Environmental noise and childrens`s sleep and health - using the MoBa cohort

Is there an association between nocturnal road traffic noise (NRTN) and children`s sleep duration? And between NRTN and children`s memory, attention and BMI? Few studies have studied these questions, which are the main questions in the present study. Some studies on adults, and a few on children, indicate that there is an association between NTRN and sleep. Sleep is important in cognition, and impaired sleep is associated with increased risk of overweight among children. NRTN may therefore be related to cognition and BMI through its impact on sleep. The present study uses data from The Norwegian Mother and Child Cohort Study (MoBa). Information on sleep is collected from questionnaires filled out by mothers, from interviews with the children, and from objective measurements, using actigraphs. NRTN outside children`s dwelling has been modelled, and some noise measurements inside and outside bedrooms have been obtained to assess uncertainty in the modelled noise exposure to improve noise models. Collaborators include scientists from the UK and Norway, including Queen Mary University in London, SINTEF, Norwegian Institute of Public Health, and City of Oslo. The present study has several strengths. These include information on residential address history for each child that has lived in Oslo, and the possibility to examine associations in children of different ages.

Environmental noise is an increasing public health problem and one in four children in Norway is exposed to road traffic noise exceeding the recommended limit of 55 dB. Several studies have focused on traffic noise and sleep disturbances in adults, and ex posure-response relationships are demonstrated. Children may be particularly vulnerable to the effects of noise as they have less capacity to cope with stressors, but knowledge about the effects of residential traffic noise on children`s sleep and health is scarce. This project will examine the association between residential night-time traffic noise and children`s sleep. Further, the project aims to explore whether poor sleep is a mediator in a prospective association between night-time noise and other h ealth outcomes such as cognitive problems and overweight/obesity. We will use data from the Oslo part (N=8800) of The Norwegian Mother & Child Cohort Study (MoBa). Main outcomes will be parental reports of children`s sleep duration and quality, nocturnal awakenings, inattention and concentration problems as well as overweight/obesity. Nocturnal traffic noise exposure will be assessed at the most and least exposed dwelling façade for each participating child in the study using the best available noise pred iction models. Improved models for noise assessment at the least exposed façade (often the bedroom façade) will be developed. This project is highly multidisciplinary and involves expertise in environmental epidemiology, statistics, psychology, physiology and acoustics. International collaboration with experts on noise effects in children will add scientific quality to the project and possibilities for comparing results from another European birth cohort, the ALSPAC cohort from the UK West Country. Emphas is will be put on strengthening the collaboration between experts in acoustics and experts in health effects of noise, to build a stronger Norwegian network of knowledge on noise and health.