Recent studies suggest that green space exposure is linked to sleep-related outcomes in adults. Only one study extended the focus towards children and found a positive link between parent-reported greenspace exposure and sleep-related outcomes. This study builds on that evidence by examining associations between nearby green space and multiple measures of sleep in children and adolescents from two different countries – Germany and Australia.
Participating children were 10-11 years old; adolescents 14-15 years old. Total number from Germany was 5633; from Australia, 6283. Participants from Australia lived in major cities; from Germany, urban and rural areas. For all participants, two sleep-related outcomes were measured: sleep sufficiency and sleep quality. In Australia, children provided the sleep-related information; in Germany, this information was provided by the parents. Objective measures of green space within a 1000-meter buffer zone around each participant's residence were obtained from land use and land cover data from each country. Parents of the participants provided information about their household's exposure to traffic noise.
Analysis of the data revealed little evidence of an association between green space and insufficient sleep or poor-quality sleep in either sample, except for insufficient sleep among 10-year-old participants in Germany. There were some differences in the prevalence of sleep-related outcomes by gender between the samples. While levels of insufficient sleep were similar between girls and boys age 10–11 in both countries, by age 14–15, insufficient sleep was markedly higher among girls compared with boys in Australia and Germany. Poor quality sleep was more common among boys than girls aged 10–11 in Australia; but by age 14-15, poor quality sleep was more common among girls than boys in this country. Levels of poor-quality sleep among 10–11-year-olds in Germany were the same for girls and boys, but by age 14-15, poor quality sleep was higher among girls than boys. Traffic noise was not associated with most of the sleep outcomes, except for sleep quality among 15-year-olds in Germany.
This study's reasonably consistent findings of the absence of association between child sleep-related outcomes and green space exposure differ from findings of previous studies. The lack of an association between traffic noise and sleep outcomes was also unexpected. Further research examining the association between nearby green space and sleep outcomes is required, and suggestions for further research are offered.