Speciation of mercury in South African coals

Total mercury (Hg_TOT) concentrations were determined by inductively coupled plasma mass spectrometry (ICP MS) for South African Highveld coals. The distribution of Hg in coals was investigated using a four-stage sequential leaching protocol and isotope dilution/gas chromatography coupled to ICP MS (ID-GC-ICP MS). The results show that Hg_TOT ranged from 144 to 303?µg?kg^?1 with a mean of 199?±?26?µg?kg^?1, while Hg_TOT leached from coals using different solvents ranged between 103 and 310?µg?kg^?1 (mean: 218?±?60?µg?kg^?1). Hg leaching rates of 53–78% were achieved in crushed coals. Hg⁰, Hg²⁺, and CH₃Hg⁺ were identified in all coals. CH₃Hg⁺ in studied coals ranged between 0.1 and 0.4 (mean: 0.2) µg?kg^?1. GC ICP MS chromatograms also showed unknown Hg peaks which were identified as other organomercury species such as ethylmercury. Modes of occurrence of Hg in coals were variable with the organic-bound (37–40%) and the sulfide-bound (37–39%) being the dominant mercury forms. Increasing the HCl concentration in the used protocol increased the amount of Hg leached (16%) during this step.     

Effects of bisphenol A on Gammarus fossarum and Lumbriculus variegatus in artificial indoor streams

The impact of bisphenol A (BPA) on Gammarus fossarum and Lumbriculus variegatus was studied in four artificial indoor streams (0, 5, 50 and 500?µg?L^?1 BPA, nominal) over 103 days in a pulse–dose exposure scenario (weekly BPA application). For G. fossarum populations at day 103, the proportions of juveniles and of breeding females from the highest BPA treatment were in tendency reduced. For individually exposed gammarid pairs an EC₁₀ of 17?µg?L^?1 BPA (nominal) for the proportion of reproductive females in the fourth brood was determined. During the first three broods, the largest brood size occurred at the highest BPA concentration, whereas in the fourth brood it decreased concentration-dependently (fourth brood EC₁₀?=?5?µg?L^?1 BPA, nominal). Effects on L. variegatus were a reduced population growth (103?d-EC₁₀ of 2?µg?L^?1 BPA, nominal) and an increase in dry weight and the number of segments in large, complete worms.     

Concentrations of lead in cosmetics commonly used in South Africa

In this study, we present evidence of lead in lip liner, oil absorbent powder, mascara, concealer, lipsticks, lip gloss, and foundation. The samples were analyzed for lead by flame atomic absorption spectrometry. The levels of lead in concealer, mascara, lip liner, and oil absorbent powder were found to be 7.4?±?1.3?µg?g^?1, 15.8?±?0.2?µg?g^?1, 29.0?±?9.2?µg?g^?1, and 17.3?±?2.9?µg?g^?1, respectively. The levels of lead in lipsticks, lip gloss, and foundation ranged from not detected to 73.1?±?5.2?µg?g^?1, 4.7 to 11.7?±?2.8?µg?g^?1, and 7.8 to 32.9?±?1.4?µg?g^?1, respectively. Thus, in the majority of samples, the concentrations of lead are higher than the USFDA maximum permissible concentration of 0.10?µg?g^?1 in candy and cosmetics. In lipsticks alone, only 25% of 40 samples were found to meet the requirement. Therefore, continuous use of cosmetic products in which lead concentration exceeds the maximum permissible level may pose a health hazard for the female population of South Africa in the long run.     

Exposure assessment for mercury from consumption of marine fish in Iran

Seven species of marine fish in the Persian Gulf and three species of marine fish in the Caspian Sea were collected from the local wholesale market in Mashhad, Iran. The mercury (Hg) concentration in muscle samples was determined by atomic absorption spectrophotometry. High total Hg concentration was found in Anchovy sprat (2.04 ± 1.23 µg g^?1) and Whitecheek shark (1.26 ± 1.85 µg g^?1) and the lowest content was detected in common carp (0.24 ± 0.24 µg g^?1) and Caspian salmon (0.25 ± 0.08 µg g^?1). The mean Hg content in all samples was 0.91 ± 1.07 µg g^?1. All samples of Persian Gulf and one sample of Caspian Sea had mean Hg concentration above 0.5 µg g^?1, the level established by joint FAO/WHO on Food Additives. Results showed that the estimated weekly intake of total Hg by a 60 kg adult is below the provisional tolerable weekly intakes recommended by joint FAO/WHO on Food Additives. For prevention of health risks, populations in Iran need to consume fish in moderate amounts.     

Comparative evaluation of trace elements in the scalp hair of arthritis patients and healthy donors

This study was aimed to evaluate the comparative distribution, correlation and apportionment of selected elements (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb and Zn) in the scalp hair of arthritis patients and healthy subjects. The hair samples collected from the patients (rheumatoid and osteoarthritis) and healthy donors were digested in nitric acid and perchloric acid mixture, followed by the quantification of trace elements using atomic absorption spectrometry. In the case of healthy donors, highest mean concentration was shown by Ca (3240?µg?g^?1), followed by Mg (340?µg?g^?1), Zn (192?µg?g^?1), Fe (184?µg?g^?1) and Pb (27?µg?g^?1), whereas, the estimated average metal levels in rheumatoid arthritis and osteoarthritis patients were 3160, 290, 197, 61 and 23?µg?g^?1, and 3090, 300, 182, 50 and 21?µg?g^?1, respectively. Most of the elements revealed diverse and random distribution in the scalp hair of the donor groups. The correlation study pointed out significant disparities in the mutual relationships among the trace elements in the patients and controls. Principal component analysis and cluster analysis of the element data manifested diverse apportionment of the selected elements in the scalp hair of the patients compared with the healthy counterparts.     

Effects of chronic bisphenol A exposure on hepatic antioxidant parameters in medaka (Oryzias latipes)

Bisphenol A (BPA), the plastic monomer and plasticizer with well-known endocrine-disrupting chemical properties, is widely present in the aquatic environment, but little is known regarding hepatic toxicity in fish. This study assessed the effects of chronic exposure to BPA on the antioxidant defense system of Japanese medaka liver. Fish were exposed to sub-lethal concentrations of BPA (0.1, 1, 10, 100, or 1000?µg?L^?1) for 60 days. Antioxidant parameters were determined and compared with controls. The results showed that the activities of catalase (CAT), superoxide dismutase, glutathione peroxidase, glutathione S-transferase, and the content of reduced glutathione were all induced at 10?µg?L^?1 BPA after 60 days. Further, hepatic CAT was sensitive to BPA at 1?µg?L^?1 concentration. In conclusion, CAT may serve as a potential early biomarker of BPA exposure in aquatic environment.     

Persistence of oxyfluorfen in soil and detection of its residues in rice crop

Oxyfluorfen is a post-emergence herbicide used for control of annual and perennial broad-leaf weeds and sedges in rice. There is increasing concern about persistence of pesticide residues in soils, agricultural products and sub-sequent contamination of ground water through runoff, leaching and drift. Thus, persistence of oxyfluorfen was evaluated under field conditions in a rice cropping system. Oxyfluorfen was sprayed at 240 and 500 g ai ha^?1 application rates to the rice crop as post-emergence herbicide. Paddy grains, straw and soil samples were collected at harvest and analyzed for oxyfluorfen residues by HPLC. Straw samples contained 0.01 and 0.03 µg g^?1 oxyfluorfen residues at 240 and 500 g ha^?1 concentrations, respectively. In the soil, 0.028 and 0.03 µg g^?1 of oxyfluorfen residues were detected when applied at 240 and 500 g ai ha^?1, respectively. However, in rice grains, 0.018 and 0.106 µg g^?1 of oxyfluorfen residues were found in 240 and 500 g ai ha^?1 treated plots. In light of the potential adverse effects of oxyfluorfen, it is important to determine herbicide levels in these crops.     

Concentrations of polycyclic aromatic hydrocarbons in soils of a mangrove forest affected by forest fire

Surface soils affected by forest fires from Igbanko mangrove forest in Nigeria were analyzed for 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) using gas chromatography–mass spectrometry (GC–MS). The total PAHs concentrations in the soils ranged from 63 to 188?µg?kg^?1 dry weight (average: 108?µg?kg^?1). The three predominant PAHs in the soils were naphthalene (Na), fluoranthene (Flu), and benzo(b)fluoranthene (BbF). Compared to the control sample (19?µg?kg^?1), elevated PAHs concentrations were observed in the soils, an indication of some level of PAHs contamination. PAHs source diagnostic ratios of Flu/(Flu?+?Pyr) and Ant/(Ant?+?Phe) indicated that the PAHs have a pyrogenic origin which may have resulted from combustion of grass, wood, or coal. An assessment based on Canadian soil quality guidelines indicated that the studied locations do not pose any serious adverse risk on human health.     

Determination of cobalt by air-assisted liquid–liquid microextraction

Abstract

A rapid and selective technique for extraction, preconcentration and determination of trace amounts of cobalt in water and pharmaceutical samples by air-assisted liquid–liquid microextraction combined with flame atomic absorption spectrometry is proposed. 1-Nitroso-2-naphthol is used as a complexing agent and 1-octanol as an extraction solvent. Parameters relevant for analytical effectivity, i.e. pH of sample solution, concentration of complexing agent, volume of extraction solvent, and number of extraction cycles are optimized using a Box–Behnken design. At optimum conditions, a dynamic linear range of 5–600?µg L^?1 is obtained, with a limit of detection of 1.2?µg L^?1. The method is used for determination of Co(II) in environmental water and pharmaceutical samples.     

Fluoride content of Ethiopian khat (Catha edulis Forsk) chewing leaves

The levels of water soluble and total fluoride concentration in 11 different varieties of Ethiopian khat (Catha edulis Forsk, an evergreen stimulant plant) commonly consumed in the country and exported to the neighboring countries were determined by fluoride ion-selective electrode. Known amounts of fresh khat samples were suspended in deionized water, stirred, and the supernatants exposed to a chelator that decomplexes fluoride were assayed. The total fluoride concentration in the leaves was also analyzed after the leaves were dried, charred, and ashed. Water soluble and total fluoride concentration in khat varieties varied, ranging from 0.19 to 0.43 µg g^?1 fresh weight and 3.4 to 7.1 µg g^?1 dry weight, respectively. The fluoride concentration in matured leaves (12 µg g^?1) was higher than that in young leaves (6.5 µg g^?1) dry weight. Assuming that daily khat leaves chewing for an adult is 100 g, fluoride intake from chewing leaves of the analyzed khat varieties is far below the daily fluoride tolerable upper limit. The safe intake of fluoride is recommended to be 1.5–4.0 mg day^?1 for adults and less for children. However, chewing khat leaves may contribute a significant amount of fluoride for the total daily intake of an individual and should not be overlooked while estimating the total dietary intake of fluoride for individuals chewing khat leaves regularly.     

Fish as an indicator of aquatic environment: Multielemental neutron activation analysis of nutrient and pollutant elements in fish from Indian coastal areas

Fish is the main food in coastal areas and its analysis for toxic metals has been used as an indicator of the pollution status of the aquatic environment. Several different fish species from the three Indian coasts, Visakhapatnam in the east, Mumbai in the west and Mangalore in the south west and also inland freshwater fish from Nagpur in the central region for comparison were analyzed for up to 20 elements (As, Au, Ba, Br, Cl, Co, Cr, Cu, Fe, Hg, K, Mn, Na, P, Rb, Sb, Sc, Se, Sr, Zn) by instrumental neutron activation analysis (INAA). Dried fish samples in powdered form were irradiated with thermal neutrons in a nuclear reactor followed by high resolution gamma ray spectrometry at different intervals. Several Reference Materials (RMs) of biological origin were analyzed for quality assurance and data validation. Elemental contents in different fish species vary in a wide range depending on the species, its size, location, and aquatic environment. Fish from Mangalore showed highest mean contents of Cr (14.8?±?29.9?µg?g^?1), Cu (1005?±?643?µg?g^?1) and Sb (849?±?888?ng?g^?1) whereas those from Mumbai exhibited highest Hg (2066?±?2146?ng?g^?1) and P (20.3?±?4.63?µg?g^?1) but lowest Cu (6.30?±?3.10?µg?g^?1) contents. Fish from all the regions showed significant amounts of nutrient elements such as Na, K, P, Mn, Fe, Se and Zn as well as some pollutant elements (Br, Cr, Sb, Hg). No regularity in variation of elemental contents with the size was observed. Prawn (Panaeus latisulcatus), a popular fish species from four different regions showed wide variation in elemental contents of Cr, Mn, Fe, Zn, Se, P including toxic pollutants, Sb and Hg. An attempt has been made to calculate daily dietary intake (DDI) for some nutrient elements from Indian fish. Elemental data for Cr, Cu, Fe, Hg, Se, and Zn have been compared with those from other fish exporting countries.     

Assessment of metals in soil extracts and their uptake and movement within Tamarix nilotica at Lake Nasser banks,Egypt

This study aims to determine heavy-metal levels in soil from the banks of Lake Nasser, the ability of Tamarix nilotica to accumulate such metals from soil and hence its potential for phytoextraction. Soil and Tamarix samples were collected from the banks of four bights around Lake Nasser and analysed for Fe, Mn, Ca, Mg, Cr, Cu, Ni, Zn, Cd and Pb by atomic absorption spectrometry, whereas Na and K were measured by atomic emission spectrophotometry. Three different methods of extraction were used for the soil samples. Lead, copper and zinc were equally distributed between the exchangeable phase and Fe/Mn oxide-bound form, while other measured metals were mainly present in the Fe/Mn oxide fraction. With the exception of iron, all metals studied showed total concentrations within the geochemical background values. T. nilotica exhibited elevated concentrations of Na (36.2–48.5?mg?g^?1) and K (2.74–4.33?mg?g^?1) in stems, and relatively high concentrations of Pb, Cd and Co (0.39–1.03?µg?g^?1, 0.24–1.3?µg?g^?1 and 1.94–5.3?µg?g^?1, respectively) are found in plant leaves. Bioaccumulation factors of Na and K (9.3 and 12.63, respectively) were high in T. nilotica stems. While the bioaccumulation of Pb, Cd, Co and Ni (2870.1, 2035.4, 10.5 and 5313.2, respectively) was high in plant leaves, Fe, Mn, Ca and Mg were accumulated relatively equally in plant stems and leaves. T. nilotica was found to secrete high amounts of Na, Ca and K, in addition to small amounts of all accumulated metals except Cd and Cu. These secreted metals appeared as salt crystals (67.5% Na; 25.8% Ca; 5% Mg; 1.5% K and 0.16% trace and minor elements) on the plant surface. The concentrations of all the metals studied in T. nilotica were higher than in the salt crystals. Statistical analysis of the database suggests bioaccumulation of these metals from soil to T. nilotica. This reflects the importance of using T. nilotica as a model in the phytoremediation process as an established environmental clean-up technology.     

Low blood lead levels and hemoglobin concentrations in preschool children in China

It is well known that lead (Pb) produces reduced haemoglobin (Hb) levels and risk of anemia when blood lead levels (BPb) are greater than 20?µg?dL^?1. Two recent studies reported an increased risk of anemia in children with BPb between 10–20?µg?dL^?1, but few studies examined the association between Hb levels or risk of anemia and BPb under 10?µg?dL^?1. In the present study this association was examined using data of 140 preschool children from a larger prospective cohort study in China. Data showed that compared to children with BPb <5?µg?dL^?1, children with BPb between 7.5–10?µg?dL^?1 had significantly lower Hb levels, but there were no marked differences for other groups. A linear regression model showed a negative relationship between BPb and Hb levels after controlling for age, gender, height, weight, and iron (Fe) deficiency. This finding, although limited by a small sample size, suggests it may be important to examine Pb-induced hemosynthesis effect at concentrations less than 10?µg?dL^?1.     

Distribution of mercury in the sediments of some freshwater bodies in Ethiopia

Sediment samples were collected from Tinishu Akaki River (TAR), Lake Awassa, and Lake Ziway, Ethiopia for determination of mercury. The air-dried samples were analyzed for mercury with a differential atomic absorption spectrometer after thermal evaporation of bound mercury converting it to its atomic form. Certified reference materials (CRMs) of sediments and soils were used to validate the method. The recovery of mercury from CRMs and sediments was in the range of 95–100%. The limit of detection for the determination of mercury was 50?ng?kg^?1. The concentration of total mercury in the sediments varied from 3.9 to 110?µg?kg^?1 for TAR, 14 to 67?µg?kg^?1 for Lake Awassa, and 17 to 110?µg?kg^?1 for Lake Ziway. It was found that the total mercury concentrations in all samples were below the United States Environmental Protection Agency guideline of 200?µg?kg^?1.     

The accumulation levels of heavy metals (Ni,Cr, Sr, & Ag) in marine algae from southwest coast of India

In the context of use of marine algae as biological indicators of heavy metal pollution in coastal waters, six species of marine algae collected from the southwest coast of India were analysed for the levels of heavy metals (Ni, Cr, Sr, and Ag). Interspecies and interclass variations were determined on a spatial and temporal scale. The metal contents varied in the ranges, Ni: 0.20–21.06?µg?g^?1 (mean?=?10.13?µg?g^?1), Cr: non-detectable level (ND)–37.18?µg?g^?1 (mean?=?13.86?µg?g^?1), Sr: 2.19–103.90?µg?g^?1 (mean =?29.40?µg?g^?1), and Ag: ND–6.39?µg?g^?1 (mean?=?1.80?µg?g^?1). Ni and Cr contents were of similar magnitude to those reported for algae from polluted areas.     

Abstracts to forthcoming papers

Food is the major source of metal exposure for the nonsmoking general population. Food samples of plant and animal origin from Ismailia, Egypt, were analyzed for the content of cadmium (Cd), lead (Pb), chromium (Cr), zinc (Zn), and copper (Cu) using AAS. The Cr, Zn, and Cu concentrations were in the range of 1.7–249?µg?kg^?1 wet weight (ww), 2–66?mg?kg^?1?ww, and 0.5–3.46?mg?kg^?1?ww, respectively. The mean daily intake of Cr, Zn, and Cu was 28.9?µg day^?1, 8.55?mg day^?1, and 1.7?mg day^?1, respectively. The intake estimates are within the range of the recommended intake established internationally. Concentrations of Cd and Pb were in the range of 10–321?µg?kg^?1?ww and 31–1200?µg?kg^?1?ww, respectively. The weekly dietary intake for Cd and Pb (4.02 and 20.4?µg?kg^?1 b.w, respectively) is lower than the FAO/WHO PTWI. Bread is the foodstuff that provided the highest rate of Pb and Cd (62 and 46% of the daily intake) to adults in Ismailia city.     

Potential correlation between perfluorinated acids and liver morphology in East Greenland polar bears (Ursus maritimus)

In this study, residual concentrations of chlorpyrifos (CPF) were determined in feed (40) and fodder (25) samples collected from various locations of Tarai region of Uttarakhand. For extracting residues, liquid–liquid partition followed by alumina column clean up was used and the detection and quantification of residues was undertaken with the help of high-performance liquid chromatography using C18 column and diode array detector at 220?nm. Of the total 40 feed samples analyzed, 7 (17.5%) samples were found positive for CPF with the mean residual concentration of 0.058?µg?g^?1; while out of 25 fodder samples, CPF residues were detected in a single (4%) sample with residual concentration of 0.39?µg?g^?1. However, none of the feed or fodder samples contained CPF residues above the prescribed limit.     

Microbiological and mycotoxicological contamination in Slovenian primary grain production

This study was aimed at investigating the contamination of grains, which are grown and used for animal diets by Slovene farmers. A total of 107 samples were examined for mesofilic aerobic molds and yeasts. The leading contaminants among molds were from Fusarium spp., detected in 73 samples, mostly in maize (50). In accordance with the European Feed Microbiology Organisation criteria, 68% of all tested samples were of the quality level I, with normal microbiological flora, and 9% of samples were estimated as quality level IV and not suitable for animal feed. Using liquid and gas chromatography methods, the presence of various mycotoxins (expressed as 12% of moisture content) was found in 77% of all samples; mostly deoxynivalenol (71%) in concentration of 150–14,420 µg kg^?1, followed by zearalenone (32%, 20–640 µg kg^?1), fumonisin B1 (31%, 10–4863 µg kg^?1), fumonisin B2 (22%, 10–1629 µg kg^?1), while HT-2 and T-2 toxins were found in low concentration in two samples, and aflatoxin B1 and ochratoxin A in one sample. By statistical evaluation, significant positive correlations were noted between the presence of deoxynivalenol and zearalenone as well as between fumonisin B1 and B2.     

Seasonal changes in inorganic nutrient concentration in the alexandria western harbour (Egypt)

Surface and bottom water samples were collected on a monthly basis from six locations in the Alexandria Western Harbour between April 2002 and March 2003. Total nitrogen, ammonia, nitrite, nitrate, total phosphorus, reactive phosphate and silicate were analysed. The average content of total nitrogen ranged from 81.1 to 65.7?µmol?l^?1 in the surface and bottom waters, respectively, while ammonia ranged from 13.77 to 15.79?µmol?l^?1 in surface and bottom waters, respectively. Also, the average concentration of nitrite was relatively higher in surface waters than in bottom waters (0.89 and 0.61?µmol?l^?1, respectively). The results of this study also indicated a considerable temporal variation in nitrate concentrations which ranged from 1.12 to 13.83?µmol?l^?1. Total phosphorus displayed an irregular pattern throughout the year, ranging from 1.9 to 11.8?µmol?l^?1 in surface waters and from 1.7 to 9.1?µmol?l^?1 in bottom waters. The results of PO₄-P analysis showed higher values in surface waters (0.28–2.75?µmol?l^?1) than in bottom waters (0.10–1.70?µmol?l^?1). The average concentration of silicates was relatively lower in the surface than in the bottom waters (8.97 and 10.1?µmol?l^?1, respectively). The analysis of variance (ANOVA) among seasons and sites revealed significant differences for ammonia, total nitrogen and phosphate, while nitrate showed no significant differences among stations. Finally, silicate did not show any significant variance among sites and seasons (ANOVA, P?>?0.05).     

Online solid phase preconcentration using EGDMA–MAA copolymer for lead determination by FAAS

A Ethylene glycol dimethacrylate (EGDMA) methacrylic acid (MAA) resin was used for preconcentration of lead at trace levels in water samples. For this purpose, a flow-injection, solid phase extraction method was developed for the determination of lead by flame atomic absorption spectrometry. Lead ions were sorbed on a EGDMA–MAA column at pH 4, followed by an elution step using 288 µL of 4.0 M nitric acid solution and determination by flame atomic absorption spectrometry. Optimum conditions for quantitative sorption involving the pH, sample volume, loading and elution flow rates, eluent type, and volume were investigated. A 868-fold enrichment factor could be reached. The detection limit for the water samples, estimated from the noise on the signal obtained for 250 mL of 10 µg L^?1 loaded at 4.9 mL min^?1 was 1.04 µg L^?1. The method was applied for lead determination in river water samples collected in Edirne, Turkey. Recoveries of spiked solutions (10 µg L^?1) to river water samples were quantitative. Finally, the method was validated by the analysis of certified reference material SRM 2704 (Buffalo River Sediment).