Formation of resistance in the Chironomus plumosus to four pesticides over 45 generations

A study was conducted on the Chironomus plumosus larvae to determine initiation of resistance to four pesticides – chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, and malathion. First generational LC₅₀ values were well within the threshold value for chironomids based upon the literature. Subsequent LC₅₀ values were observed to increase, indicating a lessening of the toxicity of the pesticides to the chironomid. In the case of chlorfenvinphos, the 96 h LC₅₀ for generations 1–23 was 6 µg L^?1, in generations 3–7 was 8.57 µg L^?1 and 11.14 µg L^?1 for generations 8–9. Generations 10–12 had an LC₅₀ value of 22.58 µg L^?1 and generation 13 had an LC₅₀ value of 35.08 µg L^?1. Generation 14 had an LC₅₀ value of 47.58 µg L^?1. Generations 15–19 and 20–24 had 96 h LC₅₀ values of 60.68 µg L^?1, 72.58 µg L^?1, 85.08 µg L^?1, 97.58 µg L^?1 and 110.08 µg L^?1, respectively. Generations 25, 26 to 30, 31 to 38 and 39 to 45 had 96 h LC₅₀ values of 160.42 µg L^?1, 210.7 µg L^?1, 262.24 µg L^?1 and 274.36 µg L^?1, respectively. The variation between LC₅₀ values was found to be statistically significant. This was observed for most pesticides tested. Larval size and life cycle duration was observed to change from generation to generation with the body size decreasing markedly from 1 to 0.3 cm with life cycle increasing from 7 to 39 days.     

Urinary arsenic methylation profile in children exposed to low arsenic levels through drinking water

There is a lack of information on arsenic metabolism in children exposed chronically to low levels of arsenic (<50 µg L^?1). The objective of this study was to determine the methylation profile of urinary arsenic metabolites in children exposed to low-level concentrations of arsenic via their drinking water. A cross-sectional study was undertaken in 50 children from four towns in the Yaqui Valley, Sonora, with total arsenic values of 39.9, 16.8, 7.3, and 5.5 µg L^?1 in their drinking water, respectively. First morning void samples were analyzed for inorganic-As (InAs), mono and dimethyl arsenic (MMA and DMA). The total arsenic excreted in urine ranged from 23.1 to 99.1 µg L^?1 and these levels did not vary by sex. Children with the highest level of total arsenic in their drinking water excreted the highest amount in urine and the length of residence and age also had significant contribution. Children with a lower range of arsenic exposure (16.8–5.5 µg L^?1) had similar amounts of arsenic in urine with values of 23.1, 28.2, and 32.6 µg L^?1, respectively. DMA had the highest proportion in urine (52.1–74.7%), followed by InAs (16.3–34.9%) and MMA (4.4–8.4%). Compared to other reports, these children excreted a low %MMA (6.1%), and children from the towns with the lowest levels of arsenic had the highest %InAs and the lowest %DMA. This variability in arsenic methylation was partially explained by arsenic concentration in drinking water, years of residence and age, and may reflect genetic differences or more contribution from different exposure routes. In conclusion, our results show that at low levels of exposure the children's ability to metabolize InAs did not have a linear association with the levels of arsenic, and overall children from the Yaqui Valley excrete a lower %MMA than expected.     

Uranium quantification in groundwater and health risk from its ingestion in Haryana,India

Uranium is a naturally occurring radioactive element which may cause toxicological or radiological hazards to the public if present in drinking water. This study reports the quantification of uranium in groundwater of major towns of the district Fatehabad, Haryana, India. Uranium concentrations ranged between 0.3 and 48 μg L^?1. In 22% of the groundwater samples, uranium concentrations were higher than the World Health Organization maximum permissible limit of 30 µg L^?1. The radiological dose for males was found to be in the range of 4.8?×?10^?4–7.1?×?10^?2 mSv y^?1 and for females 3.5?×?10^?4–5.2?×?10^?2 mSv y^?1. The results showed that due to the ingestion of groundwater in the study area, radiological cancer risk is in the range of 9.1?×?10^?7–1.3?×?10^?4, lower than the risk limit. Uranium ingestion from groundwater varied from 0.02 to 3.5 µg kg^?1 day^?1, which is within acceptable limit.     

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).     

Arsenic in freshwater ecosystems of the Bengal delta: status,sources and seasonal variability

The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L^?1 (mean 31 ± 2 µg L^?1) and sediment 1.3–37.3 mg kg^?1 (mean 10.3 ± 0.4 mg kg^?1), than those from the unaffected area: water 1–8 µg L^?1 (mean 4 ± 0 µg L^?1) and sediment 1.4–5.3 mg kg^?1 (mean 3.0 ± 0.1 mg kg^?1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region.     

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.     

Electrochemical hydride generation of tin(II) and its determination by electrothermal atomic absorption spectrometry with in situ trapping in the graphite tube atomizer

An electrolytic hydride generation system for the determination of tin(II) by means of batch electrochemical hydride generation-electrothermal atomic absorption spectrometry (EcHG-ETAAS) with in situ trapping in a graphite tube atomizer is described. The effects of four permanent chemical modifiers – palladium, tungsten, iridium, and platinum – for graphite tube treatment on analyte absorbance and the effects of four cathode materials, i.e., Pb, Sn, Pb–Sn alloy, and glassy carbon, are checked. Three electrolytes, i.e., nitric acid, sulfuric acid, and hydrochloric acid, are examined as catholyte solutions. The influence of several parameters on EcHG is investigated using multivariate and univariate methods. Interferences of some concomitant ions are evaluated. The calibration curve is linear from 1 to 200?µg?L^?1, with a detection limit of 0.8?µg?L^?1 and a relative standard deviation of 6.2% (n?=?3) for 100?µg?L^?1 Sn(II). The proposed method was successfully applied in the analysis of real environmental water samples and reference materials, and good spiked recoveries over the range of 93.1–115% were obtained. The proposed technique provides a means for developing hydride generation of other elements.     

Contamination status of arsenic,lead, and cadmium of different wetland waters

The present investigation was conducted to determine the contamination status of arsenic (As), cadmium (Cd), and lead (Pb) in the wetland waters of Bhaluka in Bangladesh. Water samples were collected from 15 selected wetlands of Bhaluka region and analyzed using an atomic absorption spectrophotometer. Estimated results of three metals detected were As (7–80?µg?L^?1), Pb (0–86?µg?L^?1) and Cd (0–70?µg?L^?1) in water samples in all wetlands. The level of As in all investigated wetlands (93%) was higher than that of WHO recommended permissible limit of drinking water except Alanga wetland. However, As levels were higher than that recommended for livestock water quality levels. Eighty-seven percent of the investigated wetlands showed lower content of Pb than WHO recommended permissible limit of drinking water, but two wetland waters (Dohuria-1 and Chowdhuri) were polluted with higher Pb levels. Sixty-seven percent of the investigated wetlands displayed higher levels of Cd than WHO recommended permissible limit in drinking water. Dissolved organic material showed no significant difference among the 15 investigated wetlands water, but total dissolved solids was significantly greater. The condition of the water of all wetlands was basic pH. All water samples were applied to linear regression equation and correlation coefficients where values showed no significant differences. Data demonstrate that the estimated high metal concentrations of these ponds may contribute to bioaccumulation within plants, food grains and shrimp.     

Green chemistry approach to analysis of formic acid and acetic acid in aquatic environment by headspace water-based liquid-phase microextraction and high-performance liquid chromatography

A simple and totally organic-free (green) method, viz. headspace water-based liquid-phase microextraction combined with high-performance liquid chromatography-ultraviolet detection has been successfully developed for analysis of formic acid and acetic acid in environmental water samples. A microdrop of an aqueous solution of sodium hydroxide was suspended from the tip of a microsyringe needle over the headspace of the stirred sample solution containing the analytes at pH 1.0 for a given time. The microdrop was then retracted into the microsyringe, diluted with HPLC mobile phase, and injected to HPLC. Optimum efficiency has been achieved for: 3.0 µL NaOH microdrop (0.1 mol L^?1) exposed for 15 min over the headspace of an aqueous sample of 6.5 mL at 55 °C, containing 15% w/v of Na₂SO₄, adjusted to pH = 1.0 and stirred at 750 rpm. Under these conditions, enrichment factors of 162 and 187, limits of detection of 0.3 and 0.1 µg L^?1 (S/N = 3) with dynamic linear ranges of 1–500 and 0.5–500 µg L^?1 were obtained for formic acid and acetic acid, respectively. A reasonable repeatability (5.8% ≤ RSD ≤ 8.8%, n = 6) and satisfactory linearity (r² ≥ 0.997) illustrated the performance of the method.     

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.     

In vivo uptake of iodine from a <Emphasis Type="Italic">Fucus serratus</Emphasis> Linnaeus seaweed bath: does volatile iodine contribute?

Seaweed baths containing Fucus serratus Linnaeus are a rich source of iodine which has the potential to increase the urinary iodide concentration (UIC) of the bather. In this study, the range of total iodine concentration in seawater (22–105 µg L^?1) and seaweed baths (808–13,734 µg L^?1) was measured over 1 year. The seasonal trend shows minimum levels in summer (May–July) and maximum in winter (November–January). The bathwater pH was found to be acidic, average pH 5.9 ± 0.3. An in vivo study with 30 volunteers was undertaken to measure the UIC of 15 bathers immersed in the bath and 15 non-bathers sitting adjacent to the bath. Their UIC was analysed pre- and post-seaweed bath and corrected for creatinine concentration. The corrected UIC of the population shows an increase following the seaweed bath from a pre-treatment median of 76 µg L^?1 to a post-treatment median of 95 µg L^?1. The pre-treatment UIC for both groups did not indicate significant difference (p = 0.479); however, the post-treatment UIC for both did (p = 0.015) where the median bather test UIC was 86 µg L^?1 and the non-bather UIC test was 105 µg L^?1. Results indicate the bath has the potential to increase the UIC by a significant amount and that inhalation of volatile iodine is a more significant contributor to UIC than previously documented.     

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.     

Effects of sublethal concentrations of permethrin on bioaccumulation of cadmium in zebra cichlid (Cichlasoma nigrofasciatum)

The aim of this study was to evaluate the synergistic and antagonistic effects of permethrin on the bioaccumulation of cadmium in zebra cichlid (Cichlasoma nigrofasciatum). Zebra cichlid was exposed to various sublethal concentrations of permethrin combined with cadmium chloride for 15 days. Although at the lowest concentrations, permethrin (0.40 µg L^?1) decreased the bioconcentration potential of cadmium in fish, bioaccumulation of cadmium increased along with increasing concentrations of permethrin (0.80–1.20 µg L^?1). However, the magnitude of changes in the accumulation of cadmium in the fishes simultaneously exposed to 1.60 µg L^?1 permetrin and cadmium chloride was similar to the cadmium levels observed in fishes after exposure to the cadmium chloride alone. The results of this study suggest that the synergistic effects of permethrin on the bioaccumulation of cadmium highly depend on the concentrations of this pesticide in water.     

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.     

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.     

Estimate of zearalenone exposure through the intake of white and brown rice in the Korean population

Rice samples (n = 482) harvested for 2010–2012 in South Korea were analyzed for zearalenone content by high-performance liquid chromatography and fluorescence detection. The exposure of the Korean populations was assessed by a deterministic approach. Because the proportion of non-detectable results was >80% in white rice but less than <60% in brown rice, the zearalenone levels for white rice were reported as 0.52 µg kg^?1 as lower bound and 2.54 µg kg^?1 as upper bound, while for brown rice the middle bound value was 13.9 µg kg^?1. The average dietary intake of zearalenone from white and brown rice by the Korean population was estimated to be 1.5 ng kg^?1 body weight (bw) day^?1 each. For heavy consumers, the average intakes were 18.5 and 10.1 ng kg^?1 bw day^?1, respectively. The age groups with the highest zearalenone intake were 1–2-year-old children for white rice and 3–6-year-old children for brown rice. Overall, the dietary exposure of the Korean population to zearalenone from white and brown rice was found to be lower than the provisional maximum tolerable daily intake of 0.5 μg kg^?1 bw day^?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.     

Accumulation of lead and cadmium by four tropical forage weeds found in the premises of an automobile battery manufacturing company in Nigeria

The potentials of tropical weeds namely, Nephrolepis biserrata, Panicum maximum, Eleusine indica, and Chromolaena odorata to accumulate lead (Pb) and cadmium (Cd) from soil within the premises of an automobile battery manufacturing company in Ota, south-western Nigeria, were explored. The weed samples were collected in both wet and dry seasons. Standard analytical methods were employed to collect, digest, and analyze the weeds. Lead levels in the weeds for both seasons ranged from 1990–4870, 1090–1730, 4800–7890, and 400–1210 µg g^?1 dry weight (DW) for Nephrolepis biserata, Panicum maximum, Eleusine indica, and Chromolaena odorata, respectively, while the cadmium level in the weeds for both seasons ranged from 3.92–6.78 µg g^?1 DW for N. biserata, 1.99–6.85 µg g^?1 DW for P. maximum, 2.90–7.40 µg g^?1 DW for E. indica, and 2.90–5.09 µg g^?1 DW for C. odorata. There was no significant difference in the accumulation of both Pb and Cd for the two seasons. All the weeds showed Pb levels higher than the phytotoxic range. On the contrary, 99% of the weeds showed Cd concentration within the phytotoxic range. The weeds demonstrate good phytoremediation potentials of contaminated soil.     

The impact of artisanal gold mining,ore processing and mineralization on water quality in Marmato,Colombia

Marmato, Colombia, has been an important centre of gold mining since before the first Spanish colonizers arrived in 1536. The Marmato deposit is hosted in a dacite and andesite porphyry stock as sheeted sulphide-rich veinlet systems. The district is currently experiencing a surge in both major mining projects and artisanal mining, driven by sustained high gold prices. Ore from small-scale and artisanal gold mining is processed in numerous small mills (entables) around Marmato, which impact surface water quality through the discharge of milled waste rock slurry, highly alkaline cyanide-treated effluent, and high dissolved metal loads. To investigate the impact of artisanal mining and ore processing, water samples were collected in January 2012 from streams around Marmato. The average dissolved metal concentrations in impacted streams were Zn, 78 mg L^?1; Pb, 0.43 mg L^?1; Cu, 403 µg L^?1 Cd, 255 µg L^?1; As, 235 µg L^?1; Ni, 67 µg L^?1; Co, 55 µg L^?1; Sb, 7 µg L^?1; and Hg, 42 ng L^?1, exceeding World Health Organization drinking water guidelines. In addition, arsenic speciation was conducted in-situ and indicated that 91–95% of inorganic arsenic species is in the form of As(V). Spatial analysis of the data suggests that entables processing ore for artisanal miners are the main contributor to water pollution, with high sediment loads, alkalinity and elevated concentrations of dissolved arsenic, cadmium, mercury and lead, caused by the processing of gold-bearing sulphides in the entables. Geochemical data from surface water were compared to a comprehensive data set of whole rock analyses from drill core and channel samples from the deposit, indicating that the deposit is significantly enriched in gold, silver, lead, zinc, arsenic, antimony, and cadmium compared to crustal averages, which is reflected in the surface water geochemistry. However, elevated mercury levels in surface water cannot be explained by enrichment of mercury in the deposit and strongly suggest that mercury is being added to concentrates during ore processing to amalgamate fine gold.