Noise in the preschool : health and preventive measures

Abstract: This thesis is based on noise recordings and health evaluations carried out at preschools in the northern part of Sweden. Sound level recordings were made on individuals and by use of stationary devices in dining rooms and play halls. Health evaluations were based on ratings by use of questionnaires and by analyses of cortisol.The average equivalent individual noise exposure was 71 dB(A). The average equivalent noise levels in the dining room and playing halls were 64 dB(A). The hearing loss of the employees was significantly higher for the frequencies tested than in an unexposed control group. Symptoms of tinnitus were reported among 31% of the employees. Noise annoyance was rated as somewhat to very annoying, and the voices of the children were the most annoying noise source. The dB(A) level and fluctuations of the noise exposure were significantly correlated with the number of children per department. Stress and energy output were pronounced among the employees. About 30% of the staff experienced strong burnout syndromes. Mental recovery was low as indicated by noise fatigue and high levels of stress after work. Increased cortisol levels during work were associated with higher number of children present at the department.An essential finding of the thesis was that noise and noise sources may impair the pedagogic work, thereby increasing the work load of employees. It is concluded that noise exposure in the preschool, isolated or in combination with other stressors, plays a fundamental role in the building up of acute as well as long term stress. An intervention study implementing six acoustical and seven organizational measures was tested, aimed to improve the noise situation in the departments. Acoustical measures improved the noise situation as well as the rated noise experiences better than the organizational measures.