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PubMed1997

Slipping on ice and snow--elderly women and young men are typical victims.

Slipping on ice or snow during winter caused 3.5 injuries per 1000 inhabitants per year in the Umeå health district; the injury rate was highest among the elderly. Most injured were elderly women, but also many young men in the age group 20-29 years were injured. Half of all injuries were fractures; for women 50 years and over two-thirds were fractures, mostly of an upper extremity. The 'cost' of medical care of these slipping injuries was almost the same as the 'cost' of all traffic injuries in the area during the same time. Injury reducing measures, such as more effective snow clearing, sand and salt spreading in strategic areas, better slip preventive aids on shoes, and 'padding' of older women, would reduce the injuries and their consequences.

Accidental Falls↗

PubMed2002

Packed capillary liquid chromatography-electrospray mass spectrometry of snow contaminated with sarin.

Packed capillary liquid chromatography-electrospray mass spectrometry (LC-ESI-MS) was used for the analysis of a snow sample that was accidentally contaminated with an organophosphorus chemical warfare agent during the destruction of a chemical munition. Sarin, its hydrolysis products and a number of related compounds were identified on the basis of acquired LC-ESI-MS data. Full mass spectra were acquired for 14 compounds, with all exhibiting MH+, [MH+ACN]+ ions and/or protonated dimers that could be used to confirm molecular mass. Sampling cone voltages from 20 to 70 V were utilized with the higher sampling voltages enhancing formation of structurally important product ions in the ESI interface. All data were acquired with a time-of-flight mass spectrometer with a resolution of 5,000 (50% valley definition), a resolution that aided in the assignment of elemental composition of the observed ions. The application of LC-ESI-MS to snow analysis appears to be an attractive alternative to the GC-MS methods, since both chemical warfare agents and their hydrolysis products may be analysed directly, eliminating the need for additional sample handling and derivatization steps.

Chemical Warfare Agents↗

PubMed2003

Snow and ice concentrations of selected persistent pollutants in the Ob-Yenisey river watershed.

As one of the largest river systems attached to the Arctic Basin, the Ob-Yenisey watershed has the potential to be a major supply route of persistent organic pollutants into marine ecosystems of the Arctic Ocean. Snowfall and ice formation taking place in the Ob-Yenisey river basin and shelf are key components of the system of processes responsible for the transfer of pollutants from this high latitude river to the adjacent Kara and Barents Seas. Here we examine a large data set on persistent organic pollutants in snow and ice determined for areas within the Ob (interior and coastal), Yenisey and adjacent shelf. Data on the levels of total oil hydrocarbons, as well as individual components for groups (PAHs, HCHs, CBs, DDTs, PCBs) were examined in this investigation for two time periods: winter (1992)-spring (1993) and winter (1993)-spring (1994). Spatial averaging of each data set for individual years was performed in order to identify large-scale geographical trends in contaminant distributions within the four regions. The analysis indicates that mean pollutant concentrations in snow are consistent throughout the watershed. Comparing data from 1992/1993 and 1993/1994, in all cases, concentrations do not vary appreciatively among the different regions. A similar finding was observed for concentrations of pollutants in ice. Persistent organic pollutants for the Ob-Yenisey watershed are in most cases not dissimilar to measurements carried out in the far north of Canada. The exception is summation operator DDT. Concentrations of this pollutant are an order of magnitude higher in the Ob-Yenisey watershed as compared to the Canadian Arctic (0.09 ng/l).

Air Movements↗

PubMed2003

Anthropogenic metal enrichment of snow and soil in north-eastern European Russia.

Trace metal composition of winter snowpack, snow-melt filter residues and top-soil samples were determined along three transects through industrial towns in the Usa basin, North-East Russia: Inta, Usinsk and Vorkuta. Snow was analysed for Ag, Al, As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr and Zn using ICP-MS (Ca and K by F-AAS for Vorkuta only), pH and acidity/alkalinity. Filter residues were analysed for: Al, Ba, Ca, Cd, Cu, K, Mg, Mn, Ni, Pb, Sr and Zn using F-AAS and GF-AAS; top-soil samples were analysed for Ba, Cu, Mg, Mn, Na, Ni, Pb, Sr, Zn using F-AAS. Results indicate elevated concentrations of elements associated with alkaline combustion ash around the coal mining towns of Vorkuta and Inta. There is little evidence of deposition around the gas and oil town of Usinsk. Atmospheric deposition in the vicinity of Vorkuta, and to a lesser extent Inta, added significantly to the soil contaminant loading as a result of ash fallout. Acid deposition was associated with pristine areas whereas alkaline combustion ash near to emission sources more than compensated for the acidity caused by SO2.

Coal Mining↗

PubMed2006

Organochlorine pesticide and polychlorinated biphenyl concentrations in snow, snowmelt, and runoff at Bow Lake, Alberta.

We present analyses of the concentrations of organochlorine (OC) contaminants (including organochlorine pesticides and PCBs) in snow, snowmelt, and runoff in glacier and snowmelt fed streams at Bow Lake, Alberta in two contrasting hydrological years (1997 and 1998). The study investigates the variability in OC burdens in snow across the catchment, the elution of OCs from the snowpack, and the relationship between OC concentrations in streams and the annual snowpack. Snowpacks in forested sites were thinner and had lower OC concentrations than snowpacks in open or sparsely vegetated sites. The first snowmelt samples exhibited very high contaminant concentrations relative to the snowpack, and even the more hydrophobic compounds (Dieldrin, DDTs, and PCBs) were highly concentrated in meltwater. Interannual changes in the mean OC concentrations in streams did not reflect year-to-year changes in the snowpack contaminant concentrations. The results indicate that the extent of glacial ice melt may be more important than mean snowpack burdens as a control on OC concentrations in runoff in glacial catchments.

Alberta↗

PubMed2005

Enrichment of organic pollutants in the sea surface microlayer (SML) at Terra Nova Bay, Antarctica: influence of SML on superficial snow composition.

Concentrations of dissolved and particle-associated n-alkanes, phthalates and polycyclic aromatic hydrocarbons (PAHs) were measured in sea surface microlayer (SML) and sub-surface water (SSL) samples collected in the coastal area of Terra Nova Bay, Antarctica, during the Austral spring 1998/1999. SML concentrations of the selected organic compounds were higher than SSL values and the enrichment factors were greater in the particulate phase than in the dissolved phase. During the same campaign, "fresh" snow samples, collected at different altitudes (from sea level up to 2670 m) near the coast on Mt Melbourne, immediately after a snowy event, were analysed in order to provide more information on air/sea exchange processes. The same classes of organic compounds found in sea water were also present in "fresh" snow samples. The surfactant fluorescent organic matter (SFOM), adsorbed on the microdrop aerosol surface, could be considered the main constituent of the enrichment and the carrier at higher altitudes of organic compounds. In fact, hydrocarbons (n-alkanes and PAHs), which are not surfactants like phthalates, could interact with SFOM and follow the same fate.

Aerosols↗

PubMed2005

Transport and modification of humic substances present in Antarctic snow and ancient ice.

We performed a study of fulvic acids extracted from fresh and aged snow, and from recent and ancient ice in Antarctica. The fresh snow samples were collected in coastal and inland sites to evaluate the influence of the distance from the sea on organic matter transport. Moreover, in a site (Melbourne Mountain) samples were collected at different heights to study the influence of altitude on transport. The obtained results showed that dissolved fulvic acid concentrations are influenced neither by distance nor by height while particulate fulvic acid concentrations are influenced by both parameters. Moreover, the results showed that fulvic acids transported for a long distance can undergo chemical modifications. Chemical modifications are better evidenced by the analysis of samples taken in trenches at different depth, which showed structural changes attributable to the loss of nitrogen-containing compounds and to an increase in aromatic character of the structures due to reduction and/or condensation processes. With ageing, the humification process proceeds with heavy carbon losses as demonstrated by results obtained from fulvic acids isolated from ice aged between twenty-five thousand and seventy thousand years.

Aerosols↗

PubMedDate not supplied

Fluoride in treated sewage and in rain and snow.

The liquid effluent of a sewage treatment plan contained 1.21 ppm ionic and total fluoride, which was higher than 1.0 ppm fluoride in the fluoridated public water supply. The discharge of the effluent into a river did not greatly raise the fluoride content of the river water because of dilution and other factors. The semisolid waste of sewage treatment also contained fluoride, but very little was volatilized on burning. Rain and snow were found to contain detectable quantities of fluoride, and the fluoride content of snow increased markedly during exposure to an urban environment.

Fluorides↗

PubMed2003

Energy cost and physiological responses of males snowshoeing with rotating and fixed toe-cord designs in powdered snow conditions.

The purpose of this study was to measure the energy cost and physiological responses of males while snowshoeing with two separate toe-cord designs (rotating toe-cord system vs. fixed toe-cord design) in powdered snow conditions. Eight males snowshoed at self-selected intensity for two, 1600 m trials in two snowshoes, with a rotating toe-cord system and a fixed-toe cord design. It was found that heart rate (HR) (140 vs. 134 beats min(-1)), oxygen consumption (VO(2)) (63.4 vs. 34.0 ml kg(-1)min(-1)), energy cost (56.0 vs. 52.4 kJ min(-1)), and ratings of perceived exertion (RPE) (13 vs. 12) were significantly (p < 0.05) higher while snowshoeing with the fixed toe-cord design than with the rotating toe-cord system. Snowshoeing with the rotating toe-cord system at an average speed of 3.96 km h(-1) produced mean VO(2) values that were 56% of VO(2) max, while snowshoeing with the fixed toe-cord design at 3.86 km h(-1) evoked mean VO(2) values that were 60% of VO(2) max. Mean HR while snowshoeing with the rotating toe-cord system was 70% of HR max, while the mean HR when snowshoeing with the fixed toe-cord design was 74% of HR max. These findings suggest that snowshoeing with a rotating toe-cord system results in lower cardiorespiratory strain in powdered snow conditions compared to snowshoeing with a fixed toe-cord design.

Energy Metabolism↗

PubMed1997

Regional molecular genetic key of thirteen snow pool Aedes species (Diptera:Culicidae) in northern Colorado.

Snow pool Aedes mosquitoes are identified easily and accurately by microscopic examination of 4th instars or male genitalia. Early instars and females cannot be identified accurately. We demonstrate that restriction fragment-length polymorphisms (RFLP) in the internal transcribed spacer (ITS) of the nuclear ribosomal DNA cistron are specific to each of 13 snow pool Aedes species found in northern Colorado. The ITS was amplified by the polymerase chain reaction (PCR) and digested with AluI and MspI restriction endonucleases. Differences in the sizes of digested fragments among the 13 species were so slight that they could only be resolved with polyacrylamide gel electrophoresis and visualized with silver staining. A key to species found in the Rocky Mountains of northern Colorado was constructed using the PCR-RFLP patterns. Three of the species were collected in California and had identical PCR-RFLP patterns, indicating that restriction sites in the ITS may be conserved within some species.

Aedes↗

PubMed1993

Effects of Arctic ozone depletion and snow on UV exposure in Finland.

The increase in the UV exposure of the Finnish population associated with the combined effects of ozone depletion and snow reflection was studied with the aid of theoretical calculations based on Green's clear sky UV model. A simple formula was utilized to transform horizontal irradiances to vertical irradiances averaged over 360 degrees azimuth angle. The model was verified with spectral and broadband measurements. The difference between the theoretical and measured UV radiation falling to horizontal surfaces was in most cases less than +/- 10%, and the additional error to theoretical vertical irradiances was less than +/- 10%. The calculations show that the annual horizontal doses in Helsinki (60.2 degrees N, 25 degrees E) are about 35% higher than in Saariselkä (68.4 degrees N, 27.5 degrees E), but the difference is only 16% for vertical doses owing to the stronger contribution to vertical (facial) surfaces of the reflection of UV from snow. At Saariselkä, the maximum vertical irradiance at the end of April approaches the midsummer values. The ozone depletions up to 40% in February and March 1992 had no significant effect on the annual doses because the total ozone returned to normal before the UV increased to biologically significant levels.

Arctic Regions↗

PubMed2025

Do Snow-Adapted Prey Facilitate Coexistence of the Sierra Nevada Red Fox With Sympatric Carnivores?

Specialist species in alpine ecosystems may be increasingly threatened by climate-driven habitat loss and encroachment by generalist competitors. Ecological theory predicts that niche differentiation through dietary specialisation can facilitate coexistence with generalist competitors. We quantified dietary overlap between a high-elevation specialist, the Sierra Nevada red fox (SNRF; Vulpes vulpes necator) and a widespread generalist, the coyote (Canis latrans), as well as other sympatric carnivores. We were especially interested in dietary items that were themselves specialised to alpine habitats, as we expected them to be most critical to SNRF. To characterise diet, we used DNA metabarcoding for vertebrate and plant-based food items of 789 carnivore scats collected from the sites of two SNRF populations (Lassen, Sierra Nevada). As expected for potential competitors, SNRFs exhibited substantial dietary overlap with coyotes overall. Dietary niche overlap was lower between SNRF and both bobcats (Lynx rufus) and martens (Martes caurina). Compared to coyotes, however, SNRF more frequently consumed snow-adapted prey, including white-tailed jackrabbits (Lepus townsendii) and American pika (Ochotona princeps) (SIMPER p ≤ 0.005), especially during periods of deep snow. Whitebark pine (Pinus albicaulis; presumably seeds) also appeared more regularly in SNRF winter diets compared to coyotes. These findings support the hypothesis that co-adapted subalpine prey facilitate coexistence between specialist and generalist carnivores by increasing the competitive advantage of specialists under snowier conditions. This environment-mediated shift in competitive dynamics implies that the fates of locally adapted predator and prey may be tightly linked, an important consideration for conservation planning in alpine ecosystems.

Animals↗

PubMed2000

Bacterial activity in South Pole snow.

Large populations (200 to 5,000 cells ml(-1) in snowmelt) of bacteria were present in surface snow and firn from the south pole sampled in January 1999 and 2000. DNA isolated from this snow yielded ribosomal DNA sequences similar to those of several psychrophilic bacteria and a bacterium which aligns closely with members of the genus Deinococcus, an ionizing-radiation- and desiccation-resistant genus. We also obtained evidence of low rates of bacterial DNA and protein synthesis which indicates that the organisms were metabolizing at ambient subzero temperatures (-12 to -17 degrees C).

Antarctic Regions↗

PubMed2001

[Determination of organic and inorganic anions in snow and ice from alpine glaciers with DX-300 ion chromatograph].

Organic and inorganic anions in snow and ice from Glacier 1 at Urumqi river head, Tianshan Mountain, Xinjiang, Northwest China, were determined using DIONEX-300 ion chromatograph with a lot of columns. AS4A-SC was selected as the separation column, AG4A-SC as the guard column, TAC-2 as the anion enrichment column, ATC-1 as the anion trap column and ASRS-II as the suppresser. It was conducted under gradient elution with sodium tetraborate (Na2B4O7) as eluent and 25 mmol/L H2SO4 as regeneration solution for chemical suppression. By preconcentration, 2 mL melted water of snow or ice can be analyzed for separation and quantitation of more than 10 anions, which were fluoride, acetate, formate, pyruvate, monochloroacetate, chloride, nitrite, bromide, nitrate, phosphate, sulfate and oxalate. The relative standard deviations for most of the anions were below 5%.

Anions↗

PubMed1989

[A snow avalanche in Vassdalen. Medical experiences].

Of 31 soldiers caught by an avalanche in Northern Norway, one was not buried, 13 were partly buried and 17 were completely buried by the mass of snow. Only one of the completely buried soldiers survived. On admission to hospital after being buried by snow for three hours he had moderate hypothermia. The cause of death in the other 16 was most probably general compression of the body with acute respiratory and circulatory failure. Five of the 13 partly buried had physical traumas. None of the nine attempts at resuscitation succeeded. Self-rescue and rescue by friends were most important to the soldiers who survived. We discuss aspects of the organized rescue operation.

Accidents↗

PubMed1998

Hyphomycetes in the snow from gymnosperm trees.

The presence of 26 hyphomycete species was noted in snow water collected from coniferous trees. Camposporium pellucidum, Monodictys peruviana, Polystratorictus fusarioideus, Sporidesmium moniliforme, Tripospermum acerinum and Veronaea botryosa were recorded for the first time to Poland. Among the 26 species found in snow water from coniferous trees predominance of the socalled aero-aquatic hyphomycetes and only a few species belong to the group of aquatic hyphomycetes.

Fresh Water↗

PubMed2002

Induction of parturition in snow skinks: can low temperatures inhibit the actions of AVT?

The influence of environmental factors on the timing of parturition has not been investigated in viviparous squamates. We investigated the interaction between temperature and parturition in two viviparous skink species, the southern snow skink (Niveoscincus microlepidotus) and the metallic skink (N. metallicus). In these species, the timing of parturition is separated from the completion of embryonic development; the delay is attributed to their cool and variable habitats. We examined whether the neurohypophyseal hormone arginine vasotocin (AVT) stimulated parturition in southern snow skinks with late stage embryos in autumn (approximately 6-7 months prior to parturition) and in metallic skinks with late stage embryos in summer (approximately 2-3 weeks prior to parturition). The experiments were conducted at a range of environmentally relevant temperatures (6 degrees C, 15 degrees C, 22 degrees C, and 28 degrees C). AVT induced parturition in both species at all temperatures; time until birth, however, occurred more quickly at warmer temperatures (22 degrees and 28 degrees C), whereas cooler temperatures delayed parturition. We hypothesize that if cool temperatures are preventing parturition, then temperature must act at some level within the brain to prevent or slow the secretion of AVT. Future experiments will need to determine how temperature influences AVT production. Further research is also required to determine how the timing of parturition is influenced by interactions between temperature, photoperiod, and seasonal hormone patterns.

Animals↗

PubMed1977

Isoenzyme status and genetic variability of serum esterases in the lesser snow goose, Anser caerulescens caerulescens.

A maximum of 22 bands comprising four esterase subgroups--acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase--were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25% average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variability found in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on "biochemical plasticity" rather than genic heterozygosity for this species. The nature of evolutionary forces acting upon multiple enzyme systems such as esterases is discussed. The concept of "conditional neutrality" is introduced and defined within this context.

Animals↗