Why not light your candle?
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Air Pollution↗
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Organohalogenated pollutants in human serum from Iassy, Romania and their relation with age and gender.
Human serum samples (n=142) from Iassy county (Eastern Romania) collected in 2005 were analyzed for p,p'-DDT and its metabolites, hexachlorobenzene, hexachlorocyclohexane (HCH) isomers, chlordane and metabolites and 14 polychlorinated biphenyl (PCB) congeners. In all samples, p,p'-DDE (principal metabolite of p,p'-DDT) and beta-HCH (most persistent HCH isomer) were the most abundant organochlorine pesticides (OCPs) with median concentrations of 1975 and 923 ng/g lipid weight (lw), respectively. Hexachlorobenzene and p,p'-DDT were also detected in all samples, but at a lower median concentration of 30 and 340 ng/g lw, respectively. The large variation of the ratio p,p'-DDT/p,p'-DDE (range between 0.02 and 0.80) suggests various degrees of exposure to DDT, including recent exposure, at least to some subgroups of the population. Chlordane and its metabolites were in most cases close to the limit of quantification suggesting a very low use of chlordane formulations in Eastern Romania. Unexpectedly, PCBs were present in all samples at sometimes considerable levels (up to 4970 ng/g lw for sum of 14 PCB congeners) indicating a higher exposure of the Romanian population than previously reported. The PCB profile consisted of persistent congeners such as 138, 153, 170 and 180 which contributed for approximately 75% to the sum PCBs. Concentrations of most pollutants correlated significantly with age (r>0.86, p<0.01). Except for p,p'-DDT and gamma-HCH, the mean levels of OCPs in females were statistically higher than in males, while, except for octa-CBs, no gender differences were found for PCBs. Levels of p,p'-DDE, penta-CBs, hexa-CBs and hepta-CBs were significantly higher in individuals with a rural main residence. In a pooled serum sample, 6 polybrominated diphenyl ether (PBDE) congeners were measured at a level of 1.04 ng/g lw. Compared to results available from Central and Eastern European countries, human serum samples from Romania contained higher levels of contamination. This emphasizes that an extensive and rigorous program for the monitoring of OCPs and PCBs in Romanian population is highly needed in the light of possible adverse health effects acknowledged for these pollutants.
Adolescent↗
[The emissions of fiber particles into the atmosphere in the region of an asbestos-processing industry].
Examination is carried out on dust taken from the atmospheric air in the town of Sevlievo, where a plant for asbestos products is situated. The concentrations of fibre particles are determined by the methods of light and electron microscopy. The results are compared with the emissions of fibres in the air of a control town. There is a significant contribution of an industrial source of emission in the atmospheric pollution by fibre particles. It was proved that the method of light-phase contrast microscopy is not suitable for analyses of low concentrations of fibres in the air. As only reliable method is that of electron microscopy.
Air Pollutants↗
Comparison of particle light scattering and fine particulate matter mass in central California.
Particle light scattering (Bsp) from nephelometers and fine particulate matter (PM2.5) mass determined by filter samplers are compared for summer and winter at 35 locations in and around California's San Joaquin Valley from December 2, 1999 to February 3, 2001. The relationship is described using particle mass scattering efficiency (sigmasp) derived from linear regression of Bsp on PM2.5 that can be applied to estimated PM2.5 from nephelometer data within the 24-hr filter sampling periods and between the every-6th-day sampling frequency. An average of sigmaSp = 4.9 m2/g was found for all of the sites and seasons; however, sigmasp averaged by site type and season provided better PM2.5 estimates. On average, the sigmasp was lower in summer than winter, consistent with lower relative humidities, lower fractions of hygroscopic ammonium nitrate, and higher contributions from fugitive dust. Winter average sigmasp were similar at non-source-dominated sites, ranging from 4.8 m2/g to 5.9 m2/g. The sigmasp was 2.3 m2/g at the roadside, 3.7 m2/g at a dairy farm, and 4.1 m2/g in the Kern County oilfields. Comparison of Bsp from nephelometers with and without a PM2.5 inlet at the Fresno Supersite showed that coarse particles contributed minor amounts to light scattering. This was confirmed by poorer correlations between Bsp and coarse particulate matter measured during a fall sampling period.
Air Pollutants, Occupational↗
First world-wide interlaboratory study on polybrominated diphenylethers (PBDEs).
The first world-wide interlaboratory study on PBDEs, organised between November 1999 and April 2000, involved five biological samples, two sediments and two standard solutions. These materials were sent to 26 participants in nine different countries. Results were returned from 18 laboratories. The results reported for BDE 47 were acceptable with a range of relative standard deviations (Rsd) of 17-40%. Results for the BDEs 99 (Rsd 25-77%), BDE 100 (Rsd 19-48%), 153 (Rsd 30-48%) and 154 (Rsd 25-43%) showed that a further improvement of these analyses is needed. The BDE 209 analysis is not under the control of the participating laboratories. The data reported for the biota samples were very variable and for the two sediments Rsd values of 48% and 78% were obtained. It is recommended that analysts pay more attention to the special requirements for the BDE 209 analysis such as avoiding exposure to intensive light and exposure for too long times to too high temperatures.
Environmental Monitoring↗
Detection of atmospheric nitrogen dioxide using a miniaturised fibre-optic spectroscopy system and the ambient sunlight.
A miniaturised fibre-optic spectrometer based system is presented for direct detection of one of the major atmospheric pollutants, nitrogen dioxide, by absorption spectroscopy using the ambient sunlight as light source. The detection system consists of a 10 cm collimator assembly, a fibre-optic cable and a portable diode-array spectrometer. The absorbance spectrum of the open-path is calculated using a reference spectrum recorded when the nitrogen dioxide (NO2) concentration in the atmosphere is low. The relative concentration of the pollutant is calculated normalising the detected spectra and subtracting the background broadband spectrum from the specific NO2 absorbance features, since the broadband spectrum changes according to atmospheric conditions and solar intensity. Wavelengths between 400 and 500 nm are used in order to maximise sensitivity and to avoid interference from other species. Calibration is carried out using Tedlar sample bags of known concentration of the pollutant. A commercial differential optical absorption spectroscopy (DOAS) system is used as a reference standard detection system to compare the results with the new system. Results show that detection of NO2 at typical urban atmospheric levels has been achieved using an inexpensive field based fibre-optic spectrometer and a readily available, easy to align, light source. In addition the new system can be used to get a semi-quantitative estimation of the nitrogen dioxide concentration within errors of 20%. While keeping the typical benefits of open-path techniques, the new system has important advantages over them such as cost, simplicity and portability.
Air Pollutants↗
Helicopter-based lidar system for monitoring the upper ocean and terrain surface.
A compact helicopter-based lidar system is developed and tested under laboratory and field conditions. It is shown that the lidar can measure concentrations of chlorophyll a and dissolved organic matter at the surface of water bodies, detect fluorescence spectra of ground vegetation at a distance of up to 530 m, and determine the vertical profile of light-scattering particle concentration in the upper ocean. The possibilities of the lidar system are demonstrated by detection of polluted areas at the ocean surface, by online monitoring of three-dimensional distribution of light-scattering layers, and by recognition of plant types and physiological states.
Journal Article↗
Establishment of atmospheric pollution standards for motor vehicles.
First we classify the various emission standards applying to light vehicles, the conditions under which the emissions are measured and the environmental standards. We then describe the way in which a standard is established according to the basic principles and procedures involved in determining acceptable environmental concentrations in practice. We refer to the economic and political considerations involved in deciding on a standard and, as an example, to the positions adopted by the various parties concerned in France when drafting the 15.05 standard. In response to the atmospheric pollution caused by motor vehicles, all the industrial countries have, some earlier than others, drawn up regulations designed to limit the extent of this pollution, to protect the environment and reduce the public health risk. Both environmental and emission standards are aimed at reducing the risks to the environment and in particular to man, arising From the presence of particular pollutants. The procedure concerned in establishing these standards is a complicated one involving scientific, economic and political considerations; furthermore, there is a great diversity of standards.
Air Pollution↗
BSD extent, an index for metal pollution screening based on the metal content within digestive cell lysosomes of mussels as determined by autometallography.
The extent of autometallographical black silver deposits (BSD) has been semiquantified at the light microscope in the gills and digestive gland of either control mussels or Zn-polluted mussels after depuration and on exposure to sublethal concentrations of Cu, Zn, and Cd. The BSD extent in the gills and digestive gland of control mussels was much reduced compared to that in other experimental mussels. The extent of BSD in the gills of depurating mussels was reduced at short depuration times due to decreased levels in the abfrontal cells while in the digestive gland it did not change with the depuration period. The extent of BSD in digestive lysosomes of Cu- and Zn-exposed mussels followed a logarithmic pattern in relation to metal concentration increasing with metal concentrations in the digestive gland. However, a reduced extent of BSD was related to the presence of high metal concentrations under Cd-exposure conditions. This is because the great extent of BSD present in the lumen of the digestive tubules was not taken into account to carry out semiquantification, but, however, the chemical analysis measured the Cd content of these BSD. As such, the extent of BSD in digestive lysosomes followed a logarithmic pattern with total metal concentrations in the digestive gland of Cd-exposed mussels. Therefore, the semiquantitative estimation of BSD in the digestive lysosomes could be considered a reliable index to reflect changes in metal bioavailability in sea water.
Analysis of Variance↗
Air pollution and human health: perspectives for the '90s and beyond.
This paper considers the health effects of air pollution from three perspectives: historical, statistical, and public policy, and also as depicted by the recent epidemiology, primarily mortality studies. The historical perspectives establish the reality of population-based health effects, and they provide data with which to evaluate more recent evidence. Statistical perspectives imply that, while there is strong evidence that associations between air quality and health persist, many details of these relationships remain obscure, especially as to the existence of concentration thresholds that might define safe exposure levels. Additional major questions include the effects of uncertainties in actual pollution exposures, the degree of prematurity of "excess" deaths, and whether the development of new cases of chronic disease is associated with air pollution. Public policy issues center around interpreting the new epidemiological studies in the light of these uncertainties and the analysis and management of the concomitant health risks.
Air Pollutants↗
Fine particulate chemical composition and light extinction at Meadview, AZ.
The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr day-night samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was +/- 0.6 microg/m3 organic material, +/- 0.3 microg/m3 ammonium sulfate, and +/- 0.07 microg/m3 ammonium nitrate. Data were also available on fine particulate crustal material, fine and coarse particulate mass from the Interagency Monitoring of Protected Visual Environments sampling system, and relative humidity (RH), light absorption, particle scattering, and light extinction measurements from Project MOHAVE. An extinction budget was obtained using mass scattering coefficients estimated from particle size distribution data. Literature data were used to estimate the change in the mass scattering coefficients for the measured species as a function of RH and for the absorption of light by elemental carbon. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. During periods of highest light extinction, contributions from fine particulate organic material, sulfate, and light-absorbing carbon dominated the extinction of light by particles. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides sources in the region indicate that the major anthropogenic contributors to light extinction were from the Los Angeles, CA, and Las Vegas, NV, urban areas. Mohave Power Project associated secondary sulfate was a negligible contributor to light extinction.
Air Pollutants↗
PHOTOACTIVATION OF POLYNUCLEAR HYDROCARBONS.
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Acridines↗
Biological desulfurization in an optical-fiber photobioreactor using an automatic sunlight collection system.
Biological desulfurization using C. thiosulfatophilum has many more advantages over conventional physico-chemical methods due to low operational cost and no production of secondary pollutants. However, it requires effective and economical supply of light energy, which is a key factor in determining the success of commercialization. In this study, optical-fiber photobioreactor with internal illumination system was applied to increase the light availability. Furthermore, sunlight was used as the main light energy in the daytime and metal-halide lamp was applied as an additional light energy at night. Most UV light was eliminated by the chromatic aberration of the aspherical lenses in the solar light collector and 60% of infrared light intensity was eliminated. Physical scratching optical fibers enhanced the light availability about five times as much as that with unscratched ones in the previous study, but it resulted in the adsorption problem of elementary sulfur particles deteriorating light diffusivity considerably in a long operation. In order to solve this problem, scratched optical fibers were inserted into pyrex-glass tubes, which made light diffusivity nearly the same as that without glass tubes. Removal rate per unit cell concentration, using sunlight in the daytime and a metal-halide lamp at night, was 0.41 <0.73 micromol H(2)S min(-1)/(mg protein l(-1)) using a 400 W metal-halide lamp day and night, since the automatic sunlight collection system can transmit the light intensity as only 10% of that with a metal-halide lamp.
Adsorption↗
Mental strain and physical symptoms among employees in modern offices.
A comprehensive questionnaire that assessed both physical and psychosocial work environments, as well as personal health and lifestyle, was answered by 133 (92%) employees. In addition, we assessed the physical/chemical and psychosocial environments of 8 randomly selected employees, of whom some had environmentally related health complaints. Environmental factors most often associated with poor work environments were improper room temperature, light reflexes (i.e., glare and reflection of light), dust, and dry air. Emission products from traffic pollution and 1,1,1-trichloroethane levels were also detected. The electromagnetic fields in both the low and the extremely low frequencies spectra were close to background levels. Individuals who had environmentally associated health symptoms worked mainly in the customer support division, and they perceived higher work demands. Their computer environment was also worse ergonomically. There were no differences with respect to objective skin signs or disease between those with and without symptoms, respectively. The results of this study point to the importance of looking at both the psychosocial and physical environments when health complaints arise in modern offices.
Adult↗
Effect of surfactants on persistence of azadirachtin-A (neem based pesticide).
Photostability of azadirachtin-A, a neem based pesticide, was studied in the presence of non-ionic surfactants. Surfactants such as Span-80, Atlox 3400B, Tween-80, Agrimul 52B, and Agrimul N4S enhanced the rate of photodegradation of azadirachtin-A, whereas surfactants such as Triton-X, Emulsol CFA, Tween-20, Emulsol MAS, and Emulsol-N-33 decreased the rate of degradation. Emulsol-N-33 was found to be the most effective surfactant, as half life of azadirachin-A in the presence of Emulsol-N-33 was found to be 94.93 min in comparison to 48 min for azadirachtin-A alone under UV light.
Environmental Pollutants↗
Ozone foliar symptoms in woody plant species assessed with ultrastructural and fluorescence analysis.
This paper compares the responses to ozone in five woody species: Fagus sylvatica (FS), Acer pseudoplatanus (AP), Fraxinus excelsior (FE), Viburnum lantana (VL) and Ailanthus altissima (AA). The hypothesis being tested was that the strategies that plants adopt to resist oxidative pressure are species-specific. The study was carried out on field grown plants in an area in Northern Italy characterized by elevated levels of ozone pollution. The observations were made both at ultrastructural (using light and electronic microscopy) and physiological (using chlorophyll a transient fluorescence and microspectral fluorometry) level. Common responses were: the hypersensitive response (i.e. the death of palisade mesophyll cells) and the formation of callose layers separating injured from healthy cells. FS and AP were capable of thickening the palisade mesophyll cell walls. This thickening process involved changes in cell wall chemical structure, evidenced by the accumulation of yellow autofluorescence compounds. Species-specific behaviours were observed with the fluorescence analysis, with special reference to the photochemical de-excitation constant (Kp). This value increased in FE and AP, and decreased in AA. The observed responses are interpreted as adaptative strategies against the ozone stress. The increase of Kp indicates that the reaction centres were working as more effective quenchers.
Chlorophyll↗
Physical factors in the indoor environment.
This comprehensive chapter presents a discussion of physical factors in the nonindustrial indoor environment that affect human health, comfort, productivity, and well-being. Areas stressed include the thermal environment, light, noise, and other mechanical energy.
Air Movements↗
Toxicity of tetracyclines and tetracycline degradation products to environmentally relevant bacteria, including selected tetracycline-resistant bacteria.
Tetracyclines used in veterinary therapy invariably will find their way as parent compound and degradation products to the agricultural field. Major degradation products formed due to the limited stability of parent tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in aqueous solution were theoretically identified at various environmental conditions, such as pH, presence of chelating metals, and light. Their potency was assessed on sludge bacteria, tetracycline-sensitive soil bacteria, and tetracycline-resistant strains. Several of the degradation products had potency at the same concentration level as tetracycline, chlortetracycline, and oxytetracycline on both the sludge and the tetracycline-sensitive soil bacteria. Further, both 5a,6-anhydrotetracycline and 5a,6-anhydrochlortetracycline had potency on tetracycline-resistant bacteria supporting a mode of action different from that of the parent compounds.
Bacteria↗