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PubMedDate not supplied

Contaminant effect on cellular metabolic differential pressure curves.

The possibility of a pressure monitoring system by differential pressure sensors to detect contaminant effects on cellular cultures metabolic activity is discussed using Saccharomyces cerevisiae, lymphocyte, and AHH1 cell cultures. Metabolic (aerobic and anaerobic) processes in cells are accompanied by CO(2) production that induces changes in pressure values when cells are cultured in sealed vessels. These values are subsequently converted in voltage units and plotted pressure dynamics versus time. This procedure leads to a standard curve, typical of the cellular line, which characterizes cellular metabolism when all parameters are controlled, such as temperature and nutrients. Different phases appear in the S. cerevisiae differential pressure curve: an initial growth up to a maximum, followed by a decrement that leads to a typical "depression" (pressure values inside the test-tubes are lower than the initial one) after about 35 h from the beginning. The S. cerevisiae differential pressure curve is successfully used to test the effects of chemical (Amuchina, trieline) and physical (UV radiation, blue light, magnetic fields) contaminants. The same technique is applied to lymphocytes and AHH1 cultures to investigate the effects generated by a 72-h exposure to a 50-Hz, 60-microT electromagnetic field. Lymphocyte samples, cultured in a PHA medium, grow less than control ones, but exhibit a greater metabolic activity: changes in the exposure system configuration influence neither sample growth differences nor metabolic response variations between control and irradiated samples, while all the other irradiation parameters remain constant. Control and irradiated lymphocyte samples, without PHA in culture medium, show the same behavior both during irradiation and metabolic test. AHH1 control and irradiated samples show no difference both in growth percentage during irradiation and in metabolic activity. Different cell cultures respond to the same stimulus in different manners.

Biosensing Techniques↗
PubMed2005

Asthma, genes, and air pollution.

OBJECTIVE: The objective of this article is to evaluate genetic risks associated with the pulmonary response to air pollutants, including particulates and ozone. METHODS: A comprehensive review of articles related to the genetics of asthma with particular attention to air pollution was conducted through a search of the National Library of Medicine's PubMed database. RESULTS: Asthma, which affects over 15 million people in the United States, is characterized by inflammation leading to reversible airflow obstruction. Triggered by exposure to numerous occupational and environmental agents, asthma has long been considered to occur more frequently in families, with upwards of a 50% higher rate in the offspring of parents with asthma. Asthma genetic studies have used two major methods: mapping techniques that pinpoint gene loci and studies that identify genes and polymorphisms associated with various asthma mechanisms such as inflammatory mediators. The most consistently replicated chromosomal regions associated with asthma have been chromosomes 2q, 5q, 6p, 12 q, and 13q. Because the formation of reactive oxygen species is a major aspect of the inflammatory process of asthma, genetic aberrations associated with antioxidants such as glutathione S-transferase (GST) may shed light on reasons why some people with asthma seem more at risk of exacerbations as a result of air pollution. People with a polymorphism at the GSTP 1 locus, which codes for GST, one of a family of pulmonary antioxidants, have higher rates of asthma. Children in Mexico City with the GSTM1 null genotype demonstrated significant ozone-related decrements in lung function. Animal studies support the key role of antioxidants in reducing the inflammatory response associated with exposure to diesel exhaust particles. CONCLUSIONS: Oxidative stress is a key mechanism underlying the toxic effects of exposure to some types of air pollution. Asthmatics with the null genotype for the antioxidant, GST, seem more at risk of the pulmonary effects of air pollution.

Air Pollution↗
PubMed2003

Surfactant dissolution and mobilization of LNAPL contaminants in aquifers.

Improper disposal, accidental spills and leaks of non-aqueous phase liquids (NAPL) such as gasoline, fuel oil and creosote result in long-term persistent sources of groundwater pollution. Column and 2-D tanks experiments were conducted to evaluate the use of surfactant-enhanced recovery of light non-aqueous phase liquids (LNAPL) in groundwater aquifers. These experiments focused on the use of surfactants to promote dissolution and mobilization in addition to evaluating the increase of aqueous phase permeability as residual NAPL is recovered. Further experiments are presented that show the innovative use of surfactants during primary pumping to recover free product can potentially increase the amount of free product recovered, can potentially reduce the amount of residual NAPL remaining after primary pumping and performs better than the use of surfactants to mobilize trapped residual NAPL.

Carcinogens↗
PubMed2005

Novel activated alumina-supported iron oxide-composite as a heterogeneous catalyst for photooxidative degradation of reactive black 5.

A novel activated alumina-supported iron oxide-composite (denoted as FeAA-500) was prepared by so-called fluidized-bed reactor (FBR) crystallization. X-ray powder diffraction (XRD), N2 adsorption/desorption, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to characterize the FeAA-500. The photo-catalytic activity of the FeAA-500 was evaluated in the photooxidative degradation of 0.1 mM azo-dye reactive black 5 (RB5) in the presence of H2O2 and UVA light (lambda = 365 nm) in a solution with a pH of 2.5. Complete decolorization of the model pollutant RB5 was achieved; the total organic carbon (TOC) removal ratio was 95%, and a trace amount of leached ferric ion was detected following 75 min of reaction when 2.0 g/L FeAA-500 was used as a catalyst. FeAA-500 has high photo-catalytic activity; it is therefore a promising heterogeneous photocatalysis of the degradation of organic compounds.

Aluminum Oxide↗
PubMed2004

Emission comparison of urban bus engine fueled with diesel oil and 'biodiesel' blend.

The chemical and toxicological characteristics of emissions from an urban bus engine fueled with diesel and biodiesel blend were studied. Exhaust gases were produced by a turbocharged EURO 2 heavy-duty diesel engine, operating in steady-state conditions on the European test 13 mode cycle (ECE R49). Regulated and unregulated pollutants, such as carcinogenic polycyclic aromatic hydrocarbons (PAHs) and nitrated derivatives (nitro-PAHs), carbonyl compounds and light aromatic hydrocarbons were quantified. Mutagenicity of the emissions was evaluated by the Salmonella typhimurium/mammalian microsome assay. The effect of the fuels under study on the size distribution of particulate matter (PM) was also evaluated. The use of biodiesel blend seems to result in small reductions of emissions of most of the aromatic and polyaromatic compounds; these differences, however, have no statistical significance at 95% confidence level. Formaldehyde, on the other hand, has a statistically significant increase of 18% with biodiesel blend. In vitro toxicological assays show an overall similar mutagenic potency and genotoxic profile for diesel and biodiesel blend emissions. The electron microscopy analysis indicates that PM for both fuels has the same chemical composition, morphology, shape and granulometric spectrum, with most of the particles in the range 0.06-0.3 microm.

Chemical Fractionation↗
PubMed2004

Accumulation of polychlorinated biphenyls in sediments of the Venice Lagoon and the industrial area of Porto Marghera.

Sediment cores, collected at seven sites in the Venice Lagoon and within the canals of the industrial area were analyzed for polychlorinated biphenyls (PCBs) in order to assess the chronology of pollution and its present trends. The surficial concentration of PCBs is very high (more than 2049 microg kg(-1)) only in the Brentella Canal, probably due to a very recent contaminating episode. Very high values downcore (up to 41,639 microg kg(-1)) can be found in different parts of the industrial area, especially in the canals Lusore-Brentelle and Salso. Lagoon samples are much less contaminated (2.7-123 microg kg(-1)), being influenced only occasionally by polluted sediments resuspended from the canals. Sediment chronology shows that the delivery of contaminants peaked in the 1970s-early 1980s, decreasing since at most sites. Congener profiles distinguish PCBs in two main categories: heavy congeners characterize a baseline pollution, probably due to a large variety of sources within the lagoon system, whereas a mixture of light PCBs was discharged into the canals Brentella and Salso.

Environmental Monitoring↗
PubMed1980

Reaction of solid carrier-adsorbed polycyclic aromatic hydrocarbons with gaseous low-concentrated nitrogen dioxide.

The interaction of gaseous NO2 with solid carrier-adsorbed polycyclic aromatic hydrocarbons was studied under laboratory conditions with a specific attention to factors that might possibly influence this reaction, such as type of carrier lighting conditions, NO2 concentration, exposure time, and temperature. At the NO2 concentration of 1.33 ppm there were detected the following nitro derivatives: nitroanthracene, nitropyrene, nitrochrysene, two mononitro derivatives of benzo/a/pyrene, and dinitrobenzo/a/pyrene. The experimental data suggest that the formation of nitroaromates in atmospheric environment is to be expected, provided that there are present, besides polycyclic aromatic hydrocarbons and nitrogen oxides, also suitable types of sorbents, such as silica gel or fly ash.

Air Pollutants↗
PubMed2004

[Hazardous substances and detrimental conditions at the workplace].

UNLABELLED: An artificially created working environment, conditioned by technological processes, puts people in circumstances unparalleled in the place of living. Working conditions exert an influence on the employee's health, thus affecting health status of the whole society. Risks occurring on the working stands may result from the presence of physical, chemical and biological agents. Their vicinity devastates the harmony of man's co-operation with the environment, activates defence mechanisms and enforces an introduction of protection systems. The target of this research was to estimate a sugar factory employees' exposure to the detrimental agents occurring in their place of work. The research was conducted in one of Lublin sugar factories and it involved an estimation of working conditions via a measurement of such physical agent parameters as microclimate, dust density, noise volume, light intensity and exposure to carbon oxide. The results of sanitary-epidemic services' inquiry into the issue were also included here. The estimation of the joint influence of the microclimatic elements in the working environment was made with the measures of temperature, humidity and air circulation were taken into account. The WBGT factor ranged from 18.80 degrees to 31.73 degrees and frequently stayed out of the limits of the thermal comfort. The measuring of the dust density showed an exceeding of the binding quotas on single working stands only. The highest weight average was 17 mg/m3. A comparison of these results with the findings of the previous years surveys shows a constant decrease in dust density. The most considerable bias from the binding quotas was noted while measuring noise level. The noise volume on some stands reached from 98 dB to 109 dB, which, taking into account the eight-hour working day, gave an average exposure level within the boundaries of 82 dB to 98 dB. CONCLUSIONS: 1. The presence of detrimental agents in working environment should lead to permanent monitoring of risks. 2. It is purposeful to undertake various preventive actions in order to minimalise effects to the employees.

Air Pollutants, Occupational↗
PubMed2004

Acousto-optic differential optical absorption spectroscopy for atmospheric measurement of nitrogen dioxide in Hong Kong.

Measurement of the atmospheric concentration of nitrogen dioxide (NO(2)) pollutant was demonstrated by differential optical absorption spectroscopy (DOAS) using a visible acousto-optic tunable filter. In a traditional spectral scanning DOAS system for atmospheric concentration monitoring, a highly stable light source is required. When the light intensity fluctuates during scanning, the concentration retrieval will be inaccurate. In order to reduce the error due to intensity fluctuations, a modified DOAS system has been developed by introducing a broadband light intensity monitoring channel. Using the measured intensity of the broadband channel as the intensity of the light source, the spectrum can be de-biased and the residual intensity variation will primarily result from atmospheric extinction. In addition, by employing the lock-in detection technique, the background light interference is also removed in the modified DOAS system. The atmospheric NO(2) concentration measurement was performed at the campus of City University of Hong Kong, and the results were compared with the concentration reported from a nearby monitoring station in Sham Shui Po, operated by the Hong Kong Environmental Protection Department.

Absorption↗
PubMed2004

Catalytic degradation of methylene blue by Fenton like system: model to the environmental reaction.

To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(III) and H2O2 in the absence of light instead of Fe(II) and H2O2 was studied. Results showed that use of Fe(III) is more promising than Fe(II). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.

Ferric Compounds↗
PubMed2005

Secondary organic aerosol production from terpene ozonolysis. 1. Effect of UV radiation.

We report secondary organic aerosol (SOA) yields from the ozonolysis of alpha-pinene under both dark and UV-illuminated conditions. Exposure to UV light reduces SOA yield by 20-40%, with a maximum reduction in yield coinciding with a minimum in the amount of terpene consumed (15-30 ppb). The data are consistent with a constant absolute reduction in the yield of approximately 0.03. Gas chromatography mass spectrometry analysis of filter samples indicates that the major products found in alpha-pinene SOA include organic acids (e.g., pinic acid), keto acids (e.g., pinonic acid), and hydroxy keto acids (e.g., 10-hydroxypinonic acid). Analysis of filter-based results suggests that yield reduction is a result of the formation of a more volatile product distribution when experiments are conducted in the presence of UV light. These results implythat previous "dark bag" experiments may overestimate SOA generation from monoterpenes and also that SOA generation in the atmosphere may depend significantly on actinic flux.

Acids↗
PubMed2003

[The study of pollutant's effects on macrophages and its significance in biological monitoring].

This study aimed to investigate the effects of environmental pollutant sulfite and inorganic mercury on the peritoneal macrophages (PM phi) of mice and further explore the significance of macrophage as a biomarker in biological monitoring. PM phi were taken from the peritoneal cavity of mice and cultivated with Na2SO3 and HgCl2 respectively in vitro, and then morphologic changes were detected under light microscope and electron microscope. Also the function of PM phi was detected in yielding nitric oxide (NO), reducing MTT and phagocytizing. After affected by the pollutants, marked morphologic changes of PM phi were observed, and NO reducing, cell vigor and phagocytizing of PM phi were obviously inhibited (p < 0.05 or p < 0.01). And some PM phi were necrotic caused by HgCl2 at high concentration(10(-4) mol/L). The results suggested that PM phi of mice was damaged distinctly by using Na2SO3 and HgCl2 which showed sulfite and inorganic mercury directly impacted on non-special defensive function of macrophages. Meanwhile the experiment indicated that macrophage could be used as an effective biomarker in biological monitoring of environmental contamination.

Animals↗
PubMed1978

[Patterns of variations for air concentrations of some pollutants].

Patterns of diurnal variations for the air concentration of some pollutants emitted from motorvehicles are presented. Primary pollutants (carbon monoxide, nitric oxide and reactive hydrocarbons) and secondary pollutants (ozone and nitrogen dioxide) are continuously monitored since 1974. Different typical patterns have been obtained in the winter and in the summer season. The values of r for 14 regression curves calculated for couples of primary pollutants are in the range from 0.73 to 0.95, indicating their common source. Diurnal patterns obtained for summer and winter are discussed in the light of photochemical atmospheric processes Values for the ratio NO/NO2 are higher than 1 in the winter season; the same ratio is lower than 1 in summer, from 13 to 24 hours.

Air Pollutants↗
PubMed2006

Airborne dust particle counting techniques.

The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena. Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17( composite function) off axis, at 163( composite function) from the light source in the visible range. On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.

Dust↗
PubMed1996

A morphometric and functional study of the toxicity of atmospheric ammonia in the extrathoracic airways in pigs.

The effects of atmospheric ammonia (NH3) on the nasal and tracheal mucosa of pigs were investigated by morphometric and functional methods. Pigs were exposed to four concentrations of NH3 [5 (control), 25, 50 and 100 ppm] for 6 days in a specially designed air-pollutant exposure chamber. Samples were taken from the turbinates and the trachea, and the respiratory mucosa was examined by light and scanning electron microscopy. Dose-response curves to carbachol and isoproterenol were constructed using isolated strips of tracheal smooth muscle, with or without epithelium. In pigs exposed to ammonia, considerable mucosal injuries were observed in the turbinates but not in the trachea. The number of neutrophils in the epithelial layer and in the lamina propria, and epithelial hyperplasia were closely and significantly correlated with the concentrations of ammonia (r = 0.894, p < 0.001; r = 0.727, P < 0.001; and r = 0.818, p < 0.001, respectively). Except for the lamina propria, all these changes were significant (p < 0.05) at ammonia concentrations as low as 25 ppm. The percentage of the surface of the turbinate mucosa that was ciliated tended to decrease with increasing ammonia concentration (r = 0.439, p < 0.082). Ammonia induced smooth-muscle hyperresponsiveness to carbachol with a close linear correlation between individual values of the carbachol-induced maximal effect and the NH3 concentrations (r = 0.526, p < 0.003). While mechanical destruction of the epithelium induced an increase in Emax in the control group, no difference was observed between the intact and denuded strips from animals exposed to ammonia. The response to isoproterenol was not influenced by ammonia. It was concluded that quantitative histological analysis of the inflammatory infiltration and epithelial hyperplasia in the turbinates is a useful tool for quantifying the effects of atmospheric pollutants in pigs; a 6-day exposure to ammonia induces nasal irritation and functional disturbances of the tracheal smooth-muscle contractions at concentrations as low as 25 ppm.

Adrenergic beta-Agonists↗
PubMed2006

Interactive factors leading to dying-off Carex tato in Momoge wetland polluted by crude oil, Western Jilin, China.

Momoge wetland is an internationally important wetland not only because it is a habitat for many rare bird species but also because it is an internationally important stopover for some rare global migratory bird species. However the petroleum exploitation in wetland has brought about many environmental problems. One of the most severe problems is crude oil pollution, which has caused the dying-off Carex tato and imposes great threat on survival of rare birds. This work studied the factors that caused the dying off of Carex tato. The results showed that death of Carex tato was the result narcosis toxicity of alcohols, intermediate biodegradation products of crude oil, on the root tissue, and the fragmentization of cuticle of leaves by light components of crude oil volatized from soil surface. However, the mechanism involved was much more complex and three interactive factors including crude oil pollution of soil, long-term drought and poor permeability of soil were responsible for the dying-off of Carex tato grassland. The distribution of crude oil in soil profile was characterized with high concentrations at top silty layer and the layer below root zone and low or no crude oil at root zone layer. This distribution was relative to root system characteristics and rhizospheric biodegradation. In root zone, substantive oxygen could be transported to root zone through dense root system and well developed aerenchyma. The crude oil in root zone was easily biodegraded by aerobic rhizosphere microbes. However, some toxic intermediate products, such as some alcohols, was sealed in root zone due to poor permeability of the top soil layer and the deeper soil layer and they had lethal effects on root tissue. Above ground, low molecular components of crude oil in top soil layer was easily volatized into atmosphere during long-term drought. Some of the volatized components were adsorbed onto leaves. SEM analysis showed that these components destroyed the leaves by fragmentization of cuticle of leave. This study also shows that although wetland has natural attenuation of pollutants, natural attenuation of pollutants by natural wetland should not be overemphasized. This attenuation function may lose under some conditions such as long-term drought and poor soil texture.

Carex Plant↗
PubMed2006

Trace metal pollution from traffic in Denizli-Turkey during dry season.

OBJECTIVE: To determine the metal contents of date palm (Pheonix dactylifera) samples in dry season from Denizli-Turkey for investigation of heavy metal-polluted traffic. METHOD: The levels of iron, copper, zinc, lead, cadmium, nickel, chromium, and manganese ions in the leaves of thirty five date palm (Pheonix dactylifera) samples collected from various levels of traffic in the streets of Denizli-Turkey were determined by graphite furnace or flame atomic absorption spectrometry. The wet, dry, and microwave digestion procedures for the date palm (Pheonix dactylifera) leaves were compared. The accuracy of the digestion procedures was checked using a standard reference material (IAEA-336 Lichen, SRM). RESULTS: Microwave digestion procedure for the leaves was preferred because it was more proper with respect to both time and recovery than dry and wet digestion. The levels of the heavy metal ions investigated were the highest on the samples from high traffic level. Also correlations between metal levels and traffic volume for all the metals were investigated. CONCLUSION: In the light of our findings, the date palm (Phoenix dactylifera) leaves are suitable as a biomonitor for atmospheric heavy metal-polluted traffic. Significant correlations can be obtained between traffic levels and heavy metal concentrations.

Air Pollutants↗