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Results 301 - 350 of 477
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Abu-Jarad F - - 2003
The results of a first phase of an indoor radon survey in a total of 1610 dwellings distributed in nine cities of the Eastern and the Western provinces of Saudi Arabia are presented. The objective of this radon survey was to obtain representative indoor radon data for seven cities in ...
Kim Jin-Gab - - 2003
The food industry is interested considerably in using ozone to enhance the shelf-life and safety of food products and in exploring new applications of the sanitizer. This interest was recently accompanied by a US governmental approval of ozone for the safe use, in gaseous and aqueous phases, as an antimicrobial ...
Gupta A K - - 2003
A long-term study of oxides of nitrogen (NOx), sulphur dioxide (SO2), and ammonia (NH3) has been performed in a port and harbor region in India from January 1997 to December 2000. Meteorological data was also collected to establish the correlation with gaseous pollutants concentrations. Monthly mean concentrations of NOx were ...
Varotsos Costas - - 2003
Varotsos (2002a,b), suggested that both the smaller-sized ozone hole over Antarctica and its splitting in two holes in September 2002 occurred due to an unprecedented major sudden stratospheric warming caused by very strong planetary waves propagated in the southern hemisphere. Subsequently, a NASA press release of December 6, 2002, also ...
Kieber Robert J - - 2002
The concentrations of the various chromium species were determined in 89 rainwater samples collected in Wilmington, NC, from October 1, 1999, to December 31, 2001. Volume-weighted annual average concentrations of Cr(total), particulate Cr, Cr(III)(aq), and Cr(VI)(aq) were 4.6, 2.2, 0.8, and 1.2 nM, respectively. There was distinct seasonal and diurnal ...
McDonald Blair G - - 2002
Photoenhanced toxicity of polycyclic aromatic hydrocarbons (PAH) is well demonstrated in laboratory and in a few in situ studies. Effects have been observed for multiple taxa and toxicological endpoints, and the mechanism of toxic action has been described. However, this phenomenon is ameliorated by physical, chemical and biotic factors. The ...
Alcalde Miguel - - 2002
Polycyclic aromatic hydrocarbons (PAHs) are highly toxic organic pollutants widely distributed in terrestrial and aquatic environments. In the present work, 2 colorimetric assays for laccase-catalyzed degradation of PAHs were developed based on studies of the oxidation of 12 aromatic hydrocarbons by fungal laccases from Trametes versicolor and Myceliophthora thermophila. Using ...
Mader Brian T - - 2002
A controlled field experiment (CFE) methodology with a filter/sorbent sampler was used to minimize artifact effects when measuring values of the gas/particle (G/P) partitioning constant (Kp, m3 microg(-1)) for semivolatile organic compounds (SOCs) in the atmosphere. CFE sampling was conducted at three different locations (Beaverton, OR; Denver, CO; and Hills, ...
Arsene Cristian - - 2002
The epicuticular composition of different body parts of the Cabbage White, Pieris rapae L., was investigated using GC and GC/MS. The major group of components, hydrocarbons, occurs in two distinct classes, which show different distributions on the cuticle of the insects. Unbranched shorter chain compounds (C21 to C31, linear group) ...
Richardson Bruce J - - 2002
The outer layers of layflat, low density polyethylene plastic tubing (the principal component of semi-permeable membrane devices, SPMDs) were biofouled at a clean site in Hong Kong coastal waters for periods of 1-4 weeks. Following pre-fouling, triolein was added to the SPMDs and, along with control (unfouled) devices, they were ...
Siegmund Barbara - - 2003
The presence of nitrated polycyclic aromatic hydrocarbons (nitro-PAHs) as contaminants in foods is nowadays a legitimate cause of concern, as they are reported to be strong direct-acting mutagens and carcinogens that may pose a risk to human health. Nevertheless, their concentrations in foods are in the ultra-trace region. In this ...
Greenwell Leona L - - 2002
A positive correlation has been established between increased levels of airborne particulate pollution and adverse health effects, the toxicological mechanisms of which are poorly understood. For toxicologists to unambiguously determine these mechanisms, truly representative samples of ambient PM10 are required. This presents problems, as PM10 collecting equipment commonly employed, such ...
Nolte Christopher G - - 2002
Source sample extracts of vegetative detritus, motor vehicle exhaust, tire dust paved road dust, and cigarette smoke have been silylated and analyzed by GC-MS to identify polar organic compounds that may serve as tracers for those specific emission sources of atmospheric fine particulate matter. Candidate molecular tracers were also identified ...
Viau Claude - - 2002
Five healthy volunteers consumed similar amounts of identical foods for 5 consecutive days. The concentration of pyrene and of benzo(a)pyrene was determined in each of the 15 meals by a short analytical method that included sample saponification, solvent extraction, and HPLC analysis. The volunteers also provided three daily total volume ...
Yang Hsi-Hsien - - 2002
In order to characterize the polycyclic aromatic hydrocarbons (PAHs) emission from steel and iron industries, this study measured the stack emission of twelve steel and iron plants in southern Taiwan to construct a set of source fingerprints. The study sampled the emissions by the USEPA's sampling method 5 with the ...
Offenberg John H - - 2002
Concentrations of semi-volatile organic compounds in dissolved and particulate forms in precipitation are related to those measured concurrently in air measured at multiple locations along the tracks of several storms. In 14 paired (air and precipitation) samples collected at urban, over-water, and downwind stations around southern Lake Michigan, compound-specific total ...
Arafa W - - 2002
The indoor radon concentration in a typical Egyptian village in Delta was measured in 50 houses during summer 1999 and winter 2000. This survey was done using three different types of charcoal canisters: 4" open-faced, 2.75" open-faced, and 2.75" diffusion barrier. The average winter to summer ratio was 2.1 and ...
Lee S C - - 2002
The assessment of volatile organic compounds (VOCs) has become a major issue of air quality network monitoring in Hong Kong. This study is aimed to identify, quantify and characterize volatile organic compounds (VOCs) in different urban areas in Hong Kong. The spatial distribution, temporal variation as well as correlations of ...
Fang Guor-Cheng - - 2002
Airborne particles and polycyclic aromatic hydrocarbons (PAHs) in industrial, background and urban atmosphere environments were investigated using toxic equivalent factors (TEFs) in central Taiwan during the period of August-December 2002. Concentrations of airborne particles were 93.4, 81.3 and 102.4 microg/m3 for industrial, background and urban sites, respectively. Concentrations of 21 ...
Kang Jong-Won - - 2002
The authors investigated Korean municipal middle school students to ascertain whether urinary 1-hydroxypyrene (1-OHP) and 2-naphthol-markers for polycyclic aromatic hydrocarbon (PAH) exposure-reflect PAHs in ambient air. The authors used the beta-ray absorption method, which is an index of ambient-air PAH exposure, to collect total suspended particulate (TSP) data. The authors ...
Borbon A - - 2002
Continuous hourly air quality data involving 37 C2-C9 non-methane hydrocarbons (NMHC) over 4 years are reported for the first time in Lille metropol, northern France, at two urban roadside and background sites. The data have been analysed in two complementary steps: univariate statistics which define the spatial and temporal characteristics ...
Ricking M - - 2002
To document the historical input the PAH-profiles of sediment cores in two different basins of the Baltic Sea, the Gotland Basin (GB) and Arkona Basin (AB), were analysed by means of GC-MS. 35 PAHs were quantified in all samples, and additionally, several marker PAHs, like Cyclopenta[cd]phenanthrene (CCP) for combustion processes ...
Law Robin J - - 2002
Fish and shellfish are exposed to a wide range of polycyclic aromatic hydrocarbons (PAH) following oil spills at sea, and can become contaminated as a result. Finfish have a more effective mixed-function oxidase enzyme system than shellfish, and are therefore able to metabolise and excrete PAH more effectively than the ...
Baeza M J - - 2002
Fire behaviour under experimental conditions is described in nine Mediterranean gorse shrublands ranging from 3-12 years of age with different fuel loads. Significant differences in the fire-line intensity, fuel load and rate of fire spread have been found to be related to the stage of development of the communities. Fire ...
Asikainen Arja H - - 2002
Two experiments were performed with an atmospheric circulating fluidized bed gasifier (ACFBG), the first with pelletized straw and the second with loose straw, to investigate the occurrence of polycyclic aromatic hydrocarbons (PAHs), chlorophenols (CIPhs), polychlorinated biphenyls (PCBs), polychlorinated benzenes (ClBzs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in the bottom ...
Gatermann R - - 2002
A method for the enantioselective separation of the chiral polycyclic musks HHCB, AHTN, AHDI, and ATII is presented. Eighteen fish samples (rudd, tench, crucian carp, eel) and one pooled zebra mussel sample from the pond of a municipal sewage treatment plant were investigated with regard to their concentrations and the ...
Ginzel Matthew D - - 2002
This study evaluates the potential for using blends of synthetic hydrocarbons in mark-recapture studies of insects. To test the durability of hydrocarbons, we applied a blend of five straight-chain hydrocarbons (C24, C21, C26. C28, C30) to detached elytra of the red milkweed beetle, Tetraopes tetrophthalmus (Forster) (Coleoptera: Cerambycidae), mounted the ...
Jones Tim - - 2002
Airborne particulate matter has been collected from within, and proximal to, an opencast coal mine in south Wales. This work forms the first part of a three year project to collect and characterise, then determine the possible toxicology of airborne particles in the south Wales region. High-resolution Field Emission SEM ...
Jaimes L - - 2002
Samples of volatile organic compounds (VOCs) were collected in a smog chamber in order to determine whether automotive exhausts or LP Gas emissions play a greater role in the source of propane and butane, which affect ozone formation and other pollutants in the ambient air of the Mexico City metropolitan ...
Youssef Tarek - - 2002
The germination behavior of Sporobolus iocladus seeds including germination percentage, accumulated germination percentage, the average incubation period to germination and germination velocity was studied under laboratory conditions. Treatments included six salinity regimes (0, 70, 140, 210, 280 and 350 mM NaCI) and three sources of oil hydrocarbons; Light Arabian Crude, ...
Fernandes Milena B - - 2002
Polycyclic aromatic and monoaromatic (benzene, toluene and xylene, or BTX) hydrocarbons were monitored in Rio de Janeiro, Brazil, during the summer of 1998/1999. The levels of these aromatic chemicals decreased with distance from main roads, indicating mobile sources are the main pollutant emitters in this Latin American city. Benzo[ghi]perylene/indeno[1,2,3-cd]pyrene and ...
Mugica V - - 2002
With the purpose of estimating the source contributions of nonmethane hydrocarbons (NMHC) to the atmosphere at three different sites in the Mexico City Metropolitan Area, 92 ambient air samples were measured from February 23 to March 22 of 1997. Light- and heavy-duty vehicular profiles were determined to differentiate the NMHC ...
Maw S J - - 2002
The evolution of NOx from grass and maize silages was measured using chemiluminescence in samples kept in airtight containers, in the silos and in a 750 kg mass removed to a mixer waggon. Measurements were made on the grass and maize silos in two consecutive years. The results show that ...
Mostafa Gamal A - - 2002
Concentrations of polycyclic aromatic hydrpcarvons (PAHs) in some seafoods caught from Lake Timsah were determined. The tested samples were tilapia fish (Oreochromis aureus), crabs (Portuns pelagicus), bivalves (Venerupis decussata), clams (Strombus tricornis) and gastropods (Munes Sp.). Where these seafoods are locally and favorite consumed foods in the area around the ...
Sahle-Demessie E - - 2002
The use of methyl tert-butyl ether (MTBE) as a gasoline additive has resulted in increasing pollution of groundwater. Most of the conventional treatment technologies are inefficient or costly when the initial concentration of MTBE is low (< 200 microg/L). To find an ecology friendly and inexpensive method for MTBE remediation, ...
Prak Dianne J Luning - - 2002
The degradation rates of mixtures of pyrene (PYR), fluoranthene (FLA), and phenanthrene (PHE) by Sphingomonas paucimobilis EPA 505 were measured in the presence of the nonionic surfactant Tween 80. For strain EPA 505, FLA and PHE are growth substrates, while PYR is not. Linear degradation rates ranging from 0.05 to ...
Wang Wen-Xiong - - 2002
The absorption efficiency (AE) of benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon compound, in the green mussel Perna viridis was measured under different biological and food conditions (body size, food quantity, and food species). Uptake of BaP from the aqueous phase by different species of phytoplankton and green mussels was ...
Lee Kiyoung - - 2002
Nitrous acid (HONO) may be generated by heterogeneous reactions of nitrogen dioxide and direct emission from combustion sources. Interactions among nitrogen oxides and ozone are important for outdoor photochemical reactions. However, little is known of indoor HONO levels or the relationship between residential HONO, NO(2), and O(3) concentrations in occupied ...
Zhong Weike - - 2002
Nine important vegetables were collected from northern Chinese wholesale markets and analyzed for polycyclic aromatic hydrocarbon (PAH) contents. Anthracene, flupranthene, benzo(a)anthracene and benzo(a)pyrene were determined. The contents of the four PAH congeners were at the same level with the mean concentrations 6.46, 4.05, 3.33, 4.51 microg kg(-1) for fresh weight ...
Rustemeier K - - 2002
Cigarette mainstream smoke from blended research cigarettes with and without the addition of ingredients was analyzed for its chemical composition. In total, 333 ingredients commonly used in cigarette manufacturing were assigned to three different groups. Each group of ingredients was introduced at a low and a high level to the ...
Telli-Karakoç Fatma - - 2002
In 1999, the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), the total PAH and polychlorinated biphenyls (PCBs) were measured in sea water, sediment and mussels collected along the coast of Izmit Bay, the most important bay of the Marmara Sea. The total-PAH concentrations, measured by Spectrofluorometry were in the range ...
Kondrashov Valery V - - 2002
Urbanization typically involves a continuous increase in motor vehicle use, resulting in congestion known as traffic jams. Idling emissions due to traffic jams combine with the complex terrain created by buildings to concentrate atmospheric pollutants in localized areas. This research simulates emissions concentrations and distributions for a congested street in ...
Bravo A H - - 2002
Wildfires in Mexico increased in 1998, compared to information for the last 6 years. The average number of wildfires in the Mexico City Metropolitan Area (MCMA) for this year (1998) were 58% (1916 events) more events than the 1992-1997 (average cases 1217 events). Mexico City affected area corresponds to 1.3% ...
Panek Jeanne A - - 2002
Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at all times of the growing season. This may be inaccurate ...
Nikolopoulos Dimitrios - - 2002
A large scale radon survey using track etch detectors has been carried out from 1995 to 1998 in Greece in order to estimate the radon concentrations in Greek dwellings and the exposure of the Greek population to radon. The total data set consisted of 1,277 samples. Residential potential alpha energy ...
Lighton John R B - - 2002
The discontinuous gas exchange cycle of the pseudoscorpion Garypus californicus, mean mass 5.9 mg, is rudimentary and is characterized by bursts of CO(2) at frequencies ranging from 3.6 mHz at 15 degrees C to 13.3 mHz at 35 degrees C. The mean volume of CO(2) emitted per burst is 3.6 ...
Kleeman M J - - 2001
A 3D Eulerian source-oriented model for an externally mixed aerosol is developed and then used to compute the contribution that different emission sources make to regional fine particle concentrations in the South Coast Air Basin surrounding Los Angeles, CA, on September 25, 1996. The model simultaneously tracks fine particle concentrations ...
Erduran M S - - 2001
Gas phase pollutants. nitric acid (HNO3), sulfur dioxide (SO2), ammonia (NH3) and particulate matter, were collected simultaneously for six months from the Eastern Mediterranean atmosphere (Küçük Calticak, Antalya) using a "filter pack" system developed in our laboratory. This system is a combination of chemically treated filters for the collection of ...
Chen B H - - 2001
The contents of polycyclic aromatic hydrocarbons (PAHs) in the smoke from model lipids and food lipids during heating were determined and the mechanism of PAH formation was studied. A Rancimat oil stability analyzer was used as a model system for heating model lipids and food lipids at 220 degrees C ...
Piccardo M T - - 2001
During 1999, a biological monitoring study was conducted at four sites along the Ligurian coast (Cornigliano, Voltri, Vado Ligure and Sanremo). At each site the concentration and composition of polycyclic aromatic hydrocarbons (PAH) were investigated in native and caged mussels. The mussels (Mytilus galloprovincialis), sampled in the Spring and the ...
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