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At least 271 records · Page 15Linked to original sources
PubMed1982

Contributions from coal and industrial materials to mercury in air, rainwater and snow.

The mean mercury level in some British coals was 0.97 (range 0.13-2.28) ppm. Mean values of 0.01-3.3 ppm have been reported for coals elsewhere in the world with maxima upto 300 ppm. Release of mercury from coal used all over the world lies in the range 0.14-2.72 x 10(9) g yr-1 depending on mean mercury concentrations in the coal and amount of mercury trapped by precipitators before release from chimney stacks. The amount released from cement manufacture is estimated to be 2.5 x 10(8) g yr-1. Iron ores had 0.09 (range 0.02-0.28) ppm, minerals 0.31 (range 0.01-0.73) ppm, the ingredients used in cement contained between 0.03-0.46 ppm, rainwater 16.7 (range 6-30) ng 1(-1), snow 13 (range 4-21) ng 1(-1) and air levels were 18.9 (range 1-66) ng m-3. Proposals to burn more coal for energy are discussed in relation to (i) the mercury released from it, (ii) the mercury already present in the environment which is constantly being revaporized and redistributed, and (iii) the mercury washed out of the atmosphere into permanent sinks such as marine sediments.

Air Pollutants↗
PubMed1987

Reduction of airborne fluoride emissions from Canadian aluminium smelters as revealed by snow chemistry.

Fluorides in surface snowcover originating from two old Canadian aluminium smelters were studied over an area of 4500 km2, in March 1978 and 1984. During that period, the completion of a depollution programme within the smelters reduced the airborne gaseous emissions from 1.5 to 0.7 kg Ft-1 of metal produced. In 1978, more than 3000 km2 of the regional area was contaminated by industrial fluorides with snowborne concentrations of up to 13 mg l-1. Reduction of the gaseous fluoride emissions, concomitant with a substantial reduction of the total particulate emissions, have greatly decreased the snowborne fluoride contamination so that the maximum concentration of fluorides in snow is now only 1 mg l-1.

Air Pollutants↗
PubMed1988

Displacement of Chernobyl fallout in snow layers of temperate Alpine glaciers.

Measurements of the gross-beta-activity and a gamma-spectrum analysis of radioactive fallout from Chernobyl distributed in vertical snow profiles on an Alpine glacier were carried out. Samples were collected in summer 1986 and in summer 1987. A displacement of isotopes to depths of approximately 6 m was observed. The mean activity per unit area amounts to 10.4 and 6.6 kBq m-2 for samples from 1986 and 1987, respectively, both values corrected to 1 May 1987. Isotopes with half-lives shorter than 110m Ag (250 days) could no longer be detected in 1987.

Accidents↗
PubMed2003

Sudden cardiac death after manual or automated snow removal.

To examine the proximate circumstances of sudden cardiac death (SCD) in the setting of major snowstorms, we reviewed records from the medical examiners' offices of 3 counties in the weeks before, during, and after 2 heavy snowfalls that occurred in the greater metropolitan Detroit area. Of those who experienced SCD due to atherosclerotic cardiovascular disease (n = 271), 36 (33 men, 3 women) were engaged in snow removal, representing the largest number of exertion-related deaths after heavy snowfalls reported to date.

Age Distribution↗
PubMed2003

The effect of technique and shaft configuration in snow shoveling on physiologic, kinematic, kinetic and productivity variables.

A repeated measures 2 x 2 factorial design using a psychophysical experimental methodology was performed to quantify the effect of shaft design (straight and bent shaft) and shoveling technique (forward and backward progression) on heart rate, perceived exertion, productivity, trunk kinematics and load kinetics. Ten male subjects performed four 8-min trials of snow shoveling on a paved asphalt surface. The most notable finding was significantly less trunk flexion with the bent shaft (41.4 degrees ) than with the straight shaft design (49.2 degrees ). The study results led to a recommendation of a bent-shaft shovel for the purpose of reducing trunk flexion. In the absence of any strong positive evidence and due to poor subjective response to backward progression while shoveling, this technique was not recommended.

Biomechanical Phenomena↗
PubMed2000

Suppressed electrostatic ion chromatography with tetraborate as eluent and its application to the determination of inorganic anions in snow and rainwater.

Tetraborate is investigated as the eluent ion for suppressed electrostatic ion chromatography (EIC) using a zwitterionic stationary phase. Good separation of a range of inorganic anions (SO4(2-), Cl-, NO3-, Br-, NO3-, ClO3-, and I-) was obtained, with detection limits for highly conducting ions (SO4(2-), Cl-, NO2-, Br- , and NO3-) being less than 8 x 10(-8) M, and for weakly conducting anions (ClO3- and I-) being 2.7 x 10(-7) and 5.8 x 10(-7) M, respectively. Calibration curves were linear up to 1.8 mM of each analyte. Retention times were found to increase with increasing eluent concentration and a linear relationship was observed between log k' and log[Na2B4O7] for all analytes. This behaviour is attributed to the progressive formation of a binary electrical double layer at the surface of the zwitterionic stationary phase. Retention times of analytes could be manipulated by varying the concentration of the eluent. This new suppressed-EIC system was applied to the determination of inorganic anions (SO4(-2) , CI-, NO3-, NO2-, and Br-) in snow and rainwater samples.

Anions↗
PubMed1998

Determination of C1-C5 alkyl nitrates in rain, snow, white frost, lake, and tap water by a combined codistillation head-space gas chromatography technique. Determination of Henry's law constants by head-space GC.

Alkyl nitrates with a chain length up to five carbon atoms have been determined in snow, white frost, and surface water. The samples were taken in the vicinity of Ulm, Germany, a region in central Europe. The determination of C1-C5-alkyl nitrates in water samples was achieved with a new water codistillation enrichment technique directly coupled with on-column head-space gas chromatography. The concentrations of the short chain alkyl nitrates in the different forms of wet deposition range from 89 ng L-1 for 1-propyl nitrate down to 35 ng L-1 for 1-pentyl nitrate. C1-C5-alkyl nitrates in wet depositions were also directly determined by static head-space gas chromatography. Gas-water partition coefficients KGW (Henry's law constant H) were determined by head-space gas chromatography and secondly by calculating the Henry's law constant by the ratio of vapor pressure to water solubility. The gas-water partition constants (dimensionless) or Henry's law constants range from KGW = 0.038 (H = 93 Pa m3 mol-1) for 1-propyl nitrate up to KGW = 0.122 (H = 302 Pa m3 mol-1) for 2-pentyl nitrate.

Chromatography, Gas↗
PubMedDate not supplied

Three-dimensional snow images by MR microscopy.

MR microscopy technique was introduced to visualize and quantify the three-dimensional structure of snowpack. Since the NMR signal from the ice was week, we looked at the air space instead filling with dodecane or aniline doped with iron acetylacetonate. Four types of snow were tested: ice spheres, large rounded poly crystals, small rounded mono-crystals and depth hoar crystals. A specific specimen-cooling system was developed to keep the temperature below 0 degrees C. In the experiments 0.5 to 2 h were necessary to accumulate the signals enough to obtain a 3D micro-image; the image matrix 128(3), voxel size (200 microm)3 or 256(3) (120 microm)3. Comparison with the 2D data using the conventional section plane method was also carried out and MR microscopy is proved to be a very useful method to visualize the microstructure of snowpack.

Ice↗
PubMed2002

Seasonal variations in nickel and vanadium in Mont Blanc snow and ice dated from the 1960s and 1990s.

Ni and V have been determined in snow and ice collected at a high altitude location (Col du Dôme) near the summit of Mont Blanc on the French-Italian border; dated from the 1960s and 1990s. Ni and V were simultaneously determined by inductively coupled plasma sector field mass spectrometry. Measured concentrations range from 6 to 700 pg g(-1) and 4 to 1,100 pg g(-1) for Ni and V, respectively. The results show pronounced seasonal variations in the concentrations of both metals, with high concentration values in summer layers and much lower values for winter layers. These seasonal variations are linked especially with the existence of inversion layers during winter months. Ni and V concentrations in excess of the contributions from rock and soil dust (Ni(excess), V(excess)) appear to be mainly associated with anthropogenic inputs, with pronounced seasonal variations. Large variations in the V(excess)/Ni(excess) ratio are observed, with a higher ratio in summer than in winter. This shows differences in anthropogenic inputs at Col du Dôme during the different parts of the year. The above ratio was compared with the corresponding ratios for oil combustion from stationary sources and the exhaust from gasoline and diesel engines. It appears that Ni and V concentrations at Col du Dôme are probably the result of changing combinations of contributions from oil combustion for power generation, industrial and residential uses, on one side, and automobile and truck traffic, on the other side, with possibly a significant contribution from Ni smelters in Russia during winter months.

Environmental Monitoring↗
PubMed1993

Snow fall and heart attacks.

Total numbers of daily hospital admissions for cardiac emergencies were obtained from 3 hospitals within the Sudbury Basin in Canada for November through March for each of 4 consecutive years (1983-1986). Major diagnostic categories were also differentiated. No statistically significant correlations were found between the amount of snowfall during the day of or the days before or after admissions for the major categories of cardiac emergency. Specific analyses, conducted to reveal possible recondite associations between extreme or cumulative snowfalls and the most extreme days of cardiac emergencies, indicated a chance association. We conclude that the occurrence of heart attacks is independent of snowfall but that, when they occur, they are attributed to shoveling if there has been a recent major snow storm.

Coronary Disease↗
PubMed2005

Neither snow, nor sleet, nor dark of night can stop a home care nurse.

With a blizzard leaving from 22 to 30 inches of snow in the Metro Boston area in January, and 8 more inches dumped two days later, home-visiting staff at the Visiting Nurse Association (VNA) of Boston switched into emergency mode. As one of the oldest and largest VNAs in the country, serving 15,000 patients annually in Greater Boston, the agency was ready.

Boston↗
PubMed2005

Glycine-rich antifreeze proteins from snow fleas.

We purified antifreeze proteins from winter-active snow fleas, Hypogastrura harveyi. These 6.5- and 15.7-kilodalton thermolabile proteins are glycine-rich (45% of the residues), and the short isoform is composed of the tripeptide repeat Gly-X-X. This makes them very different from other antifreeze proteins, including two from insects, suggesting independent adaptation to freezing environments.

Amino Acid Sequence↗
PubMed2003

Dynamics of microbial communities on marine snow aggregates: colonization, growth, detachment, and grazing mortality of attached bacteria.

We studied the dynamics of microbial communities attached to model aggregates (4-mm-diameter agar spheres) and the component processes of colonization, detachment, growth, and grazing mortality. Agar spheres incubated in raw seawater were rapidly colonized by bacteria, followed by flagellates and ciliates. Colonization can be described as a diffusion process, and encounter volume rates were estimated at about 0.01 and 0.1 cm(3) h(-1) for bacteria and flagellates, respectively. After initial colonization, the abundances of flagellates and ciliates remained approximately constant at 10(3) to 10(4) and approximately 10(2) cells sphere(-1), respectively, whereas bacterial populations increased at a declining rate to >10(7) cells sphere(-1). Attached microorganisms initially detached at high specific rates of approximately 10(-2) min(-1), but the bacteria gradually became irreversibly attached to the spheres. Bacterial growth (0 to 2 day(-1)) was density dependent and declined hyperbolically when cell density exceeded a threshold. Bacterivorous flagellates grazed on the sphere surface at an average saturated rate of 15 bacteria flagellate(-1) h(-1). At low bacterial densities, the flagellate surface clearance rate was approximately 5 x 10(-7) cm(2) min(-1), but it declined hyperbolically with increasing bacterial density. Using the experimentally estimated process rates and integrating the component processes in a simple model reproduces the main features of the observed microbial population dynamics. Differences between observed and predicted population dynamics suggest, however, that other factors, e.g., antagonistic interactions between bacteria, are of importance in shaping marine snow microbial communities.

Animals↗
PubMed2005

Temporal variability in physical speciation of metals during a winter rain-on-snow event.

Particulate matter in urban rivers transports a significant fraction of pollutants, changes rapidly during storm events, and is difficult to characterize. In this study, the physical speciation of trace metals and organic C in an urban river and upstream headwaters site in Torrington, CT, were measured during a winter rain-on-snow event. In addition, a selective fractionation scheme, using membrane and tangential-flow ultrafiltration methods to separate suspended particulate matter into sand, silt, clay, and colloid fractions, was evaluated based on the appropriateness of the chosen size categories. During peak runoff at the urban river site, total-recoverable concentrations of the metals Cu and Pb increased 6- and 13-fold to 16.9 and 9.5 microg L(-1), respectively, compared with baseflow concentrations. Concentrations of Cu and Pb reached only 0.9 and 0.86 microg L(-1) at the headwaters site. For the measured storm event, the majority of metals were transported by the urban river in association with coarse silt (20-80 microm particle diam.) during peak runoff. During peak runoff at the urban site, organic C associated with the large colloid fraction (0.1-1.0 microm) increased from 5% (at baseflow) to 54% of the total C in transport, whereas dissolved organic C and that associated with smaller colloids decreased from 91.5% (at baseflow) to 41% of the total. Other elements that were monitored as part of the study were Na, K, Ca, Mg, Fe, Mn, Al, Cd, Cl-, NO3(-), and SO4(2-). The chosen fractionation scheme was useful to characterize pollutant transport during this event, but further testing should be undertaken to determine the most appropriate size range categories, and to ensure that the sizes measured are comparable to those used in other studies.

Connecticut↗
PubMed2003

Snow on motor vehicle roofs: an informal look.

Following a snowstorm, a viewing of 4,347 moving noncommercial motor vehicles, which apparently had been outside during a storm, showed about 65% had roofs which had not been cleared of snow deposits--with vans outnumbering cars by about 2 to 1.

Accidents, Traffic↗
PubMed1993

Service in the snow. Maintaining care in rural California.

The amount of snow that falls in the Sierras is proof that all is not sunshine in rural northeastern California. Isolation and road closures were just two of the challenges that one home care agency was able to surmount with careful planning.

California↗
PubMed2004

Mosquito larvae (Diptera: Culicidae) in snow-melt pools in a Swedish Lapland area.

Culicid larvae were collected in snow-melt pools during the first half of June from 1975-1977 and 1995-1996 in the Abisko Valley, Torne Lapmark, northern Sweden. Twelve species were collected from 102 pools and 81 localities with 7,914 specimens (elevations from 300 to 650 m a.s.l.). Fourteen species are now known from the area. Ten types of larval habitats were classified and ten species were statistically analyzed on pooled values over all years for abundance, coexistence, and diversity. The greatest abundance of individuals had pools with Carex spp. on the bottom. Most widespread and abundant were Oc. hexodontus (Dyar), Oc. communis (DeGeer), Oc. pullatus (Coquillett), and Oc. punctor (Kirby). The two circumpolar, arctic species, Oc. nigripes (Zetterstedt) and Oc. impiger (Walker), were mainly confined to elevations above 400 m a.s.l. In such marginal habitats as these pools, exposed to variable abitotic conditions, the phenology of species was rather constant. Species diversity varied somewhat between habitats. Oc. hexodontus, Oc. communis, and Oc. pullatus most often occupied pools as single species. Oc. communis and Oc. hexodontus had the highest values for coexistence and also occurred with Oc. punctor. The habitats that were richest in species were those without vegetation or with detritus on the bottom and surrounded by Empetrum nigrum and Betula nana. These habitats contained between eight and ten species. Species abundance and coexistence over the years showed no stable species patterns for the habitat types in the area.

Animals↗
PubMed1996

Carbon monoxide poisonings associated with snow-obstructed vehicle exhaust systems--Philadelphia and New York City, January 1996.

On January 9, 1996, CDC was notified about carbon monoxide (CO)-related morbidity and mortality associated with the blizzard in the northeastern United States. Most of these poisonings occurred among children and elderly persons and resulted from exposures in idling automobiles with exhaust pipes blocked by snow. This report summarizes three cases of CO poisoning reported to Philadelphia's Poison Control Center on January 8-9, and 22 cases reported in New York City on January 8-9.

Aged↗