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At least 19 recordsLinked to original sources
PubMed1988

Plant life in cold climates.

Structural and functional features of plants from cold regions such as high mountain and tundra environments are characterized. Cold climates are not necessarily cold for plants at all times and influences of plant-growth form on canopy climate are substantial. Extreme low temperatures can cause temporal cessation of metabolic processes or partial tissue losses, but rarely represent an existential problem for plants native to cold regions. Low temperatures induce drastic changes in plant physiognomy and leaf anatomy, but dry matter allocation to the different plant compartments does not show a uniform trend. This suggests that generalizations of optimization and adaptation theories are not appropriate in this respect and that the functional importance of carbohydrate budgets is commonly over-estimated. Inconsistent with widespread beliefs, photosynthetic capacity in plants from cold regions is not essentially different from that in temperate regions, when comparable life forms are considered. Prevailing leaf temperatures exert minor limitations to seasonal photosynthetic carbon gain. Low temperatures come into play primarily in two ways: indirectly, via the length of the growing season and perhaps mineral nutrient availability, and directly, through influences on the growth process per se. Inherited slow or temporally restricted growth resembles an evolutionary response to long-term expectations of low resource availability. Within these genetic constraints the mitotic rate seems to be an essential point of action where low temperature determines the growth of an individual under respective local climates. Evidence is provided to support this view of an overruling significance of developmental processes in plant performance under cold conditions.

Climate↗
PubMed2003

Does living in a cold climate or recreational skiing increase the risk for obstructive respiratory diseases or symptoms?

OBJECTIVES: Respiratory symptoms and obstructive pulmonary diseases experienced during exercise and in cold weather were analysed in a large postal questionnaire study of a general adult population living in a cold climate. The aim of this study was to assess the prevalence of shortness of breath (SOB) during exercise, or in cold weather, and to find out if the risks (odds ratio=OR) for asthma, chronic bronchitis, or SOB during exercise, or in cold weather, were affected by recreational cross-country skiing, or by outdoor work in a cold climate. RESULTS: Of the 7937 invited persons, 84% responded; 876 of them were outdoor workers and 1497 were recreational cross-country skiers. Of the non-smoking responders, asthmatic subjects had the highest prevalence of SOB during exercise in cold weather (78%-82%), but allergic and bronchitic persons also had significantly higher prevalence rates (22%-38% and 27%-59%, respectively) than healthy persons (10%-19%). In all categories, the prevalence of SOB was significantly higher among current smokers than among ex- or non-smokers. Risk factor analysis revealed increased risks for respiratory conditions among those who had a family history of obstructive airway disease, or allergy. Skiers did not have a significantly increased risk for asthma, or respiratory symptoms. Among outdoor workers the risk for SOB during exercise in cold weather, OR 1.23 (CI 1.03-1.47), and for chronic bronchitis, OR 1.77 (CI 1.21-2.60), was higher than among indoor workers. CONCLUSIONS: In conclusion, the risk for chronic bronchitis and bronchitic symptoms was elevated among outdoor workers, but not among regular recreational cross-country skiers, and the risk for asthma was not significantly elevated by regular exercising, or by working in a cold climate.

Adult↗
PubMed1993

Cold climate is an important factor in explaining regional differences in coronary mortality even if serum cholesterol and other established risk factors are taken into account.

Earlier studies have shown a strong regional association between cold climate and coronary mortality in Sweden and that coronary mortality is more strongly associated with cold climate than with other explanatory factors such as drinking water hardness, socioeconomic factors, tobacco and sales of butter. To examine the joint impact of these factors and to investigate regional differences in serum cholesterol and their relation to cold climate and coronary mortality, regression analyses were performed with 259 municipalities in Sweden as units. Mortality from acute myocardial infarction in men aged 40-64 during 1975-1984 was used as the dependent variable. A cold index was calculated, this index and the above mentioned factors were used as explanatory variables. The main results were: Cold index was the strongest factor when introduced into a multiple regression model. Four other strong factors had to be used to obtain the same explanatory strength as cold index did alone, and even when introduced as the last factor, cold index increased the coefficient of determination substantially. In a subsample of 37 municipalities, serum cholesterol was not significantly associated with coronary mortality. However, there was a significant correlation between cold index and serum cholesterol.

Adult↗
PubMed2004

HVAC--the importance of clean intake section and dry air filter in cold climate.

UNLABELLED: HVAC systems, if properly designed, installed, operated and maintained, will improve thermal conditions and air quality indoors. However, the success strongly depends on the design of the system and the quality of the components we use in our HVAC installations. Regrettably, several investigations have revealed that many HVAC installations have a lot of operational and maintenance problems, especially related to moisture, rain and snow entrainment. In short, it seems that too little attention is placed on the design of the intake section, despite the fact that there exists a large number of national and international guidelines and recommendations. This is a serious problem because the air intake is the initial component of the ventilation plant and as such the first line of defense against debris and other outdoor air pollutants. Unfortunately, the design is often an argued compromise between the architect, the civil engineer and the HVAC engineer. In the future, the technical, hygienic and microbiological feature of air intakes must be better ensured in order to avoid the air intake becoming a risk component as regards contamination and indoor air quality. Further, it seems that the magnitude of the problem is not well known, or recognized, by the building designers, engineers and professionals involved in the construction and operation of buildings. This fact needs to be addressed more seriously, because obviously there is a big difference between the idealistic architectonic design, engineering intentions and the real life situation. PRACTICAL IMPLICATIONS: Several practical recommendations for design and operation of HVAC systems are presented. Following the recommendations will result in less pollution from the HVAC-system and increased indoor environmental quality.

Air Conditioning↗
PubMed2002

Effect of a cold-climate buffer zone on minimising diffuse pollution from agriculture.

Vegetative buffer zones adjacent to streams can filter diffuse pollution from agriculture. Under Nordic climatic conditions, major runoff from agriculture occurs during winter and especially during snowmelt. Field experiments documenting runoff and retention processes in buffer zones during winter conditions are essential. Agricultural runoff and buffer zone retention of nutrients and particles during winter and summer are compared. The study is based upon 8 years of data collected from 5 to 10 m wide buffer zones compared to plots without buffer zones. Volume proportional samples were collected after each runoff episode. Results show that the difference between precipitation and runoff is much higher during summer than winter, due to higher evapotranspiration and infiltration during the summer. Over 90% of total particle and phosphorus runoff occurred during winter. There was no significant difference in retention of particles and particle-bound nutrients during winter compared to summer. Sedimentation is one of the most important retention processes in surface runoff buffer zones. High retention during winter is probably caused by higher surface runoff and erosion. High surface runoff and flow velocity could cause erosion of coarser particles, which were more easily trapped in the buffer zone. High particle concentration in the runoff water may also enhance the aggregation of fine particles.

Agriculture↗
PubMed2003

Survival of indicators of bacterial and viral contamination in wastewater subjected to low temperatures and freezing: application to cold climate waste stabilisation ponds.

The survival of bacterial and viral pollution indicators and Salmonella in urban wastewaters under freezing conditions (-14 degrees C for up to 60 days) is reported. Presumptive, total and faecal coliforms (PC, TC, FC), salmonellae and coliphages were tested. The dynamics of somatic coliphage (E. coli C) and F-pili specific coliphage inactivation were compared at 4 degrees C and 25 degrees C over various run times. On freezing of the wastewater, it was found that PC, TC and FC showed a first rapid phase (days) of inactivation followed by a slower second phase (up to 4 weeks) and then stabilisation at between 1-10% of the initial population size, depending on the wastewater sample used. Salmonella spp. were detectable in 0.1 ml of raw wastewater and were still detected up to 2 days after freezing but none were detected in 100 ml samples after 4, 42 and 60 days, although microbiologically similar but antigenically different forms were found. Viral indicators of pollution showed a slow but constant decrease in viability during the first month but then stabilised at between 10-20% survivors (10% in somatic E. coli C phages, 15.8% in somatic Salmonella phages and 17.9% in F-pili specific coliphages). Using electron microscopy, no difference in susceptibility to freezing could be detected with respect to morphological phage types, which were either small icosahedral particles or complex tailed phages. The study of viral indicators at 4 degrees C versus 25 degrees C showed a higher survival of the various coliphages over time at 4 degrees C. F-pili specific leviviridae were particularly susceptible to the antiviral factors at 25 degrees C and no viable units per ml were detected after one month at that temperature, whereas somatic coliphages were detected in higher numbers after this period, especially at 4 degrees C.

Climate↗
PubMed2003

Road salts in urban stormwater: an emerging issue in stormwater management in cold climates.

Potential impacts of road salting on the environment have increased by the introduction of certain stormwater management practices. Specific impacts are discussed for four such practices, infiltration facilities, oil and grit separators, stormwater ponds and constructed wetlands. The main concerns about the hazards of chloride-laden stormwater discharges include contamination of groundwater, leaching out of trace metals, densimetric stratification and poor vertical mixing in ponds, direct and indirect toxic effects, benthic drift and reduced biodiversity. The associated environmental risks need to be reduced by chloride source controls, and prevention of excessive chloride accumulations by appropriate design and operation of stormwater facilities in winter months.

Chlorides↗
PubMed2003

Urban drainage and highway runoff in cold climates: conference overview.

This overview of research findings presented at the conference on urban drainage and highway runoff in cold climates starts with generation of urban runoff and snowmelt, followed by snowmelt and winter runoff quality, best management practices for urban snowmelt and winter runoff, and snow management in urban areas. Research on the urban hydrological cycle is lagging behind the needs in this field, particularly in terms of data availability. The current studies of winter urban runoff quality focus on road salts in the urban environment and their environmental effects. The needs for better source controls in salt applications, improved management of chloride-laden runoff, and selective adoption of environmentally safer alternative de-icers were reported. Adaptation of the conventional stormwater best management practices (BMPs) for winter operation remains a challenge. The first step in refining the existing BMPs for winter operation is to advance the understanding of their operation, as reported for some cases at the conference. Finally, snow management in urban areas may require local storage of fresh (unpolluted) snow and disposal of more polluted snow at central snow disposal sites.

Cities↗