RESUMEN
BACKGROUND: The visual conditions for computer work are complex and include several factors that need to be well controlled. These factors include the lighting system, the design of the computer and screen itself, the screens position and orientation within the room, the surface reflectances and colours of the room, and the visualability of the worker. OBJECTIVE: The objective was to review the literature (including standards) on lighting for computer work in an accessible summary. This contribution focuses on lighting for computer work, but the reader is reminded of the fact that lighting continuously interacts with the other factors mentioned above. RESULTS/CONCLUSION: The combined visual conditions shall enable the worker to see and perform the work task without causing unnecessary strain for the eyes or the other parts of the body. The main lighting-related factors in the visual environment to evaluate are: illuminance, luminance, direction of light, glare, correlated colour temperature of the light source (CCT), colour rendering of the light source, and the non-visual effects (such as non-visual flicker). A visual ergonomics checklist is presented as a guide to analyse the visual environment.
Asunto(s)
Terminales de Computador , Luz , Iluminación , Enfermedades Profesionales/etiología , Astenopía/etiología , Astenopía/prevención & control , Ergonomía , Deslumbramiento/efectos adversos , Humanos , Diseño Interior y Mobiliario , Luz/efectos adversos , Iluminación/efectos adversos , Iluminación/instrumentación , Iluminación/normas , Dolor Musculoesquelético/etiología , Dolor Musculoesquelético/prevención & control , Enfermedades Profesionales/prevención & control , PosturaRESUMEN
BACKGROUND: Sorting mail into racks for postmen is visually demanding work. This can result in backward inclination of their heads, especially more pronounced for those who use progressive addition lenses. OBJECTIVE: To evaluate the effects of customized working spectacles on the physical workload of postmen. METHODS: Twelve male postmen sorted mail on two occasions: once using their private progressive spectacles and once using customized sorting spectacles with inverted progressive lenses. Postures and movements of the head, upper back, neck, and upper arms were measured by inclinometry. The muscular load of the trapezius was measured by surface electromyography. RESULTS: With the customized sorting spectacles, both the backward inclination of the head and backward flexion of the neck were reduced (3°), as well as the muscular load of the right upper trapezius, compared to sorting with private spectacles. However, with the sorting spectacles, there was a tendency for increased neck forward flexion, and increased sorting time. CONCLUSION: The reduction in work load may reduce the risk for developing work-related musculoskeletal disorders due to the positive reduction of the backward inclination of the head. But the tendency for increased neck forward flexion may reduce the positive effects. However, the magnitude of the possible reduction is difficult to predict, especially since quantitative data on exposure-response relationships are unknown. Alternative working spectacles with inverted near progressive lenses ought to be evaluated. They should still result in a positive reduced backward inclination of the head and may not cause any increased forward flexion.
Asunto(s)
Anteojos , Salud Laboral , Servicios Postales , Postura , Brazo/fisiología , Dorso/fisiología , Cabeza/fisiología , Humanos , Masculino , Persona de Mediana Edad , Cuello/fisiología , Músculos Superficiales de la Espalda/fisiología , Análisis y Desempeño de Tareas , Carga de TrabajoRESUMEN
Visual requirements are high when sorting mail. The purpose of this visual ergonomics intervention study was to evaluate the visual environment in mail sorting facilities and to explore opportunities for improving the work situation by reducing visual strain, improving the visual work environment and reducing mail sorting time. Twenty-seven postmen/women participated in a pre-intervention study, which included questionnaires on their experiences of light, visual ergonomics, health, and musculoskeletal symptoms. Measurements of lighting conditions and productivity were also performed along with eye examinations of the postmen/women. The results from the pre-intervention study showed that the postmen/women who suffered from eyestrain had a higher prevalence of musculoskeletal disorders (MSD) and sorted slower, than those without eyestrain. Illuminance and illuminance uniformity improved as a result of the intervention. The two post-intervention follow-ups showed a higher prevalence of MSD among the postmen/women with eyestrain than among those without. The previous differences in sorting time for employees with and without eyestrain disappeared. After the intervention, the postmen/women felt better in general, experienced less work induced stress, and considered that the total general lighting had improved. The most pronounced decreases in eyestrain, MSD, and mail sorting time were seen among the younger participants of the group.
Asunto(s)
Astenopía/complicaciones , Iluminación/efectos adversos , Enfermedades Musculoesqueléticas/complicaciones , Enfermedades Profesionales/complicaciones , Salud Laboral , Servicios Postales , Adulto , Astenopía/prevención & control , Eficiencia , Ergonomía , Femenino , Deslumbramiento/efectos adversos , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculoesqueléticas/prevención & control , Enfermedades Profesionales/prevención & control , Estrés Psicológico , Suecia , Pruebas de Visión , Lugar de Trabajo/psicología , Adulto JovenRESUMEN
All municipalities in Sweden offer their inhabitants a service for disposing of large-size and hazardous waste at local recycling centres. Opening hours at these centres include hours of darkness. The aims of this study were to 1) describe user and employee experiences of lighting and signs at Swedish recycling centres, 2) measure and assess the lighting system at the two recently built recycling centres in Linköping and to assess the legibility and visibility of the signs used and 3) propose recommendations regarding lighting and signs for recycling centres. Interviews and questionnaires were used to assess experiences of employees and users, and light measurements were performed. By observing users, activities with different visual demands at different areas within the recycling centres were identified. Based on the literature, standards and stakeholder experiences, recommendations regarding lighting systems and sign design, illuminance, luminance and uniformity are proposed for recycling centres.