) and Caoshang (CS)) in Beibei, Chongqing, China in 2008. The results showed that mercury emission followed a power-law relationship with solar radiation and air temperature, and it increased exponentially with water temperature at both sites. Mercury emission was mainly influenced by the solubility of gaseous elemental Hg, photo-thermal effect, electron activity (Eh) and air Hg concentrations. Solar radiation made the greatest direct contribution to mercury emission during the daytime (0.80), with an 83.60% contribution, whereas at nighttime the water temperature (0.72) contributed to 71.65% of emissions. The temperature gradient between water and air might also influenced mercury emission across the air/water interface at nighttime. These findings suggest that paddy fields could act as a significant source of atmospheric mercury, and it can contribute significantly to the atmospheric mercury in a local region.

Mercury characterisation in urban particulate matter

AbstractA five-step sequential extraction procedure was proposed in order to assess the distribution of mercury (Hg) forms in urban particulate matter (PM): exchangeable, HCl-soluble, organic-bound, elemental and other slightly soluble Hg species, mercury(II) sulphide (HgS), and residual Hg. This process was applied to the analysis of urban dust samples collected at locations in Prague (Czech Republic) with high traffic density. In addition to sequential extractions, thermal desorption analysis was performed. The differences in Hg concentrations between untreated and thermally treated samples were indicated as the thermally releasable amount of Hg. For the study of PM-adsorbing capacity, Hg vapours were passed through the samples as long as the enrichment of materials was observed. The retained elemental Hg was readily released by thermal desorption. All Hg analyses were based on the highly sensitive pyrolysis technique of atomic absorption spectrometry using the mercury analyser AMA-254.

Amelioration of Acidic Soil using Two Modified Industrial By-products: Rice Productivity and Environmental Safety

In this study, two modified industrial by-products (modified flue gas desulfurization residue (M FGD) residue and modified white mud (M white mud) were applied to an acidic soil at the rate of 750 kg ha−1. Growth of rice (Oryza sativa L.) significantly increased compared with the untreated control. Increasing soil pH was observed as a common mechanism of action for M FGD and M white mud. Furthermore, the concentrations of organic matter, calcium (Ca), magnesium (Mg), silicon (Si), phosphorus (P), and potassium (K) in the treated soil were significantly increased. Compared with the untreated control, the concentrations of lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As) in rice grain grown in the treated soil also significantly decreased and were far less than the tolerance limits set by the National Food Standards of China. The quality of rice grain was improved after the application of modified industrial by-products. These results demonstrated that the two modified industrial by-products can be applied to modify acidic soil safely and effectively.

Human exposure to lead, cadmium and mercury through fish and seafood product consumption in Italy: a pilot evaluation

The presence of selected toxic heavy metals, such as cadmium (Cd), lead (Pb) and mercury (Hg), was investigated in fish and seafood products, namely, blue mussel, carpet shell clam, European squid, veined squid, deep-water rose shrimp, red mullet, European seabass, gilthead seabream, Atlantic cod, European hake, Atlantic bluefin tuna and swordfish so as to assess their human exposure through diet. Metals were detected by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and hydride generation atomic absorption spectrometry (Hg-AAS). Measurements of Cd, Pb and Hg were performed by means of analytical methods validated in compliance with UNI CEI EN ISO/IEC 17025 [2005. General requirements for the competence of testing and calibration laboratories. Milano (Italy): UNI Ente Nazionale Italiano di Unificazione]. The exposure assessment was undertaken matching the levels of Cd, Pb and total Hg with consumption data related to fish and seafood products selected for this purpose. In order to establish human health implications, the estimated weekly intakes (EWIs) for Cd, Pb and Hg were compared with the standard tolerable weekly intakes (TWI) for Cd and provisional tolerable weekly intakes (PTWIs) for Pb and Hg stipulated by the European Food Safety Authority (EFSA) and the Food and Agriculture Organization/World Health Organization (FAO/WHO) Joint Expert Committee on Food Additives (JECFA). The found metal concentrations were largely below the maximum levels (MLs) established at the European Union level with the exception of Cd. This metal exceeded the MLs in squid, red mullet, European hake and Atlantic cod. Squid and blue mussel showed the highest Pb concentrations which accounted for 60% and 10% of the MLs, respectively. Highest Hg levels were found in predatory fish. The concentrations of Hg in swordfish, Atlantic bluefin tuna and red mullet accounted for 50%, 30% and 30% of the MLs, respectively. The EWIs for Cd, Pb and Hg related to the consumption of fish and seafood products by the median of the Italian total population accounted for 20%, 1.5% and 10% of the standard TWI for Cd as well as PTWIs for Pb and Hg, respectively. Furthermore, the EWIs estimated using consumption data concerning Italian consumers did not exceed the standard TWI and PTWIs, except for Cd at 95th percentile.

Trace Elements in Faeces of Great Tit Nestlings in Relation to Breeding Performance in Coastal Areas in Central Portugal

This long-term study (2003-2010) compared the breeding parameters of great tits living in a paper-and-pulp-industry area to those of great tits living in a rural area on the west coast of Portugal. We also measured the abundance of caterpillar biomass, an important food source and determinant of breeding success for tits. In 2009, we further analysed trace metal [arsenic (As), calcium (Ca), cadmium, copper, mercury (Hg), nickel, lead, selenium, and zinc] as well as Ca concentrations in excrement of 15-day-old great tit nestlings. Generally, for most trace metals, fecal concentrations were similar at both sites. Nonetheless, greater Hg levels and lower As levels were detected in the industrial area. Great tits laid more eggs and produced more fledglings in the industrial area than in the rural area. Caterpillar biomass was also greater in the industrial area, which likely explains the better breeding success. Our results suggest that there are no direct effects of emissions on the studied species.

Investigation of acute toxicity of heavy metals in Artemia salina acclimated to different salinity

Environment plays a vital role in the growth and metabolism of aquatic organisms. Pollutants are known to produce marked changes in the food cycle. In order to study the impact of prey on aquaculture, this study was conducted in live fish feed Artemia salina. Since changes in the culture tank due to environmental factors were mainly responsible for the decline of aquaculture, this study focused on the effect of salinity and heavy metal, including mercury (Hg), copper (Cu), and chromium (Cr), on two life stages of A. salina. Cr-exposed groups showed the highest morality at 0.052 ppm (99%) with the growth of 60%. Percentage mortality was observed to be in the order of Cr>Hg>Cu. Growth was significantly reduced. Artemia was able to accumulate Hg (9–13%), Cu (5.4–5.9%), and Cr (16.4–35%) in the body. The concentrations of heavy metals in water samples were 50–64% of Hg, 52–78% of Cu, and 62% of Cr. Metal stress induced elevated protein content, which may be due to the stress response of the organism against free radicals.

Research Article: Evaluation of the Levels of Selected Heavy Metals in Mangrove Ecosystem and Roadside Topsoil in Ghana

Trace metals were determined in the soil and water of four lagoons, two estuaries, and four heavy-traffic roads in Greater Accra along the Atlantic coast of Ghana. The results showed that water samples from all of the water bodies studied were polluted with mercury (Hg) and less polluted with arsenic (As), nickel (Ni), and cadmium (Cd). The pollution status of water samples was confirmed by contamination degree (CD) analysis, which yielded values of >1 of Hg and <1 of As, Ni, and Cd. Evaluation of the data from the soil sample was enhanced by the application of pollution quantification tools—the pollution load index (PLI) and the index of geoaccumulation (IGEO)—which showed that the mangrove swamp soil studied is progressively degrading with Hg, As, Ni, and Cd. It was also revealed that vehicular emissions were a potential source of lead (Pb), Ni, and manganese (Mn) in the roadside soils monitored. From the results of this study, it is clear that the mangroves are gradually degrading and that measures sho...

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In order to assess mercury (Hg), selenium (Se) and arsenic (As) exposure in the Mediterranean area, total mercury (THg), monomethylmercury (MeHg), Se and As levels were measured in umbilical cord blood and breast milk from Italian (n=900), Slovenian (n=584), Croatian (n=234) and Greek (n=484) women. THg, MeHg, As, and Se levels were also determined in blood samples of the same mothers from Italy and Croatia. In addition, THg and MeHg were determined in the same women's hair from all the countries and As levels were determined in the mothers urine samples from Italy, Croatia and Greece. In addition to recording the consumption of other food items, the frequencies of fish consumption were assessed by detailed food frequency questionnaires, since fish can represents an important source of mercury, selenium and arsenic in humans. The highest levels of THg and As were found in cord blood (Med(THg) =5.8 ng/g ; Med(As) =3.3 ng/g) and breast milk (Med(THg) =0.6 ng/g ; Med(As) =0.8 ng/g) from Greek women, while the highest Se levels were found in cord blood (Med=113 ng/g) and mother’s blood (Med=117 ng/g) from Italy. Significant linear correlations were found between different biomarkers of Hg, As and Se exposure. In addition, significant relations were found between the frequencies of total fish consumption and Hg, As and Se biomarkers of exposure, possibly explaining the correlations between the elements determined in cord blood, mother's blood or breast milk. Moreover, the differences in As and Hg exposure between countries were probably due to different amounts of fish consumption and the consumption of different species of fish of different origin.

Maternal transfer of mercury to the developing embryo/fetus: is there a safe level?

Mercury (Hg) exposure is ubiquitous in modern society via vaccines, fish/crustacea, dental amalgam, food, water, and the atmosphere. This article examines Hg exposure in the context of primary exposure to pregnant women and secondary exposure experienced by their unborn babies. Babies in utero are particularly at risk of higher Hg exposure than adults (on a dose/weight basis through maternal Hg transfer via the placenta), and are more susceptible to adverse effects from mercury and its biologically active compounds. It is, therefore, critical that regulatory advisories around maximum safe Hg exposures account for pregnant women and secondary exposure that children in utero experience. This study focused on standardized embryonic and fetal Hg exposures via primary exposure to the pregnant mother of two common Hg sources (dietary fish and parenteral vaccines). Data demonstrated that Hg exposures, particularly during the first trimester of pregnancy, at well-established dose/weight ratios produced severe damage to humans including death. In light of research suggestive of a mercuric risk factor for childhood conditions such as tic disorders, cerebral palsy, and autism, it is essential that Hg advisories account for secondary prenatal human exposures.

Total Mercury and Particulate-Bound Mercury Concentrations and Content in Ambient Air in Central Taiwan

Total gaseous mercury (TGM) concentration in ambient air, particulate-bound mercury concentrations and particulate-bound mercury contents in total suspended particles (TSP) from locations in Central Taiwan were measured and discussed relative to their ranges and potential sources. Meteorological conditions in terms of average temperature, wind direction, wind speed, and humidity were also monitored at a traffic sampling site in Sha-Lu central Taiwan from July 2011 to November 2011. The results revealed that the average concentrations of total gaseous mercury (TGM) and particulate-bound mercury in TSP were 8.73±5.53 (ng/m3) and 0.000164±0.00007 (ng/m3), respectively. The monthly average TGM concentrations were highest in July (17.50±4.79 ng/m3) and lowest in November (4.10±0.72 ng/m3). The monthly average particulate-bound mercury concentrations were highest in July (0.000293±0.00021 ng/m3) and lowest in November (0.000109±0.00002 ng/m3). The average particulate-bound mercury Hg(p) contents were 0.15 (ng/g), while the monthly average particulate-bound mercury contents were highest in July (0.26 ng/g) and lowest in November (0.11 ng/g). In summer, industrial activities, especially smelting activities, were an important source of atmospheric Hg (Fu et al., 2009). Therefore, high mercury concentrations were observed in July and August. Several main sources of Hg emissions have also been identified in the study area.

Application of Zeeman Graphite Furnace Atomic Absorption Spectrometry with High-Frequency Modulation Polarization for the Direct Determination of Aluminum, Beryllium, Cadmium, Chromium, Mercury, Manganese, Nickel, Lead, and Thallium in Human Blood

Determination of aluminum (Al), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), and thallium (Tl) concentrations in human blood using high-frequency modulation polarization Zeeman graphite furnace atomic absorption spectrometry (GFAAS) was performed. No sample digestion was used in the current study. Blood samples were diluted with deionized water or 0.1 % (m/v) Triton X-100 solution for Tl. Dilution factors ranged from 1/5 per volume for Be and Tl to 1/20 per volume for Cd and Pb. For Tl, Cd, and Hg, noble metals (gold, platinum, rhodium, etc.) were applied as surface modifiers. To mitigate chloride interference, 2 % (m/v) solution of NH(4)NO(3) was used as matrix modifier for Tl and Ni assessment. The use of Pd(NO(3))(2) as oxidative modifier was necessary for blood Hg and Tl measurement. Validation of the methods was performed by analyzing two-level reference material Seronorm. The precision of the designed methods as relative SD was between 4 and 12 % (middle of a dynamic range) depending on the element. For additional validation, spiked blood samples were analyzed. Limits of detection (LoDs, 3σ, n = 10) for undiluted blood samples were 2.0 μg L(-1) for Al, 0.08 μg L(-1) for Be, 0.10 μg L(-1) for Cd, 2.2 μg L(-1) for Cr, 7 μg L(-1) for Hg, 0.4 μg L(-1) for Mn, 2.3 μg L(-1) for Ni, 3.4 μg L(-1) for Pb, and 0.5 μg L(-1) for Tl. The LoDs achieved allowed determination of Al, Cd, Cr, Mn, Ni, and Pb at both toxic and background levels. Be, Hg, and Tl could be reliably measured at toxic levels only. The methods developed are used for clinical diagnostics and biological monitoring of work-related exposure.

Measurements of size-fractionated concentration and bulk dry deposition of atmospheric particulate bound mercury

Daily samples of size-fractionated (18, 10, 2.5 and 1.0 μm) particulate-bound mercury Hg(p) were collected using Micro-Orifice Uniform Deposition Impactors (MOUDI), on randomly selected days each month between November 2010 and July 2011, at a traffic site (Hungkuang), a wetland site (Gaomei), and an industrial site (Quanxing) in central Taiwan. Bulk dry deposition was also collected simultaneously using a surrogate surface. The nine-month average (±standard deviation) Hg(p) concentrations were 0.57 (±0.90), 0.17 (±0.27), and 0.94 (±0.92) ng m−3 at Hungkuang, Gaomei, and Quanxing, respectively. Concentrations in November and December were much higher than in the other months due to a combination of high local emissions and meteorological conditions. PM1.0 contributed more than 50% to the bulk concentration at the traffic and the industrial sites, but only contributed 25% at the wetland site. PM1.0–2.5 contributed 25%–50%, depending on location, to the bulk mass. Coarse fraction (PM2.5–18) contributed 7% at Hungkuang, 25% at Gaomei, and 19% at Quanxing. Samples with very high bulk concentrations had large fine fractions. Annual dry deposition estimated from the surrogate surface measurements was in the range of 30–85 μg m−2 yr−1 at the three sites. Coarse particulate Hg(p) were estimated to contribute 50–85% of the total Hg(p) dry deposition. Daily dry deposition velocities (Vd) ranged from 0.01 to 7.7 cm s−1. The annual Vd generated from the total measured fluxes was 0.34, 0.60 and 0.29 cm s−1 at Hungkuang, Gaomei, and Quanxing, respectively. These values can be reasonably reproduced using a size-resolved model and measured size fractions.