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61.
62.
Annual concentration fields of SO2 and NOx for the period 1974-1998 are calculated for a 22 x 18 km2-grid in Oslo. In a study of lung cancer and air pollution in Oslo, 16209 men living in Oslo have been followed from 1972/73 to 1998. This paper presents a method for estimating their annual residential air pollution exposure for SO2 and NOx. In the exposure assessment the National Population Register provided information on home addresses. Each participant was given an annual average air pollutant concentration outdoors of the address he lived the largest part of that year. Persons living close to streets with high traffic were given an additional concentration, and persons who moved outside Oslo were given a region value for each year. Due to regulations of the sulfur content in fuel oil and a general change of local heating systems to electricity or distant heating, the SO2-concentrations in Central Oslo were reduced during the period from about 60 microg m(-3) in 1974-75 to about 4 microg m(-3) in 1997-98. Due to the increasing traffic the NOx-concentrations have increased slowly, from about 40 microg m(-3) in 1974-84 to about 60 microg m(-3) in 1989. After the introduction of catalyst cars the concentrations were reduced to about 45 microg m(-3) in 1997-98.  相似文献   
63.
Objective: Powered mobility devices (PMDs) are commonly used as aids for older people and people with disabilities, subgroups of vulnarable road users (VRUs) who are rarely noted in traffic safety contexts. However, the problem of accidents involving PMD drivers has been reported in many countries where these vehicles have become increasingly popular.

The aim of this study is to extract and analyze national PMD-related accident and injury data reported to the Swedish Traffic Accident Data Acquisition (STRADA) database. The results will provide valuable insight into the risks and obstacles that PMD drivers are exposed to in the traffic environment and may contribute to improving the mobility of this group in the long term.

Methods: The current study is based on data from 743 accidents and 998 persons. An analysis was performed on a subset of data (N?=?301) in order to investigate the development of accidents over a period of 10 years. Thereafter, each accident in the whole data set was registered as either single (N?=?427) or collision (N?=?315).

Results: The results show that there was a 3-fold increase in the number of PMD-related accidents reported to STRADA during the period 2007–2016.

With regard to single accidents, collisions, as well as fatalities, the injury statistics were dominated by males. Single accidents were more common than collisions (N?=?427 and N?=?316, respectively) and the level of injury sustained in each type of accident is on par.

The vast majority of single accidents resulted in the PMD driver impacting the ground (87%), due to either PMD turnover (71%) or the driver falling out of the PMD (16%). The reason for many of the single accidents was a difference in ground level (34%, typically a curb).

Cars, trucks, or buses were involved in 67% of collision events; these occured predominantly at junctions or intersections (70%).

Abbreviated Injury Scale (AIS) 3+ injuries were dominated by hip and head injuries in both single accidents and collision events.

Conclusions: The present study shows that further research on PMD accidents is required, with regard to both single accidents and collision events. To ensure that appropriate decisions are made, future work should follow up on injury trends and further improve the quality of PDM-related accident data. Improved vehicle stability and design, increased usage of safety equipment, proper training programs, effective maintenance services, and development of a supporting infrastructure would contribute to increased safety for PMD drivers.  相似文献   
64.
Along the Swedish Skagerrak coast eelgrass (Zostera marina) is a dominant phanerogam on shallow soft bottoms. Eelgrass meadows are important biotopes for many crustacean and fish species being either migratory or stationary. During the 1980s, inventories of the shallow coastal areas with eelgrass have been carried out along the Swedish west coast as a basis for coastal zone management. In the present study we revisited 2000 ha of eelgrass meadows in 5 coastal regions along 200 km of the Skagerrak coast. The inventory was made with the same methods (aquascope) as during the 1980s, but increasing the mapping accuracy by using a Global Positioning System (GPS). The results from this study show that the areal extension of Zostera marina has decreased 58% in 10-15 years with great regional variations. The decline was mainly restricted to the shallow parts of the meadow. The causes and ecological consequences are discussed.  相似文献   
65.
The two objectives of this study were to compare urinary nickel excretion in pregnant women and their newborns living in the Murmansk and Arkhangelsk Counties of Russia with that in comparable Norwegian populations living in Finnmark and the city of Bergen and to assess the influence on pregnancy outcome of different risk variables, specifically urinary nickel concentrations and questionnaire-based anamnestic information. Life-style information and urine samples were collected from 50 consecutive mother-infant pairs from hospital delivery departments in three Russian and three Norwegian communities. Pregnancy outcomes were verified from medical records. Urinary nickel excretion was significantly higher in the Russian communities, independent of the presence of a nickel refinery as a local environmental source. The birth weight and mean body mass index of the newborn children (BMIC) were significantly lower (p < 0.001) in the Russian groups, with or without adjustment for gestational age. A multivariate linear regression analysis indicated that maternal urinary nickel concentration had no impact on birth weight. The maternal body mass index (BMI) and maternal height were positive explanatory variables; maternal urinary creatinine is suggested as a weak negative factor. Smoking was shown to be a strong negative predictor only in the Norwegian group among whom there was a significantly higher smoking frequency (p = 0.005). The significant contribution of a country factor in the predictive model is interpreted to indicate that a number of important risk factors for low birth weight were not identified.  相似文献   
66.
The surface energy balance (SEB) is essential for understanding the coupled cryosphere–atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic.  相似文献   
67.
68.
The effect of wind direction on ozone levels: a case study   总被引:3,自引:0,他引:3  
This paper provides an illustrative case study on how the wind direction plays an important role in determining the ozone levels, in a suburb of Houston. Circular correlation and circular regression methods are used in the analysis and the primary goal is to illustrate how circular data analytic methods help in analyzing certain environmental issues. Received: August 2003/Revised: June 2004  相似文献   
69.
Anaerobic digestion of source-separated municipal organic waste is considered feasible in Denmark. The limited hydraulic retention in the biogas reactor (typically 15 d) does not allow full degradation of the organic waste. Storage of anaerobically digested municipal organic waste can therefore be a source of methane (CH4) emission that may contribute significantly to the potential global warming impact from the waste treatment system. This study provides a model for quantifying the CH4 production from stored co-digested municipal organic waste and estimates the production under typical Danish climatic conditions, thus quantifying the potential global warming impact from storage of the digested municipal organic waste before its use on agricultural land. Laboratory batch tests on CH4 production as well as temperature measurements in eight full-scale storage tanks provided data for developing a model estimating the CH4 production in storage tanks containing digested municipal organic waste. The temperatures measured in separate storage tanks on farms receiving digested slurry were linearly correlated with air temperature. In storage tanks receiving slurry directly from biogas reactors, significantly higher temperatures were measured due to the high temperatures of the effluent from the reactor. Storage tanks on Danish farms are typically emptied in April and have a constant inflow of digested material. During the warmest months the content of digested material is therefore low, which limits the yearly CH4 production from storage.  相似文献   
70.
Recent research has again raised the issue regarding the potential health effects of long term exposure to persistent organic pollutants (POPs) in the context of a risk-benefit analysis. There remains clear evidence of the beneficial effects of fish consumption on public health and in particular fatty fish with its essential fatty acids. In addition to providing fatty acids, fish fat constitutes an essential source to vitamin D for the northern Norwegian population. Norwegian Food Control Authorities have recommended that children and women of childbearing age should not consume fish liver due to the risk associated with high intake of POPs. The aim of this study was to assess the influence of fish liver intake on the levels of PCBs and chlorinated pesticides in a rural coastal community (n = 31) in northern Norway, applying a cross-sectional design. The geometric mean plasma levels of sum of PCBs (14 congeners) and p,p'-DDE was found to be 558 microg kg(-1) lipids and 179 microg kg(-1) lipids, respectively. These levels were not significantly affected by the reported intake of fish liver, when age and gender were considered. Age in particular, but also gender were significant predictors for most compounds. When merging the dataset with an urban population with considerable lower intake of fish liver, the intake of cod liver still did not significantly affect the levels of PCBs and p,p'-DDE when adjusted for age and gender. Age and gender remain the strongest predictors of plasma levels of POPs in this study whereas fish liver intake was not significantly associated with the POPs.  相似文献   
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