Abstract  Health risk assessment (HRA) is the process used to estimate adverse health effects on humans. The importance and sensitivity of food chains to HRA have been observed, but the impact of the transportation of food has generally been ignored. This study developed an exposure assessment to demonstrate the significance of the transportation of agricultural products in HRA. The associated case study estimated the health risks derived from various sources of arsenic emissions in Taiwan. Two assessment scenarios, self-sufficiency and transportation of agricultural products, were compared to calculate risk transfer ratios that show the impact of agriculture transportation. The risk transfer ratios found by the study range from 0.22 to 42.10, indicating that the quantity of transportation of agricultural products is the critical factor. High air deposition and high agricultural production are the two main contributors to the effect of the transportation of agricultural products on HRA. Risk reduction measures could be applied to high-pollution areas as well as to areas with high agricultural productivity to reduce ingestion risks to residents. Certain areas that are sensitive to the transportation of agricultural products may incur more risks if emissions increase in agriculturally productive counties.

Abstract  Limited information is available on the bioaccessible fraction of trace metals in the resuspended fraction of settled bus dust in order to estimate bus drivers' occupational exposure. In this study, 45 resuspended fraction of settled dust samples were collected from gasoline and compressed natural gas (CNG) powered buses and analyzed for trace metals and their fraction concentrations using a three-step sequential extraction procedure. Experimental results showed that zinc (Zn) had the greatest bioaccessible fraction, recorded as an average of 608.53mg/kg, followed in order of decreasing concentration by 129.80mg/kg lead (Pb), 56.77mg/kg copper (Cu), 34.03mg/kg chromium (Cr), 22.05mg/kg nickel (Ni), 13.17mg/kg arsenic (As) and 2.77mg/kg cadmium (Cd). Among the three settled bus dust exposure pathways, ingestion was the main route. Total exposure hazard index (HIt) for non-carcinogenic effect trace metals was lower than the safety level of 1. The incremental lifetime cancer risk (ILCR) for drivers was estimated for trace metal exposure. Pb and Ni presented relatively high potential risks in the non-carcinogenic and potentially carcinogenic health assessment for all drivers. ILCR was in the range of 1.84E-05 to 7.37E-05 and 1.74E-05 to 6.95E-05 for gasoline and CNG buses, respectively.

Abstract  Occupational skin cancer was reviewed, and the theory of cutaneous carcinogenesis was summarized. Skin cancer development involves at least three mechanistically distinct steps: initiation of mutagenic damage in cellular DNA, repeated exposure to promoting agents to stimulate proliferation of initiated cells, and conversion of premalignant tumors to malignancy. The conversion step may occur spontaneously, but its frequency may increase with exposure to certain initiating agents. Some agents, such as ultraviolet (UV) radiation, act as both initiators and promotors and are termed complete carcinogens. The roles of UV radiation, ionizing radiation, polycyclic aromatic hydrocarbons, arsenic (7440382), and immunosuppression in nonmelanoma skin cancer was discussed. Arsenic is in a category distinct from other skin carcinogens since skin tumors associated with arsenic have been attributed to ingestion, injection, or inhalation, rather than from skin contact. Immunosuppressive agents have been shown to increase the incidence of tumors on previously sun exposed regions of the body. While data comes from therapeutic rather than occupational exposure to immunosuppressive agents, a similar effect is possible with exposure to immunosuppressive industrial chemicals. Mycosis fungoides and the Sezary syndrome are relatively rare cutaneous neoplasms that arise from thymus derived helper T-lymphocytes. In a study of 44 cases at the U. S. National Cancer Institute, 40 of the patients had a history of often prolonged chemical exposure at the onset of their skin disease. In another study, an industrial background was over four times more common in patients with mycosis fungoides than in the control group, with machinist and machine operator being the most frequent occupational background. Malignant melanoma was discussed. Mortality from malignant melanoma has been steadily increasing in the fair skinned populations over the past several decades. Major etiologic agents in malignant melanoma are UV radiation and environmental chemical agents. Sunlight appears to be an important factor in melanoma genesis, particularly in those with hereditary susceptibility. Other occupational and environmental factors may play a role, but the mechanisms and causal agents are not adequately defined. Increased melanoma incidence has been reported in several occupational groups including chemists, architects, accountants, and business owners, but the interpretation of these associations is confounded by the strong association of melanoma in the general population with higher socioeconomic status.

Abstract  In Germany, the Human Biomonitoring Commission of the German Federal Environment Agency was established in 1992 to develop scientifically based criteria for the application of human biomonitoring (HBM). The goal is to clarify fundamental and practical issues related to HBM. Following the assessment of pollutants in body fluids, the commission derives two different kinds of guideline values: reference values and HBM values (HBM I and HBM II values). This article gives a review of the current reference values, HBM values, and the work of the German Human Biomonitoring Commission. (C) 2007 Elsevier GmbH. All rights reserved.

Abstract  Reactions of As(III) and As(V) with pyrite were investigated using pristine pyrite (produced and reacted in a rigorously anoxic environment with P(O2)<10(-8)atm) and using surface-oxidized pyrite (produced under anoxic conditions, exposed to air, then stored and reacted under rigorously anoxic conditions). Results with surface-oxidized pyrite were similar to previously reported arsenic-pyrite results. However As(III) adsorbed over a broader pH range on pristine pyrite than on surface-oxidized pyrite, As(V) adsorbed over a narrower pH range on pristine pyrite than on surface-oxidized pyrite, and adsorbed As(V) on pristine pyrite was reduced to As(III) but adsorbed As(V) was not reduced with surface-oxidized pyrite. Reduction of As(V) with pristine pyrite was first-order in total As(V), Fe(II) was released, and sulfur was oxidized. The proposed mechanism for pyrite oxidation by As(V) was similar to the published mechanism for oxidation by O(2) and rates were compared. The results can be used to predict the removals of As(V) and As(III) on pyrite in continuously anoxic environments or on pyrite in intermittently oxic/anoxic environments. Rigorous cleanup and continuous maintenance of strictly anoxic conditions are required if commercial or produced pyrites are to be used as surrogates for pristine pyrite.

Abstract  Chronic human exposure to inorganic arsenic (iAs), a potent environmental oxidative stressor, is associated with increased prevalence of type 2 diabetes, where impairment of pancreatic β-cell function is a key pathogenic factor. Nuclear factor E2-related factor 2 (Nrf2) is a central transcription factor regulating cellular adaptive response to oxidative stress. However, persistent activation of Nrf2 in response to chronic oxidative stress, including inorganic arsenite (iAs³⁺) exposure, blunts glucose-triggered reactive oxygen species (ROS) signaling and impairs glucose-stimulated insulin secretion (GSIS). In the current study, we found that MIN6 pancreatic β-cells with stable knockdown of Nrf2 (Nrf2-KD) by lentiviral shRNA and pancreatic islets isolated from Nrf2-knockout (Nrf2⁻/⁻) mice exhibited reduced expression of several antioxidant and detoxification enzymes in response to acute iAs³⁺ exposure. As a result, Nrf2-KD MIN6 cells and Nrf2⁻/⁻ islets were more susceptible to iAs³⁺ and monomethylarsonous acid (MMA³⁺)-induced cell damage, as measured by decreased cell viability, augmented apoptosis and morphological change. Pretreatment of MIN6 cells with Nrf2 activator tert-butylhydroquinone protected the cells from iAs³⁺-induced cell damage in an Nrf2-dependent fashion. In contrast, antioxidant N-acetyl cysteine protected Nrf2-KD MIN6 cells against acute cytotoxicity of iAs³⁺. The present study demonstrates that Nrf2-mediated antioxidant response is critical in the pancreatic β-cell defense mechanism against acute cytotoxicity by arsenic. The findings here, combined with our previous results on the inhibitory effect of antioxidants on ROS signaling and GSIS, suggest that Nrf2 plays paradoxical roles in pancreatic β-cell dysfunction induced by environmental arsenic exposure.

Abstract  A comparative hydrogeochemical study was carried out in West Bengal, India covering three physiographic regions, Debagram and Chakdaha located in the Bhagirathi-Hooghly alluvial plain and Baruipur in the delta front, to demonstrate the control of geogenic and anthropogenic influences on groundwater arsenic (As) mobilization. Groundwater samples (n=90) from tube wells were analyzed for different physico-chemical parameters. The low redox potential (Eh=-185 to -86mV) and dominant As(III) and Fe(II) concentrations are indicative of anoxic nature of the aquifer. The shallow (<100m) and deeper (>100m) aquifers of Bhagirathi-Hooghly alluvial plains as well as shallow aquifers of delta front are characterized by Ca(2+)HCO(3)(-) type water, whereas Na(+) and Cl(-) enrichment is found in the deeper aquifer of delta front. The equilibrium of groundwater with respect to carbonate minerals and their precipitation/dissolution seems to be controlling the overall groundwater chemistry. The low SO(4)(2-) and high DOC, PO(4)(3-) and HCO(3)(-) concentrations in groundwater signify ongoing microbial mediated redox processes favoring As mobilization in the aquifer. The As release is influenced by both geogenic (i.e. geomorphology) and anthropogenic (i.e. unsewered sanitation) processes. Multiple geochemical processes, e.g., Fe-oxyhydroxides reduction and carbonate dissolution, are responsible for high As occurrence in groundwaters.

Abstract  EDTA amendments are widely used for micronutrient fertilization in arid soils, besides their effectiveness in the remediation process of heavy metal from contaminated soils. However, the persistence of EDTA in arsenic contaminated soil may have further negative effects on the grown plants. To investigate the influences of EDTA on soil As, a pot experiment was conducted using a sandy clay loam As-polluted soil treated with gradual rates of EDTA (0, 1.0, 2.5 and 5mmolkg(-1)) and planted with maize for two months. The key findings reveal that EDTA applications increased AB-DTPA extractable and water soluble As significantly. Such increases seemed to be the main reasons behind the increase in As uptake by maize plants as the addition of EDTA at the rates of 1.0, 2.5 and 5.0mmolkg(-1) increased significantly As uptake by shoots 1.5, 2.4 and 3.0 folds, respectively compared to the untreated soil. On the other hand, As uptake by roots did not increase significantly except with the highest application rates of 2.5 and 5.0mmolkg(-1). The results also show that arsenic translocation factor (TF) values were too low to attain successful phytoextraction. In conclusion, the bioavailable fraction of As is important to investigate the phytoextraction and phytotoxicity of As.

Abstract  A simple and selective method is described for the determination of arsenic(III) by kinetic fluorometry. The fluorescence intensity of pyronine B is decreased by adding some KIO(3). However, the fluorescence intensity of pyronine B is further decreased with the presence of arsenic(III), because the pyronine B oxidation by KIO(3) with arsenic(III) as catalyst was formulated in sulfuric acid medium. There is a good linearity between the fluorescence intensity of pyronine B and the concentration of arsenic(III). The method allows for the determination of arsenic(III) in the range from 2.0-300 mu g/L and the limit of detection is 1.4 mu g/L. It has been successfully applied to the determination of arsenic(III) in real samples and the RSD is 2.4% at 100 mu g/L arsenic(III) (n = 11).

Abstract  Aging is characterized by increased sympatho-excitation, expressed through both the α-adrenergic and RAAS (renin-angiotensin-aldosterone) pathways. Although the independent contribution of these two pathways to elevated vasoconstriction with age may be substantial, significant cross-talk exists that could produce potentiating effects. To examine this interaction, 14 subjects (n=8 young, n=6 old) underwent brachial artery catheterization for administration of AngII (angiotensin II; 0.8-25.6 ng/dl per min), NE [noradrenaline (norepinephrine); 2.5-80 ng/dl per min] and AngII with concomitant α-adrenergic antagonism [PHEN (phentolamine); 10 μg/dl per min]. Ultrasound Doppler was utilized to determine blood flow, and therefore vasoconstriction, in both infused and contralateral (control) limbs. Arterial blood pressure was measured directly, and sympathetic nervous system activity was assessed via microneurography and plasma NE analysis. AngII sensitivity was significantly greater in the old, indicated by both greater maximal vasoconstriction (-59±4% in old against -48±3% in young) and a decreased EC50 (half-maximal effective concentration) (1.4±0.2 ng/dl per min in old against 2.6±0.7 μg/dl per min in young), whereas the maximal NE-mediated vasoconstriction was similar between these groups (-58±9% in old and -62±5% in young). AngII also increased venous NE in the old group, but was unchanged in the young group. In the presence of α-adrenergic blockade (PHEN), maximal AngII-mediated vasoconstriction in the old was restored to that of the young (-43±8% in old and -39±6% in young). These findings indicate that, with healthy aging, the increased AngII-mediated vasoconstriction may be attributed, in part, to potentiation of the α-adrenergic pathway, and suggest that cross-talk between the RAAS and adrenergic systems may be an important consideration in therapeutic strategies targeting these two pathways.

Abstract  Constructed wetland (CW) and constructed pond (CP) are commonly utilized for removal of excess nutrients and certain pollutants from stormwater. This study characterized shallow groundwater quality for pre- and post-CW and CP system conditions using data from monitoring wells. Results showed that the average concentrations of groundwater phosphorus (P) decreased from pre-CW to post-CW but increased from pre-CP to post-CP. The average concentrations of groundwater total Kjeldahl nitrogen and ammonium (NH(4)(+)) increased from pre-CW (or CP) to post-CW (or CP), whereas the average concentrations of groundwater arsenic (As), chromium, nickel, and zinc (Zn) decreased from pre-CW to post-CW regardless of the well locations. Variations of groundwater cadmium, copper, and Zn concentrations were larger in pre-CP than in post-CP and had a tendency to decrease from pre-CP to post-CP. In general, the average concentrations of groundwater aluminum and manganese decreased and of groundwater calcium, iron, magnesium, and sodium increased from pre-CP to post-CP. The average values of water levels (depth from the ground surface), redox potential, and conductance decreased and of chloride and sulfate (SO(4)(-2)) increased after the wetland and pond were constructed regardless of the well locations. Results further revealed that there were significant differences (α = 0.05) between the pre- and post-CW (or CP) for redox potential, water level, and As. This study suggests that the CW-CP system had discernible effects on some of the shallow groundwater quality constituents. This information is very useful for fully estimating overall performance of stormwater treatment with the CW-CP system.

Abstract  Whole-cell patch-clamp recordings and high-resolution morphometry were used to assess functional and structural properties of layer 3 pyramidal neurons in early (<4 months) and advanced (>8 months) stages of tauopathy in frontal cortical slices prepared from rTg4510 tau mutant (P301L) mice. In early tauopathy, dendritic architecture is preserved. In advanced tauopathy, neurons can be categorized as either "atrophic" (58 %)-exhibiting marked atrophy of the apical tuft, or "intact" (42 %)-with normal apical tufts and, in some instances, proliferative sprouting of oblique branches of the apical trunk. Approximately equal numbers of atrophic and intact neurons contain neurofibrillary tangles (NFTs) or are tangle-free, lending further support to the idea that NFTs per se are not toxic. Spine density is decreased due to a specific reduction in mushroom spines, but filopodia are increased in both atrophic and intact neurons. By contrast to these morphological changes, which are robust only in the advanced stage, significant electrophysiological changes are present in the early stage and persist in the advanced stage in both atrophic and intact neurons. The most marked of these changes are: a depolarized resting membrane potential, an increased depolarizing sag potential and increased action potential firing rates-all indicative of hyperexcitability. Spontaneous excitatory postsynaptic currents are not reduced in frequency or amplitude in either stage. The difference in the time course of functionally important electrophysiological changes versus regressive morphological changes implies differences in pathogenic mechanisms underlying functional and structural changes to neurons during progressive tauopathy.

Abstract  The oxidation potentials of As(0)/As(III) and Sb(0)/Sb(III) on the gold electrode are very close to each other due to their similar chemistry. Arsenic concentration in seawater is low (10-20 nM), Sb occurring at ~0.1 time that of As. Methods are shown here for the electroanalytical speciation of inorganic arsenic and inorganic antimony in seawater using a solid gold microwire electrode. Anodic stripping voltammetry (ASV) and chronopotentiometry (ASC) are used at pH ≤2 and pH 8, using a vibrating gold microwire electrode. Under vibrations, the diffusion layer size at a 5 μm diameter wire is 0.7 μm. The detection limits for the As(III) and Sb(III) are below 0.1 nM using 2 min and 10 min deposition times respectively. As(III) and Sb(III) can be determined in acidic conditions (after addition of hydrazine) or at neutral pH. In the latter case, oxidation of As(0) to As(III) was found to proceed through a transient As(III) species. Adsorption of this species on the gold electrode at potentials where Sb(III) diffused away is used for selective deposition of As(III). Addition of EDTA removes the interfering effect of manganese when analysing As(III). Imposition of a desorption step for Sb(III) analysis is required. Total inorganic arsenic (iAs=As(V)+As(III)) can be determined without interference from Sb nor mono-methyl arsenious acid (MMA) at 1.6<pH<2 using E(dep)=-1 V. Total inorganic antimony (iSb=Sb(V)+Sb(III)) is determined at pH 1 using E(dep)=-1.8 V without interference by As. The methods were tested in samples from the Irish Sea (Liverpool Bay). As(III) was determined on-board ship immediately after sampling. As(III) concentrations were found to range from 0.44 to 1.56 nM and were higher near the coast. Sb(III) was below the detection limit (<0.1 nM Sb(III)), iAs was comprised between 8 and 25 nM while iSb varied from 0.5 to 1.7 nM.

Abstract  Studies investigating the prognostic role of UA (uric acid) in patients with Type 2 diabetes mellitus have given conflicting findings. We undertook the present study to assess the association between UA and outcome in patients with Type 2 diabetes mellitus and CAD (coronary artery disease). The study included 3705 patients with diabetes mellitus and angiography-proven CAD. UA was measured before coronary angiography. The primary outcome was 1-year all-cause mortality. The UA concentration [median (25th-75th quartiles)] was 6.44 mg/dl (5.40-7.70 mg/dl). There were 264 deaths (7.1%) during follow-up: 45 deaths in patients of the first UA quartile, 43 deaths in patients of the second UA quartile, 51 deaths in patients of the third UA quartile and 125 deaths in patients of the fourth UA quartile {Kaplan-Meier estimates of mortality, 5.1, 4.8, 5.6 and 14.0% respectively; unadjusted HR (hazard ratio), 2.81 [95% CI (confidence interval), 2.21-3.58]; P<0.001 for fourth quartile compared with first-third quartiles combined}. In the multivariable analysis, UA predicted all-cause mortality with an adjusted HR of 1.29 (95% CI, 1.12-1.48; P<0.001), for each S.D. increase in the logarithmic scale of UA level. The inclusion of UA in the multivariable model alongside known cardiovascular risk factors and other relevant variables increased the discriminatory power of the model regarding prediction of all-cause mortality [absolute and relative IDI (integrated discrimination improvement) 0.034 and 20.5% respectively; P<0.001]. In conclusion, in patients with Type 2 diabetes mellitus and confirmed CAD, elevated levels of UA predict mortality independently of known cardiovascular risk factors.

Abstract  Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are an effective treatment for advanced non-small cell lung cancer. The objective of the present study was to compare the efficacy of gefitinib and erlotinib in patients with pulmonary adenocarcinoma, whose tumor EGFR mutation status was known. Pulmonary adenocarcinoma patients who began receiving gefitinib or erlotinib treatment from January 2005 to December 2010, and whose tumor EGFR mutation status had been determined, were included. Clinical data, type of treatment response and survival time data were collected. Of the 224 patients enrolled, 124 received gefitinib treatment and 100 received erlotinib treatment. Of these patients, 146 individuals had tumors with EGFR-activating mutations (exon 19 deletions and/point mutation of L858R in exon 21) and 78 did not. There was no difference in treatment response whether or not the patients had tumors with EGFR-activating mutations at the time they received gefitinib or erlotinib treatment. The median progression-free survival (PFS) of the gefitinib and erlotinib groups was 7.6 and 7.9 months, respectively (p=0.4731). PFS was significantly longer for patients without EGFR-activating mutations who received erlotinib treatment (n=48; median, 4.5 months) than for those who received gefitinib treatment (n=30; median, 2.3 months), with a hazard ratio of 0.58 (95% CI, 0.35-0.96; p=0.0339). Patients whose tumors had EGFR-activating mutations displayed no difference in PFS with either gefitinib (n=94; median, 10.5 months) or erlotinib treatment (n=52; median, 10.4 months). In conclusion, PFS showed no difference with either agent in patients whose tumors had EGFR-activating mutations, but was significantly longer in patients whose tumors did not have EGFR-activating mutations when receiving erlotinib treatment.

Abstract  Biosis copyright: biol abs. rrm fish wildlife pesticide herbicide petroleum hydrocarbon heavy metal pollution industry hazardous waste sediment water quality management

Abstract  The study empirically evaluates the abatement of As(III) uptake in rice seedlings (7d), in presence of Se and phosphate (P) under hydroponic condition. Positive correlation between As(III) translocation to the shoots of As(III) and P treated seedlings, shows P dependent As(III) translocation in rice. Whereas, presence of both P (5 and 10μgml-1) and (0.75μgml-1) of Se significantly reduces the As(III) uptake in rice seedlings. Application of Se alone also reduces As(III) uptake both in shoots and roots significantly, however, the seedlings suffers from lipid peroxidation. Among all the studied treatments, lower rates of P (5μgml-1) and Se (0.75μgml-1) when co-applied, significantly reduced As(III) translocation to the shoots without inflicting much toxicity in the seedlings which is manifested as significant increase in biomass with lower thio-barbituric reactive substances (TBARS). Also, significantly lower TBARS in seedlings receiving As(4)+Se(0.75) and higher TBARS in As(4)+Se(1.5), demonstrates that Se applied at lower rates (0.75μgml-1), lowers As induced toxicity. Higher SOD, APX and guaiacol peroxidase (POD) activities in As(4)+P(5)+Se(0.75) compared to that of As(4)+P(5) and As(4)+Se(0.75), supports that lower rate of P and Se provides tolerance towards As induced stress. The nitrogen metabolism in As(4)+P+Se treated seedlings is affected adversely at higher rates of Se and P application. Overall study concluded that application of lower rates of P (5μgml-1) and Se (0.75μgml-1) provides maximum amelioration of As(III) toxicity in rice seedlings.

Abstract  Arsenate and arsenite typically co-exist in groundwater. Arsenite is more toxic than arsenate, while it is more difficult to be removed than arsenate. In order to effectively remove arsenate and arsenite simultaneously from water solution, a nanostructured zirconium-manganese binary hydrous oxide was successfully developed in this study. The amorphous sorbent was aggregate of nanoparticles with a high surface area of 213m2g-1. Our sorption experiments showed that the nano-scale particles could effectively oxidize As(III) to As(V) and greatly remove both As(V) and As(III). The maximal adsorption capacities of As(V) and As(III) were 80 and 104mgg-1 at pH 5.0, respectively. As(V) uptake may be mainly achieved through replacement of hydroxyl groups and sulfate anions on the surface of the oxide and formation of inner complexes. The As(III) removal was essentially due to a sorption coupled with oxidation process; the MnO2 was mainly responsible for oxidization of As(III) to As(V) that was subsequently adsorbed onto ZrO2.

Abstract  Several chemical elements are required by living organisms in addition to the four elements carbon, hydrogen, nitrogen and oxygen usually present in common organic molecules. Many metals (e.g. sodium, potassium, magnesium, calcium, iron, zinc, copper, manganese, chromium, molybdenum and selenium) are known to be required for normal biological functions in humans. Disorders of metal homeostasis and of metal bioavailability, or toxicity caused by metal excess, are responsible for a large number of human diseases. Metals are also extensively used in medicine as therapeutic and/or diagnostic agents. In the past 5000 years, metals such as arsenic, gold and iron have been used to treat a variety of human diseases. Nowadays, an ever-increasing number of metal-based drugs is available. These contain a broad spectrum of metals, many of which are not among those essential for humans, able to target proteins and/or DNA. This mini-review describes metal-containing compounds targeting DNA or proteins currently in use, or designed to be used, as therapeutics against cancer, arthritis, parasitic and other diseases, with a special focus on the available information, often provided by X-ray studies, about their mechanism of action at a molecular level. In addition, an overview of metal complexes used for diagnosing diseases is presented.

Abstract  The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in mitigating oxidative stress in wheat seedlings exposed to arsenic (As). Seedlings were treated with NO donor (0.25 mM sodium nitroprusside, SNP) and As (0.25 and 0.5 mM Na(2)HAsO(4)·7H(2)O) separately and/or in combination and grown for 72 h. Relative water content (RWC) and chlorophyll (chl) content were decreased by As treatment but proline (Pro) content was increased. The ascorbate (AsA) content was decreased significantly with increased As concentration. The imposition of As caused marked increase in the MDA and H(2)O(2) content. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) significantly increased with an increase in the level of As (both 0.25 and 0.5 mM), while the GSH/GSSG ratio decreased at higher concentration (0.5 mM). The ascorbate peroxidase and glutathione S-transferase activities consistently increased with an increase in the As concentration, while glutathione reductase (GR) activities increased only at 0.25 mM. The monodehydroascorbate reductase (MDHAR) and catalase (CAT) activities were not changed upon exposure to As. The activities of dehydroascorbate reductase (DHAR) and glyoxalase I (Gly I) decreased at any levels of As, while glutathione peroxidase (GPX) and glyoxalase II (Gly II) activities decreased only upon 0.5 mM As. Exogenous NO alone had little influence on the non-enzymatic and enzymatic components compared to the control seedlings. These inhibitory effects of As were markedly recovered by supplementation with SNP; that is, the treatment with SNP increased the RWC, chl and Pro contents; AsA and GSH contents and the GSH/GSSG ratio as well as the activities of MDHAR, DHAR, GR, GPX, CAT, Gly I and Gly II in the seedlings subjected to As stress. These results suggest that the exogenous application of NO rendered the plants more tolerant to As-induced oxidative damage by enhancing their antioxidant defense and glyoxalase system.

Abstract  Arsenic species have been investigated in Anemonia sulcata, which is frequently consumed food staple in Spain battered in wheat flour and fried with olive oil. Speciation in tissue extracts was carried out by anion/cation exchange chromatography with inductively coupled plasma mass spectrometry (HPLC-(AEC/CEC)-ICP-MS). Three methods for the extraction of arsenic species were investigated (ultrasonic bath, ultrasonic probe and focused microwave) and the optimal one was applied. Arsenic speciation was carried out in raw and cooked anemone and the dominant species are dimethylarsinic acid (DMAV) followed by arsenobetaine (AB), AsV, monomethylarsonic acid (MAV), tetramethylarsonium ion (TETRA) and trimethylarsine oxide (TMAO). In addition, arsenocholine (AsC), glyceryl phosphorylarsenocholine (GPAsC) and dimethylarsinothioic acid (DMAS) were identified by liquid chromatography coupled to triple quadrupole mass spectrometry (HPLC-MS). These results are interesting since GPAsC has been previously reported in marine organisms after experimental exposure to AsC, but not in natural samples. In addition, this paper reports for the first time the identification of DMAS in marine food.

Abstract  In the present work the pollutant content of diverse building materials was evaluated by the combination of spectrometric and chromatographic techniques. A first non-destructive analysis carried out by μ-XRF and Raman spectroscopy revealed a high impact of pollutants, which reached depths higher than 6mm. The quantitative analyses pointed out that black crust as accumulation nucleus where concentration values up to 3408mg/kg of lead, 752mg/kg of chromium or 220mg/kg of arsenic, high amounts of diverse sulphates and nitrates as well as substantial amounts of polycyclic aromatic hydrocarbons (PAHs) of a clear pyrolytic source were determined. On the other hand, samples without black crust showed also a surprising soluble salt content up to 5%. Polychlorinated biphenyls (PCB) were found to be absent in all material types. The chemometric analysis of the quantitative results revealed that the accumulation capacity and the subsequent pollutant content depends on the type of construction materials, being mortars the most susceptible.

Abstract  Urine arsenic and prevalent albuminuria: evidence from a population-based study.

Abstract  Chronic exposure to arsenic in drinking water, especially in utero or perinatal exposure, can initiate neurological and cognitive dysfunction, as well as memory impairment. Several epidemiological studies have demonstrated cognitive and learning deficits in children with early exposure to low to moderate levels of arsenic, but pathogenic mechanisms or etiology for these deficits are poorly understood. Since in vivo studies show a role for histone acetylation in cognitive performance and memory formation, we examined if prenatal exposure to arsenic causes changes in the epigenomic landscape. We exposed C57Bl6/J mice to 100 μg/L arsenic in the drinking water starting 1 week before conception till birth and applied chromatin immunoprecipitation followed by high-throughput massive parallel sequencing (ChIP-seq) to evaluate H3K9 acetylation pattern in the offspring of exposed and control mice. Arsenic exposure during embryonic life caused global hypo-acetylation at H3K9 and changes in functional annotation with highly significant representation of Krüppel associated box (KRAB) transcription factors in brain samples from exposed pups. We also found that arsenic exposure of adult mice impaired spatial and episodic memory, as well as fear conditioning performance. This is the first study to demonstrate: a) genome wide changes in H3K9 acetylation pattern in an offspring prenatally exposed to arsenic, and b) a connection between moderate arsenic exposure and cognitive impairment in adult mice. The results also emphasize the applicability of Next Generation Sequencing methodology in studies aiming to reveal the role of environmental factors, other than dietary restriction, in developmental reprogramming through histone modifications during embryonic development.

Abstract  Eighteen dry dog foods obtained commercially in the United States were digested using microwave assisted nitric acid digestion and a simulated gastric digestion. Digests were analysed for 23 elements using inductively coupled plasma-mass spectrometry. Data, expressed as dry matter concentrations, were compared to published nitric acid digestion results. Nitric acid data obtained in the present study were not statistically different from published data, with the exception of Mo, Sn, Sb, Tl and Th. However, significant differences in individual intra-sample results were observed between published studies and the present work. Simulated gastric digestions demonstrated lower extraction efficiencies (<50% nitric acid digestions) that were statistically significant. Much lower bioavailability was observed for Al, Ba and Pb. In general, elemental concentrations were determined to be lower than the appropriate Mineral Tolerance Limit or consistent with background concentrations in foodstuffs. Evaluation against Reference Doses (RfDs) showed concentrations for many elements obtained by nitric acid digestion to be above RfD levels. However, the respective simulated gastric digestion data were below or only moderately elevated above RfDs. Only arsenic displayed median and maximum concentrations at factors of five and ten above the relevant RfD.