Addition of softwood biochar to contaminated soils decreases the mobility, leachability and bioaccesibility of potentially toxic elements.

Softwood-derived biochar (5% w/w) was added to two mining soils (S1 and S2) contaminated with Cd (4.8-74 mg kg-1), Pb (318-1899 mg kg-1) and Zn (622-3803 mg kg-1), to evaluate its immobilization capabilities towards such potentially toxic elements (PTEs). Biochar addition (S + B) increased soil pH, organic carbon content, extractable phosphorous and calcium. Sequential extractions showed that biochar reduced the labile pools of PTEs (e.g. -29, 55 and 79% of water-soluble and exchangeable Cd, Zn and Pb respectively in S1 + B compared to S1) and at the same time increased their most stable and less mobile fractions. Leaching experiments revealed a significant decrease of DOC, N-NO3-, P and PTEs in biochar-treated soils, and an increase of leached K. Kinetic equations derived from leaching data showed that PTEs in control soils were quickly mobilized, while those in biochar-treated soils needed longer time to leachate. In vitro tests showed that biochar was effective at reducing the bioaccessibility of Cd and Pb in the gastric phase of S2 and that of Zn and Pb in the intestinal phase of S1. The results obtained showed that biochar could be used as alternative amendment for the recovery of PTEs-contaminated soils.

Complementary assessment of As, Cu and Zn environmental availability in a stabilised contaminated soil using large-bore column leaching, automatic microcolumn extraction and DGT analysis.

Soil pollution with trace elements is a concerning issue worldwide. Monitoring of soil pollution and remediation protocols need still from valid complementary analytical approaches able to detect changes in speciation and lability of metals in soils (e.g. stabilization or mobility). In this work, we compare three different analytical approaches to assess potential changes in environmental availability of Cu, As and Zn in a Mediterranean polluted soil that was amended with different combinations of iron sulphate and alkaline paper sludge waste. The studied methods were: (i) a standard large-bore flow-through column system (macrocolumn), (ii) an automatic dynamic flow-through microcolumn extraction system, and (iii) the diffusive gradients in thin gels technique (DGT). The three analytical approaches tested showed immobilization of Zn and Cu in contaminated mine soils after co-application of paper sludge and iron sulphate, but they differ quantitatively in terms of As mobility. Interconversion between oxidation states of inorganic As is observed to occur to a larger extent in macrocolumn. Because this may only occur in very specific Mediterranean scenarios (i.e. organic matter application to intermittently flooded mine soils), macrocolumn extraction procedures might not appropriately mimic the environmental availability of As in soils with organic amendments (e.g., paper sludge waste). Microcolumn leaching is the fastest screening tool to ascertain the efficiency of chemical amendments, but DGT is a good alternative with less technical demands.

Aridity and reduced soil micronutrient availability in global drylands.

Drylands cover more than 40% of terrestrial surface, and their global extent and socio-ecological importance will increase in the future due to the forecasted increases in aridity driven by climate change. Despite the essential role of metallic micronutrients in life chemistry and ecosystem functioning, it is virtually unknown how their bioavailability changes along aridity gradients at the global scale. Here we analysed soil total and available Cu, Fe, Mn, and Zn in 143 drylands from all continents, except Antarctica, covering a broad range of aridity and soil conditions. We found that total and available micronutrient concentrations in dryland soils were low compared to averages commonly found in soils of natural and agricultural ecosystems globally. Aridity negatively affected the availability of all micronutrients evaluated, mainly indirectly by increasing soil pH and decreasing soil organic matter. Remarkably, the available Fe:Zn ratio decreased exponentially as aridity increased, pointing to stoichiometric alterations. Our findings suggest that increased aridity conditions due to climate change will limit the availability of essential micronutrients for organisms, particularly that of Fe and Zn, which together with other adverse effects (e.g., reduced water availability) may pose serious threats to key ecological processes and services, such as food production, in drylands worldwide.

Synergic use of chemical and ecotoxicological tools for evaluating multi-contaminated soils amended with iron oxides-rich materials.

Abandoned waste piles from ancient mining activities are potential hot spots for the pollution of the surrounding areas. A pot experiment was carried out to check the potential toxicity of the dumping material present in one of these scenarios, and several amendments were tested to attenuate the spread of the contamination events. The waste material had an acid pH and a large total concentration of As and Cu. A dose-response experiment was performed with this material following OCDE 208 test. A proportion 90:10 uncontaminated soil: dumping material (% w/w) was selected for the following experiment, in order to surpass the amount of dumping material that caused 50% reduction in plant growth. Pots were filled with the 90:10 mixture, planted with seeds of Brassica napus and amended with the following materials: three iron oxides of Bayoxide® E33 series, iron (II) sulphate in combination with de-inking paper sludge (Fe+PS), iron oxide-rich rolling mill scale (ROL) and iron oxide-rich cement waste (CEM). Amendment effectiveness evaluation was based on chemical and biological assays: extractable trace element concentration, soil enzymatic activities, inhibition of light emission of V. fischeri and Anabaena sp., B. napus L. fresh weight and screening test for emergence of B. napus L. seedlings. Amendments E33HCF and Fe+PS were the most effective in reducing extractable As and Zn concentration. B. napus weight and dehydrogenase and ß-glucosidase activities were positively increased with the two above mentioned treatments but they triggered more toxic effects for V. fischeri luminescence. E33P treatment was the only in which the EC50 was higher than in the control. Anabaena sp. was less sensitive than V. fischeri as its luminescence was not hampered by any treatment. Trace element concentration did not significantly affect the failure in seed emergence. E33HCF and Fe+PS could act as proper amendments as they decreased extractable As and Zn. Further, plant fresh weight, enzymatic activities and some of the bioassays identified the latter treatments as the best ones among those tested here to this type of multi-contaminated soil.

Carcinoma primario de células en anillo de sello de íleon terminal / Primary signet-ring cell carcinoma of the terminal ileum

No disponible

Sprinkler irrigation of rice fields reduces grain arsenic but enhances cadmium.

Previous studies have demonstrated that rice cultivated under flooded conditions has higher concentrations of arsenic (As) but lower cadmium (Cd) compared to rice grown in unsaturated soils. To validate such effects over long terms under Mediterranean conditions a field experiment, conducted over 7 successive years was established in SW Spain. The impact of water management on rice production and grain arsenic (As) and cadmium (Cd) was measured, and As speciation was determined to inform toxicity evaluation. Sprinkler irrigation was compared to traditional flooding. Both irrigation techniques resulted in similar grain yields (~3000 kg grain ha(-1)). Successive sprinkler irrigation over 7 years decreased grain total As to one-sixth its initial concentration in the flooded system (0.55 to 0.09 mg As kg(-1)), while one cycle of sprinkler irrigation also reduced grain total As by one-third (0.20 mg kg(-1)). Grain inorganic As concentration increased up to 2 folds under flooded conditions compared to sprinkler irrigated fields while organic As was also lower in sprinkler system treatments, but to a lesser extent. This suggests that methylation is favored under water logging. However, sprinkler irrigation increased Cd transfer to grain by a factor of 10, reaching 0.05 mg Cd kg(-1) in 7 years. Sprinkler systems in paddy fields seem particularly suited for Mediterranean climates and are able to mitigate against excessive As accumulation, but our evidence shows that an increased Cd load in rice grain may result.

Amendment application in a multi-contaminated mine soil: effects on soil enzymatic activities and ecotoxicological characteristics.

Several amendments were tested on soils obtained from an arsenopyrite mine, further planted with Arrhenatherum elatius and Festuca curvifolia, in order to assess their ability to improve soil's ecotoxicological characteristics. The properties used to assess the effects were: soil enzymatic activities (dehydrogenase, ß-glucosidase, acid phosphatase, urease, protease and cellulase), terrestrial bioassays (Eisenia fetida mortality and avoidance behaviour), and aquatic bioassays using a soil leachate (Daphnia magna immobilisation and Vibrio fischeri bioluminescence inhibition). The treatment with FeSO4 1 % w/w was able to reduce extractable As in soil, but increased the extractable Cu, Mn and Zn concentrations, as a consequence of the decrease in soil pH, in relation to the unamended soil, from 5.0 to 3.4, respectively. As a consequence, this treatment had a detrimental effect in some of the soil enzymatic activities (e.g. dehydrogenase, acid phosphatase, urease and cellulase), did not allow plant growth, induced E. fetida mortality in the highest concentration tested (100 % w/w), and its soil leachate was very toxic towards D. magna and V. fischeri. The combined application of FeSO4 1 % w/w with other treatments (e.g. CaCO3 1 % w/w and paper mill 1 % w/w) allowed a decrease in extractable As and metals, and a soil pH value closer to neutrality. As a consequence, dehydrogenase activity, plant growth and some of the bioassays identified those as better soil treatments to this type of multi-contaminated soil.

Efficacy of the vaccination in inflammatory bowel disease.

Inflammatory bowel disease (IBD) is associated with conditions that may predispose to infections, such as the lack of an appropriate innate immune response to infectious agents, malnutrition, surgery, and immunosuppressive and biological drugs. Some of these infections may be preventable by vaccination. Therefore, for this particular patient population, the benefits of implementing a well-established immunization protocol in daily clinical practice are potentially even greater than for the general population. In recent years international consensus guidelines have been published, but in spite of theses recommendations, studies have shown that a significant number of patients with IBD remain inadequately immunized. Another important issue regarding immunization in this population is that vaccine efficacy among patients receiving immunosuppressive therapies has been variable. In a healthy population, a humoral immune response to hepatitis B vaccination (HBV) is expected in > 90%, whereas a much lower rate is achieved in the IBD patients. Immunosuppressive, anti-tumor necrosis factor therapy and disease activity have been implicated in the impaired efficacy of the vaccination. The serological response to HBV should be confirmed and patients with an inadequate response should receive a second full series of vaccine. Modified dosing regimens, including doubling the standard antigen dose, might increase the effectiveness. Response to influenza, pneumococcal and tetanus immunization is still not clear, as there are studies that show a normal response to the vaccination while others demonstrate a lack of efficacy. We pose a series of questions on the efficacy of the different vaccinations recommended for IBD patients and attempt to answer them using scientific evidence.

Clinical significance of cytomegalovirus infection in patients with inflammatory bowel disease.

Cytomegalovirus (CMV) infection is common in humans. The virus then enters a "latency phase" and can reactivate to different stimuli such as immunosuppression. The clinical significance of CMV infection in inflammatory bowel disease is different in Crohn's disease (CD) and ulcerative colitis (UC). CMV does not interfere in the clinical course of CD. However, CMV reactivation is frequent in severe or steroid-resistant UC. It is not known whether the virus exacerbates the disease or simply appears as a bystander of a severe disease. Different methods are used to diagnose CMV colitis. Diagnosis is classically based on histopathological identification of viral-infected cells or CMV antigens in biopsied tissues using haematoxylin-eosin or immunohistochemistry, other tests on blood or tissue samples are currently being investigated. Polymerase chain reaction performed in colonic mucosa has a high sensitivity and a positive result could be associated with a worse prognosis disease; further studies are needed to determine the most appropriate strategy with positive CMV-DNA in colonic mucosa. Specific endoscopic features have not been described in active UC and CMV infection. CMV colitis is usually treated with ganciclovir for several weeks, there are different opinions about whether or not to stop immunosuppressive therapy. Other antiviral drugs may be used. Multicenter controlled studies would needed to determine which subgroup of UC patients would benefit from early antiviral treatment.

Factors influencing sick leave episodes in Mexican workers with rheumatoid arthritis and its impact on working days lost.

To evaluate impact of working days lost and factors for developing sick leave episodes in Mexicans workers with rheumatoid arthritis (RA). A prospective cohort of 123 patients with RA was followed for 1 year. Factors evaluated for sick leave episodes included: demographics, job characteristics, comorbidity, depressive symptoms, and clinical/therapeutic variables. Rates of sick leave episodes, working days lost, and permanent work disability (PWD) were identified. Statistical analysis included Cox regression models estimating hazard risks (HR) and their 95 % confidence intervals (95% CI). Cumulative time of follow-up for the cohort was 43,380 days, 24 % of workers had at least one episode of sick leave, with a mean of working days lost per patient-year of 18.36; 4.1 % developed PWD. Development of sick leave in the Kaplan-Meier analysis was associated with: age ≥40 years (p = 0.04), having a couple (p = 0.04), performing manual work (p = 0.03), suffering depressive symptoms (p = 0.04), limitations in functioning (p = 0.01), and poor global functional status ≥ III (p = 0.01). Cox regression models identified HAQ-Di ≥ 0.6 as the stronger predictor for sick leave (HR = 4.04, 95 % CI 1.41-11.58, p = 0.009) followed by age (HR = 1.05, 95 % CI 1.01-1.11, p = 0.04), ≥4 risk factors had a HR to 9.4 (95 % CI: 2.1-42.7) for sick leave. In this prospective cohort of Mexican workers with RA, we identified several factors associated with sick leave episodes and working days lost that should be potentially addressed by a multidisciplinary approach, being required to revaluate these strategies with the aim of increasing the work permanence of these patients.

Heavy metals distribution in soils surrounding an abandoned mine in NW Madrid (Spain) and their transference to wild flora.

The present work concerns the distribution and mobility of heavy metals (Fe, Mn, Cu, Zn and Cd) in the surrounding soils of a mine site and their transfer to wild flora. Thus, soils and plants were sampled from a mining valley in NW Madrid (Spain), and total and extractable heavy metals were analysed. Soils affected by mining activities presented total Cd, Cu and Zn concentrations above toxic thresholds. The percentage of extractable element was highest for Cd and lowest for Cu. A highly significant correlation was observed between the total and extractable concentrations of metals in soils, indicating that, among the factors studied, total metals concentration is the most relevant for heavy metals extractability in these soils. (NH(4))(2)SO(4)-extractable metal concentrations in soils are correlated better with metal concentrations in several plant species than total metals in soils, and thus can be used as a suitable and robust method for the estimation of the phytoavailable fraction present in soils. Twenty-five vascular plant species (3 ferns and 22 flowering plants) were analysed, in order to identify exceptional characteristics that would be interesting for soil phytoremediation and/or reclamation. High Cd and Zn concentrations have been found in the aerial parts of Hypericum perforatum (Cd), Salix atrocinerea (Cd, Zn) and Digitalis thapsi (Cd, Zn). The present paper is, to the best of our knowledge, the first report of the metal accumulation ability of the two latter plant species. The phytoremediation ability of S. atrocinerea for Cd and Zn was estimated, obtaining intervals of time that could be considered suitable for the phytoextraction of polluted soils.

[Motives of requirement for health care consultations and factors associated to mortality due to poisoning]. / Motivos que generan demanda de atención y factores asociados a mortalidad en un centro especializado en toxicología.

BACKGROUND: The poisoning is a public health problem. This problem requires continuous evaluation to decrease it. Our objective was to identify causes of requirement for health care consults and factors associated to mortality due to poisoning. METHODS: We assessed the requirements for health care consults during one year and the outcomes of these consultations in a center of toxicology. Odds ratios (OR) were used as risk estimator. RESULTS: There were 3116 consultations due to poisons. From these 79% required hospitalization. The identified causes were: be bite and wound inflected by poisonous animals in 57 % (44 % of these were due to scorpions); medications in 15 %; agrochemicals in 5 % and in 4 % prohibit substances (marihuana or cocaine). A poisoning caused by suicidal attempt was observed in 28 %. Mortality rate was 3/1000, and the mortality rate for suicidal attempt was 0.7 % meaning an OR = 6 (95 % CI = 1.3 to 31) compared with the overall mortality rate. The most frequent cause of mortality was organophosphorates poisoning (OR = 30, 95 % CI = 2.86-759). CONCLUSIONS: The poisoning secondary to animals represented the most frequent cause for consultation. The suicidal attempt and organophosphorates intoxication were associated with higher mortality.