Temporal variations of atmospheric aerosol in four European urban areas

Purpose

The concentrations of PM₁₀ mass, PM_2.5 mass and particle number were continuously measured for 18 months in urban background locations across Europe to determine the spatial and temporal variability of particulate matter.

Methods

Daily PM₁₀ and PM_2.5 samples were continuously collected from October 2002 to April 2004 in background areas in Helsinki, Athens, Amsterdam and Birmingham. Particle mass was determined using analytical microbalances with precision of 1 ??g. Pre- and post-reflectance measurements were taken using smoke-stain reflectometers. One-minute measurements of particle number were obtained using condensation particle counters.

Results

The 18-month mean PM₁₀ and PM_2.5 mass concentrations ranged from 15.4 ??g/m³ in Helsinki to 56.7 ??g/m³ in Athens and from 9.0 ??g/m³ in Helsinki to 25.0 ??g/m³ in Athens, respectively. Particle number concentrations ranged from 10,091 part/cm³ in Helsinki to 24,180 part/cm³ in Athens with highest levels being measured in winter. Fine particles accounted for more than 60% of PM₁₀ with the exception of Athens where PM_2.5 comprised 43% of PM₁₀. Higher PM mass and number concentrations were measured in winter as compared to summer in all urban areas at a significance level p?Conclusions Significant quantitative and qualitative differences for particle mass across the four urban areas in Europe were observed. These were due to strong local and regional characteristics of particulate pollution sources which contribute to the heterogeneity of health responses. In addition, these findings also bear on the ability of different countries to comply with existing directives and the effectiveness of mitigation policies.     

Loss of plant species richness and habitat connectivity in grasslands associated with agricultural change in Finland

The drastic loss of seminatural grasslands and the decrease in species diversity in Europe during the 20th century are closely linked to social-economic factors. Development in agricultural production drives land-use changes, and thus controls the capacity of landscapes to maintain biodiversity. In this study, we link agricultural production changes to landscape fragmentation and species diversity. Our results show that the termination of grazing on seminatural grassland caused significant changes in landscape structure and a decline in the number of vascular plant species. The decline of grazed grasslands has been driven mainly by farm-level economic efficiency and profitability interests, which have been connected with agricultural policy measures. Since 1995, when Finland joined the European Union, the area of grazed patches in our study area has again increased as a result of a support scheme for the management of seminatural grasslands.     

Ergonomic Aspects of a Virtual Environment

A virtual environment is an interactive graphic system mediated through computer technology that allows a certain level of reality or a sense of presence to access virtual information. To create reality in a virtual environment, ergonomics issues are explored in this paper, aiming to develop the design of presentation formats with related information, that is possible to attain and to maintain user-friendly application.     

Footedness and Mounting—Short Review and Two Case Studies

Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).     

Temporal increase in nest defence intensity of the willow tit (Parus montanus): parental investment or methodological artifact?

Summary Nest defence responses of experimentally naive and revisited willow tits (Parus montanus) towards a predator model were studied near Oulu, northern Finland, in 1988–1989. Intensity was measured with three variables in 228 trials at 90 nests. Two hypotheses explaining the temporal changes in the nest defence behavior were examined. In naive birds the nest defence intensity was positively correlated with the brood age, supporting the parental investment hypothesis. The number of previous trials did not cause additional variation in nest defence behavior in comparison between naive and revisited birds. Similarly, experiences in a previous breeding attempt did not affect the nest defence behavior during the course of the subsequent brood. Thus, the temporal increase in multiply visited nests was not due to the birds becoming familiar with the nest threat, i.e., no support was found for the so-called positive reinforcement hypothesis. We think that methodological problems in avian nest defence studies can hide the adaptive significance of the behavior, not explain it. Offprint requests to: S. Rytkönen     

Chlorinated phenols as contaminants of soil and water in the vicinity of two Finnish sawmills

Contamination of soil and water in the vicinity of two sawmills using preservative against blue staining fungi that contained chlorophenols was studied. The soil around the treatment basins was found to contain up to 70 mg chlorophenols per kg and that in the storage area for treated lumber up to 6 mg per kg. Contamination extended to a depth of at least 2 meters near the treatment basins. Surface water inside the sawmill area was found to contain the same chlorophenols as those used in wood preservation, plus some additional isomers. The ground water and lake water around the sawmill areas was found to be contaminated by wood preservative.