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Oropharyngeal cancer is a significant public health issue in the world. The incidence of oropharyngeal cancer has been increased among people who have habit of chewing smokeless tobacco (SLT) in Pakistan. The aim of present study was to evaluate the concentration of nickel (Ni) in biological samples (whole blood, serum) of oral (n?=?95) and pharyngeal (n?=?84) male cancer patients. For comparison purposes, the biological samples of healthy age-matched referents (n?=?150), who consumed and did not consumed SLT products, were also analyzed for Ni levels. As the Ni level is very low in biological samples, a preconcentration procedure has been developed, prior to analysis of analyte by flame atomic absorption spectrometry (FAAS). The Ni in acid-digested biological samples was complexed with ammonium pyrrolidinedithio carbamate (APDC), and a resulted complex was extracted in a surfactant Triton X-114. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by FAAS. The chemical variables, such as pH, amounts of reagents (APDC, Triton X-114), temperature, incubation time, and sample volume were optimized. The resulted data indicated that concentration of Ni was higher in blood and serum samples of cancer patients as compared to that of referents who have or have not consumed different SLT products (p?=?0.012–0.001). It was also observed that healthy referents who consumed SLT products have two to threefold higher levels of Ni in both biological samples as compared to those who were not chewing SLT products (p? Figure
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Problems related with industrials effluents can be divided in two parts: (1) their toxicity associated to their chemical content which should be removed before discharging the wastewater into the receptor media; (2) and the second part is linked to the difficulties of pollution characterisation and monitoring caused by the complexity of these matrixes. This investigation deals with these two aspects, an electrochemical treatment method of an olive mill wastewater (OMW) under platinized expanded titanium electrodes using a modified Grignard reactor for toxicity removal as well as the exploration of the use of some specific analytical tools to monitor effluent phenolic compounds elimination. The results showed that electrochemical oxidation is able to remove/mitigate the OMW pollution. Indeed, 87% of OMW color was removed and all aromatic compounds were disappeared from the solution by anodic oxidation. Moreover, 55% of the chemical oxygen demand (COD) and the total organic carbon (TOC) were reduced. On the other hand, UV- Visible spectrophotometry, Gaz chromatography/mass spectrometry, cyclic voltammetry and 13 C Nuclear Magnetic Resonance (NMR) showed that the used treatment seems efficaciously to eliminate phenolic compounds from OMW. It was concluded that electrochemical oxidation in a modified Grignard reactor is a promising process for the destruction of all phenolic compounds present in OMW. Among the monitoring analytical tools applied, cyclic voltammetry and 13 C NMR are among the techniques that are introduced for the first time to control the advancement of the OMW treatment and gave a close insight on polyphenols disappearance.  相似文献   
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Peat respiration that releases carbon dioxide (CO2) to the atmosphere contributes to regional and global change. Aeration associated with soil water content levels controls emission rates, but soil amendments might mitigate respiration. The objectives of this study were to examine the effects of various water content levels and laterite application on microbial (heterotrophic) respiration in peat soil. Bulk samples of surface (0–20 cm depth) and subsurface (30–50 cm depth) layers were collected from an oil palm plantation in Riau Province, Indonesia. Peat water content was adjusted to 20, 40, 60, 80, and 100 % water filled pore space (WFPS). Laterite soil (clay containing high Al and Fe oxides) was applied to 3, 6, and 12 mg g?1 dry weight (1.2, 2.4, and 4.8 Mg ha?1) peat samples at 60 % and 100 % WFPS. Results showed peat respiration was notably affected by water content, but less affected by laterite application. Peat respiration increased sharply from wet (≥80 % WFPS) to moist soil (60 to 40 % WFPS), and decreased when soil dried (≤40 % WFPS). Laterite as a peat ameliorant accelerated rather than reduced peat respiration, and is therefore not a viable choice for CO2 emissions reduction.  相似文献   
5.
More than 25 studies have employed land use regression (LUR) models to estimate nitrogen oxides and to a lesser extent particulate matter indicators, but these methods have been less commonly applied to ambient concentrations of volatile organic compounds (VOCs). Some VOCs have high plausibility as sources of health effects and others are specific indicators of motor vehicle exhaust. We used LUR models to estimate spatial variability of VOCs in Toronto, Canada. Benzene, n-hexane and total hydrocarbons (THC) were measured from July 25 to August 9, 2006 at 50 locations using the TraceAir organic vapor monitors. Nitrogen dioxide (NO2) was also sampled to assess its spatial pattern agreement with VOC exposures. Buffers for land use, population density, traffic density, physical geography, and remote sensing measures of greenness and surface brightness were also tested. The remote sensing measures have the highest correlations with VOCs and NO2 levels (i.e., explains >36% of the variance). Our regression models explain 66–68% of the variance in the spatial distribution of VOCs, compared to 81% for the NO2 model. The ranks of agreement between various VOCs range from 48 to 63% and increases substantially – up to 75% – for the top and bottom quartile groups. Agreements between NO2 and VOCs are much smaller with an average rank of 36%. Future epidemiologic studies may therefore benefit from using VOCs as potential toxic agents for traffic-related pollutants.  相似文献   
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The extent to which smokeless tobacco endangers human health is an ongoing subject of debate. In this study, concentrations of toxic metals, cadmium (Cd), lead (Pb), and nickel (Ni), were measured in different snuff products (dry brown and black and moist green and brown), available and consumed in Pakistan. Concentrations of Cd, Pb, and Ni were determined in 23 samples of various brands of snuff by electrothermal atomic absorption spectrometry, after microwave-assisted acid digestion. The reliability of methodology was assured by analyzing certified reference material. The resulted data of toxic metals in different snuff products are comparable to the existing information with limited exceptions. It was estimated that 10 g intake of different types of snuff could contribute 14–68, 17–47, and 20–73 % of the provisional maximum tolerable daily intake for Cd, Ni, and Pb, respectively.  相似文献   
8.
Water-soluble inorganic ions in aerosol samples have been studied. The sample collection took place during summer in 2003 at a European background site which is operating within the framework of the European Monitoring and Evaluation Program. Gent type PM10 stacked filter unit (SFU) samplers were operated in parallel on a day and night basis to collect particles in separate coarse (2.0-10 microm) and fine (<2.0 microm) size fractions. Particulate masses were measured gravimetrically; the filters from one of the SFU samplers were analyzed by particle-induced X-ray emission spectrometry (PIXE) and instrumental neutron activation analysis (INAA). Filters from the other SFU sampler were analyzed by ion chromatography (IC) for major inorganic anions (MSA-, NO2(-), NO3(-), Cl-, Br-, SO4(2-), oxalate) and cations (Na+, K+, NH4(+), Mg2+, Ca2+). The water-soluble inorganic ions measured were responsible for 44% and 16% of the total fine and coarse particulate mass, respectively. In the fine size fraction, the main ionic components were SO4(2-) and NH4(+) accounting for about 90% of fine ionic mass. In the coarse fraction the main ionic components were Ca2+ and NO3(-), followed by SO4(2-). Significant day and night difference in the mass concentrations was observed only for fine NO3(-). The molar ratios of fine NH4(+) to SO4(2-) indicated their complete neutralization to (NH4)2SO4. According to the cation-to-anion ratios the coarse particles were alkaline, while the fine particles were slightly acidic or neutral. By comparing the corresponding concentrations obtained from PIXE/INAA and IC, we determined the water-extractable part of the individual species. We also investigated the effect of long-range transported air masses on the local air concentrations, and we found that the air quality of this background monitoring station was affected by regional pollution sources.  相似文献   
9.
Biofilm fermentation is a newly developed promising technique in fermentation technology. In this study no.3 and no.3S media have been used for the lipopeptide antibiotic iturin A production by Bacillus subtilis RB14. The main component of no.3 and no.3S media is Polypepton and Polypepton S, respectively. B. subtilis RB14 produces thick stable biofilm and high amount of iturin A in no.3S medium. Whereas, impaired biofilm formation and lower iturin A production was observed in no.3 medium. From the analytical information it was observed that the amounts of metal ions, such as K+, Ca2+ and Mn2+, cysteine and cellulose are lower in Polypepton compared to the Polypepton S. To investigate their effect on biofilm formation and iturin A production cysteine, cellulose, K+, Ca2+ and Mn2+ were added respectively into the no.3 medium at similar amount that Polypepton S contains. It was observed that individual addition of K+, Ca2+, cysteine and cellulose had no effect on biofilm formation, cellular growth induction or iturin A production. However, when Mn2+ was supplemented in no.3 medium, biofilm development was restored with an improved production of iturin A. Finally, combined addition of investigated substances into the no.3 medium resulted with highly folded, thick biofilm with high cellular growth and iturin A production compared to the original no.3 medium.  相似文献   
10.

The combined exposure to aluminum (Al) and cadmium (Cd) causes more pronounced adverse health effects on humans. The kidneys are the main organs affected by internal exposure to Cd and Al via food and non-food items. The objective of present study was to measure the Al and Cd concentrations in cigarettes tobacco (branded and non-branded) and drinking water (domestic treated, ground and lake water) samples in southern part of Pakistan, to assess the risk due to ingestion of water and inhalation of cigarettes smoke containing high concentrations of both elements. The study population (kidney disorder and healthy) divided into two group based on consuming lake and ground water, while smoking non-branded cigarette as exposed, while drinking domestic treated water and smoking branded cigarette as non-exposed. Electrothermal atomic absorption spectrometry was used to determined Cd and Al concentrations in tobacco, drinking water and blood samples. The resulted data indicated that the levels of Al and Cd in lake and underground water were higher than the permissible limit in drinking water recommended by the World Health Organization. The biochemical parameters of exposed and referent patients, especially urinary N-acetyl-h-glucosaminidase, were used as a biomarkers of kidney disorder. Exposed kidney disorder patients have higher levels of Cd and Al than the exposed referents subjects, while difference was significant when compared to resulted data of non-exposed patients and referents (p = 0.01–0.001). The pearson correlation showed positive correlation between both toxic element concentrations in water, cigarettes versus blood samples of exposed subjects (r = 0.20–0.67 and 0.71–0.82), while lower values were observed for non-exposed subjects (r = 0.123–0.423 and 0.331–0.425), respectively.

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