Research on office environment evaluation and worker fatigue

1. 1. The purpose of this research was to study the relationship between indoor environment and fatigue by analyzing office workers' fatigue and evaluation of indoor environment according to occupation.

2. 2. This study concerned office workers' fatigue (before and after work), questionnaires on indoor environment, and measurement of the physical environment. The subject (562 people) were businessmen, interior designers, and salesmen.

3. 3. The result of this study showed that there was a high correlation between the office workers' feeling of fatigue and the office environment.

4. 4. This research demonstrated that the workers of each type of occupation responde differently to similar office environments.

Indoor environmental study and post occupancy evaluation in an office environment

1. 1. The objective of this paper is to investigate the indoor environment from the viewpoint of interaction between physical environment and the human responses. The field survey has been conducted over 1 year.

2. 2. A continuous measurement has been carried out for 1 week and distribution of variables have been measured for 1 day.

3. 3. The attitude of workers was investigated by a questionnaire.

4. 4. As the result, average luminance represented more than 1000 lx in the new building, in contrast with less tha 300 lx in the existing building.

5. 5. There was a significant difference of the occupants' response to the light environment between the two buildings.

6. 6. Measured thermal conditions are on the edge of the ASHRAE comfort envelope in summer, and in the neighborhood of the lower dry limit of the envelope in spring.

7. 7. The occupants' evaluations were remarkably changed before and after the moving. The office environment is better than that of the factory.

A pilot experiment on a method for evaluating acceptability of a daylit luminous environment

1. 1. We propose a hierarchical model as a hypothesis to evaluate comfort in lighting environments.

2. 2. The model consists of physical quantities such as stimuli, and visual sensations as the first response, and then overall evaluation.

3. 3. A pilot experiment in a side-lit classroom usng 147 subjects was made to examine this model.

4. 4. It was found that in the side-lit classroom the most effective answers for discrimination between “acceptable” and “not acceptable” were “the surface of desk was not considered dark” and “not to experience any reflectance of lighting on the sheet of paper on which they wrote”.

5. 5. Moreover all of the effective items relate to the task area, namely desk and blackboard, and this meant that subjects gave priority to workability in the classroom.

A study on body temperature regulation and residential thermal environments of the elderly—I. whole country survey of residential thermal environment and evaluation methods: RTE-index

1. 1. As part of “research on environmental comfort,” that is, research which aims to make people's living environment more comfortable, we attempted to clarify the relation between the living environment of elderly people and physiological and psychological factors. We carried out a comprehensive study with a view to establishing comfort standards for the residential thermal environment, and for creating evaluation and control systems.

2. 2. The comfort of the living environment is closely related to the thermal environment and the temperature-regulation ability of the human body. This ability of the body to regulate temperature develops during childhood and recedes as the adult ages.

3. 3. We therefore carried out: (a) experiments on body-temperature regulation and on special characteristics of the body-temperature regulation of elderly people, (b) a nationwide survey of the actual residential thermal environments of elderly people and (c) a survey of the daily activities of elderly people, and how elderly people's physiological and psychological conditions change when they are engaged in these activities.

4. 4. As a result of these experiments and surveys, we were able to: (d) formulate standards for evaluation of the residential thermal environment and (e) numerically express the results of systematic evaluation of residential thermal environments of elderly people, by means of a RTE-index.

Conventional vs CO2 demand-controlled ventilation systems

1. 1. The feasibility of controlling the ventilation system using the occupant-generated carbon dioxide as an indicator of ventilation rate and indoor air quality has been investigated in an eleven storey office building.

2. 2. The study compares the indoor environment created by two different types of ventilation control systems.

3. 3. The two ventilation systems tested consisted of: a conventional system controlled by outdoor temperatures, and a demand-controlled system regulated by indoor carbon dioxide concentration.

4. 4. The results show that the CO₂-based demand-controlled ventilation system does not worsen indoor air quality and thermal comfort. It was also noticed that an energy saving of 12% was achieved using the CO₂ control system.

5. 5. The occupants perceived that their productivity is proportional to their perception of the indoor environment; indicating that higher productivity rates can be achieved by better controlling the working environment above satisfactory levels.

Some problems and counter-measures in modern labour. From single causal factors assessment to the analysis of multiple forms of hardship at work

1. 1. Methods are needed through which work situations can be analyzed in terms of the complex set of circumstances which they in fact involve.

2. 2. A number of office workplaces were examined with respect to both physical aspects of the work premises and the content of work. The study of task-related complaints was limited to those which are related to aspects of office work conducted using computer terminals (VDT work).

3. 3. For the purpose of illuminating the combined importance of office design and working conditions of the VDT work, the study considered the occurrence of complaints related to both sources.

4. 4. A questionnaire study (containing about 250 questions) covering all employees in eight workplaces and 269 people in total, of which 195 were VDT operators.

5. 5. The concepts, source of complain, type of complaint and were used to provide an analysis of the composite picture of complaints.

6. 6. A combination of premises-related and VDT-related complaints applies to a large number of office workers and only a few people stated were wholly free from difficulties.

7. 7. The findings indicate that by also taking account of the design of office premiss as a source of hardship, we have obtained further report for the view that the pattern of complaints is rather complicated in the case of most people who devote themselves to VDT work.

8. 8. Climatic problems arise extremely frequently, as too do problems in obtaining an appropriate balance between privacy and social contact at work.

Relationship between cerebrovascular disease and indoor thermal environment in two selected towns in Miyagi Prefecture, Japan

1. 1. This paper describes the results of an investigation of the relationship between mortality from cerebrovascular disease (hereafter called stroke) and the indoor thermal environment in two selected towns with different socioeconomic compositions: Shiwahime, an agricultura town with relatively high stroke mortality, and Karakuwa, a fishing town with relatively low stroke mortality, using a case-control research design.

2. 2. The measurement of the indoor thermal environments were conducted and the surveyed with a questionnaire during the winter of 1986.

3. 3. The findings are summarized as detailed below.

4. 4. Room temperatures in the control households were generally higher than those in the case households by up to 1.3°C.

5. 5. The thermal conditions of the housing in the case households were a little inferior to those in the control households.

6. 6. Despite much lower room temperatures than the so-called comfort temperature, members of both the case and the control households did not express feelings of being cold in the rooms.

7. 7. It is concluded, including the survey results from other literature, that improvements in the indoor thermal environment should receive more attention with respect of the reduction in stroke mortality, particularly in areas of cold climates.

Autonomic thermoregulatory effects of electrical stimulation of the hypothalamus in the sheep (Ovis aries)

1. 1.|The effects of electrical stimulation of the preoptic region, on autonomic thermoregulatory responses, were studied in conscious sheep at ambient temperatures of 5, 20, and 40°C.

2. 2.|Stimulation of the dorsal preoptic region elicited co-ordinated thermoregulatory responses characterized by increased respiratory frequency (RF), vasodilation of the ears and lowered body temperature. Stimulation inhibited shivering in cold environments.

3. 3.|The thermoregulatory responses were greater at 5°C in unshorn than in shorn sheep. Increased RF, induced at 20 and 40°C, persisted several minutes after stimulation ceased.

4. 4.|Intraventricular injection of noradrenaline reduced both normal and electrically-induced panting.

5. 5.|Sheep would press panels to electrically stimulate the preoptic region and this “self-stimulation” activated heat-loss mechanisms.

Criteria for a comfortable indoor environment in buildings

1. 1. The major purpose of buildings is to provide a healthy and comfortable environment for occupants.

2. 2. The indoor environment is a complex system including factors like thermal, visual and acoustic conditions, indoor air quality, electromagnetic fields, static electricity and vibration.

3. 3. To obtain an indoor environment that is acceptable in terms of health as well as comfort, criteria for these factors need to be established.

4. 4. The present paper gives an overview of the criteria recommended in current existing standards and guidelines.

5. 5. As most studies to date have focussed on thermal conditions and indoor air quality, these two factors are described in more detail.

Effect of fiber type and fabric moisture content on the hydration state of human stratum corneum

1. 1. The purpose of this study was to determine the effect of fiber type and fabric moisture content on SC hydration.

2. 2. Using three similarly constructed fabrics, six fabric type/moisture content combinations were selected.

3. 3. Fabric swatches were placed on both “normal” and “hydrated” volar forearm skin of five subjects for a specified period, then removed.

4. 4. Two minutes after removal, evaporative water loss (EWL) and skin temperature were measured.

5. 5. Data were analyzed using analyses of variance and Bonferroni t-tests.

6. 6. For normal skin, SC hydration generally increased as fabric moisture content increased. SC was significantly drier after being in contact with cotton swatches at regain than at the two moisture content levels above regain, and also under polyester swatches.

7. 7. For hydrated skin, hydration state was significantly lower under the cotton swatch at regain than at 38.6% moisture content or at saturation, but was not significantly different under the polyester swatch at regain or at saturation.

A relationship between heat load and plasma enzyme concentration

1. 1. The sensitivity of serum enzyme levels as indicators of tissue damage is less well established in the prodromal period of heatstroke, especially for sub-lethal stress conditions.

2. 2. Anaesthetized rats were exposed to two different sets of thermal conditions.

3. 3. Plasma levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK) and lactate dehydrogenase (LD) were assayed in each group upon termination of stress, 6 h post-stress and 24 h post-stress.

4. 4. The tissue “damage” sustained was mild to moderate and completely reversible.

5. 5. The rate of rise in body temperature may constitute an important factor in the ultimate pathology.

6. 6. CK proved to be the most sensitive parameter of tissue “damage”.

A theory of evaluation applied to human-environment systems

1. 1. The writers present the general theory of evaluation that is being developed by their group.

2. 2. The evaluation of a human environment is a complex mental process.

3. 3. In an effort to express numerically the quality of an environment, one tends to oversimplify the complex aspects of it and the entailing problems in relation to its inhabitants.

4. 4. In this paper, some examples are taken in the evaluation of thermal environments, wherein much has been said and done in setting up numerical scales to express human comfort, and yet neither clear-cut explanations nor convincing logic seem to exist to terminate the argument over the widely scattered and sometimes seemingly contradicting experimental data.

5. 5. The writers suggest that many of the reasons for this confusion may be traced back to the oversimplified notion of evaluation.

6. 6. It is shown that there are various possibilities when looking at the scales of evaluation.

7. 7.|The nominal scale, least studied of all the four traditional scales, may be given a prominent place in evaluating a thermal environment. The pseudo-interval order scale is another example.

Heat death and cellular heat injury

1. 1.|Evidence is presented implicating cellular membranes in cellular heat injury. It is proposed this is the site of the primary lesion.

2. 2.|Secondary and tertiary events, resulting from the primary lesion, cause organism death. Those events may be unique to the life style and grade of organisation of the organism.

3. 3.|Thus hyperthermia may cause “excessive” fluidisation of membranes and so cause impairment of membrane permeability and disrupt the stability of membrane enzymes.

4. 4.|Homeoviscous adaptation of membrane fluidity may well have an important role in resistance acclimation as well as resistance adaptation.

An experimental study of effects of low-level sound in our daily life on a mental task

1. 1. It is often reported that any sound from the neighborhood disturbs one's reading or study, even though it is at a low level.

2. 2. This study was done to clarify the mechanism by which the low level sound in our daily life exerts an influence upon mental tasks.

3. 3. Two experiments were carried out, one by an ordinary, and the other by a social psychological test. In both, a random number generation test was applied as the mental exercise. The levels of presented sounds in each condition were 34–45 dBA in Leq.

4. 4. One of various conditions was in conformity with a setting of“low level noise”, where existence of low level sound is not recognized as an inevitable phenomenon but perceived as the noise.

5. 5. The quality of performance tends to be worse, though the quantitative side can be maintained.

Lactate modeling and its application to endurance training

1. 1. In this short review, previous studies regarding the modeling of lactate (La) response to exercise and its application to endurance training have been summarized.

2. 2. Additionally the result of a recent study by the present authors are shown.

3. 3. Several models for La response to step and ramp exercise are already proposed and deductions derived from them are used for practical purposes such as the prediction of race performance in middle-and long-distance runners as well as for construction of their training regimens.

4. 4. Only a limited number of models however have tried to quantify whole body La kinetics to exercise in humans concomitantly with describing physiological mechanisms underlying the observed phenomenon.

5. 5. In a recent study described further in this paper a 2 compartment model was used for the purpose of clarifying the current “La production vs degradation” controversy during La adaptation to training.

6. 6. It was determined from this investigation that the La metabolic clearance rate during recovery is enhanced by the endurance training.

7. 7. This is in accordance with another recent observation of an increased La metabolic clearance rate at high absolute work rates and all relative work rates during exercise.

Work at cold storage

1. 1. Work activities in cold storage rooms were assessed by a mailed questionnaire survey of cold storage facilities in Japan.

2. 2. There are nearly 4000 cold storage facilities and about 80% are being kept at temperatures below −20°C.

3. 3. The chief items of stock in storage were marine products, livestock products, frozen food and agricultural products.

4. 4. Methods used for loading and unloading in cold storage rooms are forklift, manual handling, and automatic machines.

5. 5. Use of forklifts appeared to be widespread.

6. 6. Working time differed according to the ambient temperature of the cold storage rooms.

7. 7. Common ailments of cold storage workers are lumbago, bronchitis, neuralgia etc.

Discrimination of thermal sensation in unhomogeneous thermal environments using theory of quantification II

1. 1. One hundred and forty-five thermal-sensation tests by subjects were performed in unhomogeneous thermal environments and the whole body and the lower leg thermal-sensations were discriminated with physical data of the thermal environments using the discrimination analysis and the expanded theory of quantification II which is able to deal with data including quantitative continuous-variables and qualitative category-variables simultaneously.

2. 2. The discrimination of the whole-body thermal-sensations on the basis of the local-body thermal sensations was also done.

3. 3. As a result, it is shown that the discrimination analysis and the expanded theory of quantification II are able to discriminate the thermal sensation in unhomogeneous environments.

Preferred temperature of the elderly after cold and heat exposures determined by individual self-selection of air temperature

1. 1. The purpose of the study was to investigate the preferred temperature of the elderly after cold and heat exposures.

2. 2. Eight elderly and 9 young females wearing the same type of clothing were exposed to cold (10°C), moderate (25°C) or hot (35°C) environments for 30 min in the exposure room.

3. 3. Then they moved to the self-control room in which the temperature was set at 25°C, and the room temperature increased or decreased continuously by 0.4°C every minute.

4. 4. The subjects were instructed to operate the switch when they felt uncomfortably warm or cool during a 90-min period.

5. 5. In operating the switch, the changing in room temperature shifted to the opposite direction.

6. 6. The ambient temperature was recorded continuously and analyzed as the preferred temperature, which was defined as the midpoint temperature of the crest and trough of temperature records.

7. 7. The preferred temperatures after the cold exposure were significantly higher than those of other exposure conditions in the elderly.

8. 8. On the other hand, in the young, there was no significant difference in the preferred temperature among the exposure conditions.

9. 9. Although the effect of exposure to cold or hot environments decreased in the latter parts of self-control, the elderly still preferred the higher temperature after cold exposure.

Relationship between energy conservation in buildings and indoor air quality

1. 1. Problems with regard to the relationship between energy conservation and indoor air quality in buildings are discussed with a brief history of legislation and practices in Japan since the oil crisis in 1973.

2. 2. In spite of energy conservation as widely advocated the sick building syndrome has hardly been manifested in most of the office spaces in Japan owing to the Law on the Assurance of Healthy Conditions in Buildings which enforced CO₂ concentration to be kept lower than 1000 ppm.

The high-energy state of the thylakoid system as indicated by chlorophyll fluorescence and chloroplast shrinkage

Certain long-term fluorescence phenomena observed in intact leaves of higher plants and in isolated chloroplasts show a reverse relationship to light-induced absorbance changes at 535 nm (“chloroplast shrinkage”).

1. 1. In isolated chloroplasts with intact envelopes strong fluorescence quenching upon prolonged illumination with red light is accompanied by an absorbance increase. Both effects are reversed by uncoupling with cyclohexylammonium chloride.

2. 2. The fluorescence quenching is reversed in the dark with kinetics very similar to those of the dark decay of chloroplast shrinkage.

3. 3. In intact leaves under strong illumination with red light in CO₂-free air a low level of variable fluorescence and a strong shrinkage response are observed. Carbon dioxide was found to increase fluorescence and to inhibit shrinkage.

4. 4. Under nitrogen, CO₂ caused fluorescence quenching and shrinkage increase at low concentrations. At higher CO₂ levels fluorescence was increased and shrinkage decreased.

5. 5. In the presence of CO₂, the steady-state yield of fluorescence was lower under nitrogen than under air, whereas chloroplast shrinkage was stimulated in nitrogen and suppressed in air.

6. 6. These results demonstrate that the fluorescence yield does not only depend on the redox state of the quencher Q, but to a large degree also on the high-energy state of the thylakoid system associated with photophosphorylation.