Benefits of photobiological light exposure during night-shift work

In the Netherlands, 16% of the working population sometimes or regularly works between midnight and 6 a.m. This percentage is comparable to those of other countries. Two of the most common and harmful problems associated with shift work are reduced quality of sleep and a reduced alertness while at work. Photobiological light can be used to reduce these problems. A clear distinction can be made between long term shift schedules (> 7 days in length), and rapidly rotating shift schedules (2-3 days). Several lighting solutions for long term shift schedules have been proposed. Even though the rapidly changing shift schedule is known as being harshest on the body, a maximum of 5 successive night shifts are allowed in the Dutch labor act, in recognition of the social needs of shift workers. To further reduce negative working conditions, optimum stimulating light regimens can be offered to support the shift workers in their overall daily rhythms. This paper presents a proposal of a night-shift lighting plan for Dutch workers.