Evaluation of chelating and cytoprotective activity of vanillin against the toxic action of mercuric chloride as an alternative for phytoremediation

Environmental Geochemistry and Health - Mercury is widely found in nature, however, in low concentrations, but anthropological activities have increased its concentration considerably. This causes...     

Symptoms prevalence among office workers of a sealed versus a non-sealed building: Associations to indoor air quality

ObjectivesAn increasing number of complaints related to time spent in artificially ventilated buildings have been progressively reported and attributed, at least in part, to physical and chemical exposures in the office environment. The objective of this research was to investigate the association between the prevalence of work-related symptoms and the indoor air quality, comparing a sealed office building with a naturally ventilated one, considering, specially, the indoor concentration of TPM, TVOCs and the main individual VOCs.MethodsA cross-sectional study was performed to compare the prevalence of sick building syndrome (SBS) symptoms among 1736 office workers of a sealed office building and 950 of a non-sealed one, both in Rio de Janeiro's downtown. The prevalence of symptoms was obtained by a SBS standardized questionnaire. The IAQ of the buildings was evaluated through specific methods, to determine the temperature, humidity, particulate matter and volatile organic compound (VOC) concentrations.ResultsUpper airways and ophthalmic symptoms, tiredness and headache were highly prevalent in both buildings. Some symptoms were more prevalent in the sealed building: “eye dryness” 33.3% and 27.1% (p: 0.01); “runny nose” 37.3% and 31.3% (p: 0.03); “dry throat” 42% and 36% (p: 0.02); and “lethargy” 58.5% and 50.5% (p: 0.03) respectively. However, relative humidity and indoor total particulate matter (TPM) concentration as well as total volatile organic compounds (TVOCs) were paradoxically greater in the non-sealed building, in which aromatic compounds had higher concentration, especially benzene. The analysis between measured exposure levels and resulting symptoms showed no association among its prevalence and TPM, TVOCs, benzene or toluene concentration in none of the buildings.ConclusionsOther disregarded factors, like undetected VOCs, mites, molds and endotoxin concentrations, may be associated to the greater prevalence of symptoms in the sealed building.     

Bioavailable metals and cellular effects in the digestive gland of marine limpets living close to shallow water hydrothermal vents

The pressure exerted by shallow water hydrothermal vents on edible gastropods and their cellular responses triggered by these stresses are almost unknown. The aims of this study were to evaluate the bioavailability of metals in the Macaronesian endemic limpet Patella candei gomesii living close to shallow water hydrothermal vents, and the structural differences in their digestive gland as well as the levels of apoptosis in that organ. Limpets were sampled in four sites, two with the presence of hydrothermalism and the other two without it. Whole body concentrations of several metals (Ca, Cd, Cs, Co, Cu, Fe, Hg, Mg, Mn, Pb, Rb, Se, Sr, and Zn) were obtained, morphometry analysis of the digestive gland and TUNEL test for apoptosis were also performed. Results revealed that the presence of shallow water hydrothermal vents is a source of chronic metal stress to limpets, imposing modifications in the morphometry and cell composition of the digestive gland of those limpets that may constitute cell and tissue adaptations to the environment they live in. This study sets up new baseline data for further research on the influence of shallow water hydrothermal vents over communities living in these habitats.     

Evaluation of residue risk and toxicity of different treatments with diazinon insecticide applied to mushroom crops

ABSTRACT

This work describes the phytotoxic effect of different doses of diazinon and different application times on Agaricus bisporus mycelium, and determines the residue levels in mushrooms from the first three flushes. Mushroom cultivation is a widespread commercial activity throughout the world. The application of insecticide diazinon to the compost or casing layer is a common practice to control two mushroom pests, the phorid Megaselia halterata and the sciarid Lycoriella auripila. Application to the compost does not result in any appreciable fall in yield or quality, and does not delay the harvest time. In contrast, application to the casing led to a slight fall (6.2%) in production and a smaller number of mushrooms although they are larger in size. Residue levels of more than 0.01 ppm are detected in many of the samples analyzed, and raising the question whether the product should continue to be used in mushroom cultivation in the conditions in which it is currently applied.     

Airborne polycyclic aromatic hydrocarbons in a medium-sized city affected by preharvest sugarcane burning and inhalation risk for human health

Polycyclic aromatic hydrocarbons (PAHs) in air were measured in a municipality where sugarcane plantations are extensive, at three sites, one in the city center and two in rural localities. Twenty-four-hour sampling was done using PS1 PUF samplers from Andersen Instruments Inc., at least 1 day per month per site, from June 2009 to October 2009. The chemical analyses were performed by gas chromatography–mass spectrometry (GC/MS) for the 16 most toxic PAHs. The incremental lifetime cancer risk (ILTR) by inhalation was determined by the Monte Carlo method for the urban population using Crystal Ball software. The total concentration of the 16 PAHs at all sites varied from 6.2 to 65.7 ng m^?3, with an average of 25.9 ± 18.2 ng m^?3. The average concentrations per site were 14.1 ± 13.0 ng m^?3 at rural site B, 20.7 ± 11.5 ng m^?3 at rural site A, and 36.1 ± 22.7 ng m^?3 at the central site. The cancer risk for infants, children, and adults was approximately 14%, 25%, and 61% of the total IRLT, respectively. The mean (95% upper probability limit [95% UPL]) values were 1.2 × 10^?7 (2.2 × 10^?7) for infants, 2.2 × 10^?7 (4.1 × 10^?7) for children, and 8.9 × 10^?7 (1.1 × 10^?6) for adults. Although the three most abundant PAHs found were phenanthrene, fluoranthene, and pyrene, the three most important contributions to the incremental risk of cancer came from benzo[a]pyrene, benzo[b]fluoranthene, and naphthalene. Compared with the risks in big cities such as São Paulo, this would be low, but not negligible. Analysis of ratios of PAHs according to the literature showed that vehicle exhaust and biomass burning, including sugarcane burning, seem to be the most important contributors to PAH concentrations in the central area of Araraquara City.

Implications:The growth of biofuel use worldwide, especially ethanol, together with preharvesting burning practice, is cause of concern with regard to possible health effects, due to increased air pollution levels in cities in regions where sugarcane plantation and processing are intensive. This paper shows that the risk of cancer from PAH inhalation in an urban area surrounded by sugarcane agriculture was of the same order of magnitude as the tolerable risk value of 10^?6. As other classical and hazardous pollutants are also present, care should be taken to keep pollution as low as possible to protect human health.     

Source Apportionment of PM10 and PM25 in Five Chilean Cities Using Factor Analysis

ABSTRACT

Chile is a fast-growing country with important industrial activities near urban areas. In this study, the mass and elemental concentrations of PM₁₀ and PM_2.5 were measured in five major Chilean urban areas. Samples of particles with diameter less than 10 um (PM₁₀) and 2.5 um (PM_2.5) were collected in 1998 in Iquique (northern Chile), Valparaiso, Vina del Mar, Rancagua (central Chile), and Temuco (southern Chile). Both PM₁₀ and PM₂₅ annual mean concentrations (PM₁₀: 56.9-77.6 u,g/m³; PM₂₅: 22.4-42.6 u.g/m³) were significantly higher than the corresponding European Union (EU) and U.S. Environmental Protection Agency (EPA) air quality standards. Moreover, the 24-hr PM₁₀ and PM₂₅ U.S. standards were exceeded infrequently for some of the cities (Rancagua and Valparaiso).     

Potentiation of antifungal effect of a mixture of two antifungal fractions obtained from Baccharis glutinosa and Jacquinia macrocarpa plants

The aim of the present work was to evaluate the effect of mixtures of antifungal fractions extracted from Baccharis glutinosa and Jacquinia macrocarpa plants on the development of the filamentous fungi Aspergillus flavus and Fusarium verticillioides. The minimal inhibitory concentration that inhibited 50% of growth (MIC₅₀) of each plant antifungal fraction was determined from the percentage radial growth inhibition of both fungi. Binomial mixtures made with both plant fractions were used at their MIC₅₀ to determine the Fractional Inhibitory Concentration index (FIC index) for each fungus in order to evaluate their synergistic effect. Each synergistic mixture was analyzed in their effect on spore germination, spore size, spore viability, mitotic divisions, hyphal diameter and length, and number of septa per hypha. Some antifungal mixtures, even at low concentrations, showed higher antifungal effect than those of the individual antifungal fraction. The FIC indices of mixtures that showed the highest antifungal activity against A. flavus and F. verticillioides were 0.5272 and 0.4577, respectively, indicating a synergistic effect against both fungi. Only 12% and 8% of the spores of A. flavus and F. verticillioides, respectively, treated with the synergistic mixtures, were able to germinate, although their viability was not affected. An increase in the number of septa per hypha of both fungi was observed. The results indicated that the synergistic mixtures strongly affected the fungal growth even at lower concentrations than those of the individual plant fractions.     

Mercury transfer from soil to olive trees. A comparison of three different contaminated sites

Mercury contents in soil and olive tree leaves have been studied in 69 plots around three different source areas of this element in Spain: Almadén (Ciudad Real), Flix (Tarragona) and Jódar (Jaén). Almadén was the world’s largest cinnabar (HgS) mining district and was active until 2003, Flix is the oldest Spanish chlor-alkali plant (CAP) and has been active from 1898 to the present day and Jódar is a decommissioned CAP that was active for 14 years (1977–1991). Total mercury contents have been measured by high-frequency modulation atomic absorption spectrometry with Zeeman effect (ZAAS-HFM) in the soils and olive tree leaves from the three studied areas. The average soil contents range from 182 μg kg^?1 in Flix to 23,488 μg kg^?1 in Almadén, while the average leaf content ranges from 161 μg kg^?1 in Jódar to 1213 μg kg^?1 in Almadén. Despite the wide range of data, a relationship between soil–leaf contents has been identified: in Almadén and Jódar, multiplicative (bilogarithmic) models show significant correlations (R?=?0.769 and R?=?0.484, respectively). Significant correlations were not identified between soil and leaf contents in Flix. The continuous activity of the Flix CAP, which remains open today, can explain the different uptake patterns for mercury, which is mainly atmospheric in origin, in comparison to the other two sites, where activity ceased more than 10 years ago and only soil uptake patterns based on the Michaelis–Menten enzymatic model curve are observed.