Rikard Küller

Health and behavior of children in classrooms with and without windows

Abstract The aims of the study were to assess the effects of light on the production of stress hormones, classroom performance, body growth, and sick leave, of school children. About 90 children were investigated in their school environment for a duration of one school year. The children were situated in four classrooms differing in respect to the access to natural daylight and artificial fluorescent light. The results indicated the existence of a systematic seasonal variation with more stress hormones in summer than in winter. The children situated in the one classroom lacking both natural daylight and fluorescent daylight tubes demonstrated a marked deviation from this pattern. High levels of morning cortisol were associated with sociability, while moderate or low levels seemed to promote individual concentration. Annual body growth was smallest for the children with the highest levels of morning cortisol. Possibly, the production of cortisol had some influence on sick leave. It may be concluded, that windowless classrooms should be avoided for permanent use.

The impact of flicker from fluorescent lighting on well-being, performance and physiological arousal

In working environments all over the world, fluorescent tubes are by far the dominating light source. Still, there have been very few studies on the impact of the non-visible flicker from fluorescent tubes. The purpose of the study was to compare the impact on subjective well-being, performance and physiological arousal of fluorescent light powered by conventional and high-frequency ballasts. Thirty-seven healthy males and females were subjected to either condition in a laboratory office on two separate occasions with 1 week in between. Although the methodology was quite extensive, only a few general effects were observed. However, when the light was powered by the conventional ballasts, individuals with high critical flicker fusion frequency (CFF) responded with a pronounced attenuation of EEG alpha waves, and an increase in speed and decrease in accuracy of performance. These results may be understood in terms of heightened arousal in the central nervous system in response to the pronounced light modulation caused by the conventional ballasts. In order to alleviate this potential stress source, it is recommended that fluorescent lighting be powered by electronic high-frequency ballasts of good quality.

The subterranean work environment: Impact on well-being and health

Abstract The purpose of the present study was to compare subterranean environments with environments above ground. More specifically, the study focused on the impact of reduced diurnal and seasonal variations and reduced sensory stimulation for persons working underground. The spaces below ground were perceived to be more enclosed, the lighting was considered to be less bright and less pleasant, and there were complaints of visual fatigue. Light measurements showed that the illuminances were on the average twice as high in the offices above ground. There was somewhat more noise in the subterranean environments. The level of morning cortisol displayed a substantial annual variation in personnel above ground, whereas the annual variation below ground was much less pronounced. Also, the afternoon level of cortisol was lower for the personnel working in the subterranean environments. The concentration of melatonin was almost three times higher during nighttime than during daytime, and this diurnal variation (amplitude) was much larger in the underground personnel. The personnel working underground slept almost half an hour more every night. Concerning illness, there was no overall difference, but the annual incidence patterns were distinctly different.

The Social Psychological Worlds of Swedes and Turks in and Around Retirement

Five hundred and two Swedish (60 to 71 years of age) and 448 Turkish (55 to 71 years of age) respondents of both genders were interviewed in depth concerning the characteristics of their social networks and evaluations of their current life situations in relation to self-images, life satisfaction, attitudes toward aging, and feelings of loneliness. Results indicated that (a) the Turks, especially men, had both larger social networks and interacted more frequently than the Swedes; (b) compared to Swedes, Turks had less positive attitudes toward getting older, higher feelings of personal loneliness, and lower life satisfaction; (c) within each culture, women had less positive attitudes toward aging and higher feelings of personal loneliness; Turkish women had lower and men had higher self-images than the Swedish men and women who did not differ from each other; (d) in both countries, a positive attitude toward aging was correlated with low personal loneliness and positive self-image; (e) gender differences were more pronounced for Turkey compared to Sweden.

The Perception of an Interior as a Function of its Colour

Abstract Colour is n basic aspect of human perception. This paper considers whether it is possible to study how this aspect influences the perception of a total environment. In order to do this, colour was described in terms of two different versions of the Swedish Natural Colour System. Perception of the environment was measured by semantic scales which had previously been worked out for this purpose. In the experiments a drawing of a room was varied with respect to colour composition of walls and interior details. Some of the main results were then checked in full scale rooms.

Individual factors influencing the assessment of the outdoor lighting of an urban footpath

During the hours of darkness, the mobility of young women, the elderly and the disabled is limited in urban areas. In a field study possible predictors of the perceived visual accessibility and the perceived danger of an urban footpath were investigated. Eighty-one people individually walked along the footpath after dark. They subjectively assessed the environment and answered a questionnaire about personality and socio-demographics. Visual accessibility was predicted by visual field, environmental trust and brightness. Danger was predicted by the pleasantness of the lighting, gender, brightness and environmental trust. Consequently, the influence of individual characteristics, including the subjective judgments of brightness and hedonic tone and the personality dimension of trust in the physical environment, should be considered in the design of exterior lighting for urban footpaths.

Simulated Studies of Color, Arousal, and Comfort

Color psychology is applied all the time in our everyday environments, in the form of paint and graphics both outdoors and indoors, and also in the form of artificially lit spaces. Are the effects of color on the human organism so extreme that our physical and mental hygiene depends on them? Could lack of color in our internal and external spaces not only cause ugliness and boredom but also be responsible for physiological discomfort or stress reactions? The aim of the present chapter is to review the research on color in three areas that have caused considerable confusion during the last 50 years. Most of this research has been carried out in simulated situations, some of which seem to have been barren of any contact with reality.

The Finnish Kaamos: Escapes from Short Days and Cold Winters

Geographer William Mead (1968: 16) wrote “Finns are first and foremost concerned with the challenge of high latitude. The principal consequence of high latitude is that winter prevails over summer.” Residents of high latitudes in both hemispheres experience and adjust to daylight-nighttime regimens differently from those in the middle and lower latitudes (Tonello 2001). During the northern hemisphere winter, the prolonged periods of darkness last several months. These periods result not only in some changes in biorhythms and psychological problems, but also require adjustments in human activities and behavior (Kuller and Wetterberg 1996; Killer et al. 1999). We consider how Finns cope with this period of prolonged darkness, or kaamos, by discussing first the physical origins of the phenomenon and then the lived worlds or coping mechanisms.