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31.

The present study assessed the DNA damage in environmentally exposed volunteers living in seven municipalities in an industrial coal region, through the use of the comet assay with blood cells and the micronucleus test with buccal cells. Blood and buccal smears were collected from 320 male volunteers living in seven cities inserted in a coal region. They were ages of 18 and 50 years and also completed a questionnaire intended to identify factors associated with DNA damage through a Poisson regression analysis. The comet assay detected significant differences in DNA damage in volunteers from different municipalities, and neighboring cities (Pedras Altas, Aceguá, and Hulha Negra) had a higher level of DNA damage in relation to control city. Some of the risk factors associated with identified DNA lesions included residence time and life habits. On the other hand, the micronucleus test did not identify differences between the cities studied, but the regression analysis identified risk factors such as age and life habits (consumption of mate tea and low carbohydrates diet). We conclude that there are differences in the DNA damage of volunteers from different cities of the carboniferous region, but the presence of micronuclei in the oral mucosa does not differ between the same cities. Furthermore, we alert that some related factors may increase the risk of genotoxicity, such as residence location and time, and living and food habits. Finally, we suggest the need for continuous biomonitoring of the population, as well as for investing in health promotion in these vulnerable populations.

  相似文献   
32.
Fish is the main single source of polychlorinated biphenyls (PCBs) exposure in men. Anecdotal reports suggest high wild fish consumption rates among sport fishermen in Sanski Most area, Bosnia and Herzegovina (BiH). Presence of PCBs in the environment in BiH was previously documented. The main objective of this work was to estimate the magnitude of PCBs exposure and assess the potential health risk in sport fishermen in Sanski Most. The fishing pattern and magnitude of fish consumption were estimated in the questionnaire survey conducted during April 2012 among members (n = 60) of the local sport fishermen association in Sanski Most. Calculated median and high-end (90th percentile) fish consumption rates were 31 g d?1 and 126 g d?1, respectively. The PCB concentrations (as Aroclor 1254 equivalents), determined by ELISA immunoassay in 28 fish fillets ranged from undetectable to 208 μg kg?1. Two different exposure scenarios were used: (a) median exposure, calculated from the median fish consumption rate and median PCB concentrations, and (b) “worst case” scenario, calculated from the high-end fish consumption rate and mean PCB concentrations. The results suggest negligible lifelong cancer and non-cancer risks in case of low to moderate fish consumption rate, but possibly unacceptable risk levels in high-end consumers.  相似文献   
33.
In this study, an analytical methodology was developed for the determination of psycho-active drugs in the treated effluent of the University Hospital at the Federal University of Santa Maria, RS – Brazil. Samples were collected from point A (Emergency) and point B (General effluent). The adopted methodology included a pre-concentration procedure involving the use of solid phase extraction and determination by liquid chromatography coupled to mass spectrometry. The limit of detection for bromazepam and lorazepam was 4.9 ± 1.0 ng L−1 and, for carbamazepine, clonazepam and diazepam was 6.1 ± 1.5 ng L−1. The limit of quantification was 30.0 ± 1.1 ng L−1, for bromazepam, clonazepam and lorazepam; for carbamazepine was 50.0 ± 1.8 ng L−1 and was 40.0 ± 1.0 ng L−1 for diazepam. The mean concentrations in the Emergency and General effluent treated currents were as follows: for bromazepam, 195 ± 6 ng L−1 and 137 ± 7 ng L−1; for carbamazepine, 590 ± 6 ng L−1 and 461 ± 10 ng L−1; for diazepam, 645 ± 1 ng L−1 and 571 ± 10 ng L−1; for lorazepam, 96 ± 7 ng L−1 and 42 ± 4 ng L−1; and for clonazepam, 134 ± 10 ng L−1 and 57 ± 10 ng L−1. A preliminary risk assessment was conducted: carbamazepine and diazepam require considerable attention owing to their environmental toxicity. The occurrence of these psychoactive-drugs and the environmental risks that they pose demonstrated the need for a more efficient treatment system. As far we are aware, there have been no comparable studies to this on the hazards of hospital effluents in Brazil, and very few that have carried out a risk assessment of psycho-active drugs in hospital effluent in general.  相似文献   
34.
In the last decade, the development of novel analytical methodologies enabled the identification of several environmental pollutants responsible for health problems associated with indoor exposure. Polycyclic aromatic hydrocarbons (PAHs) are among the potential hazardous chemicals present in ambient air. Due to their bioaccumulation potential and carcinogenic/mutagenic effects, 16 PAHs are currently listed as priority air pollutants. The main goal of this work was to implement a new and simple method for sampling and determination of PAHs in air by using a thermal desorption (TD) technique followed by gas chromatography coupled with mass spectrometry analysis. A detailed study was carried out to optimise the experimental method in each of its phases, including (active) sampling, TD and chromatographic analysis. The results demonstrate that this approach allowed the detection and quantification of the six more volatile PAHs, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, and anthracene. Acceptable precision and good linearity over the explored range were obtained. No carry-over was observed during experimental tests and the method provided a reproducible answer. The applicability of the novel methodology was tested in real environment, namely, on the roof of a building in an urban area, in a domestic kitchen and in a collective car garage. The method enabled the identification of two PAHs in the field samples, specifically, naphthalene (two rings) and phenanthrene (three rings). With regard to PAHs sample composition, the most abundant PAH found, in the three different locations, was naphthalene, accounting for about 84–100 % of the total PAH mass detected.  相似文献   
35.
This is a case study of contamination by a non-aqueous phase liquid (NAPL) that leaked from a chemical plant. The remediation procedure adopted for the initial phase of the plume migration was a plastic diaphragm wall coupled with a series of water extraction wells designed to avoid environmental impact on the surrounding ecosystems. Monitoring has shown that the containment is successful, and additional measures that contribute to accelerating remediation have been adopted. The authors wished to investigate how remediation might be further enhanced. The use of in situ aeration coupled with a system of soil vapor extraction (AS/SVE) has been chosen, since the remediation of sites with characteristics similar to those in this study, if based exclusively on dissolved-phase control, would take several decades to be completed. The transport of contaminant plumes has been simulated by using an analytical model to evaluate the effectiveness of the natural attenuation of the contaminant. The results of the simulation have confirmed the limited effectiveness of the natural attenuation of the contaminant, as well as the effective increase of remediation that would occur if the AS/SVE system is applied. A sensitivity analysis that included several combinations of increments of parameters that correspond to the decay rate of the source and the dissolved plume has simulated what might happen if the AS/SVE system is implemented.  相似文献   
36.
Martins JM  Mermoud A 《Chemosphere》1999,38(3):601-616
This paper presents a study on degradation, sorption and transport of the sulfonylurea herbicide rimsulfuron and its major metabolites in alluvial soil columns. The formulation of rimsulfuron was found to strongly affect its degradability. Hydrolysis of pure rimsulfuron takes place rapidly in distilled water (t(1/2)=2.2 days) or indeed instantaneously in alkaline solution. The formulated rimsulfuron (Titus, 25% rimsulfuron, Du Pont De Nemours) is more persistent in alluvial soil suspensions (t(1/2)=7.5 days). The study of sorption of Titus and its two major metabolites (1 and 2) revealed that these three chemicals are potentially highly mobile in the studied soil: in suspension distribution coefficients of 0.0028, 0.125 and 0.149 cm3 g(-1) were obtained respectively. Given the instability of rimsulfuron in alkaline solutions, the pH effect was evaluated with metabolite 2 in water saturated Fontainebleau sand columns at pH 6, 8 and 10. Transport was found to be strongly dependent on pH; a linear relationship was obtained between pH and the retardation factor or the dispersion coefficient. In alluvial soil columns, rimsulfuron from Titus was found to be very mobile (R=1.2) and rapidly degraded into metabolites 1 and 2, which were transported at a similar velocity. Nevertheless, the risks of groundwater contamination by rimsulfuron seem very low, as it is rapidly degraded under dynamic conditions (t(1,2)=1.4 days). On the other hand the relatively stable metabolite 2 seems likely to persist in the soil and to be transported to the groundwater. Special attention should thus be given to this compound at least as long as its harmlessness is not demonstrated.  相似文献   
37.
Abstract

The São Paulo Metropolitan area (SPMA) is characterized as having one of the worst air pollution problems in Brazil,with frequent violations of air quality standards for particulate matter. This paper presents the results of a eceptor model source apportionment study carried out to develop a quantitative database on which a control strategy could be developed. The study was conducted in four sites with distinct land uses. Fine, coarse (CP), and total suspended particles (TSP) samples were collected on Teflon and glass filters and analyzed by x-ray fluorescence XRF), ion chromatography, and thermal evolution. The sources were characterized by similar methodology. Chemical mass balance (CMB) receptor modeling indicated that carbonaceous material plays an important role in the aerosol composition; that the three major source categories contributing to the fine particles are vehicles, secondary carbon, and sulfates; and that the main contributors to CP and TSP are road dust and vehicles. All sampling sites presented the same general pattern in terms of source contribution, although this contribution varied from site to site.  相似文献   
38.
39.
Carbon dioxide (CO2) is one of the primary greenhouse gases that contribute to climate change. Consequently, emission reduction technologies will be needed to reduce CO2 atmospheric concentration. Microalgae may have an important role in this context. They are photosynthetic microorganisms that are able to fix atmospheric CO2 using solar energy with efficiency ten times higher than terrestrial plants. The objectives of this study were: (i) to analyse the effect of light supply on the growth of Chlorella vulgaris and Pseudokirchneriella subcapitata; (ii) to assess the atmospheric CO2 capture by these microalgae; and (iii) to determine the parameters of the Monod model that describe the influence of irradiance on the growth of the selected microalgae. Both microalgae presented higher growth rates with high irradiance values and discontinuous light supply. The continuous supply of light at the highest irradiance value was not beneficial for C. vulgaris due to photooxidation. Additionally, C. vulgaris achieved the highest CO2 fixation rate with the value of 0.305 g-CO2 L?1 d?1. The parameters of the Monod model demonstrated that C. vulgaris can achieve higher specific growth rates (and higher CO2 fixation rates) if cultivated under higher irradiances than the studied values. The presented results showed that microalgal culture is a promising strategy for CO2 capture from atmosphere.  相似文献   
40.
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