Optimizing Work Environments: Lighting and Thermal Comfort
Workplace Environmental Factors
Lighting in the Workplace
Light is electromagnetic radiation to which the human eye is sensitive. It is an environmental factor of great importance in the workplace because appropriate conditions ensure tasks are performed effectively and safely. The following types of lighting are recognized:
- Natural Lighting: This is the most desirable due to its advantages, being a free source and carrying the implied health benefits associated with sun exposure.
- Artificial Lighting: This is based on the generation of light by any of the following sources: temperature radiation, fluorescence, and gas discharges. Artificial lighting should be generated and spread evenly over the entire working area. It can also be localized to provide higher light levels in specific tasks that require them.
Lighting Legislation and Standards
Minimum illumination conditions are contained in the Royal Decree establishing minimum safety and health conditions in workplaces. It states the following:
- Preference for natural over artificial lighting. Artificial lighting should supplement natural light when it does not guarantee adequate visibility. In such cases, general illumination is preferred, supplemented with localized lighting in specific areas where high levels of illumination are required.
- Lighting should not produce glare or oscillations.
- In workplaces where a lighting failure endangers the safety of workers, emergency evacuation and security lighting must be available.
Thermal Conditions and Comfort
Comfort at work is largely determined by temperature, humidity, and ventilation, which should therefore be related to the physical activity performed.
Heat Exposure and Management
When heat affects the human body, thermoregulation mechanisms begin to act, with the objective of keeping the body’s internal temperature under control. Peripheral circulation of the blood increases to transport accumulated heat from the interior to the skin, where it is cooled in contact with the air. This adds a workload to the heart and circulatory system. The process of perspiration (the evaporation of sweat across the body surface) is the main source of heat loss. Another defense mechanism is acclimatization, which is manifested by a decreased heart rate, increased sweating, and a reduction of salt concentration in sweat. Diverse effects of heat include distress, and in severe cases, heatstroke, characterized by a sudden cessation of sweating and a rapid increase in internal body temperature.
Cold Exposure and Management
In low-temperature environments, body heat must be retained to maintain brain temperature and ensure adequate blood supply to the extremities. Two thermoregulatory processes begin:
- The blood vessels that supply the skin and extremities constrict to reduce heat loss to the environment.
- The body starts to shiver, which increases the rate of heat production.
Prolonged exposure to cold can cause frostbite or a drop in body temperature (hypothermia). Protective measures include:
- Use of warm clothing.
- Adequate rest periods.
- Good health and acclimatization.
- Avoiding exposure of skin to wind by using screens or barriers.