Satellite-derived data on greenness and access to green spaces are related to children's health indicators

• Main Author: Markevych, Iana
• Format: Others
• Published: Ludwig-Maximilians-Universität München 2015
• Subjects: Medizinische Fakultät
• Online Access: http://edoc.ub.uni-muenchen.de/18017/1/Markevych_Iana.pdf; http://nbn-resolving.de/urn:nbn:de:bvb:19-180179

There is increasing epidemiologic evidence on beneficial effects of green environments on survival, perceived health and quality of life, mental health, obesity and physical activity. However, most studies have been conducted in adults. Further research to assess the impacts of green environments on children's health is warranted. Moreover, an investigation of potential mechanisms underlying the associations is required. This thesis comprises three publications, which are based on data from the German birth cohorts GINIplus and LISAplus. The first publication assessed the effects of residential greenness at the mother's residential address as well as access to green spaces assessed by satellite-derived data on birth weight of newborns. Greenness in a 500-m buffer around the mother's residential address at delivery was positively associated with the birth weight of neonates. Air pollution, noise, population density and maternal stress during pregnancy did not mediate the discovered association. In the stratified analyses, the association between greenness and birth weight was more pronounced in mothers with low socioeconomic status. Access to green spaces and birth weight were not associated. Thus, increased accessibility to green spaces also does not explain the observed association with greenness. The second publication investigated whether access to green spaces as well as residential greenness are associated with behavioural problems in 10-year-old children. Hyperactivity/inattention and peer relationship problems were positively associated with increasing distances to urban green spaces. The observed association with hyperactivity/inattention was only statistically significant among males. Children living further than 500 m away from any urban green space had more overall behavioural problems than those living within 500 m of an urban green space. Behavioural problems were not associated with the distance to a forest or with residential surrounding greenness. Thus, our findings suggest beneficial effects of living in close proximity to well-maintained green spaces on children's mental health. The third publication explored for the first time an association between residential greenness and blood pressure in 10-year-old children. The found association was not influenced by environmental stressors (ambient temperature and air pollution, noise annoyance, altitude and level of urbanisation). The discovered link is in line with the existing evidence from experimental studies and thus, with the psychoevolutionary theory of Ulrich; the latter argues that green environments mitigate stress by activating the parasympathetic system. The associations were only significant in the urban Munich study area but null in the rural Wesel area. This result might indicate that children living in urbanised regions, which generally lack vegetation, might bene t more from high residential greenness than those from the rural areas. In summary, these results support the hypothesis that better access to green spaces as well as higher residential surrounding greenness bene t children health. The results of my thesis suggest that greenness might improve health through the mechanism of physiological stress alleviation. But, contrary to my expectations, the observed effects of greenness and green spaces could not be additionally explained by mediation via physical activity, air pollution, noise, or urbanisation, possibly, because of insufficient data. Thus, future research should test more specifically what stands behind the discovered associations. Finally, health impacts of green environmentson children's health should be further investigated in different geographic areas with incorporation of data on time spent in the neighbourhood and the activities conducted as well as area-level socioeconomic status.